TBCRC 030: a phase II study of preoperative cisplatin versus paclitaxel in triple-negative breast cancer: evaluating the homologous recombination deficiency (HRD) biomarker

BACKGROUND

Cisplatin and paclitaxel are active in triple-negative breast cancer (TNBC). Despite different mechanisms of action, effective predictive biomarkers to preferentially inform drug selection have not been identified. The homologous recombination deficiency (HRD) assay (Myriad Genetics, Inc.) detects impaired double-strand DNA break repair and may identify patients with BRCA1/2-proficient tumors that are sensitive to DNA-targeting therapy. The primary objective of TBCRC 030 was to detect an association of HRD with pathologic response [residual cancer burden (RCB)-0/1] to single-agent cisplatin or paclitaxel.

PATIENTS AND METHODS

This prospective phase II study enrolled patients with germline BRCA1/2 wild-type/unknown stage I-III TNBC in a 12-week randomized study of preoperative cisplatin or paclitaxel. The HRD assay was carried out on baseline tissue; positive HRD was defined as a score ≥33. Crossover to an alternative chemotherapy was offered if there was inadequate response.

RESULTS

One hundred and thirty-nine patients were evaluable for response, including 88 (63.3%) who had surgery at 12 weeks and 51 (36.7%) who crossed over to an alternative provider-selected preoperative chemotherapy regimen due to inadequate clinical response. HRD results were available for 104 tumors (74.8%) and 74 (71.1%) were HRD positive. The RCB-0/1 rate was 26.4% with cisplatin and 22.3% with paclitaxel. No significant association was observed between HRD score and RCB response to either cisplatin [odds ratio (OR) for RCB-0/1 if HRD positive 2.22 (95% CI: 0.39-23.68)] or paclitaxel [OR for RCB-0/1 if HRD positive 0.90 (95% CI: 0.19-4.95)]. There was no evidence of an interaction between HRD and pathologic response to chemotherapy.

CONCLUSIONS

In this prospective preoperative trial in TNBC, HRD was not predictive of pathologic response. Tumors were similarly responsive to preoperative paclitaxel or cisplatin chemotherapy.

Abstract P3-08-10: Characterization of oncotype DX recurrence score and chemotherapy utilization patterns in young women (≤40) with early stage ER+/HER-, lymph node negative breast cancer

Background: Meta-analyses have demonstrated that young women ≤40 (YW) derive the most benefit from chemotherapy (EBCTCG, Lancet. 1998). Oncotype DX was designed to determine the benefit of chemotherapy in women with ER+/HER2-, node-negative (LN-) breast cancer based on recurrence score (RS). TAILORx reported clinically meaningful benefits in freedom-from-distant recurrence in women <50 with the addition of chemotherapy to endocrine therapy when RS was 16-25. Recent TAILORx analyses suggest that women <40 with an intermediate (int) RS do not derive chemotherapy benefit, though YW comprised <4% of the trial population [1]. Defining the optimal adjuvant treatment strategy for this population of YW remains a clinical challenge. We sought to determine national patterns of RS utilization in association with receipt of chemotherapy and to characterize the association of RS with tumor characteristics and demographics among YW with early stage ER+, LN- breast cancer.

Methods: Using the National Cancer Data Base (NCDB), we identified individuals age <75, diagnosed 2010-2015 with stage I-II, ER+/HER2-, LN- breast cancer with known RS. Cohorts were defined as low (0-10), int (11-25), and high (>25) RS. Age categories were classified as ≤40, 41-50, and >50. Chi-square tests or Fisher’s exact tests were used to compare categorical variables. Logistic regression was used to estimate the association of RS score and age group with adjuvant chemotherapy use, after adjustment for known covariates. Kaplan-Meier curves were used to visualize unadjusted overall survival (OS), and Cox proportional hazards models were used to estimate adjusted OS.

Results: 120,051 women were identified, of whom 4,781 were ≤40 years, 24,846 were 41-50, and 90,424 were >50. By age group, 20% of YW had a high RS compared to 12% of women age 41-50 and 15% of women >50 (p<0.001). Among YW, black women were more likely than white women to have a high RS; 29% vs. 19% (p<0.001). RS was strongly associated with receipt of chemotherapy in YW (86% of high RS vs. 33% of int RS vs. 7% of low RS, p<0.001). Chemotherapy was omitted in 55% of YW with RS 16-25. YW in multivariate analysis with a low or int RS were more likely than women 41-50 or >50 to receive chemotherapy (p<0.001). Receipt of chemotherapy for YW with an int RS was associated with younger chronologic age (p<0.001), ductal histology (p=0.02), high grade (p<0.001), and higher pathologic T-stage (p<0.001). Among YW, the unadjusted 5-year OS (95% CI) was as follows: low RS= 100% (0.99-1), int RS= 100% (1-1), high RS= 93% (0.90-0.96). Chemotherapy did not influence 5 year OS in YW with an int RS. In univariate analysis, a high RS was associated with a worse 5-year OS in YW (log-rank p<0.001). After adjustment for race and chemotherapy receipt, high vs. low RS was associated with an increased risk of death (HR=5.86, 95% CI 1.19-28.82, p=0.03) in YW.

Conclusions: High RS is more common in YW (≤40) than those age 41-50 or >50, and is associated with worse OS. YW with an int or low RS are more likely to receive chemotherapy despite unclear benefit. Chemotherapy was omitted in over half of YW with RS of 16-25, highlighting the uncertainty in clinical practice which will remain until further studies inform optimal systemic treatment specific to YW.

1. Sparano, J.A., et al., Clinical and Genomic Risk to Guide the Use of Adjuvant Therapy for Breast Cancer. New England Journal of Medicine, 2019. 380(25): p. 2395-2405.

Citation Format: Sarah Sammons, Yi Ren, Jeremy Force, Oluwadamilola M. Fayanju, Laura H. Rosenberger, Jennifer K. Plichta, Gretchen Kimmick, Kelly Westbrook, Susan Dent, Carey Anders, Samantha M. Thomas, Terry Hyslop, E. S. Hwang, P. K. Marcom, Rachel A. Greenup. Characterization of oncotype DX recurrence score and chemotherapy utilization patterns in young women (≤40) with early stage ER+/HER-, lymph node negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-10.

The immune profile of small HER2-positive breast cancers: a secondary analysis from the APT trial

BACKGROUND

Previous data suggest that the immune microenvironment plays a critical role in human epidermal growth factor receptor 2 (HER2) -positive breast cancer; however, there is little known about the immune profiles of small HER2-positive tumors. In this study, we aimed to characterize the immune microenvironment of small HER2-positive breast cancers included in the Adjuvant paclitaxel and trastuzumab for node-negative, HER2-positive breast cancer (APT) trial and to correlate the immune markers with pathological and molecular tumor characteristics.

PATIENTS AND METHODS

The APT trial was a multicenter, single-arm, phase II study of paclitaxel and trastuzumab in patients with node-negative HER2-positive breast cancer. The study included 406 patients with HER2-positive, node-negative breast cancer, measuring up to 3 cm. Exploratory analysis of tumor infiltrating lymphocytes (TIL), programmed death-ligand 1 (PD-L1) expression (by immunohistochemistry), and immune gene signatures using data generated by nCounter PanCancer Pathways Panel (NanoString Technologies, Seattle, WA), and their association with pathological and molecular characteristics was carried out.

RESULTS

Of the 406 patients, 328 (81%) had at least one immune assay carried out: 284 cases were evaluated for TIL, 266 for PD-L1, and 213 for immune gene signatures. High TIL (≥60%) were seen with greater frequency in hormone-receptor (HR) negative, histological grades 2 and 3, as well in HER2-enriched and basal-like tumors. Lower stromal PD-L1 (≤1%) expression was seen with greater frequency in HR-positive, histological grade 1, and in luminal tumors. Both TIL and stromal PD-L1 were positively correlated with 10 immune cell signatures, including Th1 and B cell signatures. Luminal B tumors were negatively correlated with those signatures. Significant correlation was seen among these immune markers; however, the magnitude of correlation did not indicate a monotonic relationship between them.

CONCLUSION

Immune profiles of small HER2-positive breast cancers differ according to HR status, histological grade, and molecular subtype. Further work is needed to explore the implication of these findings on disease outcome.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT00542451.

Abstract P3-08-07: Distinct biological signatures describe differences in BRCA mutated subgroups

Background: BRCA mutated (BRCA+) breast cancers are expected to have increased activation of Homologous Recombination Deficiency (HRD) and altered DNA damage repair pathways when compared to BRCA wildtype (BRCA-). To better understand differences in these populations, biological patterns and immune responses to BRCA+ breast cancers were evaluated. The primary aim of our study was to use novel gene expression tools to assess early stage breast cancers with and without germline BRCA mutations, and within distinct BRCA+ subgroups.

Methods: We identified 124 early stage untreated breast cancers with and without BRCA mutations (n = 62 and 62, respectively). Our BRCA- group was matched by hormone receptor (HR) status, age, and stage to the BRCA+ group. The NanoString Breast Cancer 360 panel was applied to RNA isolated from 80 breast tumors (BRCA+ = 39; BRCA- = 41). The BRCA+ group had a BRCA1+ subgroup (n=17) and a BRCA2+ subgroup (n=22).

Results: There was a significant increase in two BC360 signatures in both the BRCA1+ and BRCA2+ tumors compared with the BRCA- population: Prosigna™Risk of Recurrence (ROR) score [BRCA1+: HR: 1.142 (95% CI 1.019, 1.279), p=0.02; BRCA2+: HR: 1.321 (95% CI 1.190, 1.466), p<0.001] and HRD [BRCA1+: HR: 3.576 (95% CI 2.174, 5.880), p=0.02; BRCA2+: HR: 1.801 (95% CI 1.142, 2.840), p<0.001]. BRCA1+ tumors had lower expression of ESR1 [p=0.03], PGR [p=0.02], ER signaling [p<0.001], and differentiation [p=0.005]; while BRCA2+ tumors had lower expression of stroma markers [p=0.02] and inflammatory chemokines [p=0.001]. The two BRCA+ subgroups had distinct molecular subtype correlation trends that were highly significant. BRCA1+ tumors were positively associated with a basal subtype [p<0.001], whereas this association was not significant for BRCA2+ tumors. BRCA2+ tumors were associated with an increase in luminal B subtype [p=0.05]. All BRCA+ tumors had a decrease in luminal A subtype correlation [BRCA1+: p<0.001; BRCA2+: p=0.002]. In addition to the BC360 signatures, a differential analysis of all genes in the BC360 panel revealed more single gene differences in BRCA2+ than BRCA1+ tumors when compared to BRCA- tumors.

Conclusions: In early stage BRCA+ breast cancer, tumors have higher ROR and increased HRD signature scores compared to BRCA- tumors. Furthermore, BRCA1+ and BRCA2+ tumors have both signature and single gene expression differences when compared to BRCA- tumors, indicating distinct subgroup-related biology. The greater correlation of BRCA1+ tumors with basal-like biology and BRCA2+ tumors with aggressive hormonal biology confirms these trends. Distinctions in hormone receptor signaling, DNA-damage pathways, and microenvironment/inflammatory features between BRCA1 and BRCA2 associated cancers suggest a need for different prevention and therapeutic strategies for each of these breast cancer subtypes. The unique biological patterns identified here should be further evaluated as predictive or prognostic tools that could be translated into clinical care for early stage BRCA+ patients.

Citation Format: Force J, Plichta J, Stashko I, Kimmick G, Westbrook K, Sammons S, Hwang S, Hyslop T, Kauff N, Castellar E, Nair S, Weinhold K, Davis S, Mashadi-Hossein A, Brauer HA, Marcom PK. Distinct biological signatures describe differences in BRCA mutated subgroups [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-07.

Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Background

Homologous recombination defects in BRCA1/2-mutated tumors result in sensitivity to poly(ADP-ribose) polymerase inhibitors, which interfere with DNA damage repair. Veliparib, a potent poly(ADP-ribose) polymerase inhibitor, enhanced the antitumor activity of platinum agents and temozolomide in early phase clinical trials. This phase II study examined the safety and efficacy of intermittent veliparib with carboplatin/paclitaxel (VCP) or temozolomide (VT) in patients with BRCA1/2-mutated breast cancer.

Patients and methods

Eligible patients ≥18 years with locally recurrent or metastatic breast cancer and a deleterious BRCA1/2 germline mutation were randomized 1 : 1 : 1 to VCP, VT, or placebo plus carboplatin/paclitaxel (PCP). Primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and overall response rate (ORR).

Results

Of 290 randomized patients, 284 were BRCA+, confirmed by central laboratory. For VCP versus PCP, median PFS was 14.1 and 12.3 months, respectively [hazard ratio (HR) 0.789; 95% CI 0.536-1.162; P = 0.227], interim median OS 28.3 and 25.9 months (HR 0.750; 95% CI 0.503-1.117; P = 0.156), and ORR 77.8% and 61.3% (P = 0.027). For VT (versus PCP), median PFS was 7.4 months (HR 1.858; 95% CI 1.278-2.702; P = 0.001), interim median OS 19.1 months (HR 1.483; 95% CI 1.032-2.131; P = 0.032), and ORR 28.6% (P < 0.001). Safety profile was comparable between carboplatin/paclitaxel arms. Adverse events (all grades) of neutropenia, anemia, alopecia, and neuropathy were less frequent with VT versus PCP.

Conclusion

Numerical but not statistically significant increases in both PFS and OS were observed in patients with BRCA1/2-mutated recurrent/metastatic breast cancer receiving VCP compared with PCP. The addition of veliparib to carboplatin/paclitaxel significantly improved ORR. There was no clinically meaningful increase in toxicity with VCP versus PCP. VT was inferior to PCP. An ongoing phase III trial is evaluating VCP versus PCP, with optional continuation single-agent therapy with veliparib/placebo if chemotherapy is discontinued without progression, in this patient population.

Clinical trial information

NCT01506609.

Abstract P2-04-19: Elucidating the tumor immune microenvironment phenotype in early stage untreated BRCA mutated breast cancer patients

Background: Increased stromal tumor infiltrating lymphocytes (TILs) are predictive and prognostic for improved outcomes from neoadjuvant or adjuvant chemotherapy in triple negative breast cancer. Increased tumor mutational burden may promote neoantigens causing immune system upregulation. Microsatellite instability in gastrointestinal cancer predicts for response to checkpoint inhibition and is associated with inherited cancer predisposition. The immune system response in BRCA mutated breast cancer has not been described. The purpose of this study is to assess tumor infiltrating immune cells in early stage breast cancer patients with and without BRCA gene mutations.

Methods: We retrospectively investigated 124 early stage breast cancer patients with BRCA mutations (n=62, BRCA+) and without BRCA mutations (n=62, BRCA WT). The %TILs was measured manually by H&E. Our control group consisted of age, stage, and receptor status matched early stage untreated breast cancer patients who were deemed BRCA WT by extended gene panel testing or were negative for BRCA 1/2 and had a posttest probability of harboring an autosomal dominant mutated gene of ≤ 1% using the Bayes-Mendel algorithm. We used a two-sample binomial arcsin approximation to detect a 20% difference in TILs between cohorts to attain 80% power with a one-side alpha of 0.05. Wilcoxon Rank-Sums test was used to compare differences in the central tendencies for continuous variables. We used the Nanostring PanCancer immune profiling panel to immunophenotype a portion of the BRCA+ and BRCA WT cohorts and used nSolver for quality control, normalization, and bioinformatics analyses.

Results: Here we report TILs from the first 21 patients of our study. Thirteen patients harbored BRCA mutations and eight patients did not. All patients were HER2 negative. Eight (61%) and four (50%) patients were hormone receptor positive (HR+) in the BRCA+ and BRCA WT cohorts, respectively. Median %TILs were not significantly different between the BRCA+ (15, range 0-70) and BRCA WT (17.5, range 5-60; p=0.7) groups. Median %TILs in the HR+/BRCA+ (12.5, range 0-50) and HR-/BRCA+ (15, range 5-70) cohorts were not statistically different when compared to HR+/BRCA WT (10, range 5-15; p=0.4) and HR-/BRCA WT (30, range 20-60; p=0.2) cohorts, respectively. There were 2 patients with lymphocyte predominant breast cancer (n=1, HR-/BRCA+; n=1, HR-/BRCA WT).

Conclusions: This is the first study to characterize TILs and a tumor immune microenvironment phenotype in early stage breast cancer patients with BRCA mutations. These results suggest harboring a BRCA mutation is not associated with increased TILs in early stage untreated breast cancer patients. This conclusion stayed true regardless of hormone receptor status. However, a trend of decreased TILs was seen in HR-/BRCA+ patients when compared to those with HR-/BRCA WT disease. Moreover, the median and range of TILs were higher in the HR+/BRCA+ group compared to the HR+/BRCA WT group. This suggests increased TILs may exist in some HR+ patients with a BRCA mutation. Further investigation of TILs and immune profiling of early stage untreated breast cancer patients with and without BRCA mutations is warranted.

Citation Format: Force J, Abbott S, Broadwater G, Kimmick G, Westbrook K, Hwang S, Kauff N, Stashko I, Weinhold K, Nair S, Hyslop T, Blackwell K, Castellar E, Marcom PK. Elucidating the tumor immune microenvironment phenotype in early stage untreated BRCA mutated breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-04-19.

Abstract P1-01-01: Circulating tumor cell number and CTC-endocrine therapy index predict clinical outcomes in ER positive metastatic breast cancer patients: Results of the COMETI Phase 2 trial

Introduction: Only half of hormone receptor positive (HR+) metastatic breast cancer (MBC) patients (pts) benefit from endocrine therapy (ET). Circulating tumor cells (CTC) are prognostic in pts with MBC using CellSearch® technology. The CTC-endocrine therapy index (CTC-ETI) provides semi-quantitative analyses of CTC-ER (estrogen receptor), BCL2, HER2, and Ki67 expression. We hypothesized that CTC-ETI high (elevated CTC number and/or low expression of ER and BCL2, and high expression of HER2 and Ki-67) might predict resistance to ET in a prospective, multi-institutional clinical trial: COMETI-P2-2012.0 (NCT01701050).

Methods: 121 pts with ER+, HER2 negative (-), and progressive MBC after one or more lines of ET or within 12 months (mos) of completing adjuvant ET, who were initiating a new ET, were enrolled after informed consent. CTC and CTC-ETI were determined as previously reported (Paoletti C et al, CCR 2015) at baseline (BL), 1, 2, 3, and 12 mos, and/or at the time of progression. Imaging was performed every 3 mos. Association of CTC levels and CTC-ETI with patient outcomes (progression free survival (PFS); rapid progression (RP) defined as progression within 3 mos) was assessed using logrank and Fisher's exact tests. Trial design estimated 85 PFS and 51 RP events, providing &gt;90% power (2-sided a=0.05); pts with unsuccessful BL CTC-ETI or ineligible were unevaluable. Only baseline (BL) data are reported in this abstract.

Results: 32% of enrolled pts had progression within 12 mos of completing adjuvant ET, whereas 40%, 20%, and 8% had 1, 2, ≥3 lines of ET for MBC. CTC-ETI was successfully determined in 93% of pts (90% CI, 88% to 97%). CTC were ≥5 CTC/7.5 ml whole blood in 37/108 (34%) pts evaluable for clinical validity. Elevated CTC was associated with worse PFS (median (m) PFS: 3.3 vs. 5.9 mos; P&lt;0.01). Low, intermediate, and high CTC-ETI were observed in 75 (69%), 6 (6%), and 27 (25%) pts, respectively. CTC-ETI was associated with PFS (logrank P&lt;0.01): pts with low, intermediate, and high CTC-ETI had mPFS of 5.7, 8.5, and 2.8 mos, respectively. In the 96 pts eligible for determination, elevated CTC was associated with RP, (65.6% vs. 42.2%; P=0.05) as was CTC-ETI (P=0.003): 79.2% (95% CI, 57.8% to 92.9%) of pts with high CTC-ETI had RP versus 41.2% (95% CI, 29.4% to 53.8%) with low CTC-ETI; in the small group with intermediate CTC-ETI 1 of 4 pts (25%) had RP.

Conclusions: In this multi-institutional, prospective study, CTC-ETI was accurately determined, confirming the previously established analytical validity of the assay, meeting the primary objective of the trial. Elevated CTC and CTC-ETI high compared to low were associated with poor outcomes to ET. CTC-ETI distribution resulted in a small number of patients assigned to the intermediate group, restricting our ability to associate this group with outcomes. These results suggest that CTC-biomarker phenotype and enumeration have clinical validity. CTC-ETI may identify ER+ HER2– MBC pts who are unlikely to benefit from ET and might be better treated with ET in combination with other therapies or proceed to chemotherapy. Further analyses including CTC-ETI at serial time points during ET are planned.

Citation Format: Paoletti C, Regan MM, Liu MC, Marcom PK, Hart LL, Smith II JW, Tedesco KL, Amir E, Krop IE, DeMichele AM, Goodwin PJ, Block M, Aung K, Cannell EM, Darga EP, Baratta PJ, Brown ME, McCormack RT, Hayes DF. Circulating tumor cell number and CTC-endocrine therapy index predict clinical outcomes in ER positive metastatic breast cancer patients: Results of the COMETI Phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-01.

Abstract P4-22-02: Evaluation of veliparib (V) and temozolomide (TMZ) in a phase 2 randomized study of the efficacy and tolerability of V+TMZ or carboplatin (C) and paclitaxel (P) vs placebo (Plc)+C/P in patients (pts) with BRCA1 or BRCA2 mutations and metastatic breast cancer

Background: V is a potent, poly(ADP-ribose) polymerase (PARP) inhibitor that obstructs DNA damage repair. BRCA1/2 tumors are defective in homologous recombination, which leads to more error-prone mechanisms of DNA repair and increased sensitivity to PARP inhibition. V enhances the antitumor activity of alkylating agents such as TMZ in preclinical models. In addition, V+TMZ showed promising activity in a single-arm phase 2 study in pts with BRCA1/2 mutations. This phase 2 trial (NCT01506609) investigated the efficacy and tolerability of V+TMZ (or V+C/P) compared to Plc+C/P in pts with locally recurrent or metastatic breast cancer harboring a BRCA1 or BRCA2 mutation. Results from the primary analysis for the V+TMZ arm vs Plc+C/P are presented, and the V+C/P vs Plc+C/P results will be presented separately.

Methods: Male and female pts aged ≥18 years with histologically confirmed locally recurrent or metastatic breast cancer were randomized 1:1:1 to: 1) V 40 mg BID D1–7 + TMZ 150–200 mg/m2 QD D1–5, 28-D cycle; 2) V 120 mg BID D1–7 + C AUC 6, D3 and P 175 mg/m2, D3, 21-D cycle; 3) placebo BID D1–7 + C/P. Key eligibility criteria included known deleterious BRCA1/2 mutation, ≤2 prior chemotherapies for metastatic disease, no prior platinum agent, and no CNS metastases. Randomization was stratified by hormone receptor status, prior cytotoxic therapy (yes vs no), and ECOG PS (0–1 vs 2). The primary endpoint was progression-free survival (PFS) per RECIST 1.1 by independent review. Overall survival (OS), objective response rate (ORR), and safety/tolerability were also evaluated.

Results: A total of 290 pts (284 BRCA+ per central lab) were randomized (V+TMZ, n=94 [91 BRCA+]). Baseline demographics and disease characteristics were comparable among treatment arms; 41.3% of pts had triple-negative breast cancer (TNBC) and 31.7% had received &gt;2 prior regimens. Median study drug exposure was 6 cycles for the V+TMZ arm and 10 cycles for the Plc+C/P arm. Median PFS, median OS (interim), and ORR for V+TMZ were inferior to Plc+C/P (PFS 7.4 vs 12.3 mo, OS 19.1 vs 25.0 mo, and ORR 28.6% vs 61.3%). In pts with TNBC, median PFS was 5.5 (3.1–8.5) mo; 8.4 (6.8–10.6) mo for pts with non-TNBC. Treatment-emergent adverse events (AEs) of interest occurring differentially with V+TMZ are shown in Table 1. Grade ≥3 AEs in ≥30% of pts in the V+TMZ arm were thrombocytopenia (48%) and neutropenia (37%).

Conclusions: V+TMZ provided durable responses, with less neutropenia, alopecia, and neuropathy than Plc+C/P; however, PFS, OS, and ORR were inferior in the TMZ arm compared to C/P.

Table 1Treatment-Emergent AEs, n (%)V+TMZ, n=93Plc+C/P, n=96Neutropenia46 (50)71 (74)Alopecia10 (11)55 (57)Peripheral neuropathy11 (12)56 (58)Thrombocytopenia73 (79)67 (70)Nausea70 (75)56 (58)

Citation Format: Diéras V, Han HS, Robson ME, Palácová M, Marcom PK, Jager A, Bondarenko I, Citrin D, Campone M, Telli ML, Domchek SM, Friedlander M, Kaufman B, Ratajczak C, Coates A, Bonnet P, Qin Q, Qian J, Giranda VL, Shepherd SP, Puhalla S, Isakoff SJ. Evaluation of veliparib (V) and temozolomide (TMZ) in a phase 2 randomized study of the efficacy and tolerability of V+TMZ or carboplatin (C) and paclitaxel (P) vs placebo (Plc)+C/P in patients (pts) with BRCA1 or BRCA2 mutations and metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-02.

Abstract P6-04-11: The foundation one assay influences clinical decision making in metastatic breast cancer

Background:

Tumor DNA sequencing is now readily available in metastatic breast cancer (MBC). The purpose of this study was to determine the effect of molecular testing on clinical decision-making in MBC at an academic cancer center.

Methods:

We obtained the Foundation One (FO) tests that were requested from Duke Cancer Institute breast oncologists between 12/2013 and 4/2015. We examined the following: ER/PR/HER2 status, histology, biopsy site and time, #months (mons) from time tissue was obtained to testing, #lines of prior therapy prior to tissue sampling and FO testing, #mons from initial diagnosis/MBC to FO. The following variables from the FO test were abstracted: #genomic alterations, #rx with potential benefit, #clinical trials available, #variations of unknown significance (VUS). Physicians were retrospectively surveyed regarding influence of FO results on clinical treatment decisions and on clinical trial consideration.

Results:

To date, 58 specimens have been sent for FO testing. From the time of FO testing, the mean #of mons since initial diagnosis (dx) was 84.4(7-435) and the mean #of mons since the dx of MBC was 31.4(1-140). Pts with triple negative breast cancer (TNBC) were more likely to have FO ordered within 1 year of MBC diagnosis (OR=2.93, p=0.048). On average, pts had received 3.78 lines of rx for MBC (0-10) at the time FO was sent. The timing of tissue acquisition for FO testing was bimodal (45% had a new bx for the assay whereas 55% had the FO test on archival bx). 50% of un-resulted (unsuccessful) FO assays were from archival tissue with a mean #mons since the archival tissue was obtained of 42 mons (18-74). To date, 56% of resulted samples were from archival tissue with a mean #mons since the archival tissue was obtained of 19.6(2-75).

Per the FO report: the mean #genomic alterations per pt = 6.21 (1-16); the mean #VUS per pt = 11.5 (3-30); the mean #mutation-directed rx per pt= 3.4 (0-15), the mean #mutation-directed clinical trials per pt= 9.33 (0-20). Genomic alterations occurring in ≥ 10% patients included: TP53 (48%), CCND1 (27%), FGF4 (27%), FGF19 (27%), FGFR1 (25%), PIK3CA (25%), FGF3 (25%), MYC (25%), ZNF703 (21%), ESR1 (19%), MCL1 (15%), CDH1 (13%), ERBB2 (10%), EMSY (10%), MYST3 (10%).

36 pts had invasive ductal carcinoma (IDC), 6 pts had inflammatory breast cancer (IBC), and 6 had invasive lobular carcinoma (ILC). No genomic alterations were associated with a sub-type of MBC with the exception of ESR1 mutations in ER+ IDC (100%) and CDH1 mutations in ILC (67%). Pts found to have ESR1 mutations had on average 63 mons(10-200) of endocrine therapy at the time of tissue sampling.

When the breast cancer medical oncology physicians were retrospectively surveyed, 42% FO assays influenced clinical treatment decisions and 14% resulted in clinical trial enrollment.

Conclusions:

FO utilization is variable based on MBC sub-type and the timing of tissue collection is bimodal. ESR1 mutations were associated with history of prolonged endocrine rx treatment in ER+ IDC and CDH1 mutations were associated with ILC. FO assays frequently influenced clinical treatment decisions but did not result in a high number of pts enrolled on clinical trials. We will update our dataset with additional FO assays and clinicopathologic variables.

Citation Format: Harnden KK, Kimmick GG, Marcom PK, Westbrook KE, Blackwell KL. The foundation one assay influences clinical decision making in metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-11.

Abstract P2-16-13: Phase I dose escalation clinical trial of the PI3K inhibitor BKM120 and capecitabine (C) in metastatic breast cancer (MBC)

Background: PIK3CA is one of the most frequently mutated genes in human breast cancer, and the high expression of a PIK3CA-pathway signature is associated with the poor prognosis Luminal B and Basal-like expression subtypes. BKM120 is an oral pan-class I phosphatidylinositol-3-kinase (PI3K) inhibitor, which has shown activity in preclinical and early clinical testing, and synergy with both endocrine and chemotherapy. In this trial we sought to evaluate the safety and estimate the maximum tolerated dose (MTD) of the combination of BKM120 and C in patients (pts) with MBC.

Methods: In a 3+3 dose escalation design, we evaluated four cohorts of BKM 120 daily plus C BID x 14 days in 21 day cycles. Standard definitions for DLT and MTD were used and evaluated on the first cycle. Toxicity was graded by CTCAE version 4. Response was evaluated after 2 cycles by RECIST criteria. Pts with MBC appropriate for treatment with C who had &lt;4 prior chemotherapy regimens and normal organ, bone marrow and cardiac parameters were eligible.

Results: 21 pts (11 hormone receptor (HR)+, 3 HER2+, 9 HR/HER2-negative) were enrolled and treated. All were evaluable for toxicity and 14 for response to date. Median age was 54 (range 35-65). Median prior chemotherapy regimens for MBC was 2 (range 1-4). The following dose levels (DL) were evaluated: BKM120 50 mg/d + C 1000 mg/m2/BID x 14(DL 1-4 pts), BKM120 80 mg/d + C 1000 mg/m2/BID x 14 (DL2-3 pts), BKM120 100 mg/d + C 1000 mg/m2/BID x 14 (DL3-9 pts), BKM120 100 mg/d + C 1250 mg/m2/BID x 14 (DL4-5 pts). Most frequent adverse events (all grades) included: Nausea (12), mood disorders (11), PPE (9), diarrhea (8), fatigue (7), vomiting (5) mucositis (4), rash (4), photosensitivity (3), hyperglycemia (3). Grade 3 or higher AEs in any cycle were transaminitis (3) diarrhea (2) mood disorder (2), hyperglycemia, fatigue, photosensitivity, PPE (1 pt each). DLTs: grade 3 hyperglycemia (1/6 pts at DL3), and grade 3 mood disorder in 1/5 pts DL 4. Additionally 4 of 5 patients at DL 4 required dose reduction or delay prior to C3D1. Thus DL 4 exceeded the MTD and DL 3 was expanded for further safety evaluation. Antitumor activity was seen with best responses of 1 CR (at DL 3), 3 PR (DL1 and 4) and 7 SD.

PK analysis, assessment of tumor PIK3CA mutation status and intrinsic subtype by PAM50 is ongoing.

Conclusions: The combination of BKM120 100 mg po q day and C 1000 mg/m2 / BID x 14 d in 21 day cycles is tolerable and appears active. PK and biomarker analysis are ongoing. A phase II trial is planned.

Acknowledgements: This study was funded by Novartis Pharmaceuticals and by a grant from Susan G. Komen for the Cure (SAC 110044).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-13.

Abstract S4-03: Exome sequencing reveals clinically actionable mutations in the pathogenesis and metastasis of triple negative breast cancer

Triple negative breast cancer (TNBC) represents a particularly aggressive and difficult to treat form of breast cancer. No specific genetic alterations have been described as characteristic of the disease, with the exception of association with BRCA1/2, EGFR, and KRAS mutations. In this study, we sought to define clinically actionable mutations in untreated metastatic tumors as well as compare the mutational status of metastatic samples with germ-line and primary tumors using whole exome sequencing.

We prospectively enrolled 38 patients with newly diagnosed metastatic TNBC and collected matched specimens of germ-line DNA, primary tumor and metastatic tumor. Median DFI from time of initial primary diagnosis to recurrence was 18 months (IQR = 1-24 months) and 9 patients presented with de novo metastatic disease. 34/38 patients went on to receive first-line treatment with nab-paclitaxel, carboplatin, and bevacizumab and ORR/PFS/OS are available.

Sites of TNBC metastatic tissue (n = 31) included: liver (10), chest wall (13), non-regional lymph nodes (4), and lung (4). 7 patients had inadequate metastatic tumor for sequencing. We performed whole-exome sequencing for all samples using the Agilent solution-based system of exon capture, which uses RNA baits to target all protein coding genes (CCDS database), as well as ∼700 human miRNAs from miRBase (v13). In all, we generated over 10 GB of sequencing data using high throughput sequencing on the Illumina platform.

We observed striking genetic heterogeneity among the metastatic and primary tumors. There was no single driver mutation that was common to the metastatic tumors indicating the diverse genetic pathways that contribute to metastasis. Early analysis suggests that mutations in APC and MTOR occur more frequently in metastatic tumors than in primary tumors. Nonsense mutations of ER were detected in both primary and metastatic tumors but not in germ-line DNA. EGFR and HER2 mutations were not found in any of the primary or metastatic TNBC samples.

This data provides the most comprehensive genetic portrait of metastatic and primary TNBC to date, and represents a significant first step in identifying the genetic causes of the disease, drivers of recurrence, and potential therapeutic targets. Full results, including the primary versus metastatic tumor mutational analysis will be presented.

This study was funded by a Susan G. Komen Grant SAC 100001.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S4-03.

Abstract P3-06-07: Ki67 as a Predictive Marker of Response to Neoadjuvant Chemotherapy in Patients with Early-Stage Breast Cancer (ESBC): A Systematic Review and Evidence Summary

Background: Immunohistochemical (IHC) assessment of the proportion of cells staining for the KI67 nuclear antigen is being increasing utilized in the management of patients with early-stage breast cancer (ESBC). A comprehensive systematic review and evidence synthesis of biomarkers potentially predictive of response to systemic therapy was initiated as a part of an NCI-funded comparative effectiveness research program.

Methods: Studies of chemotherapy response prediction based on baseline IHC assessment of Ki67 in patients with ESBC receiving neoadjuvant systemic therapy were identified. Response was specified as pathologic complete response (pCR) or clinical response (ClinR). Assay predictive performance for response was assessed on the basis of sensitivity, specificity, predictive value and predictive odds ratio (POR±95%CLs) utilizing mixed effects models. Study results were fitted in an ROC analysis based on the method of DerSimonian and Laird. Publication bias was evaluated on the basis of funnel plot asymmetry assessed by Egger's regression intercept and Begg and Mazumdar's rank correlation.

Results: Of 469 potentially eligible studies, dual blind full text review identified 42 eligible studies reporting 44 independent cohorts with 6,716 patients (21–979). While Ki67 cutpoints varied considerably, they were most commonly between 10%–30% (median 20%, range 1–50%). The analysis prsented here is limited to the 30 studies of ESBC patients (N = 3,343) receiving neoadjuvant therapy of which 14 reported fewer than 100 patients. The proportion of patients with elevated Ki67 across studies ranged from 0.20–0.92 (median = 0.54). Sensitivity and specificity for treatment response in patients with high vs. low baseline Ki67 was 0.65 [0.61, 0.68] and 0.52 [0.50, 0.54], respectively. Estimated response rates across studies in patients with high vs. low Ki67 were 31% [29%, 34%] and 19% [17%, 21%], respectively. The estimated POR for response across studies was 2.82 [2.14, 3.72; P &lt; .001].

P5-13-17: Multigene Signature Assays in Patients with Early-Stage Breast Cancer (ESBC) Receiving Neoadjuvant Chemotherapy: An NCI-Funded Systematic Review and Evidence Summary of Predictive Performance

Background: A comprehensive literature search and evidence synthesis of multigene signatures predictive of response to systemic chemotherapy in patients with breast cancer was initiated as a part of an NCI-funded program on Comparative Effectiveness Research.

Methods: Validation studies were sought of multigene signatures for prediction of chemotherapy response (favorable vs unfavorable) in ESBC patient cohorts different from those used for signature development. Pooled estimates [±95% CI] of assay performance for predicting clinical outcome included sensitivity, specificity, likelihood ratio, predictive value (PV) and predictive odds ratio (POR) utilizing mixed effects models based on the method of Mantel-Haenszel. Exploratory metaregression analyses on log (POR) were also performed. Studies were classified by validation type including cell lines to patients, independent internal sample, random split sample, or external validation. Evidence for publication bias was assessed by Egger's regression intercept and Begg and Mazumdar's rank correction. Results: Dual-blind review of abstracts identified 33 studies of neoadjuvant chemotherapy response of which 29 stratified treatment response by signature classifier category. Classifier development was based on tumor response prediction in 20 studies, prognosis in 5, and molecular classification in 4. The Table shows assay performance measures overall and by study validation type. Assay performance based on the POR was positively associated with overall study quality (P=.015) and journal impact factor (P=.020). However, strong evidence for publication bias was observed based on both regression intercept (P&lt;.001) and rank correlation (P=.005). No significant differences in assay performance were noted for assays originally developed for response prediction (POR=5.3), prognosis (POR=6.6) or molecular classification (P=6.9) (P=.770).

P3-14-04: Assessment of Genomic Prognostic Signatures as Predictors of Response to Neoadjuvant Chemotherapy in Patients with Early Stage Breast Cancer

Background: Based on results from randomized clinical trials, adjuvant and neoadjuvant chemotherapy (NCT) strategies in early stage breast cancer patients (ESBC) achieve comparable long term results. Recently, a number of genomic signatures have been reported, distinguishing patients with low versus high risk of recurrence. While developed primarily as prognostic assays, these classifiers have also been proposed to be predictive of benefit from systemic chemotherapy. Neoadjuvant studies provide an opportunity to evaluate their predictive value for response to NCT.

Methods: A systematic review of gene expression profile studies in ESBC patients receiving chemotherapy was conducted. Medline search of original research articles of human studies published between January 2000 and February 2011 was based on key words and MeSH heading terms. Publications presenting outcomes for chemotherapy treated patients in groups stratified by multi-gene array signatures and utilizing a new independent cohort of patients compared to the original development cohort were selected. Information from eligible studies was extracted by dual abstraction. Reported results were synthesized into combined diagnostic odds ratio (DOR) using method of Mantel-Haenszel. This analysis is restricted to neoadjuvant studies investigating the association of genomic signature prognostic categories with objective tumor response to chemotherapy. Results: A total of 42 articles were eligible for data abstraction. Out of these, 6 publications evaluated response to NCT in good (low risk of recurrence) versus poor prognosis groups based on genomic prediction. Since two of the studies analyzed the same signature on a cohort with large overlap, only 5 studies were included in the final analysis, accounting for n=918 patients. Response consisted of pathologic complete response (pCR) in 3 studies, pCR or minimal residual disease (1 study), and clinical complete response (1 study). Prognostic genomic assays included Oncotype DX (1), MammaPrint (1), Genomic Grade Index (2) and PAM50 Risk of Relapse Score (1). Eight different chemotherapy regimens were utilized. The most common drugs were cyclophosphamide, anthracyclines, taxanes, and 5-fluorouracil. Across all genomic signatures, good prognosis patients, as defined by gene expression data, demonstrated consistently low rates of response to chemotherapy (median 3%, range 0–12%) compared to patients with less favorable prognosis (median 32%, range 19–43%). Odds ratio for response in poor versus good prognosis patients ranged from 3.9 to 21.7 with combined DOR= 6.6 (95% CI 3.9−11.3, P&lt;0.0001). No heterogeneity was determined across studies (P=0.4). The C-statistic estimating assay discriminatory ability was reported in 3 studies ranged from 0.72 to 0.78.

Conclusions: Across all genomic prognostic signatures reported, only a very small proportion of patients with signature predicted good prognosis achieved complete response to NCT. This suggests low sensitivity to chemotherapy among good prognosis patients, as determined by the prognostic genomic signatures. This further confirms the association between poor prognosis tumors and higher responsiveness to chemotherapy.

Funding: NCI: UC2CA14041-01

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-04.

Abstract PD06-09: Sentinel Node Biopsy Versus Axillary Lymph Node Dissection in Early-Stage Breast Cancer: A Meta-Analysis of Randomized Controlled Trials

Background: Lymphatic mapping with sentinel node biopsy (SNB) has become a widely used technology for reducing morbidity associated with breast cancer staging despite limited data from randomized controlled trials (RCTs). A previous review of cohort studies conducted for ASCO guidelines prior to results from RCTs found considerable variation in SNB staging accuracy. (Kim et al, Cancer 2005; Lyman GH et al J Clin Oncol 2005). Early results from several RCTs of SNB have now been reported. Methods: A systematic review of RCTs of SNB for breast cancer staging was conducted utilizing electronic databases. Study eligibility was limited to RCTs comparing SNB alone in SNB negative patients versus axillary lymph node dissection (ALND) with or without prior SNB. SNB staging accuracy was assessed in study arms where patients were randomized to immediate ALND. Data abstraction was conducted by two independent reviewers. Rates of axillary, locoregional and all recurrence were evaluated along with all-cause and breast cancer-specific mortality. Heterogeneity was assessed by Cochran's Q-statistic and the Inconsistency Index (I2). Weighted summary measures of relative risk (RR) and absolute risk difference (ARD) with 95% CIs were estimated using the method of Mantel-Haenszel.

Results: Seven eligible RCTs were identified of which six, involving 9,389 patients, reported either SNB performance and/or rates of recurrence and mortality. Eligibility in these studies was restricted to patients with clinically negative nodes with four limiting accrual to tumors &lt;2-3 cm. Technical success of mapping was reported in five trials including 4,184 (97.1%) and 4,180 (96.8%) patients randomized to SNB versus SNB with immediate ALND, respectively. SNB was positive in 26.5% and 25.4% in those randomized to the SNB and SNB plus ALND arms, respectively. The false negative rate with SNB ranged from 5.5% to 22.9% with a summary estimate of 11.3% [7.5%-16.8%]. The median duration of follow-up across trials ranged from 12 to 95 months with an overall median of 65 months. The risk of axillary recurrence ranged from 0 - 0.8% in SNB patients and 0-0.9% in ALND patients, respectively with RR for axillary recurrence for SNB versus ALND patients of 1.59 [0.67-3.75; P=.292] and ARD of 0.2% [-0.01%-0.4%; P=.082]. The risk of locoregional recurrence ranged from 0.2%-4.6% in SNB patients and 0.8%-3.5% in ALND patients with RR of 1.13 [0.53-2.33; P=.776] and ARD of 0.3% [-1.0%-1.5%; P=.679]. Mortality from any cause has been reported in 222 and 196 patients in the SNB and ALND arms, respectively, with RR for mortality of 1.13 [0.94-1.36; P=.202] and ARD of 0.6% [-0.3%-1.6%; P=.201]. Breast cancer-specific mortality has been reported in 31 and 34 patients in the SNB and ALND arms, respectively, with a RR of 0.90 [0.56-1.45;P=.676] and ARD of 0.3% [-1.6%-1.0%; P=.676].

Conclusions: The overall false negative rate with SNB greater than 10% and limited follow-up continue to raise concerns. While no increase in risk of recurrence or mortality in low risk patients managed primarily with SNB is evident to date, continued observation in these studies will be important in addition to more specific data on the accuracy and safety of SNB in higher risk patients.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD06-09.

ACOSOG Z1031: A randomized phase II trial comparing exemestane, letrozole, and anastrozole in postmenopausal women with clinical stage II/III estrogen receptor-positive breast cancer

LBA513

Background: Neoadjuvant aromatase inhibitor (AI) therapy is a rational and effective approach to improving the breast conservation surgery (BCS) rate for postmenopausal patients with large, estrogen receptor (ER) rich breast cancers. Barriers to adopting this strategy include lack of experience in this management approach in the US and uncertainty regarding the comparative effectiveness of the three approved aromatase inhibitors for this indication.

Methods: ACOSOG Z1031 is a multicenter, open-label, neoadjuvant phase III screening study that randomized postmenopausal women with clinical stage II/III ER rich (Allred score 6-8) breast cancer to 16 weeks of either exemestane (EXE) 25 mg daily, letrozole (LET) 2.5 mg daily, or anastrozole (ANA) 1 mg daily. At baseline study participants were either marginal for BCS (MBCS), candidates for mastectomy only (MO), or inoperable (IO). Planned enrolment was 125 patients per arm in order that the likelihood of the treatment with the “best” 16-week clinical response rate (based on caliper measurements) by WHO criteria (cRR) was included among the subset of treatments with “similar” cRR (90% power). Secondary endpoints included: extent of surgery, radiologic and pathologic response rates.

Results: From 4/1/2006 to 10/1/2009, 377 postmenopausal women with clinical stage II or III ER rich breast cancer were enrolled. 374 women began treatment and were included in an intent-to-treat analysis. Median age was 66 yrs (range: 43-90 yrs), Median tumor size was 4.0 cm (range: 2-13 cm). The 16-week cRR was 60.5% (95%CI: 51.3-69.1%) for EXE; 70.9% (95% CI: 62.2-78.6%) for LET, and 66.7% (95% CI: 57.6-74.9%) for ANA. Seventeen patients did not have surgery due to refusal (12 pts), progression (3 pts) or other medical conditions (2 pts). The BCS rate was 78% (163/207) in MBCS group; 42% (77/163) in MO group; and 75% in IO group (3/4). Surgeons made the decisions regarding procedure choice 75% of the time in both the MBCS and the MO categories.

Conclusions: This large multicenter screening trial selected non-steroidal AIs for further development due to their higher observed cRR. The study demonstrates that high response and breast conservation rates and low rates of disease progression can be achieved through patient selection based on high ER expression. We are currently refining our approach for early detection of poor response to AIs through an assessment of the tumor Ki67 proliferation index at 2 to 4 weeks (Z1031 Cohort B).

[Table: see text]

Implementation of genomic predictors of chemotherapy response for guiding preoperative therapy in a prospective breast cancer trial

11057

Background: Personalized approaches to breast cancer therapy depend on genomic assays. While assays based on fixed tissues offer greater convenience, the spectrum of biology interrogated is limited. Full-transcriptome assays using microarrays are more challenging, but have the advantage of providing multiple prognostic and predictive signatures in one assay. We have created a clinical infrastructure with the objective of obtaining full genome expression data on breast cancer samples as a clinical assay for use in a prospective trial. Methods: “Performance of Genomic Expression Profiles to Direct the Use of Preoperative Chemotherapy for Early Stage Breast Cancer” is a prospective trial validating genomic signatures for predicting response to doxorubicin (A) or docetaxel (T) treatment in HER2 negative cancers. Fresh-frozen cores are reviewed by the study pathologist for tumor content. RNA is then extracted and probe generated to hybrize to an Affymetrix U133Plus2.0 microarray. Microarray data quality is determined using summary metrics for U133Plus2.0 arrays and principal component analysis (PCA) plots. The data is then used for predicting A or T sensitivity. Results: Thirteen cancers have been analyzed in the context of the above trial. Histologic type was lobular for 1, and predominantly ductal for 12 (10 ER positive, 3 ER negative). Median tumor size was 3.4 cm (range, 1.8–5.7). Microarray analysis was successful on 11 tumors (84%), providing data of sufficient quality to make predictions of A and T sensitivity. One sample hybridization failed QC as detected by PCA analysis, and one sample had insufficient RNA. The median “tissue to array data” time and “study consent to initiation of treatment” time were 5 days (range, 3–8) and 14 days (range, 11–36), respectively. Conclusions: Our initial experience shows that full-genome expression analysis on frozen tumor using an Affymetrix platform is feasible as a clinical assay for breast cancer. The resulting data is being used in a prospective marker validation protocol for predicting chemosensitivity. The data can also be analyzed for a variety of other potential prognostic and predictive signatures for guiding therapy.

No significant financial relationships to disclose.

Assays of circulating tumor cells and outcome in the triple-negative breast cancer trial TBCRC001

Abstract #6048

Introduction. Basal-like breast cancer (BBC) has low expression of ER, PR, and HER2, and is often called triple negative (TN) BrCa. TBCRC 001 is a multicenter randomized phase II study of cetuximab (C) alone or combined with carboplatin (P) in TN BrCa. Pts randomized to Arm 1 received C alone (400 mg/m2, then 250 mg/m2 weekly) with P (AUC 2, 3 of 4 weeks) added upon progression (PD). Pts on Arm 2 received C+P throughout. The primary endpoint was objective response. To explore markers of activity and response, we measured circulating tumor cells (CTCs) in pts on study and directly compared two methods of CTC enumeration; CellSearch (Veridex) and immunomagnetic enrichment followed by flow cytometry (IE/FC). A subset of samples were isolated for molecular profiling.&#x2028; Methods. Blood was obtained from consenting pts at baseline, 7 to 14 days after the first infusion, then monthly until the end of the study. CellSearch assay was performed as previously described using 7.5 cc blood in a CellSave tube and the CellSpotter analyzer, and the percent of CTCs staining for EGFR was also measured. For IE/FC, 20 ml of blood was subjected to IE using anti-EpCAM MAb-conjugated iron particles, followed by multiparameter FC for EpCAM, CD45, and nucleic acid content. CTC results were correlated by method, and to time on study treatment. In this preliminary analysis, the endpoint is time on study treatment (to progression/toxicity, TST).&#x2028; Results: Safety and efficacy data from arms 1 and 2 have been presented (Carey et al; SABCS 2007, ASCO 2008). Of 102 TN pts enrolled in this study, 65 had CTC measurements by both methods on at least one time point. CTC levels by the two assays were highly correlated at all time points. At baseline, Spearman's rank correlation coefficient was 0.67 (p&lt;0.0001). Using the cutoffs shown below, CTC by IE/FC or CellSearch at baseline and first follow-up correlated with TST. This relationship was observed in both arm 1 and 2.&#x2028; &#x2028; Conclusion: In this phase II trial of C or C+P in pts with TN metastatic BrCa, CTCs measured by two different techniques were highly correlated. CTC levels at baseline and 7-14 days predicted longer vs. shorter TST, suggesting that CTCs may be an early marker of response to targeted therapy. Additional molecular data on CTCs will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6048.

A phase II study to optimize dasatinib dosing in metastatic breast cancer patients using real-time pharmacodynamic tissue and urinary biomarkers

Abstract #3123

Background: In order to optimize drug efficacy and patient selection for targeted agents such as dasatinib, a tyrosine kinase inhibitor, there is a need for adaptive trial methodologies and validated marker endpoints. Predictive and pharmacodynamic (PD) biomarkers of dasatinib activity will be crucial for individualized drug dosing and enrichment of patient populations treated with the drug. Multiple potential predictive and PD markers exist for dasatinib including active/total Src, active/total EphA2, and downstream targets of Src such as focal adhesion kinase (FAK) and paxillin (pax). Given Src's role in bone modeling, markers of bone resorption may also serve as important biomarkers. We designed a phase II trial in metastatic breast cancer (MBC) wherein real-time assessment of these potential biomarkers is used to optimize the dose and anti-tumor effects of dasatinib.&#x2028; Material and methods: Key eligibility includes patient with MBC, ECOG 0-1, unlimited prior therapies, and biopsiable tumor. Patients with bone-only MBC were excluded due to tissue quality required for PD analysis. Metastatic biopsies at baseline and week 4 of dasatinib therapy were analyzed using quantitative immunohistochemistry (IHC) (measured in optical densitometry (OD) units) for the following markers: phospho-Src (p-Src), phospho-FAK (p-FAK) and phospho-pax (p-pax). For patients who tolerated the starting dose of dasatinib (50 mg bid), and displayed suboptimal Src inhibition (&lt;80% inhibition of phosphorylation of either biomarker), dasatinib dosing was escalated at week 4 to 70 mg bid. Urinary N-telopeptide (NTX), a marker of bone resorption, was measured monthly.&#x2028; Results: Since 12/2007, 12 patients have enrolled and 8 have evaluable, paired metastatic biopsies. Of the other 4 patients, 2 withdrew due to toxicity, 1 voluntarily withdrew, and 1 patient has not yet reached week 4. There has been one case of dyspnea related to possible drug toxicity. Other grade 3/4 toxicities are as follows: anorexia (3), pleural effusion (1), DVT (1). All eligible patients underwent dasatinib dose escalation at week 4 based on their individual tumor biomarker results. All tumors displayed some level of Src inhibition but none of the tumors reached the pre-defined "optimal" level of Src inhibition at week 4; the median changes in tissue biomarker levels are as follows: p-FAK -20%, p-pax -13%, p-Src -9%, and urinary NTX level -11%.&#x2028; Conclusions: Our initial analysis of sequential tumor biopsies collected in a phase II trial of single-agent dasatinib in MBC illustrates that real-time biomarkers will both optimize the dosing of targeted agents and define potential on- and off-target drug effects. Accrual is ongoing and updated results of all biomarker endpoints as well as efficacy and toxicity data will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3123.

Molecular signatures characterize early stage breast cancer arising in young women and have prognostic and therapeutic implications independent of ER status

522

Background: Breast cancer in young women [YW] has a poorer prognosis, is less likely hormone sensitive, and has yet to be defined as a unique biologic phenotype. The identification of molecular pathways unique to YW should enable refinement of treatment strategies. Methods: To optimize characterization of breast cancer arising in YW vs. older women [OW], we prospectively defined 2 age groups constituting pre- and post-menopausal women [YW = 45 yrs (median 40 yrs); OW = 65 yrs (median 71 yrs)]. Age groups were applied to 784 clinically-annotated microarray (Affymetrix) data. 411 patients (n = 200 = 45yrs; n = 211 = 65 yrs) were eligible. In addition to clinical parameters and differential gene expression analysis, genomic signatures of oncogenic pathway deregulation (Ras, E2F, β-catenin, PI3K, Myc, Src) and chemotherapeutic sensitivity were evaluated. Results: In the 2 age-defined tumor sets, there was no difference between ER or PR status by IHC (p = ns). Consistent with previous data sets, YW demonstrated higher IHC expression of ErbB2 (p = 0.037), higher grade tumors (p < 0.0001), larger tumor size (p = 0.0002) and greater lymph node positivity (p = 0.045). Quantitative ER expression (mRNA) was lower (p < 0.0001) among YW. In comparing deregulation of oncogenic pathways between age groups, a statistically higher probability of PI3K (p = 0.005) and Myc (p = 0.02) pathway deregulation was observed among YW. Importantly, hierarchical clustering revealed unique patterns of pathway deregulation. In YW, PI3K and β-catenin deregulation conferred a worse prognosis compared to those with Myc and Src deregulation (HR = 4.15; p = 0.008). In contrast, among OW, E2F deregulation with concurrent low probability of PI3K and Myc deregulation was associated with a poorer outcome (HR = 2.7; p = 0.006). Conclusion: Results of this large study demonstrate that breast cancer arising in YW represents a distinct biologic entity characterized by unique patterns of deregulated signaling pathways that are prognostic, independent of currently available clinical variables such as ER. Further data, including unique patterns of chemotherapeutic sensitivity as they relate to clinical parameters and oncogenic pathway status, will also be presented.

[Table: see text]

Study participants’ perceptions of the process and impact of receiving results of N9831

518

Background: There has been growing interest in providing clinical trial participants with study results. We sought to evaluate the process of sharing results from a large cooperative group trial in an effort to guide clinicians and clinical investigators. Methods: We mailed surveys to a subset of women who participated in NCCTG 9831, Phase III Trial of Adjuvant Chemotherapy with or without Trastuzumab for Women with HER2+ Breast Cancer, after the preliminary study results were mailed to participants. Surveys were sent to all trial participants enrolled through 9 CALGB/ECOG institutions. Results: Of 228 surveys sent, 160 (70%) have been returned. Average age of respondents was 51 years (range 26–76); 84% were white; 61% were college graduates; 4% reported recurrent disease. Women reported receiving results by mail (84%), from a health care provider in person or by phone (43%), and/or from the media (47%); 2% reported that they were not informed of the results. 29% heard the results first from the media; 27% first heard by mail. 35% of women might have preferred to be offered results, with the option of not receiving them, but only 4% of women indicated that they would have declined results had they been offered first. 89% of women found the results information easy to understand; 69% correctly interpreted the results of the study; 31% either had an incorrect interpretation or were unsure of the findings. 81% of women were satisfied with how results were shared; 63% of women felt that learning results had an impact on their lives, 24% were more anxious after learning the results; 36% were less anxious. Multivariable analyses evaluating factors associated with greater satisfaction and increased anxiety will be presented. Conclusions: Sharing results is met with overwhelmingly favorable responses from patients, although a substantial proportion of patients may not initially understand the findings. Some patients desire to be offered results first, but few would decline them. The potential for increased anxiety should be considered, and psychosocial support may be required by some. A plan to share results should be routinely and prospectively included in the design of clinical trials. (Supported in part by an ASCO Career Development Award (AHP)

No significant financial relationships to disclose.

Trastuzumab and vinorelbine or taxane chemotherapy for HER2+ metastatic breast cancer: The TRAVIOTA study

650

Background: The optimal trastuzumab/chemotherapy regimen for advanced breast cancer is not known. We performed a multicenter, randomized clinical trial to compare TRastuzumab And VInorebline Or TAxane (TRAVIOTA) chemo- and bio-therapy combination treatment given on a weekly schedule for HER2+ metastatic breast cancer. Patients and Methods: Eligible patients had stage IV breast cancer, measurable disease (by RECIST criteria), HER2+ tumors (IHC 3+ or FISH+), no prior chemotherapy or trastuzumab for advanced breast cancer, and LVEF > 50%. Patients were randomized 1:1 to trastuzumab (4 mg/kg loading dose, 2 mg/kg weekly thereafter) with either weekly vinorelbine (25 mg/m2) or weekly taxane (paclitaxel 80 mg/m2 or docetaxel 35 mg/m2, selected by the treating investigator). The primary endpoint was response rate. The study opened in August 2001 and planned to accrue 250 patients. It was closed in December 2003 having accrued only 85 patients. Results are presented for the 81 patients who received any protocol-based therapy. Results: Patients receiving trastuzumab and vinorelbine tended to have higher response rates and TTP than those assigned trastuzumab and taxane therapy but the results were not statistically significant (see Table ). Vinorelbine therapy was associated with more frequent grade 3 or 4 hematological toxicity and dose delay because of myelosuppression. Other toxicities generally reflected the known side effects of the chemotherapy agents. Conclusions: The TRAVIOTA study suggests at least comparable clinical activity of trastuzumab with vinorelbine as with weekly taxane chemotherapy in HER2+ metastatic breast cancer, with side effect profiles consistent with previous experience with these regimens.

[Table: see text]

[Table: see text]

Relationship between numeracy and breast cancer patients’ estimates of adjuvant treatment benefit

586

Background: Based on clinical anecdotes and existing literature, the general population has trouble understanding and making use of statistical information. We explored the accuracy of breast cancer patients’ (pts) estimates of treatment outcomes (probabilities of remaining cancer free versus recurring) relative to data provided by ‘Adjuvant! Online‘ decision aid program, and whether accuracy differed by pts numeracy skills (i.e. use of mathematical concepts and operations). Methods: 43 ER+ women with early stage, node-negative breast cancer were recruited (mean age 56, 72% Caucasian). After signing an informed consent and completing an assessment of numeracy (Lipkus et al., 2001), pts discussed case-specific Adjuvant! print-outs with an oncologist. Pts then estimated their chances of being cancer free after receiving no further treatment, hormonal therapy only, chemotherapy only, or both. Pts also were asked to select the treatment option that afforded their best chance of remaining cancer free. Results: Compared to the estimates provided by Adjuvant! Online, pts underestimated their chance of being cancer free after receiving no further treatment (M=62 vs. 48 out of 100), hormonal therapy only (M=72 vs. 45), chemotherapy only, (M=71 vs.42), and combined therapy (M=78 vs. 54). 63% correctly selected the treatment option that afforded the highest estimate of being cancer free. More numerate patients were more likely to correctly specify which treatment option provided the best chance of being cancer free (OR=0.67, 95% CI: 0.50, 0.89, p<.006); and less likely to give personal estimates of being cancer free inconsistent with estimates provided by Adjuvant! for hormonal therapy (OR=0.17, 95% CI: 0.04, 0.72, p<.02), chemotherapy (OR=0.62, 95% CI: 0.39, 0.99, p<.05) and combined therapy (OR=0.44, 95% CI: 0.23, 0.85, p<.02). Conclusions: Findings suggest that pt numeracy skills are important in comprehending statistical data about adjuvant treatment outcomes. Numeracy skills may have implications for how statistical information about treatment is presented and discussed, affecting processes of informed decision-making and pt quality of life.

No significant financial relationships to disclose.

Changes in weight, body composition, and factors influencing energy balance among premenopausal breast cancer patients receiving adjuvant chemotherapy

PURPOSE

Weight gain is a common problem among breast cancer patients who receive adjuvant chemotherapy (CT). We undertook a study to determine the causes of this energy imbalance.

PATIENTS AND METHODS

Factors related to energy balance were assessed at baseline (within 3 weeks of diagnosis) and throughout 1 year postdiagnosis among 53 premenopausal women with operable breast carcinoma. Thirty-six patients received CT and 17 received only localized treatment (LT). Measures included body composition (dual energy x-ray absorptiometry), resting energy expenditure (REE; indirect calorimetry), dietary intake (2-day dietary recalls and food frequency questionnaires) and physical activity (physical activity records).

RESULTS

Mean weight gain in the LT patients was 1.0 kg versus 2.1 kg in the CT group (P =.02). No significant differences between groups in trend over time were observed for REE and energy intake; however, a significant difference was noted for physical activity (P =.01). Several differences between groups in 1-year change scores were detected. The mean change (+/- SE) in LT versus CT groups and P values for uncontrolled/controlled (age, race, radiation therapy, baseline body mass index, and end point under consideration) analysis are as follows: percentage of body fat (-0.1 +/- 0.4 v +2.2 +/- 0.6%; P =.001/0.04); fat mass (+0.1 +/- 0.3 v +2.3 +/- 0.7 kg; P =.002/0.04); lean body mass (+0.8 +/- 0.2 v -0.4 +/- 0.3 kg; P =.02/0.30); and leg lean mass (+0.5 +/- 0.1 v -0.2 +/- 0.1 kg; P =.01/0.11).

CONCLUSION

These data do not support overeating as a cause of weight gain among breast cancer patients who receive CT. The data suggest, however, that CT-induced weight gain is distinctive and indicative of sarcopenic obesity (weight gain in the presence of lean tissue loss or absence of lean tissue gain). The development of sarcopenic obesity with evidence of reduced physical activity supports the need for interventions focused on exercise, especially resistance training in the lower body, to prevent weight gain.

Phase I study of Doxil and vinorelbine in metastatic breast cancer

BACKGROUND

Vinorelbine and Doxil (liposomal doxorubicin) are active chemotherapeutic agents in metastatic breast cancer. A phase I study was designed to evaluate combination therapy.

PATIENTS AND METHODS

Thirty women with metastatic breast cancer were enrolled. Dose-limiting toxicity was determined through a dose escalation scheme, and defined for the first treatment cycle, only. Pharmacokinetic studies were performed during the first cycle of treatment.

RESULTS

In the first cohort of Doxil 30 mg/m2 day 1 and vinorelbine 25 mg/m2 days 1 and 8, patients experienced severe neutropenia. Vinorelbine administration was changed thereafter to days 1 and 15 of each cycle. Dose limiting toxicity was observed at Doxil 50 mg/m2 and vinorelbine 25 mg/m2. Doxil 40 mg/m2 and vinorelbine 30 mg/m2 was defined as the maximally tolerated dose. Few toxicities (principally neutro penia) were seen at this dose level, with the notable absence of significant nausea, vomiting, or alopecia. Though 63% of patients had received prior anthracycline-based chemotherapy, only one patient developed grade 2 cardiac toxicity. Pharmacokinetic studies revealed prolonged exposure to high doxorubicin concentrations for several days following Doxil administration.

CONCLUSIONS

Combination chemotherapy with Doxil and vinorelbine affords treatment with two active drugs in women with metastatic breast cancer, and appears to have a favorable toxicity profile. A schedule of Doxil 40 mg/m2 day 1 and vinorelbine 30 mg/m2 days 1 and 15 given every 28 days is recommended for phase II studies.

Topical thrombin and acquired coagulation factor inhibitors: clinical spectrum and laboratory diagnosis

Topical bovine thrombin preparations are used extensively in cardiovascular, neurosurgical, and otolaryngologic procedures. Patients who are treated with these topical thrombin preparations may develop antibodies to bovine coagulation factors that may cross-react with the endogenous human clotting proteins. We have identified four patients with acquired factor inhibitors following exposure to topical thrombin at Duke University Medical Center and summarize these cases in addition to 13 patients previously reported in the literature. In most cases, the inhibitor developed following a second (or subsequent) exposure to topical thrombin. The clinical course was extremely variable, ranging from totally asymptomatic to life-threatening hemorrhage. The most consistent laboratory abnormality was a prolonged bovine thrombin clotting time, which corrected, at least partially, when human thrombin was substituted for bovine thrombin. Some of these patients also developed factor V inhibitors with prolonged prothrombin and activated partial thromboplastin times. Although these patients have prolonged clotting times, they should not be considered "autoanticoagulated," since thromboembolic complications can still occur. Therapeutic intervention is largely empirical and depends on the clinical manifestations of the individual patient.

Rocky Mountain spotted fever complicated by gangrene: report of six cases and review

Although mortality due to fulminant Rocky Mountain spotted fever (RMSF) is well appreciated, the ability of the disease to cause survivors to become permanently disabled is not as widely known. We report six cases of RMSF complicated by gangrene. Although four patients required multiple limb and/or digital amputations, only one death resulted. Our review of the English-language literature revealed 23 additional cases of RMSF complicated by gangrene. Pathophysiologically, gangrene is most likely related to small-vessel occlusion. Skin necrosis and gangrene in association with RMSF are the extreme end on a continuum from reversible to irreversible skin and tissue damage caused by Rickettsia rickettsii. Most patients with RMSF have a typical skin rash that resolves without sequelae. Some patients develop minute cicatrices marking the location of focal cutaneous necrosis; for other patients, digital ischemia occurs transiently or evolves to produce severe ischemic changes without gangrene that result in permanent impairment. At the far end of this clinical continuum are patients who develop gangrene requiring amputation.

Sodium channel density in hypomyelinated brain increased by myelin basic protein gene deletion

Trophic control over the expression and membrane distribution of voltage-dependent ion channels is one of the principal organizing events underlying the maturation of excitable cells. The myelin sheath is a major structural determinant of regional ion channel topography in central axons, but the exact molecular signals that mediate local interactions between the oligodendrocyte and axolemma are not known. We have found that large caliber fibre pathways in the brain of the mutant mouse shiverer (shi, gene on chromosome 18), whose developmental fate of myelination is averted by deletion of five exons in the myelin basic protein gene, have a striking excess of sodium channels. As cytoplasmic membranes of shiverer oligodendroglia still adhere to axons, the evidence indicates that myelin basic protein or a myelin basic protein-dependent glial transmembrane signal associated with compact myelin formation, rather than a simple glial-axon contact inhibition or an intrinsic genetic program of neuronal differentiation, could be critical in downregulating sodium channel density in axons. Here we use the shiverer mutant to show that mature central nervous system projection neurons with large caliber unmyelinated fibres sustain functional excitability by increasing sodium channel density. This axon plasticity, triggered by the absence of a single glial protein, contributes to the unexpectedly mild degree of neurological impairment in the mutant brain without myelin, and may be a potentially inducible mechanism determining the recovery of function from dysmyelinating disease.