Efficacy of Chemotherapy for ER-Negative and ER-Positive Isolated Locoregional Recurrence of Breast Cancer: Final Analysis of the CALOR Trial.

Purpose Isolated locoregional recurrence (ILRR) predicts a high risk of developing breast cancer distant metastases and death. The Chemotherapy as Adjuvant for LOcally Recurrent breast cancer (CALOR) trial investigated the effectiveness of chemotherapy (CT) after local therapy for ILRR. A report at 5 years of median follow-up showed significant benefit of CT for estrogen receptor (ER)-negative ILRR, but additional follow-up was required in ER-positive ILRR. Patients and Methods CALOR was an open-label, randomized trial for patients with completely excised ILRR after unilateral breast cancer. Eligible patients were randomly assigned to receive CT or no CT and stratified by prior CT, hormone receptor status, and location of ILRR. Patients with hormone receptor-positive ILRR received adjuvant endocrine therapy. Radiation therapy was mandated for patients with microscopically involved margins, and anti-human epidermal growth factor receptor 2 therapy was optional. End points were disease-free survival (DFS), overall survival, and breast cancer-free interval. Results From August 2003 to January 2010, 162 patients were enrolled: 58 with ER-negative and 104 with ER-positive ILRR. At 9 years of median follow-up, 27 DFS events were observed in the ER-negative group and 40 in the ER-positive group. The hazard ratios (HR) of a DFS event were 0.29 (95% CI, 0.13 to 0.67; 10-year DFS, 70% v 34%, CT v no CT, respectively) in patients with ER-negative ILRR and 1.07 (95% CI, 0.57 to 2.00; 10-year DFS, 50% v 59%, respectively) in patients with ER-positive ILRR ( Pinteraction = .013). HRs were 0.29 (95% CI, 0.13 to 0.67) and 0.94 (95% CI, 0.47 to 1.85), respectively, for breast cancer-free interval ( Pinteraction = .034) and 0.48 (95% CI, 0.19 to 1.20) and 0.70 (95% CI, 0.32 to 1.55), respectively, for overall survival ( Pinteraction = .53). Results for the three end points were consistent in multivariable analyses adjusting for location of ILRR, prior CT, and interval from primary surgery. Conclusion The final analysis of CALOR confirms that CT benefits patients with resected ER-negative ILRR and does not support the use of CT for ER-positive ILRR.

Treatment Efficacy, Adherence, and Quality of Life Among Women Younger Than 35 Years in the International Breast Cancer Study Group TEXT and SOFT Adjuvant Endocrine Therapy Trials.

Purpose To describe benefits and toxicities of adjuvant endocrine therapies in women younger than 35 years with breast cancer (n = 582) enrolled in the Suppression of Ovarian Function Trial (SOFT) and Tamoxifen and Exemestane Trial (TEXT). Methods In SOFT, women still premenopausal after surgery with or without chemotherapy were randomly assigned to tamoxifen alone, tamoxifen plus ovarian function suppression (OFS), or exemestane plus OFS. In TEXT, all received OFS with or without concomitant chemotherapy and were randomly assigned to exemestane plus OFS or tamoxifen plus OFS. We summarize treatment efficacy, quality of life, and adherence of the cohort of women younger than 35 years in SOFT and TEXT, alongside data from the cohort of older premenopausal women. Results For 240 human epidermal growth factor receptor 2-negative patients younger than 35 years enrolled in SOFT after receiving chemotherapy, the 5-year breast cancer-free interval (BCFI) was 67.1% (95% CI, 54.6% to 76.9%) with tamoxifen alone, 75.9% with tamoxifen plus OFS (95% CI, 64.0% to 84.4%), and 83.2% with exemestane plus OFS (95% CI, 72.7% to 90.0%). For 145 human epidermal growth factor receptor 2-negative patients younger than 35 years in TEXT, 5-year BCFI was 79.2% (95% CI, 66.2% to 87.7%) with tamoxifen plus OFS and 81.6% (95% CI, 69.8% to 89.2%) with exemestane plus OFS. The most prominent quality of life symptom for patients younger than 35 years receiving OFS was vasomotor symptoms, with the greatest worsening from baseline at 6 months (on the order of 30 to 40 points), but loss of sexual interest and difficulties in becoming aroused were also clinically meaningful (≥ 8-point change). The level of symptom burden was similar in older premenopausal women. A total of 19.8% of women younger than 35 years stopped all protocol-assigned endocrine therapy early. Conclusion In women younger than 35 years with hormone receptor-positive breast cancer, adjuvant OFS combined with tamoxifen or exemestane produces large improvements in BCFI compared with tamoxifen alone. Menopausal symptoms are significant but are not worse than those seen in older premenopausal women.

Cholesterol, Cholesterol-Lowering Medication Use, and Breast Cancer Outcome in the BIG 1-98 Study.

Purpose Cholesterol-lowering medication (CLM) has been reported to have a role in preventing breast cancer recurrence. CLM may attenuate signaling through the estrogen receptor by reducing levels of the estrogenic cholesterol metabolite 27-hydroxycholesterol. The impact of endocrine treatment on cholesterol levels and hypercholesterolemia per se may counteract the intended effect of aromatase inhibitors. Patients and Methods The Breast International Group (BIG) conducted a randomized, phase III, double-blind trial, BIG 1-98, which enrolled 8,010 postmenopausal women with early-stage, hormone receptor-positive invasive breast cancer from 1998 to 2003. Systemic levels of total cholesterol and use of CLM were measured at study entry and every 6 months up to 5.5 years. Cumulative incidence functions were used to describe the initiation of CLM in the presence of competing risks. Marginal structural Cox proportional hazards modeling investigated the relationships between initiation of CLM during endocrine therapy and outcome. Three time-to-event end points were considered: disease-free-survival, breast cancer-free interval, and distant recurrence-free interval. Results Cholesterol levels were reduced during tamoxifen therapy. Of 789 patients who initiated CLM during endocrine therapy, the majority came from the letrozole monotherapy arm (n = 318), followed by sequential tamoxifen-letrozole (n = 189), letrozole-tamoxifen (n = 176), and tamoxifen monotherapy (n = 106). Initiation of CLM during endocrine therapy was related to improved disease-free-survival (hazard ratio [HR], 0.79; 95% CI, 0.66 to 0.95; P = .01), breast cancer-free interval (HR, 0.76; 95% CI, 0.60 to 0.97; P = .02), and distant recurrence-free interval (HR, 0.74; 95% CI, 0.56 to 0.97; P = .03). Conclusion Cholesterol-lowering medication during adjuvant endocrine therapy may have a role in preventing breast cancer recurrence in hormone receptor-positive early-stage breast cancer. We recommend that these observational results be addressed in prospective randomized trials.

Poor Prognosis After Second Locoregional Recurrences in the CALOR Trial.

BACKGROUND: Isolated locoregional recurrences (ILRRs) of breast cancer confer a significant risk for the development of distant metastasis. Management practices and second ILRR events in the Chemotherapy as Adjuvant for LOcally Recurrent breast cancer (CALOR) trial were investigated. METHODS: In this study, 162 patients with ILRR were randomly assigned to receive postoperative chemotherapy or no chemotherapy. Descriptive statistics characterize outcomes according to local therapy and the influence of hormone receptor status on subsequent recurrences. Competing risk regression models, Kaplan-Meier estimates, and Cox proportional hazards models were used to evaluate associations between treatment, site of second recurrence, and outcome. RESULTS: The median follow-up period was 4.9 years. Of the 98 patients who received breast-conserving primary surgery 89 had an ipsilateral-breast tumor recurrence. Salvage mastectomy was performed for 73 patients and repeat lumpectomy for 16 patients. Another eight patients had nodal ILRR, and one patient had chest wall ILRR. Among 64 patients whose primary surgery was mastectomy, 52 had chest wall/skin ILRR, and 12 had nodal ILRR. For 15 patients, a second ILRR developed a median of 1.6 years (range 0.08-4.8 years) after ILRR. All second ILRRs occurred for patients with progesterone receptor-negative ILRR. Death occurred for 7 (47 %) of 15 patients with a second ILRR and 19 (51 %) of 37 patients with a distant recurrence. As shown in the multivariable analysis, the significant predictors of survival after either a second ILRR or distant recurrence were chemotherapy for the primary cancer (hazard ratio [HR], 3.55; 95 % confidence interval [CI], 1.15-10.9; p = 0.03) and the interval (continuous) from the primary surgery (HR, 0.87; 95 % CI, 0.75-1.00; p = 0.05). CONCLUSIONS: Second ILRRs represented about one third of all recurrence events after ILRR, and all were PR-negative. These second ILRRs and distant metastases portend an unfavorable outcome.

Impact of CYP19A1 and ESR1 variants on early-onset side effects during combined endocrine therapy in the TEXT trial.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in the estrogen receptor 1 (ESR1) and cytochrome P450 19A1 (CYP19A1) genes have been associated with breast cancer risk, endocrine therapy response and side effects, mainly in postmenopausal women with early breast cancer. This analysis aimed to assess the association of selected germline CYP19A1 and ESR1 SNPs with early-onset hot flashes, sweating and musculoskeletal symptoms in premenopausal patients enrolled in the Tamoxifen and Exemestane Trial (TEXT). METHODS: Blood was collected from consenting premenopausal women with hormone-responsive early breast cancer, randomly assigned to 5-years of tamoxifen plus ovarian suppression (OFS) or exemestane plus OFS. DNA was extracted with QIAamp kits and genotyped for two CYP19A1 (rs4646 and rs10046) and three ESR1 (rs2077647, rs2234693 and rs9340799) SNPs by a real-time pyrosequencing technique. Adverse events (AEs) were recorded at baseline and 3-monthly during the first year. Associations of the genotype variants with grade ≥2 early-onset targeted AEs of hot flashes/sweating or musculoskeletal events were assessed using logistic regression models. RESULTS: There were 2660 premenopausal patients with breast cancer in the intention-to-treat population of TEXT, and 1967 (74 %) are included in this translational study. The CYP19A1 rs10046 variant T/T, represented in 23 % of women, was associated with a reduced incidence of grade ≥2 hot flashes/sweating (univariate odds ratio (OR) = 0.78; 95 % CI 0.63-0.97; P = 0.03), more strongly in patients assigned exemestane + OFS (TT vs CT/CC: OR = 0.65, 95 % CI = 0.48-0.89) than assigned tamoxifen + OFS (OR = 0.94, 95 % CI = 0.69-1.27, interaction P = 0.03). No association with any of the CYP19A1/ESR1 genotypes and musculoskeletal AEs was found. CONCLUSION: The CYP19A1 rs10046 variant T/T favors lower incidence of hot flashes/sweating under exemestane + OFS treatment, suggesting endocrine-mediated effects. Based on findings from others, this SNP may potentially enhance treatment adherence and treatment efficacy. We plan to evaluate the clinical impact of this polymorphism during time, pending sufficient median follow up. TRIAL REGISTRATION: ClinicalTrials.gov NCT00066703, registered August 6, 2003.

Timing of Radiation Therapy and Chemotherapy After Breast-Conserving Surgery for Node-Positive Breast Cancer: Long-Term Results From International Breast Cancer Study Group Trials VI and VII.

PURPOSE: To update the previous report from 2 randomized clinical trials, now with a median follow-up of 16 years, to analyze the effect of radiation therapy timing on local failure and disease-free survival. PATIENTS AND METHODS: From July 1986 to April 1993, International Breast Cancer Study Group trial VI randomly assigned 1475 pre-/perimenopausal women with node-positive breast cancer to receive 3 or 6 cycles of initial chemotherapy (CT). International Breast Cancer Study Group trial VII randomly assigned 1212 postmenopausal women with node-positive breast cancer to receive tamoxifen for 5 years, or tamoxifen for 5 years with 3 early cycles of initial CT. For patients who received breast-conserving surgery (BCS), radiation therapy (RT) was delayed until initial CT was completed; 4 or 7 months after BCS for trial VI and 2 or 4 months for trial VII. We compared RT timing groups among 433 patients on trial VI and 285 patients on trial VII who received BCS plus RT. Endpoints were local failure, regional/distant failure, and disease-free survival (DFS). RESULTS: Among pre-/perimenopausal patients there were no significant differences in disease-related outcomes. The 15-year DFS was 48.2% in the group allocated 3 months initial CT and 44.9% in the group allocated 6 months initial CT (hazard ratio [HR] 1.12; 95% confidence interval [CI] 0.87-1.45). Among postmenopausal patients, the 15-year DFS was 46.1% in the no-initial-CT group and 43.3% in the group allocated 3 months initial CT (HR 1.11; 95% CI 0.82-1.51). Corresponding HRs for local failures were 0.94 (95% CI 0.61-1.46) in trial VI and 1.51 (95% CI 0.77-2.97) in trial VII. For regional/distant failures, the respective HRs were 1.15 (95% CI 0.80-1.63) and 1.08 (95% CI 0.69-1.68). CONCLUSIONS: This study confirms that, after more than 15 years of follow-up, it is reasonable to delay radiation therapy until after the completion of standard CT.

Tumor-infiltrating lymphocytes (TILs) are a powerful prognostic marker in patients with triple-negative breast cancer enrolled in the IBCSG phase III randomized clinical trial 22-00.

The purpose of this study was to assess the prognostic and predictive value of tumor-infiltrating lymphocytes (TILs) in the triple-negative breast cancer (TNBC) cohort of the phase III IBCSG trial 22-00, comparing low-dose oral 'metronomic' cyclophosphamide-methotrexate maintenance chemotherapy (CM-maintenance) to no-CM-maintenance in early breast cancer. TILs were evaluated in full-face hematoxylin-and-eosin-stained sections of tumor samples confirmed centrally as TNBC (< 1 % of ER and PgR immunoreactivity and absence of HER2 overexpression or amplification). Mononuclear cells were evaluated in the stromal area within the borders of the invasive tumor. The primary endpoint was breast cancer-free interval (BCFI). Cox proportional hazards regression model assessed the association of BCFI and secondary endpoints with TILs score. In the 647 tumor samples, the median percentage of TILs was 18 % (IQR = 8-40 %), with 18 % having TILs ≥ 50 % (lymphocyte-predominant breast cancer, LPBC). At a median follow-up of 6.9 years, TILs were associated with better prognosis. For every 10 % increase of TILs, BCFI risk reduction was 13 % (HR 0.87, 95 % CI 0.79-0.95,P = 0.003). DFS, DRFI, and OS risk reductions were 11 % (P = 0.005), 16 % (P = 0.003), and 17 % (P < 0.001), respectively. Multivariable analysis confirmed the independent prognostic value of TILs. No significant TILs-by-treatment interaction was observed (P = 0.39) for associations of TILs with BCFI, although patients with LPBC receiving CM-maintenance had a greater breast cancer risk reduction (HR 0.64,95 % CI 0.23-1.78) than those with non-LPBC (TILs < 50 %) (HR 0.96, 95 % CI 0.67-1.40). TILs score is a potent prognostic factor in patients with TNBC. Low-dose chemotherapy confers a greater (not statistically significant) clinical benefit in patients with LPBC.

Low-Dose Oral Cyclophosphamide and Methotrexate Maintenance for Hormone Receptor-Negative Early Breast Cancer: International Breast Cancer Study Group Trial 22-00.

PURPOSE: To evaluate the benefit of low-dose cyclophosphamide and methotrexate (CM) maintenance, which previously demonstrated antitumor activity and few adverse effects in advanced breast cancer, in early breast cancer. PATIENTS AND METHODS: International Breast Cancer Study Group (IBCSG) Trial 22-00, a randomized phase III clinical trial, enrolled 1,086 women (1,081 intent-to-treat) from November 2000 to December 2012. Women with estrogen receptor- and progesterone receptor-negative (< 10% positive cells by immunohistochemistry) early breast cancer any nodal and human epidermal growth factor receptor 2 status, were randomly assigned anytime between primary surgery and 56 days after the first day of last course of adjuvant chemotherapy to CM maintenance (cyclophosphamide 50 mg/day orally continuously and methotrexate 2.5 mg twice/day orally on days 1 and 2 of every week for 1 year) or to no CM. The primary end point was disease-free survival (DFS), which included invasive recurrences, second (breast and nonbreast) malignancies, and deaths. RESULTS: After a median of 6.9 years of follow-up, DFS was not significantly better for patients assigned to CM maintenance compared with patients assigned to no CM, both overall (hazard ratio [HR], 0.84; 95% CI, 0.66 to 1.06;P = .14) and in triple-negative (TN) disease (n = 814; HR, 0.80; 95% CI, 0.60 to 1.06). Patients with TN, node-positive disease had a nonstatistically significant reduced HR (n = 340; HR, 0.72; 95% CI, 0.49 to 1.05). Seventy-one (13%) of 542 patients assigned to CM maintenance did not start CM. Of 473 patients who received at least one CM maintenance dose (including two patients assigned to no CM), 64 (14%) experienced a grade 3 or 4 treatment-related adverse event; elevated serum transaminases was the most frequently reported (7%), followed by leukopenia (2%). CONCLUSION: CM maintenance did not produce a significant reduction in DFS events in hormone receptor-negative early breast cancer. The trend toward benefit observed in the TN, node-positive subgroup supports additional exploration of this strategy in the TN, higher-risk population.

Treatment Adherence and Its Impact on Disease-Free Survival in the Breast International Group 1-98 Trial of Tamoxifen and Letrozole, Alone and in Sequence.

PURPOSE: To investigate adherence to endocrine treatment and its relationship with disease-free survival (DFS) in the Breast International Group (BIG) 1-98 clinical trial. METHODS: The BIG 1-98 trial is a double-blind trial that randomly assigned 6,193 postmenopausal women with hormone receptor-positive early breast cancer in the four-arm option to 5 years of tamoxifen (Tam), letrozole (Let), or the agents in sequence (Let-Tam, Tam-Let). This analysis included 6,144 women who received at least one dose of study treatment. Conditional landmark analyses and marginal structural Cox proportional hazards models were used to evaluate the relationship between DFS and treatment adherence (persistence [duration] and compliance with dosage). Competing risks regression was used to assess demographic, disease, and treatment characteristics of the women who stopped treatment early because of adverse events. RESULTS: Both aspects of low adherence (early cessation of letrozole and a compliance score of < 90%) were associated with reduced DFS (multivariable model hazard ratio, 1.45; 95% CI, 1.09 to 1.93; P = .01; and multivariable model hazard ratio, 1.61; 95% CI, 1.08 to 2.38; P = .02, respectively). Sequential treatments were associated with higher rates of nonpersistence (Tam-Let, 20.8%; Let-Tam, 20.3%; Tam 16.9%; Let 17.6%). Adverse events were the reason for most trial treatment early discontinuations (82.7%). Apart from sequential treatment assignment, reduced adherence was associated with older age, smoking, node negativity, or prior thromboembolic event. CONCLUSION: Both persistence and compliance are associated with DFS. Toxicity management and, for sequential treatments, patient and physician awareness, may improve adherence.

Absolute Benefit of Adjuvant Endocrine Therapies for Premenopausal Women With Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer: TEXT and SOFT Trials.

PURPOSE: Risk of recurrence is the primary consideration in breast cancer adjuvant therapy recommendations. The TEXT (Tamoxifen and Exemestane Trial) and SOFT (Suppression of Ovarian Function Trial) trials investigated adjuvant endocrine therapies for premenopausal women with hormone receptor-positive breast cancer, testing exemestane plus ovarian function suppression (OFS), tamoxifen plus OFS, and tamoxifen alone. We examined absolute treatment effect across a continuum of recurrence risk to individualize endocrine therapy decision making for premenopausal women with human epidermal growth factor receptor 2 (HER2) -negative disease. PATIENTS AND METHODS: The TEXT and SOFT hormone receptor-positive, HER2-negative analysis population included 4,891 women. The end point was breast cancer-free interval (BCFI), defined as time from random assignment to first occurrence of invasive locoregional, distant, or contralateral breast cancer. A continuous, composite measure of recurrence risk for each patient was determined from a Cox model incorporating age, nodal status, tumor size and grade, and estrogen receptor, progesterone receptor, and Ki-67 expression levels. Subpopulation treatment effect pattern plot methodology revealed differential treatment effects on 5-year BCFI according to composite risk. RESULTS: SOFT patients who remained premenopausal after chemotherapy experienced absolute improvement of 5% or more in 5-year BCFI with exemestane plus OFS versus tamoxifen plus OFS or tamoxifen alone, reaching 10% to 15% at intermediate to high composite risk; the benefit of tamoxifen plus OFS versus tamoxifen alone was apparent at the highest composite risk. The SOFT no-chemotherapy cohort-for whom composite risk was lowest on average-did well with all endocrine therapies. For TEXT patients, the benefit of exemestane plus OFS versus tamoxifen plus OFS in 5-year BCFI ranged from 5% to 15%; patients not receiving chemotherapy and with lowest composite risk did well with both treatments. CONCLUSION: Premenopausal women with hormone receptor-positive, HER2-negative disease and high recurrence risk, as defined by clinicopathologic characteristics, may experience improvement of 10% to 15% in 5-year BCFI with exemestane plus OFS versus tamoxifen alone. An improvement of at least 5% may be achieved for women at intermediate risk, and improvement is minimal for those at lowest risk.

Adjuvant ovarian function suppression and cognitive function in women with breast cancer.

BACKGROUND: To examine the effect on cognitive function of adjuvant ovarian function suppression (OFS) for breast cancer. METHODS: The Suppression of Ovarian Function (SOFT) trial randomised premenopausal women with hormone receptor-positive breast cancer to 5 years adjuvant endocrine therapy with tamoxifen+OFS, exemestane+OFS or tamoxifen alone. The Co-SOFT substudy assessed objective cognitive function and patient reported outcomes at randomisation (T0), and 1 year later (T1); the primary endpoint was change in global cognitive function, measured by the composite objective cognitive function score. Data were compared for the pooled tamoxifen+OFS and exemestane+OFS groups vs the tamoxifen alone group using the Wilcoxon rank-sum test. RESULTS: Of 86 participants, 74 underwent both T0 and T1 cognitive testing; 54 randomised to OFS+ either tamoxifen (28) or exemestane (26) and 20 randomised to tamoxifen alone. There was no significant difference in the changes in the composite cognitive function scores between the OFS+ tamoxifen or exemestane groups and the tamoxifen group (mean±s.d., -0.21±0.92 vs -0.04±0.49, respectively, P=0.71, effect size=-0.20), regardless of prior chemotherapy status, and adjusting for baseline characteristics. CONCLUSIONS: The Co-SOFT study, although limited by small samples size, provides no evidence that adding OFS to adjuvant oral endocrine therapy substantially affects global cognitive function.

Adjuvant Tamoxifen Plus Ovarian Function Suppression Versus Tamoxifen Alone in Premenopausal Women With Early Breast Cancer: Patient-Reported Outcomes in the Suppression of Ovarian Function Trial.

PURPOSE: The Suppression of Ovarian Function trial showed improved disease control for tamoxifen plus ovarian function suppression (OFS) compared with tamoxifen alone for the cohort of premenopausal patients who received prior chemotherapy. We present the patient-reported outcomes. PATIENTS AND METHODS: The quality-of-life (QoL) analysis includes 1,722 of 2,045 premenopausal patients with hormone receptor-positive breast cancer randomly assigned to receive adjuvant treatment with 5 years of tamoxifen plus OFS or tamoxifen alone. Chemotherapy use before enrollment was optional. Patients completed a QoL form consisting of global and symptom indicators at baseline, every 6 months for 24 months, and annually during years 3 to 6. Differences in the change of QoL from baseline between the two treatments were tested at 6, 24, and 60 months with mixed models for repeated measures with and without chemotherapy and overall. RESULTS: Patients on tamoxifen plus OFS were more affected than patients on tamoxifen alone by hot flushes at 6 and 24 months, by loss of sexual interest and sleep disturbance at 6 months, and by vaginal dryness up to 60 months. Without prior chemotherapy, patients on tamoxifen alone reported more vaginal discharge over the 5 years than patients on tamoxifen plus OFS. Symptom-specific treatment differences at 6 months were less pronounced in patients with prior chemotherapy. Changes in global QoL indicators from baseline were small and similar between treatments over the whole treatment period. CONCLUSION: Overall, OFS added to tamoxifen resulted in worse endocrine symptoms and sexual functioning during the first 2 years of treatment, with variable magnitudes of treatment differences. Short-term differences in symptom-specific QoL, treatment burden, and coping effort between treatment groups were less pronounced for patients with prior chemotherapy, the cohort that benefited most from OFS in terms of disease control.

Annual Hazard Rates of Recurrence for Breast Cancer During 24 Years of Follow-Up: Results From the International Breast Cancer Study Group Trials I to V.

PURPOSE: Predicting the pattern of recurrence can aid in the development of targeted surveillance and treatment strategies. We identified patient populations that remain at risk for an event at a median follow-up of 24 years from the diagnosis of operable breast cancer. PATIENTS AND METHODS: International Breast Cancer Study Group clinical trials I to V randomly assigned 4,105 patients between 1978 and 1985. Annualized hazards were estimated for breast cancer-free interval (primary end point), disease-free survival, and overall survival. RESULTS: For the entire group, the annualized hazard of recurrence was highest during the first 5 years (10.4%), with a peak between years 1 and 2 (15.2%). During the first 5 years, patients with estrogen receptor (ER)--positive disease had a lower annualized hazard compared with those with ER-negative disease (9.9% v 11.5%; P = .01). However, beyond 5 years, patients with ER-positive disease had higher hazards (5 to 10 years: 5.4% v 3.3%; 10 to 15 years: 2.9% v 1.3%; 15 to 20 years: 2.8% v 1.2%; and 20 to 25 years: 1.3% v 1.4%; P < .001). Among patients with ER-positive disease, annualized hazards of recurrence remained elevated and fairly stable beyond 10 years, even for those with no axillary involvement (2.0%, 2.1%, and 1.1% for years 10 to 15, 15 to 20, and 20 to 25, respectively) and for those with one to three positive nodes (3.0%, 3.5%, and 1.5%, respectively). CONCLUSION: Patients with ER-positive breast cancer maintain a significant recurrence rate during extended follow up. Strategies for follow up and treatments to prevent recurrences may be most efficiently applied and studied in patients with ER-positive disease followed for a long period of time.

Twelve-Month Estrogen Levels in Premenopausal Women With Hormone Receptor-Positive Breast Cancer Receiving Adjuvant Triptorelin Plus Exemestane or Tamoxifen in the Suppression of Ovarian Function Trial (SOFT): The SOFT-EST Substudy.

PURPOSE: To describe estradiol (E2), estrone (E1), and estrone sulfate (E1S) levels during the first year of monthly triptorelin plus exemestane or tamoxifen and to assess possible suboptimal suppression while receiving exemestane plus triptorelin. PATIENTS AND METHODS: Premenopausal patients with early breast cancer on the Suppression of Ovarian Function Trial who selected triptorelin as the ovarian suppression method and were randomly assigned to exemestane plus triptorelin or tamoxifen plus triptorelin were enrolled until the target population of 120 patients was reached. Blood sampling time points were 0, 3, 6, 12, 18, 24, 36, and 48 months. Serum estrogens were measured with a highly sensitive and specific assay. This preplanned 12-month analysis evaluated E2, E1, E1S, follicle-stimulating hormone, and luteinizing hormone levels in all patients and the proportion of patients with E2 levels greater than 2.72 pg/mL at any time point during treatment with exemestane plus triptorelin. RESULTS: One hundred sixteen patients (exemestane, n = 86; tamoxifen, n = 30; median age, 44 years; median E2, 51 pg/mL; 55% prior chemotherapy) started triptorelin and had one or more samples drawn. With exemestane plus triptorelin, median reductions from baseline E2, E1, and E1S levels were consistently ≥ 95%, resulting in significantly lower levels than with tamoxifen plus triptorelin at all time points. Among patients on exemestane plus triptorelin, 25%, 24%, and 17% had an E2 level greater than 2.72 pg/mL at 3, 6, and 12 months, respectively. Baseline factors related to on-treatment E2 level greater than 2.72 pg/mL were no prior chemotherapy (P = .06), higher body mass index (P = .05), and lower follicle-stimulating hormone and luteinizing hormone (each P < .01). CONCLUSION: During the first year, most patients on exemestane plus triptorelin had E2 levels below the defined threshold of 2.72 pg/mL, consistent with levels reported in postmenopausal patients on aromatase inhibitors, but at each time point, at least 17% of patients had levels greater than the threshold.

ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer.

Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.

Predictive value and clinical utility of centrally assessed ER, PgR, and Ki-67 to select adjuvant endocrine therapy for premenopausal women with hormone receptor-positive, HER2-negative early breast cancer: TEXT and SOFT trials.

The SOFT and TEXT randomized phase III trials investigated adjuvant endocrine therapies for premenopausal women with hormone receptor-positive (HR+) early breast cancer. We investigated the prognostic and predictive value of centrally assessed levels of estrogen receptor (ER), progesterone receptor (PgR), and Ki-67 expression in women with HER2-negative disease. Of 5707 women enrolled, 4115 with HER2-negative (HR+/HER2-) disease had ER, PgR, and Ki-67 centrally assessed by immunohistochemistry. Breast cancer-free interval (BCFI) was defined from randomization to first invasive local, regional, or distant recurrence or contralateral breast cancer. The prognostic and predictive values of ER, PgR and Ki-67 expression levels were assessed using Cox modeling and STEPP methodology. In this HR+/HER2- population, the median ER, PgR, and Ki-67 expressions were 95, 90, and 18 % immunostained cells. As most patients had strongly ER-positive tumors, the predictive value of ER levels could not be investigated. Lower PgR and higher Ki-67 expression were associated with reduced BCFI. There was no consistent evidence of heterogeneity of the relative treatment effects according to PgR or Ki-67 expression levels, though there was a greater 5-year absolute benefit of exemestane + ovarian function suppression (OFS) versus tamoxifen with or without OFS at lower levels of PgR and higher levels of Ki-67. Women with poor prognostic features of low PgR and/or high Ki-67 have greater absolute benefit from exemestane + OFS versus tamoxifen + OFS or tamoxifen alone, but individually PgR and Ki-67 are of limited predictive value for selecting adjuvant endocrine therapy for premenopausal women with HR+/HER2- early breast cancer.

Relative Effectiveness of Letrozole Compared With Tamoxifen for Patients With Lobular Carcinoma in the BIG 1-98 Trial.

PURPOSE: To evaluate the relative effectiveness of letrozole compared with tamoxifen for patients with invasive ductal or lobular carcinoma. PATIENTS AND METHODS: Patients diagnosed with early-stage invasive ductal carcinoma (IDC) or classic invasive lobular carcinoma (ILC) who were randomly assigned onto the Breast International Group (BIG) 1-98 trial and who had centrally reviewed pathology data were included (N = 2,923). HER2-negative IDC and ILC were additionally classified as hormone receptor-positive with high (luminal B [LB] -like) or low (luminal A [LA] -like) proliferative activity by Ki-67 labeling index. Survival analyses were performed with weighted Cox models that used inverse probability of censoring weighted modeling. RESULTS: The median follow-up time was 8.1 years. In multivariable models for disease-free survival (DFS), significant interactions between treatment and histology (ILC or IDC; P = .006) and treatment and subgroup (LB like or LA like; P = .01) were observed. In the ILC subset, there was a 66% reduction in the hazard of a DFS event with letrozole for LB (hazard ratio [HR], 0.34; 95% CI, 0.21 to 0.55) and a 50% reduction for LA subtypes (HR, 0.50; 95% CI, 0.32 to 0.78). In the IDC subset, there was a significant 35% reduction in the hazard of a DFS event with letrozole for the LB subtype (HR, 0.65; 95% CI, 0.53 to 0.79), but no difference between treatments was noted for IDC and the LA subtype (HR, 0.95; 95% CI, 0.76 to 1.20). CONCLUSION: The magnitude of benefit of adjuvant letrozole is greater for patients diagnosed with lobular carcinoma versus ductal carcinoma.

Patient-reported outcomes with adjuvant exemestane versus tamoxifen in premenopausal women with early breast cancer undergoing ovarian suppression (TEXT and SOFT): a combined analysis of two phase 3 randomised trials.

BACKGROUND: The combined efficacy analysis of the TEXT and SOFT trials showed a significant disease-free survival benefit with exemestane plus ovarian function suppression (OFS) compared with tamoxifen plus OFS. We present patient-reported outcomes from these trials. METHODS: Between Nov 7, 2003, and April 7, 2011, 4717 premenopausal women with hormone-receptor positive breast cancer were enrolled in TEXT or SOFT to receive unmasked adjuvant treatment with 5 years of exemestane plus OFS or tamoxifen plus OFS. Gonadotropin-releasing hormone analogue triptorelin, bilateral oophorectomy, or bilateral ovarian irradiation were used to achieve OFS. Chemotherapy use was optional. Randomisation with permuted blocks was done with the International Breast Cancer Study Group's internet-based system and was stratified by chemotherapy use and status of lymph nodes. Patients completed a quality of life (QoL) form comprising several global and symptom indicators at baseline, every 6 months for 24 months, and then every year during years 3 to 6. Differences in the change of QoL from baseline between the two treatments were tested at 6 months, 24 months, and 60 months with mixed-models for repeated measures for each trial with and without chemotherapy and overall. The analysis was by intention to treat. At the time of analysis, the median follow-up was 5·7 years (IQR 3·7-6·9); treatment and follow-up of patients continue. The trials are registered with ClinicalTrials.gov, as NCT00066703 (TEXT) and NCT00066690 (SOFT). FINDINGS: Patients on tamoxifen plus OFS were more affected by hot flushes and sweats over 5 years than were those on exemestane plus OFS, although these symptoms improved. Patients on exemestane plus OFS reported more vaginal dryness, greater loss of sexual interest, and difficulties becoming aroused than did patients on tamoxifen plus OFS; these differences persisted over time. An increase in bone or joint pain was more pronounced, particularly in the short term, in patients on exemestane plus OFS than patients on tamoxifen plus OFS. Changes in global QoL indicators from baseline were small and similar between treatments over the 5 years. INTERPRETATION: Overall, from a QoL perspective, there is no strong indication to favour either exemestane plus OFS or tamoxifen plus OFS. The distinct effects of the two treatments on the burden of endocrine symptoms need to be addressed with patients individually. FUNDING: Pfizer, International Breast Cancer Study Group, and US National Cancer Institute.

CYP19A1 polymorphisms and clinical outcomes in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial.

To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34-0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03-1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59-0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07-1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54-0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92-1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs.

Adjuvant ovarian suppression in premenopausal breast cancer.

BACKGROUND: Suppression of ovarian estrogen production reduces the recurrence of hormone-receptor-positive early breast cancer in premenopausal women, but its value when added to tamoxifen is uncertain. METHODS: We randomly assigned 3066 premenopausal women, stratified according to prior receipt or nonreceipt of chemotherapy, to receive 5 years of tamoxifen, tamoxifen plus ovarian suppression, or exemestane plus ovarian suppression. The primary analysis tested the hypothesis that tamoxifen plus ovarian suppression would improve disease-free survival, as compared with tamoxifen alone. In the primary analysis, 46.7% of the patients had not received chemotherapy previously, and 53.3% had received chemotherapy and remained premenopausal. RESULTS: After a median follow-up of 67 months, the estimated disease-free survival rate at 5 years was 86.6% in the tamoxifen-ovarian suppression group and 84.7% in the tamoxifen group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.83; 95% confidence interval [CI], 0.66 to 1.04; P=0.10). Multivariable allowance for prognostic factors suggested a greater treatment effect with tamoxifen plus ovarian suppression than with tamoxifen alone (hazard ratio, 0.78; 95% CI, 0.62 to 0.98). Most recurrences occurred in patients who had received prior chemotherapy, among whom the rate of freedom from breast cancer at 5 years was 82.5% in the tamoxifen-ovarian suppression group and 78.0% in the tamoxifen group (hazard ratio for recurrence, 0.78; 95% CI, 0.60 to 1.02). At 5 years, the rate of freedom from breast cancer was 85.7% in the exemestane-ovarian suppression group (hazard ratio for recurrence vs. tamoxifen, 0.65; 95% CI, 0.49 to 0.87). CONCLUSIONS: Adding ovarian suppression to tamoxifen did not provide a significant benefit in the overall study population. However, for women who were at sufficient risk for recurrence to warrant adjuvant chemotherapy and who remained premenopausal, the addition of ovarian suppression improved disease outcomes. Further improvement was seen with the use of exemestane plus ovarian suppression. (Funded by Pfizer and others; SOFT ClinicalTrials.gov number, NCT00066690.).