High tumor mutation burden fails to predict immune checkpoint blockade response across all cancer types.

BACKGROUND: High tumor mutation burden (TMB-H) has been proposed as a predictive biomarker for response to immune checkpoint blockade (ICB), largely due to the potential for tumor mutations to generate immunogenic neoantigens. Despite recent pan-cancer approval of ICB treatment for any TMB-H tumor, as assessed by the targeted FoundationOne CDx assay in nine tumor types, the utility of this biomarker has not been fully demonstrated across all cancers. PATIENTS AND METHODS: Data from over 10 000 patient tumors included in The Cancer Genome Atlas were used to compare approaches to determine TMB and identify the correlation between predicted neoantigen load and CD8 T cells. Association of TMB with ICB treatment outcomes was analyzed by both objective response rates (ORRs, N = 1551) and overall survival (OS, N = 1936). RESULTS: In cancer types where CD8 T-cell levels positively correlated with neoantigen load, such as melanoma, lung, and bladder cancers, TMB-H tumors exhibited a 39.8% ORR to ICB [95% confidence interval (CI) 34.9-44.8], which was significantly higher than that observed in low TMB (TMB-L) tumors [odds ratio (OR) = 4.1, 95% CI 2.9-5.8, P < 2 × 10-16]. In cancer types that showed no relationship between CD8 T-cell levels and neoantigen load, such as breast cancer, prostate cancer, and glioma, TMB-H tumors failed to achieve a 20% ORR (ORR = 15.3%, 95% CI 9.2-23.4, P = 0.95), and exhibited a significantly lower ORR relative to TMB-L tumors (OR = 0.46, 95% CI 0.24-0.88, P = 0.02). Bulk ORRs were not significantly different between the two categories of tumors (P = 0.10) for patient cohorts assessed. Equivalent results were obtained by analyzing OS and by treating TMB as a continuous variable. CONCLUSIONS: Our analysis failed to support application of TMB-H as a biomarker for treatment with ICB in all solid cancer types. Further tumor type-specific studies are warranted.

Talazoparib versus chemotherapy in patients with germline BRCA1/2-mutated HER2-negative advanced breast cancer: final overall survival results from the EMBRACA trial.

BACKGROUND: In EMBRACA, talazoparib prolonged progression-free survival versus chemotherapy (hazard ratio [HR] 0.542 [95% confidence interval (CI) 0.413-0.711]; P < 0.0001) and improved patient-reported outcomes (PRO) in germline BRCA1/2 (gBRCA1/2)-mutated advanced breast cancer (ABC). We report final overall survival (OS). PATIENTS AND METHODS: This randomized phase III trial enrolled patients with gBRCA1/2-mutated HER2-negative ABC. Patients received talazoparib or physician's choice of chemotherapy. OS was analyzed using stratified HR and log-rank test and prespecified rank-preserving structural failure time model to account for subsequent treatments. RESULTS: A total of 431 patients were entered in a randomized study (287 talazoparib/144 chemotherapy) with 412 patients treated (286 talazoparib/126 chemotherapy). By 30 September 2019, 216 deaths (75.3%) occurred for talazoparib and 108 (75.0%) chemotherapy; median follow-up was 44.9 and 36.8 months, respectively. HR for OS with talazoparib versus chemotherapy was 0.848 (95% CI 0.670-1.073; P = 0.17); median (95% CI) 19.3 months (16.6-22.5 months) versus 19.5 months (17.4-22.4 months). Kaplan-Meier survival percentages (95% CI) for talazoparib versus chemotherapy: month 12, 71% (66% to 76%)/74% (66% to 81%); month 24, 42% (36% to 47%)/38% (30% to 47%); month 36, 27% (22% to 33%)/21% (14% to 29%). Most patients received subsequent treatments: for talazoparib and chemotherapy, 46.3%/41.7% received platinum and 4.5%/32.6% received a poly(ADP-ribose) polymerase (PARP) inhibitor, respectively. Adjusting for subsequent PARP and/or platinum use, HR for OS was 0.756 (95% bootstrap CI 0.503-1.029). Grade 3-4 adverse events occurred in 69.6% (talazoparib) and 64.3% (chemotherapy) patients, consistent with previous reports. Extended follow-up showed significant overall improvement and delay in time to definitive clinically meaningful deterioration in global health status/quality of life and breast symptoms favoring talazoparib versus chemotherapy (P < 0.01 for all), consistent with initial analyses. CONCLUSIONS: In gBRCA1/2-mutated HER2-negative ABC, talazoparib did not significantly improve OS over chemotherapy; subsequent treatments may have impacted analysis. Safety was consistent with previous observations. PRO continued to favor talazoparib.

Quality of life with talazoparib versus physician's choice of chemotherapy in patients with advanced breast cancer and germline BRCA1/2 mutation: patient-reported outcomes from the EMBRACA phase III trial.

Background: In the EMBRACA phase III trial, talazoparib (1 mg daily, orally) demonstrated a statistically significant improvement in PFS versus physician's choice of chemotherapy (PCT; capecitabine, eribulin, gemcitabine, or vinorelbine) in patients with HER2-negative advanced breast cancer carrying a germline BRCA1/2 mutation; we evaluated patient-reported outcomes (PROs). Patients and methods: Patients were randomized 2 : 1 to receive talazoparib or PCT. PROs were assessed at day 1 (baseline), the start of each treatment cycle (every 3 weeks), and at the end of treatment, using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-30) and its breast cancer module, QLQ-BR23. Prespecified exploratory analyses included a longitudinal mixed-effect model comparing treatment arms and a time to definitive clinically meaningful deterioration (TTD) analysis carried out in the global health status/quality of life (GHS/QoL), and all functional and symptom scales from the EORTC QLQ-C30 and -BR23 questionnaires. Between-arm TTD comparisons were made using a stratified log-rank test and a Cox proportional hazards model. Results: Baseline scores were similar between arms. Statistically significant estimated overall improvement from baseline in GHS/QoL was seen for talazoparib compared with statistically significant deterioration for PCT {3.0 [95% confidence interval (CI) 1.2, 4.8] versus -5.4 [95% CI -8.8, -2.0]; between arms, P < 0.0001}. A statistically significant greater delay was observed in TTD in GHS/QoL, favoring talazoparib over PCT [hazard ratio, 0.38 (95% CI 0.26, 0.55; median, 24.3 versus 6.3 months, respectively; P < 0.0001)]. A statistically significant overall change and a statistically significant delay in TTD, all favoring talazoparib, were also observed in multiple functions and symptoms. Conclusion: Patients who received talazoparib had significant overall improvements and significant delay in TTD in multiple cancer-related and breast cancer-specific symptoms, functions, and GHS/QoL. ClinicalTrials.gov: NCT01945775.

A feasibility study of neoadjuvant talazoparib for operable breast cancer patients with a germline BRCA mutation demonstrates marked activity.

This study was undertaken to determine the feasibility of enrolling breast cancer patients on a single-agent-targeted therapy trial before neoadjuvant chemotherapy. Specifically, we evaluated talazoparib in patients harboring a deleterious BRCA mutation (BRCA+). Patients with a germline BRCA mutation and ≥1 cm, HER2-negative primary tumors were eligible. Study participants underwent a pretreatment biopsy, 2 months of talazoparib, off-study core biopsy, anthracycline, and taxane-based chemotherapy ± carboplatin, followed by surgery. Volumetric changes in tumor size were determined by ultrasound at 1 and 2 months of therapy. Success was defined as 20 patients accrued within 2 years and <33% experienced a grade 4 toxicity. The study was stopped early after 13 patients (BRCA1 + n = 10; BRCA2 + n = 3) were accrued within 8 months with no grade 4 toxicities and only one patient requiring dose reduction due to grade 3 neutropenia. The median age was 40 years (range 25-55) and clinical stage included I (n = 2), II (n = 9), and III (n = 2). Most tumors (n = 9) were hormone receptor-negative, and one of these was metaplastic. Decreases in tumor volume occurred in all patients following 2 months of talazoparib; the median was 88% (range 30-98%). Common toxicities were neutropenia, anemia, thrombocytopenia, nausea, dizziness, and fatigue. Single-agent-targeted therapy trials are feasible in BRCA+ patients. Given the rapid rate of accrual, profound response and favorable toxicity profile, the feasibility study was modified into a phase II study to determine pathologic complete response rates after 4-6 months of single-agent talazoparib.

Revisiting the definition of estrogen receptor positivity in HER2-negative primary breast cancer.

BACKGROUND: Although 1% has been used as cut-off for estrogen receptor (ER) positivity, several studies have reported that tumors with ER < 1% have characteristics similar to those with 1% ≤ ER < 10%. We hypothesized that in patients with human epidermal growth factor 2 (HER2)-negative breast cancer, a cut-off of 10% is more useful than one of 1% in discriminating for both a better pathological complete response (pCR) rate to neoadjuvant chemotherapy and a better long-term outcome with adjuvant hormonal therapy. Our objectives were to identify a percentage of ER expression below which pCR was likely and to determine whether this cut-off value can identify patients who would benefit from adjuvant hormonal therapy. PATIENTS AND METHODS: Patients with stage II or III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery between June 1982 and June 2013 were included. Logistic regression models were used to assess the association between each variable and pCR. Cox models were used to analyze time to recurrence and overall survival. The recursive partitioning and regression trees method was used to calculate the cut-off value of ER expression. RESULTS: A total of 3055 patients were analyzed. Low percentage of ER was significantly associated with high pCR rate (OR = 0.99, 95% CI = 0.986-0.994, P < 0.001). The recommended cut-off of ER expression below which pCR was likely was 9.5%. Among patients with ER ≥ 10% tumors, but not those with 1%≤ER < 10% tumors, adjuvant hormonal therapy was significantly associated with long time to recurrence (HR = 0.24, 95% CI = 0.16-0.36, P < 0.001) and overall survival (HR = 0.32, 95% CI = 0.2-0.5, P < 0.001). CONCLUSION: Stage II or III HER2-negative primary breast cancer with ER < 10% behaves clinically like triple-negative breast cancer in terms of pCR and survival outcomes and patients with such tumors may have a limited benefit from adjuvant hormonal therapy. It may be more clinically relevant to define triple-negative breast cancer as HER2-negative breast cancer with <10%, rather than <1%, of ER and/or progesterone receptor expression.

Primary analysis of a prospective, randomized, single-blinded phase II trial evaluating the HER2 peptide AE37 vaccine in breast cancer patients to prevent recurrence.

BACKGROUND: AE37 is the Ii-Key hybrid of the MHC class II peptide, AE36 (HER2 aa:776-790). Phase I studies showed AE37 administered with granulocyte macrophage colony-stimulating factor (GM-CSF) to be safe and highly immunogenic. A prospective, randomized, multicenter phase II adjuvant trial was conducted to evaluate the vaccine's efficacy. METHODS: Clinically disease-free node-positive and high-risk node-negative breast cancer patients with tumors expressing any degree of HER2 [immunohistochemistry (IHC) 1-3+] were enrolled. Patients were randomized to AE37 + GM-CSF versus GM-CSF alone. Toxicity was monitored. Clinical recurrences were documented and disease-free survival (DFS) analyzed. RESULTS: The trial enrolled 298 patients; 153 received AE37 + GM-CSF and 145 received GM-CSF alone. The groups were well matched for clinicopathologic characteristics. Toxicities have been minimal. At the time of the primary analysis, the recurrence rate in the vaccinated group was 12.4% versus 13.8% in the control group [relative risk reduction 12%, HR 0.885, 95% confidence interval (CI) 0.472-1.659, P = 0.70]. The Kaplan-Meier estimated 5-year DFS rate was 80.8% in vaccinated versus 79.5% in control patients. In planned subset analyses of patients with IHC 1+/2+ HER2-expressing tumors, 5-year DFS was 77.2% in vaccinated patients (n = 76) versus 65.7% in control patients (n = 78) (P = 0.21). In patients with triple-negative breast cancer (HER2 IHC 1+/2+ and hormone receptor negative) DFS was 77.7% in vaccinated patients (n = 25) versus 49.0% in control patients (n = 25) (P = 0.12). CONCLUSION: The overall intention-to-treat analysis demonstrates no benefit to vaccination. However, the results confirm that the vaccine is safe and suggest that vaccination may have clinical benefit in patients with low HER2-expressing tumors, specifically TNBC. Further evaluation in a randomized trial enrolling TNBC patients is warranted.

Open-label randomized clinical trial of standard neoadjuvant chemotherapy with paclitaxel followed by FEC versus the combination of paclitaxel and everolimus followed by FEC in women with triple receptor-negative breast cancer†.

BACKGROUND: Everolimus synergistically enhances taxane-induced cytotoxicity in breast cancer cells in vitro and in vivo in addition to demonstrating a direct antiproliferative activity. We aim to determine pharmacodynamics changes and response of adding everolimus to standard neoadjuvant chemotherapy in triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Phase II study in patients with primary TNBC randomized to T-FEC (paclitaxel 80 mg/m(2) i.v. weekly for 12 weeks, followed by 5-fluorouracil 500 mg/m(2), epirubicin 100 mg/m(2), and cyclophosphamide 500 mg/m(2) every 3 weeks for four cycles) versus TR-FEC (paclitaxel 80 mg/m(2) i.v. and everolimus 30 mg PO weekly for 12 weeks, followed by FEC). Tumor samples were collected to assess molecular changes in the PI3K/AKT/mTOR pathway, at baseline, 48 h, 12 weeks, and at surgery by reverse phase protein arrays (RPPA). Clinical end points included 12-week clinical response rate (12-week RR), pathological complete response (pCR), and toxicity. RESULTS: Sixty-two patients were registered, and 50 were randomized, 27 received T-FEC, and 23 received TR-FEC. Median age was 48 (range 31-75). There was downregulation of the mTOR pathway at 48 h in the TR-FEC arm. Twelve-week RR by ultrasound were 29.6% versus 47.8%, (P = 0.075), and pCR were 25.9% versus 30.4% (P = 0.76) for T-FEC and TR-FEC, respectively. mTOR downregulation at 48 h did not correlate with 12-week RR in the TR-FEC group (P = 0.58). Main NCI grade 3/4 toxicities included anemia, neutropenia, rash/desquamation, and vomiting in both arms. There was one case of grade 3 pneumonitis in the TR-FEC arm. No grade 3/4 stomatitis occurred. CONCLUSION: The addition of everolimus to paclitaxel was well tolerated. Everolimus downregulated mTOR signaling but downregulation of mTOR at 48 h did not correlate with 12-week RR in the TR-FEC group. CLINICAL TRIAL NUMBER: NCT00499603.

Prognostic value of the trichorhinophalangeal syndrome-1 (TRPS-1), a GATA family transcription factor, in early-stage breast cancer.

BACKGROUND: TRPS-1 is a new GATA transcription factor that is differentially expressed in breast cancer (BC) where it been found recently to regulate epithelial-to-mesenchymal transition (EMT). PATIENTS AND METHODS: We carried out a quantitative immunohistochemistry (qIHC) analysis of TRPS-1 expression in 341 primary-stage I-III BC samples in relation to patient clinical characteristics as well as its prognostic value, especially in an estrogen receptor-positive (ER+) subgroup. RESULTS: Higher TRPS-1 expression was significantly associated with a number of clinical and pathological characteristics as well as with improved overall survival (OS) and disease-free survival (DFS). Among stage I/II ER+ BC patients who received endocrine therapy alone, those with high TRPS-1 expression had significantly longer OS and DFS. There was also a strong association between TRPS-1 levels and the EMT marker E-cadherin in the ER+ invasive ductal carcinoma cases. Analysis of gene expression data on a panel of BC lines found that TRPS-1 expression was low or absent in BC lines having enriched mesenchymal features. CONCLUSIONS: Our data indicated that TRPS-1 is an independent prognostic marker in early-stage BC and a new EMT marker that can distinguish patients with ER+ BC who will respond longer to adjuvant endocrine therapy.

Pathologic complete response to neoadjuvant chemotherapy with trastuzumab predicts for improved survival in women with HER2-overexpressing breast cancer.

BACKGROUND: We sought to determine the prognostic value of pathologic response to neoadjuvant chemotherapy with concurrent trastuzumab. PATIENTS AND METHODS: Two hundred and twenty-nine women with HER2/neu (HER2)-overexpressing breast cancer were treated with neoadjuvant chemotherapy plus trastuzumab between 2001 and 2008. Patients were grouped based on pathologic complete response (pCR, n = 114) or less than pCR (

Outcome of metastatic breast cancer in selected women with or without deleterious BRCA mutations.

The aim of this study was to compare the time-to progression and overall survival (OS) in patients with metastatic breast cancer (MBC) with and without deleterious BRCA1/2 mutations. 195 women with MBC who were referred for BRCA genetic testing between 1997 and 2011 were included in the study. Logistic regression models and Cox proportional hazards models were fit to determine the associations between clinical variables and outcomes. Of 195 women with MBC, 21 % (n = 41) were positive for BRCA1/2 mutations. The number of metastatic sites at the time of metastatic disease was not different between BRCA1 versus BRCA2 carriers versus non-carriers (P = 0.77). The site of first metastasis was visceral-only in 70 % of BRCA1 carriers compared to 9 % in BRCA2 carriers and 37 % in non-carriers (P = 0.001). Median follow-up was 2.8 years. BRCA non-carriers and BRCA2 carriers had a longer time-to progression and OS compared to BRCA1 carriers (median time-to progression = 1.3 vs. 0.9 vs. 0.7 years; P = 0.31, and median OS = 4.88 vs. 4.94 vs. 1.34 years; P = 0.0065). In a multivariate model, no association was identified between BRCA positivity and time-to-event outcomes (P > 0.28). In addition, patients with triple-negative MBC carried a poorer prognosis irrespective of their BRCA status (P = 0.058 and P = 0.15 for the interaction term of BRCA status and triple-negative for time-to progression and OS, respectively). Our data indicate that BRCA1 carriers diagnosed with MBC have worse outcomes compared to BRCA2 carriers and non-carriers. However, the differences in outcome did not reach statistical significance likely due to small sample sizes.

Communication of BRCA1 and BRCA2 genetic test results to health care providers following genetic testing at a tertiary care center.

Individuals at high risk for hereditary cancers often receive genetic counseling and testing at tertiary care centers; however, they may receive care for long-term management of their cancer risk in community settings. Communication of genetic test results to health care providers outside of tertiary care settings can facilitate the long-term management of high risk individuals. This study assessed women's communication of BRCA1/BRCA2 genetic test results to health care providers outside of tertiary care settings (termed "outside" health care providers, or OHCPs) and women's perceptions regarding communication of results. Women (n = 312) who underwent BRCA1/BRCA2 genetic counseling and testing completed a questionnaire assessing whether or not they shared test results with OHCPs and perceptions regarding the communication of test results to OHCPs. Most (72%) shared genetic test results with OHCPs. Women with no personal history of cancer were more likely to have shared results compared to women with a personal history of cancer. Mutation status did not significantly predict sharing of genetic information. Most reported positive perceptions regarding the disclosure of genetic test results to OHCPs. The majority did not report any concerns about potential insurance discrimination (88%) and indicated that OHCPs were able to appropriately address their questions (81%). Although most women shared their genetic test results with OHCPs, those with a personal history of cancer may need further encouragement to share this information. Tertiary care centers should facilitate outreach and education with OHCPs in order to assure appropriate long-term cancer risk management for high risk populations.