Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer.

BACKGROUND: Patients who have residual invasive breast cancer after receiving neoadjuvant chemotherapy plus human epidermal growth factor receptor 2 (HER2)-targeted therapy have a worse prognosis than those who have no residual cancer. Trastuzumab emtansine (T-DM1), an antibody-drug conjugate of trastuzumab and the cytotoxic agent emtansine (DM1), a maytansine derivative and microtubule inhibitor, provides benefit in patients with metastatic breast cancer that was previously treated with chemotherapy plus HER2-targeted therapy. METHODS: We conducted a phase 3, open-label trial involving patients with HER2-positive early breast cancer who were found to have residual invasive disease in the breast or axilla at surgery after receiving neoadjuvant therapy containing a taxane (with or without anthracycline) and trastuzumab. Patients were randomly assigned to receive adjuvant T-DM1 or trastuzumab for 14 cycles. The primary end point was invasive disease-free survival (defined as freedom from ipsilateral invasive breast tumor recurrence, ipsilateral locoregional invasive breast cancer recurrence, contralateral invasive breast cancer, distant recurrence, or death from any cause). RESULTS: At the interim analysis, among 1486 randomly assigned patients (743 in the T-DM1 group and 743 in the trastuzumab group), invasive disease or death had occurred in 91 patients in the T-DM1 group (12.2%) and 165 patients in the trastuzumab group (22.2%). The estimated percentage of patients who were free of invasive disease at 3 years was 88.3% in the T-DM1 group and 77.0% in the trastuzumab group. Invasive disease-free survival was significantly higher in the T-DM1 group than in the trastuzumab group (hazard ratio for invasive disease or death, 0.50; 95% confidence interval, 0.39 to 0.64; P<0.001). Distant recurrence as the first invasive-disease event occurred in 10.5% of patients in the T-DM1 group and 15.9% of those in the trastuzumab group. The safety data were consistent with the known safety profile of T-DM1, with more adverse events associated with T-DM1 than with trastuzumab alone. CONCLUSIONS: Among patients with HER2-positive early breast cancer who had residual invasive disease after completion of neoadjuvant therapy, the risk of recurrence of invasive breast cancer or death was 50% lower with adjuvant T-DM1 than with trastuzumab alone. (Funded by F. Hoffmann-La Roche/Genentech; KATHERINE ClinicalTrials.gov number, NCT01772472 .).

Exposure-response analyses of trastuzumab emtansine in patients with HER2-positive advanced breast cancer previously treated with trastuzumab and a taxane.

PURPOSE: In the phase III EMILIA study, trastuzumab emtansine (T-DM1) significantly improved progression-free survival (PFS) and overall survival (OS) versus capecitabine plus lapatinib (control) in previously treated human epidermal growth factor receptor 2-positive advanced breast cancer. Using EMILIA data, we evaluated the T-DM1 exposure-response relationship. METHODS: Exposure-response relationships were examined with four exposure metrics [model-predicted and observed minimum concentration (C min) and area under the concentration-time curve from time zero to day 21 of T-DM1 at cycle 1] and multiple efficacy (OS, PFS, objective response rate) and safety (grade ≥ 3 adverse events, grade ≥ 3 thrombocytopenia, grade ≥ 3 hepatotoxicity) endpoints. RESULTS: An apparent exposure-response trend was observed between model-predicted exposure metrics and efficacy; trends for observed exposure metrics were shallower and often not significant. Although median OS and PFS were numerically longer in patients with higher versus lower model-predicted cycle 1 C min, OS and PFS hazard ratios for T-DM1-treated patients in the lowest exposure quartile (Q1) versus control were < 1 after adjusting for baseline risk factors (e.g., ECOG status, tumor burden, measurable disease, and number of disease sites). No meaningful exposure-response relationship was observed for any safety endpoints. CONCLUSION: Exposure-response relationships for efficacy were inconsistent across exposure metrics; model-predicted cycle 1 C min showed the strongest exposure-response trend. The Q1 subgroup based on model-predicted cycle 1 C min had numerically similar or better OS and PFS versus control following covariate adjustment. The approved T-DM1 dose (3.6 mg/kg every 3 weeks) has a positive benefit-risk ratio versus control, even for the T-DM1 Q1 subgroup.

Population pharmacokinetics and exposure-response of trastuzumab emtansine in advanced breast cancer previously treated with ≥2 HER2-targeted regimens.

AIMS: We conducted population pharmacokinetic (PopPK) and exposure-response analyses for trastuzumab emtansine (T-DM1), to assess the need for T-DM1 dose optimization in patients with low exposure by using TH3RESA [A Study of Trastuzumab Emtansine in Comparison With Treatment of Physician's Choice in Patients With human epidermal growth factor receptor 2 (HER2)-positive Breast Cancer Who Have Received at Least Two Prior Regimens of HER2-directed Therapy] study data (NCT01419197). The randomized phase III TH3RESA study investigated T-DM1 vs. treatment of physician's choice (TPC) in patients with heavily pretreated HER2-positive advanced breast cancer. METHODS: We compared a historical T-DM1 PopPK model with T-DM1 pharmacokinetics in TH3RESA and performed exposure-response analyses using model-predicted cycle 1 maximum concentration (Cmax ), cycle 1 minimum concentration (Cmin ) and area under the concentration-time curve at steady state (AUCss ). Kaplan-Meier analyses [overall survival (OS), progression-free survival (PFS)] and logistic regression [overall response rate (ORR), safety] were stratified by T-DM1 exposure metrics. Survival hazard ratios (HRs) in the lowest exposure quartile (Q1) of cycle 1 Cmin were compared with matched TPC-treated patients. RESULTS: T-DM1 concentrations in TH3RESA were described well by the historical PopPK model. Patients with higher cycle 1 Cmin and AUCss exhibited numerically longer median OS and PFS and higher ORR than patients with lower exposure. Exposure-response relationships were less evident for cycle 1 Cmax . No relationship between exposure and safety was identified. HRs for the comparison of T-DM1-treated patients in the Q1 subgroup with matched TPC-treated patients were 0.96 [95% confidence interval (CI) 0.63, 1.47] for OS and 0.92 (95% CI 0.64, 1.32) for PFS. CONCLUSIONS: Exposure-response relationships for efficacy were inconsistent across exposure metrics. HRs for survival in patients in the lowest T-DM1 exposure quartile vs. matched TPC-treated patients suggest that, compared with TCP, the approved T-DM1 dose is unlikely to be detrimental to patients with low exposure.

Trastuzumab emtansine versus treatment of physician's choice in patients with previously treated HER2-positive metastatic breast cancer (TH3RESA): final overall survival results from a randomised open-label phase 3 trial.

BACKGROUND: In the randomised, parallel assignment, open-label, phase 3 TH3RESA study, progression-free survival was significantly longer with trastuzumab emtansine versus treatment of physician's choice in previously treated patients with HER2-positive advanced breast cancer. We report results from the final overall survival analysis of the TH3RESA trial. METHODS: Eligible patients for the TH3RESA trial were men and women (aged ≥18 years) with centrally confirmed HER2-positive advanced breast cancer previously treated with both trastuzumab and lapatinib (advanced setting) and a taxane (any setting) and with progression on two or more HER2-directed regimens in the advanced setting. Patients had to have an Eastern Cooperative Oncology Group performance status of 0-2, left ventricular ejection fraction of at least 50%, and adequate organ function. Patients were randomly assigned (2:1) by an interactive voice and web response system with permuted block randomisation in blocks of six to receive trastuzumab emtansine (3·6 mg/kg intravenously every 21 days) or treatment of physician's choice administered per local practice. Randomisation was stratified by world region, number of previous regimens for advanced breast cancer, and presence of visceral disease. On Sept 12, 2012, the study protocol was amended to allow patients with disease progression to crossover from treatment of physician's choice to trastuzumab emtansine. The coprimary endpoints for TH3RESA were investigator-assessed progression-free survival and overall survival in the intention-to-treat population. We report results from a preplanned second interim analysis of overall survival, which was planned for when approximately 67% (n=330) of 492 expected deaths had occurred. This study is registered with ClinicalTrials.gov, number NCT01419197. FINDINGS: Between Sept 14, 2011, and Nov 19, 2012, 602 patients were enrolled from 146 centres in 22 countries and randomly assigned to trastuzumab emtansine (n=404) or treatment of physician's choice (n=198). At data cutoff (Feb 13, 2015), 93 (47%) of 198 patients in the physician's choice group had crossed over to trastuzumab emtansine. Overall survival was significantly longer with trastuzumab emtansine versus treatment of physician's choice (median 22·7 months [95% CI 19·4-27·5] vs 15·8 months [13·5-18·7]; hazard ratio 0·68 [95% CI 0·54-0·85]; p=0·0007). As the stopping boundary for overall survival was crossed, this overall survival analysis serves as the final and confirmatory analysis of overall survival and the study was terminated according to the protocol. The incidence of grade 3 or worse adverse events was 161 (40%) of 403 patients in the trastuzumab emtansine group and 87 (47%) of 184 patients in the treatment of physician's choice group. Of the most common grade 3 or worse adverse events (affecting ≥2% of patients in either group), those with a 3% or greater difference in incidence between groups that were more frequent with treatment of physician's choice than with trastuzumab emtansine were diarrhoea (three [1%] of 403 patients in the trastuzumab emtansine group vs eight [4%] of 184 patients in the treatment of physician's choice group), neutropenia (ten [3%] vs 29 [16%]), and febrile neutropenia (one [<1%] vs seven [4%]); whereas those that were more frequent with trastuzumab emtansine were thrombocytopenia (24 [6%] of 403 patients vs five [3%] of 184 patients) and haemorrhage of any type (17 [4%] of 403 vs one [<1%] of 184). Serious adverse events were reported in 102 (25%) of 403 patients in the trastuzumab emtansine group and 41 (22%) of 184 in the physician's choice group. Deaths from adverse events were reported in three patients (2%) in the physician's choice group (of which one was judged to be treatment related) and nine (2%) in the trastuzumab emtansine group (of which three were judged to be treatment related). INTERPRETATION: In patients who had progressed on two or more HER2-directed regimens, trastuzumab emtansine treatment resulted in a significant improvement in overall survival versus treatment of physician's choice. These data further solidify the role of trastuzumab emtansine in the management of patients with previously treated HER2-positive advanced breast cancer, and validate HER2 as a therapeutic target even after multiple lines of previous therapy. FUNDING: F Hoffman-La Roche/Genentech.

Relationship between tumor biomarkers and efficacy in TH3RESA, a phase III study of trastuzumab emtansine (T-DM1) vs. treatment of physician's choice in previously treated HER2-positive advanced breast cancer.

In the phase III TH3RESA study (NCT01419197), 602 patients with HER2-positive advanced breast cancer who received prior taxane therapy and ≥2 HER2-directed regimens, including trastuzumab and lapatinib (advanced setting), were randomized to trastuzumab emtansine (T-DM1) or treatment of physician's choice (TPC). A statistically significant progression-free survival (PFS) benefit favoring T-DM1 was demonstrated. Here, we examine the relationship between HER2-related biomarkers and PFS in an exploratory analysis. Biomarkers assessed included HER2 (n = 505) and HER3 (n = 505) mRNA expression, PIK3CA mutation status (n = 410) and PTEN protein expression (n = 358). For biomarkers with continuous data (HER2, HER3, PTEN), subgroups were defined using median values (>median and ≤median). For all biomarker subgroups, median PFS was longer with T-DM1 vs. TPC. The PFS benefit favoring T-DM1 vs. TPC was numerically greater in the HER2 mRNA >median subgroup (7.2 vs. 3.4 months; unstratified hazard ratio [HR], 0.40; 95% CI, 0.28-0.59; p < 0.0001) vs. ≤median subgroup (5.5 vs. 3.9 months; HR, 0.68; 95% CI, 0.49-0.92; p = 0.0131). The PFS benefit with T-DM1 was similar among HER3, PIK3CA and PTEN subgroups. Consistent with other reports, benefit was seen with T-DM1 regardless of PIK3CA mutation status. In a multivariate analysis including an interaction term (treatment group by log2-transformed HER2 mRNA), patients with higher HER2 mRNA levels benefited more from receiving T-DM1 (HR, 0.84; 95% CI, 0.75-0.94; interaction p value = 0.0027). In summary, T-DM1 prolonged median PFS in all biomarker subgroups analyzed, including activating PIK3CA mutations, with numerically greater benefit in patients with tumors expressing HER2 mRNA >median vs. ≤median.

Clinical development of new drug-radiotherapy combinations.

In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures include the use of radiotherapy, either as a single modality or combined with other treatments. Radiotherapy can provide enormous benefit to patients with cancer. In the past decade, significant technical advances, such as image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic radiotherapy, and proton therapy enable higher doses of radiotherapy to be delivered to the tumour with significantly lower doses to normal surrounding tissues. However, apart from the combination of traditional cytotoxic chemotherapy with radiotherapy, little progress has been made in identifying and defining optimal targeted therapy and radiotherapy combinations to improve the efficacy of cancer treatment. The National Cancer Research Institute Clinical and Translational Radiotherapy Research Working Group (CTRad) formed a Joint Working Group with representatives from academia, industry, patient groups and regulatory bodies to address this lack of progress and to publish recommendations for future clinical research. Herein, we highlight the Working Group's consensus recommendations to increase the number of novel drugs being successfully registered in combination with radiotherapy to improve clinical outcomes for patients with cancer.

Feasibility and cardiac safety of trastuzumab emtansine after anthracycline-based chemotherapy as (neo)adjuvant therapy for human epidermal growth factor receptor 2-positive early-stage breast cancer.

PURPOSE: Trastuzumab emtansine (T-DM1), an antibody-drug conjugate comprising the cytotoxic agent DM1, a stable linker, and trastuzumab, has demonstrated substantial activity in human epidermal growth factor receptor 2 (HER2) -positive metastatic breast cancer, raising interest in evaluating the feasibility and cardiac safety of T-DM1 in early-stage breast cancer (EBC). PATIENTS AND METHODS: Patients (N = 153) with HER2-positive EBC and prechemotherapy left ventricular ejection fraction (LVEF) ≥ 55% received (neo)adjuvant doxorubicin plus cyclophosphamide or fluorouracil plus epirubicin plus cyclophosphamide followed by T-DM1 for four cycles. Patients could then receive three to four cycles of optional docetaxel with or without trastuzumab. T-DM1 was then resumed with optional radiotherapy (sequential or concurrent) for 1 year (planned) of HER2-directed therapy. The coprimary end points were rate of prespecified cardiac events and safety. RESULTS: Median follow-up was 24.6 months. No prespecified cardiac events or symptomatic congestive heart failures were reported. Four patients (2.7%) had asymptomatic LVEF declines (≥ 10 percentage points from baseline to LVEF < 50%), leading to T-DM1 discontinuation in one patient. Of 148 patients who received ≥ one cycle of T-DM1, 82.4% completed the planned 1-year duration of HER2-directed therapy. During T-DM1 treatment, 38.5% and 2.7% of patients experienced grade 3 and 4 adverse events, respectively. Approximately 95% of patients receiving T-DM1 plus radiotherapy completed ≥ 95% of the planned radiation dose with delay ≤ 5 days. CONCLUSION: Use of T-DM1 for approximately 1 year after anthracycline-based chemotherapy was feasible and generally well tolerated by patients with HER2-positive EBC, providing support for phase III trials of T-DM1 in this setting.

Trastuzumab emtansine in human epidermal growth factor receptor 2-positive metastatic breast cancer: an integrated safety analysis.

PURPOSE: The antibody-drug conjugate trastuzumab emtansine (T-DM1) combines the cytotoxic activity of DM1 with the human epidermal growth factor receptor 2 (HER2) -targeted, antitumor properties of trastuzumab. T-DM1 has shown activity in phase I and II single-arm studies in patients with pretreated HER2-positive metastatic breast cancer (MBC) and has demonstrated superior efficacy and improved tolerability versus standard MBC treatments in randomized phase II and III studies. This analysis, combining available data from all single-agent T-DM1 studies to date, was conducted to better define the T-DM1 safety profile. PATIENTS AND METHODS: Six studies in patients with HER2-positive MBC who received T-DM1 3.6 mg/kg every 3 weeks and follow-up data from patients in an extension study were analyzed. Analyses included adverse events (AEs) by grade; AEs leading to death, drug discontinuation, or dose reduction; and select AEs. RESULTS: Among 884 T-DM1-exposed patients, the most commonly reported all-grade AEs were fatigue (46.4%), nausea (43.0%), thrombocytopenia (32.2%), headache (29.4%), and constipation (26.5%). The most common grade 3 to 4 AEs were the laboratory abnormalities of thrombocytopenia (11.9%) and increased AST serum concentration (4.3%). These were manageable and not generally associated with clinical symptoms. There were 12 AE-related deaths. AEs resulted in dose reductions in 17.2% of patients and drug discontinuations in 7.0%. CONCLUSION: In this analysis of 884 T-DM1-exposed patients, grade 3 or greater AEs were infrequent and typically asymptomatic and manageable. This favorable safety profile makes T-DM1 treatment suitable for exploration in other breast cancer settings.

Trastuzumab emtansine versus treatment of physician's choice for pretreated HER2-positive advanced breast cancer (TH3RESA): a randomised, open-label, phase 3 trial.

BACKGROUND: Patients with progressive disease after two or more HER2-directed regimens for recurrent or metastatic breast cancer have few effective therapeutic options. We aimed to compare trastuzumab emtansine, an antibody-drug conjugate comprising the cytotoxic agent DM1 linked to trastuzumab, with treatment of physician's choice in this population of patients. METHODS: This randomised, open-label, phase 3 trial took place in medical centres in 22 countries across Europe, North America, South America, and Asia-Pacific. Eligible patients (≥18 years, left ventricular ejection fraction ≥50%, Eastern Cooperative Oncology Group performance status 0-2) with progressive HER2-positive advanced breast cancer who had received two or more HER2-directed regimens in the advanced setting, including trastuzumab and lapatinib, and previous taxane therapy in any setting, were randomly assigned (in a 2:1 ratio) to trastuzumab emtansine (3·6 mg/kg intravenously every 21 days) or physician's choice using a permuted block randomisation scheme by an interactive voice and web response system. Patients were stratified according to world region (USA vs western Europe vs other), number of previous regimens (excluding single-agent hormonal therapy) for the treatment of advanced disease (two to three vs more than three), and presence of visceral disease (any vs none). Coprimary endpoints were investigator-assessed progression-free survival (PFS) and overall survival in the intention-to-treat population. We report the final PFS analysis and the first interim overall survival analysis. This study is registered with ClinicalTrials.gov, number NCT01419197. FINDINGS: From Sept 14, 2011, to Nov 19, 2012, 602 patients were randomly assigned (404 to trastuzumab emtansine and 198 to physician's choice). At data cutoff (Feb 11, 2013), 44 patients assigned to physician's choice had crossed over to trastuzumab emtansine. After a median follow-up of 7·2 months (IQR 5·0-10·1 months) in the trastuzumab emtansine group and 6·5 months (IQR 4·1-9·7) in the physician's choice group, 219 (54%) patients in the trastuzumab emtansine group and 129 (65%) of patients in the physician's choice group had PFS events. PFS was significantly improved with trastuzumab emtansine compared with physician's choice (median 6·2 months [95% CI 5·59-6·87] vs 3·3 months [2·89-4·14]; stratified hazard ratio [HR] 0·528 [0·422-0·661]; p<0·0001). Interim overall survival analysis showed a trend favouring trastuzumab emtansine (stratified HR 0·552 [95% CI 0·369-0·826]; p=0·0034), but the stopping boundary was not crossed. A lower incidence of grade 3 or worse adverse events was reported with trastuzumab emtansine than with physician's choice (130 events [32%] in 403 patients vs 80 events [43%] in 184 patients). Neutropenia (ten [2%] vs 29 [16%]), diarrhoea (three [<1%] vs eight [4%]), and febrile neutropenia (one [<1%] vs seven [4%]) were grade 3 or worse adverse events that were more common in the physician's choice group than in the trastuzumab emtansine group. Thrombocytopenia (19 [5%] vs three [2%]) was the grade 3 or worse adverse event that was more common in the trastuzumab emtansine group. 74 (18%) patients in the trastuzumab emtansine group and 38 (21%) in the physician's choice group reported a serious adverse event. INTERPRETATION: Trastuzumab emtansine should be considered as a new standard for patients with HER2-positive advanced breast cancer who have previously received trastuzumab and lapatinib. FUNDING: Genentech.

A phase II study evaluating the efficacy and safety of AMG 102 (rilotumumab) in patients with recurrent glioblastoma.

This phase II study evaluated the efficacy and safety of AMG 102 (rilotumumab), a fully human monoclonal antibody against hepatocyte growth factor/scatter factor (HGF/SF), in patients with recurrent glioblastoma (GBM). Patients with histologically confirmed, measurable recurrent GBM or gliosarcoma (World Health Organization grade 4) and ≤3 relapses or prior systemic therapies received AMG 102 (10 or 20 mg/kg) by infusion every 2 weeks. The primary endpoint was best confirmed objective response rate (central assessment) per Macdonald criteria. Of the 61 patients who enrolled, 60 received AMG 102. Twenty-nine patients (48%) had previously received bevacizumab. There were no objective responses per central assessment, but 1 patient had an objective response per investigator assessment. Median overall survival (95% CI) in the 10- and 20-mg/kg cohorts was 6.5 months (4.1-9.8) and 5.4 months (3.4-11.4), respectively, and progression-free survival (PFS) per central assessment was 4.1 weeks (4.0-4.1) and 4.3 weeks (4.1-8.1), respectively. PFS was similar among patients who had previously received bevacizumab compared with bevacizumab-naive patients. The most common adverse events were fatigue (38%), headache (33%), and peripheral edema (23%). AMG 102 serum concentrations increased approximately dose-proportionally with 2-fold accumulation at steady state. Plasma total HGF/SF and soluble c-Met concentrations increased 12.05- and 1.12-fold, respectively, from baseline during AMG 102 treatment. AMG 102 monotherapy at doses up to 20 mg/kg was not associated with significant antitumor activity in heavily pretreated patients with recurrent GBM.

A phase II study of the efficacy and safety of AMG 102 in patients with metastatic renal cell carcinoma.

OBJECTIVE: • To evaluate the efficacy and safety of single-agent AMG 102, an investigational, fully human monoclonal antibody to hepatocyte growth factor/scatter factor (HGF/SF), in renal cell carcinoma (RCC). PATIENTS AND METHODS: • This open-label phase II study included patients ≥ 18 years old with histologically confirmed, advanced or metastatic RCC (mRCC) and Eastern Cooperative Oncology Group performance status 0 to 2. AMG 102 was administered i.v. at 10 or 20 mg/kg once every 2 weeks. • A two-stage design was used at each dose level and the primary endpoint was objective best confirmed response (by Response Evaluation Criteria in Solid Tumours) at any time. RESULTS: • Sixty-one patients with mRCC enrolled and received AMG 102 (40 at 10 mg/kg; 21 at 20 mg/kg). Overall, 70.5% were men, median age was 59 years (range, 39 to 84 years), and 92% had received previous anti-vascular endothelial growth factor therapy. RCC histologies were: clear cell (75.4%), papillary (11.5%), chromophobe (4.9%) and unclassified (8.2%). • One confirmed partial response occurred at 10 mg/kg, maintained for over 2.5 years; 26 patients (43%) had stable disease, 10 (16%) for ≥ 32 weeks. The median profression-free survival was 3.7 months at 10 mg/kg and 2.0 months at 20 mg/kg. The commonest adverse events were oedema (45.9%), fatigue (37.7%) and nausea (27.9%). Grade 3 or 4 adverse events occurred in 33% of patients, the most common being oedema (9.8%). • Baseline levels of plasma HGF/SF and soluble c-Met as well as archival-tumour c-Met did not correlate with measures of efficacy. CONCLUSION: • Single-agent AMG 102 was tolerable, but it is unclear if AMG 102 was growth inhibitory in this population of patients with mRCC.

Dose-volume characteristics of a 50-kV electronic brachytherapy source for intracavitary accelerated partial breast irradiation.

PURPOSE: To describe dose-volume data from a 50-kV electronic brachytherapy source in intracavitary accelerated partial breast irradiation. METHODS AND MATERIALS: Three spherical balloon applicators were imaged on a CT scanner in a water phantom and inflated throughout their suggested fill volume range. The planning target volume (PTV) was defined as a 1-cm margin around the balloon surface. Plans were created achieving 80%, 85%, and 90% coverage of the PTV, with a prescription dose of 34Gy in 10 fractions. The PTV, V(90), V(100), V(150), V(200), and V(300) were recorded for each plan. RESULTS: For 80% target coverage, the V(200) varies from 11 to 14 cm(3) and the V(150) from 26 to 49 cm(3) over all the balloon applicators and fill volumes. For 85% coverage, the V(200) varies from 14 to 18 cm(3) and the V(150) from 27 to 53 cm(3). For 90% coverage, the V(200) varies from 16 to 22 cm(3) and the V(150)cm(3) from 30 to 61 cm(3). CONCLUSIONS: Fifty-kilovolt electronic brachytherapy can provide PTV coverage similar to (192)Ir in the setting of intracavitary accelerated partial breast irradiation.

Association of clinical and pathologic variables with lumpectomy surgical margin status after preoperative diagnosis or excisional biopsy of invasive breast cancer.

PURPOSE: To evaluate the impact of preoperative diagnosis in obtaining negative lumpectomy margins. MATERIALS AND METHODS: Five hundred and thirty five patients who underwent breast conserving therapy for stage I/II cancer from 1971 to 1996 were included in this IRB-approved retrospective analysis. Three hundred and ninety five patients had a defined inked margin status after initial excision. The following factors were evaluated for correlation with margins at initial excision: age (< or >45), grade (3/1 or 2), family history (present/absent), histology (lobular/other), estrogen receptor (ER) status, presence of extensive intraductal carcinoma (EIC), presence of lymphovascular invasion (LVI), and biopsy type (excisional/preoperative). RESULTS: Biopsy type (P < 0.0001), EIC (P = 0.002), ER status (P = 0.02), lobular histology (P = 0.02) and age (P = 0.02) were significantly correlated with initial margin status among the entire group. For patients who underwent preoperative diagnostic biopsy, 52% (35/67) had negative initial margins as compared to 29% (94/328) for excisional biopsy. Among patients who underwent preoperative biopsy, only lobular histology (P = 0.04) and LVI (P = 0.04) were related to initial margin status. The rate of re-excision was 34% for patients diagnosed preoperatively versus 61% with excisional biopsy (P < 0.0001). The percentage of patients with negative final margin status was similar with either core/needle or excisional biopsy (79 and 78%, respectively). CONCLUSIONS: Preoperative diagnosis is the most significant predictor of initial margin status in patients undergoing breast conservation. Patients with lobular histology may require improved preoperative and/or intraoperative assessment to increase the rate of negative margins at initial excision.

Predictors of local recurrence after breast-conservation therapy.

Breast-conserving therapy (BCT) is a proven local treatment option for select patients with early-stage breast cancer. This paper reviews pathologic, clinical, and treatment-related features that have been identified as known or potential predictors for ipsilateral breast tumor recurrence in patients treated with BCT. Pathologic risk factors such as the final pathologic margin status of the excised specimen after BCT, the extent of margin involvement, the interaction of margin status with other adverse features, the role of biomarkers, and the presence of an extensive intraductal component or lobular carcinoma in situ all impact the likelihood of ipsilateral breast tumor recurrence. Predictors of positive repeat excision findings after conservative surgery include young age, presence of an extensive intraductal component, and close or positive margins in prior excision. Finally, treatment-related factors predicting ipsilateral breast tumor recurrence include extent of breast radiation therapy, use of a boost to the lumpectomy cavity, use of tamoxifen or chemotherapeutic agents, and timing of systemic therapy with irradiation. The ability to predict for an increased risk of ipsilateral breast tumor recurrence enhances the ability to select optimal local treatment strategies for women considering BCT.

Selection criteria for accelerated partial-breast irradiation: impact on applicability.

This study examines the potential applicability of accelerated partial-breast irradiation (APBI) based on clinical and pathologic selection criteria in patients with stage I/II breast cancer. The records of 535 patients treated with breast-conserving surgery and radiation were reviewed. The patient database was analyzed for the following factors: age, extensive intraductal carcinoma (EIC), lymphovascular invasion (LVI), margin status, histologic type, pathologic nodal status, and pathologic tumor size. Two hundred seventeen records were located. The minimal selection criteria for APBI were assumed to include patient age of >/= 45 years, nonlobular histology, negative margins (> 2 mm), absence of EIC, and node-negative status. The potential variations in selection criteria for age, tumor size, and LVI were investigated with regard to the proportion of patients who would be eligible for APBI. In addition, predictors for true versus diffuse recurrence were examined among 40 patients who had a local recurrence. Using variable patient age cutoffs and T2 tumors as well as LVI, 9%-47% of patients could have been considered for APBI in this study. Using an age cutoff of >/= 65 years, 9%-15% of patients could have been eligible for APBI. However, using an age cutoff of >/=45 years, 28%-47% might be eligible, with the consideration of LVI becoming important. Among 40 local recurrences, 12 occurred at the primary site; 15 occurred elsewhere, diffusely, or with dermal involvement; and the locations of 13 could not be determined. Extensive intraductal carcinoma was the only significant predictor for recurrence at the primary site (P = 0.01). The potential impact of APBI on breast radiation therapy practice needs to be further delineated, and appropriate selection criteria should be refined.

Predictors of reexcision findings and recurrence after breast conservation.

PURPOSE: To identify predictors of reexcision findings and local recurrence in the setting of breast-conserving therapy with radiation. METHODS: The records of 535 patients who underwent breast-conserving surgery followed by radiation for Stage I or II cancer between 1972 and 1996 were reviewed. The mean follow-up period for surviving patients without evidence of recurrence is 6 years. Various clinical and pathologic prognostic factors were examined for significance with regard to reexcision findings and recurrence rates. Pathologic margin status was classified as negative, close (

Metaplastic breast cancer.

A case of metaplastic breast cancer in a patient with a history of infiltrating ductal carcinoma is presented, including representative mammographic and pathologic findings. The correlation between coarse calcifications on mammography and heterologous osseous elements on histologic review is noted. A brief summary of the typical clinical and pathologic features, as well as clinical studies relating to metaplastic breast cancer, are presented.