Citations

1049 Background: CALGB 40503 randomized HR+ MBC postmenopausal pts to Let alone or Let+Bev as first-line therapy. Adding Bev to Let prolonged progression-free survival (PFS) but not overall survival (OS) (Dickler JCO 2016). We performed a correlative study to assess prognostic and predictive value of CTCs in this population. Methods: Blood was collected prior to initiation of treatment. CTCs were enumerated using US FDA-cleared CellSearch assay; samples with ≥5 CTCs per 7.5 mLs of blood were considered CTC-positive (CTC+). Correlation of CTCs with PFS and OS was assessed using Cox regression analysis. Median follow-up was 39 months (mo). Results: Of 343 pts treated, 294 had CTC data and were included in this analysis. Original study results that showed improved PFS (HR = 0.75; 95% CI: 0.59-0.96) but not OS (HR = 0.87; 95% CI: 0.65-1.18) in pts receiving Let+Bev compared to Let were recapitulated in this subset. In multivariable analysis, CTC+ pts (31%) had significantly reduced PFS (HR = 1.49; 95% CI: 1.12-1.97) and OS (HR = 2.08; 95% CI: 1.49-2.93) compared to CTC- pts. Moreover, CTC+ pts who did not receive Bev had worse PFS (HR = 2.31; 95% CI: 1.54-3.47) and OS (HR = 2.64; 95% CI: 1.59-4.40) (Table). CTC+ pts who received Bev had numerically longer median PFS (18.0 vs. 7.0 mo) and OS (33.6 vs. 27.1 mo) compared to CTC+ pts with no Bev; however, tests for interaction between CTC status and Bev (yes vs. no) were not statistically significant for PFS (p=0.70) or OS (p=0.84). Conclusions: CTCs were highly prognostic in this study involving addition of Bev to first-line Let in postmenopausal HR+ MBC. Further research to determine the potential predictive value of CTCs in the setting of both metastatic disease and early breast cancer is warranted. Support: U10CA180821, U10CA180882; Genentech; https://acknowledgments.alliancefound.org ; NCT00601900. Survival in HR+ MBC pts receiving Let or Let+Bev stratified by CTC status. Clinical trial information: NCT00601900. [Table: see text]

Abstract Background: In women with breast cancer receiving neoadjuvant chemotherapy, residual cancer burden (RCB) predicts distant recurrence and survival. In those with high risk tumors, locoregional recurrence (LRR) remains a concern, and has been associated with type of local therapy received. We evaluated the impact of local therapy on LRR in the ISPY-2 TRIAL. Methods: Data were analyzed in Stata 14.2, using Chi2 test, log rank test, and a Cox proportional hazards model. RCB was considered a categorical variable (0/1 versus 2/3), as described in prior publications. Breast surgery categories were lumpectomy +/- radiotherapy, or mastectomy +/- radiotherapy. Axillary surgery was defined as sentinel lymph node (SLN) surgery (≤6 nodes removed) or axillary dissection (>6 nodes). Results: Follow up data from the I-SPY2 TRIAL were available for 630 patients (median follow up 2.76 yrs, range 0.4-7.2). Type of local therapy was significantly associated with clinical stage at presentation, with stage III patients most frequently undergoing mastectomy + radiation (p<0.001). Women with higher RCB were more likely to undergo mastectomy than those with lower RCB (61.3% vs 48.8% mastectomy rate, p=0.002), and more likely to receive adjuvant radiotherapy (62.0% vs 53.9%, p=0.048). There was no association between clinical stage, type of surgery, or radiotherapy and LRR (Table). Higher RCB was significantly associated with LRR, with 3 year locoregional recurrence free rate of 95.1% in RCB 0/1 versus 89.9% in RCB 2/3 (p=0.003). In a Cox model adjusting for clinical stage, tumor subtype, surgical therapy, RCB status, nodal radiation, and age, significant predictors for LRR were tumor subtype and RCB status. Hazard ratio (HR) for LRR in those with RCB 0/1 was 0.39 compared to those with RCB 2/3 (95% CI 0.17-0.87, p=0.021). There was no difference in LRR between breast conservation and mastectomy; within the breast conservation group, those who had lumpectomy alone had higher hazard of LRR compared to those having lumpectomy + radiation (HR 3.1, 95% CI 1.1-9.2, p=0.043). Conclusions: Extent of surgical therapy was not associated with local tumor control, regardless of advanced tumor stage at presentation. Rather, tumor biology and response to therapy were the best predictors of LRR. These data highlight the opportunity to minimize the morbidity of extensive surgical therapy for patients with excellent response to systemic therapy. LRR rates by clinical features and treatment status FrequencyLRR RateP valueClinical Stage 0.5I240 (47.5%)5.8% II185 (36.6%)8.7% III80 (15.8%)6.3% Tumor Subtype 0.014ER+PR+Her2-161 (26.4%)3.1% ER+PR-Her2-56 (9.2%)3.6% Her2+176 (28.9%)6.3% Triple negative216 (35.5%)11.1% Local therapy 0.169Lumpectomy85 (13.5%)11.8% Lumpectomy with radiation198 (31.4%)5.6% Mastectomy173 (27.5%)5.2% Mastectomy with radiation174 (27.6%)8.6% Axillary surgery 0.23None5 (0.8%)20% SLN329 (52.2%)5.8% ALND296 (47%)8.5% Axillary radiation 0.535Yes42 (6.7%)9.5% No588 (93.3%)7.0% Axillary management 0.2No surgery or radiation5 (0.8%)20.0% SLN312 (50%)5.3% SLN+Axillary radiation17 (2.7%)8.3% ALND271 (43%)10.3% ALND+Axillary radiation25 (4%)5.4% RCB 0.0020/1293 (50.1%)3.8% 2/3292 (49.9%)10.3% Citation Format: Silverstein J, Suleiman L, Yau C, Price ER, Singhrao R, Yee D, DeMichele A, Isaacs C, Albain KS, Chien AJ, Forero-Torres A, Wallace AM, Pusztai L, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Leyland-Jones B, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, I-SPY 2 TRIAL Consortium, Berry DA, Asare SM, Esserman LJ, Boughey JC, Mukhtar RA. The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL [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 P2-14-01.

Abstract Background: Thirty percent of patients with breast cancer may experience chest wall recurrence, which is associated with a higher risk of developing distant metastases and a poor prognosis. Cancer cells may evade immune rejection through the programmed cell death 1 (PD-1) pathway. Pembrolizumab, an anti-PD-1 antibody, binds PD-1 and inhibits its interaction with the programmed death ligand 1 (PD-L1) to facilitate tumor immune rejection. We hypothesize that pembrolizumab may be an effective therapy in chest wall recurrence, given the inflammatory nature, and the high expression of PD-1 in tumors with lymphovascular invasion. Platinum agents may enhance anti-tumor immunity in a synergistic manner, and the combination of pembrolizumab and carboplatin has demonstrated efficacy in advanced lung cancer. In this study, the combination of pembrolizumab and carboplatin is being evaluated in breast cancer patients with chest wall disease. Methods: This is a randomized phase II study of breast cancer patients with advanced, unresectable breast cancer involving the chest wall, being conducted through the Translational Breast Cancer Research Consortium (TBCRC). Patients may have hormone resistant disease (at least 2 prior lines of hormone therapy), triple negative breast cancer, or refractory HER2+ disease for enrollment. They may have other sites of distant metastases, have received any number of prior lines of therapy, have had prior surgery, but prior chest wall radiation is not necessary. Eighty-four patients at 7 TBCRC sites will be randomized 2:1 to treatment with pembrolizumab 200 mg IV and carboplatin AUC 5 IV every 3 weeks followed by pembrolizumab 200 mg IV alone every 3 weeks (Arm A, n=56) or carboplatin AUC 5 IV every 3 weeks (Arm B, n=28), with an option for patients in Arm B to cross-over to single agent pembrolizumab 200 mg IV every 3 weeks (arm Bx) on progression. Patients will undergo imaging with CT chest, abdomen, and pelvis at baseline and every 2 cycles of treatment for response evaluation. The primary endpoint is the disease control rate in the chest wall and distant sites at 18 weeks of treatment, and this study is powered to determine a 20% difference in disease control rates between arms A and B (hazard ratio of 0.52, α= 0.10, β= 0.20). After 18 patients are enrolled into Arm B, an interim analysis for futility will be conducted to enable early closure of that arm for lack of efficacy. Secondary endpoints in the study are toxicity, progression free survival, and response based on PD-L1 expression and irRECIST. Exploratory endpoints, which will be studied using peripheral blood testing and chest wall tumor biopsies at baseline and after 2 cycles of treatment, include determining associations of response with changes in tumor and peripheral blood immune composition, soluble PD-L1 expression, circulating tumor cells, cell free DNA, and tumor PD-L1 and MYC genomic expression. Ultimately this study promises to improve our understanding of checkpoint inhibition and chemotherapy for chest wall disease, and the underlying mechanism of action. This study is open for enrollment and 2 patients are currently enrolled. (NCT03095352). Citation Format: Vidula N, Goga A, Hwang J, Liu MC, Park BH, Nanda R, Pohlmann PR, Storniolo AM, Brufsky A, Abramson V, Rugo HS. A randomized phase II study of pembrolizumab in combination with carboplatin versus carboplatin alone in breast cancer patients with chest wall disease, with immunologic and genomic correlative studies [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 OT3-04-04.

Abstract Background: Patients achieving a pathologic complete response (pCR) following neoadjuvant therapy have significantly improved event-free survival relative to those who do not; and pCR is an FDA-accepted endpoint to support accelerated approval of novel agents/combinations in the neoadjuvant treatment of high risk early stage breast cancer. Previous studies have shown that recurrence risk increased with increasing burden of residual disease (as assessed by the RCB index). As well, these studies suggest that patients with minimum residual disease (RCB-I class) also have favorable outcomes (comparable to those achieving a pCR) within high risk tumor subtypes. In this study, we assess whether integrating RCB with MRI functional tumor volume (FTV), which in itself is prognostic, can improve prediction of distant recurrence free survival (DRFS); and identify a subset of patients with minimal residual disease with comparable DRFS as those who achieved a pCR. Imaging tools can then be used to identify the subset that will do well early and guide the timing of surgical therapy. Method: We performed a pooled analysis of 596 patients from the I-SPY2 TRIAL with RCB, pre-surgical MRI FTV data and known follow-up (median 2.5 years). We first assessed whether FTV predicts residual disease (pCR or pCR/RCB-I) using ROC analysis. We applied a power transformation to normalize the pre-surgical FTV distribution; and assessed its association with DRFS using a bi-variate Cox proportional hazard model adjusting for HR/HER2 subtype. We also fitted a bivariate Cox model of RCB index adjusting for subtype; and assessed whether adding pre-surgical FTV to this model further improves association with DRFS using a likelihood ratio (LR) test. For the Cox modeling, penalized splines approximation of the transformed FTV and RCB index with 2 degrees of freedom was used to allow for non-linear effects of FTV and RCB on DRFS. Result: Pre-surgical MRI FTV is significantly associated with DRFS (Wald p<0.00001), and more effective at predicting pCR/RCB-I than predicting pCR alone (AUC: 0.72 vs. 0.65). Larger pre-surgical FTV remains associated with worse DRFS adjusting for subtype (Wald p <0.00001). The RCB index is also significantly associated with DRFS adjusting for subtype (Wald p<0.00001). Adding FTV to a model containing RCB and subtype further improves association with DRFS (LR p=0.0007). RCB-I patients have excellent DRFS (94% at 3 years compared to 95% in the pCR group). Efforts are underway to identify an optimal threshold for dichotomizing pre-surgical FTV and FTV change measures for use in combination with pCR/RCB-I class to generate integrated RCB (iRCB) groups as a composite predictor of DRFS. Conclusion: Pre-surgical MRI FTV is effective at predicting minimal residual disease (RCB0/I) in the I-SPY 2 TRIAL. Despite the association between FTV and RCB, FTV appears to provide independent added prognostic value (to RCB and subtype), suggesting that integrating MRI volume measures and RCB into a composite predictor may improve DRFS prediction. Citation Format: Hylton NM, Symmans WF, Yau C, Li W, Hatzis C, Isaacs C, Albain KS, Chen Y-Y, Krings G, Wei S, Harada S, Datnow B, Fadare O, Klein M, Pambuccian S, Chen B, Adamson K, Sams S, Mhawech-Fauceglia P, Magliocco A, Feldman M, Rendi M, Sattar H, Zeck J, Ocal I, Tawfik O, Grasso LeBeau L, Sahoo S, Vinh T, Yang S, Adams A, Chien AJ, Ferero-Torres A, Stringer-Reasor E, Wallace A, Boughey JC, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, Haugen PK, van't Veer LJ, Perlmutter J, Melisko ME, Wilson A, Peterson G, Asare AL, Buxton MB, Paoloni M, Clennell JL, Hirst GL, Singhrao R, Steeg K, Matthews JB, Sanil A, Berry SM, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, I-SPY 2 TRIAL Consortium, Yee D, Pusztai L, DeMichele A, Asare SM, Berry DA, Esserman LJ. Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden [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 P2-07-03.

These NCCN Guidelines Insights highlight the updated recommendations for use of multigene assays to guide decisions on adjuvant systemic chemotherapy therapy for women with hormone receptor–positive, HER2-negative early-stage invasive breast cancer. This report summarizes these updates and discusses the rationale behind them.