Krings, Gregor

Abstract Background: Patients who achieve a pathological complete response (pCR- defined as no invasive cancer) after neoadjuvant chemotherapy (NAC) for breast cancer (BC) have improved outcomes, but there is still controversy about the significance of residual ductal carcinoma in situ (DCIS) on local recurrence rate (LRR). The I-SPY 2 TRIAL is an adaptive neoadjuvant platform trial evaluating novel experimental regimens in comparison to standard chemotherapy in women with high-risk breast cancer. The purpose of this study is to determine if residual DCIS after NAC in early BC affects LRR in patients with or without residual invasive disease in the I-SPY 2 TRIAL. Methods: 933 I-SPY 2 patients with residual cancer burden (RCB) and follow-up data were included in this analysis. Residual DCIS was defined as any carcinoma in situ > 0% on RCB evaluation. Local recurrence was defined as recurrence in breast, chest wall or locoregional nodes and/or skin and subcutaneous tissue. We stratified our cohort into four groups: those without residual invasive disease (defined as RCB0) ± residual DCIS, and those with residual invasive disease (RCB>0) ± residual DCIS. We estimated LRR within each group using the Kaplan Meier method; and used Cox proportional hazards models to assess LRR differences between groups, with: patients with no residual disease (invasive or in situ) as reference group. Results: Among 933 patients assessed, median follow up time was 3.9 years. RCB 0 status was achieved in 337 patients (36%). Of these, 267 (29%) had no residual DCIS, which represents our reference group, and 70 (7%) had residual DCIS. Among 596 (64%) patients who had RCB>0, 296 (32%) had residual DCIS. For patients with RCB0 without DCIS and RCB0 with DCIS, the LRR at 3 years were similar: 2% vs 3% respectively (Hazard ratio: 1.29 [0.26-6.39]). Results were also similar in the RCB>0 group, with a LRR of 10% at 3 years in those without residual DCIS, and 11% in those with residual DCIS. Both RCB>0 groups had significantly higher LRR when compared to the patients with RCB0 without DCIS (Hazard ratio: 5.25 [2.20-12.5]) and HR 5.85 [2.47-13.9] respectively). Conclusion: There was no association between residual DCIS and LRR after neoadjuvant chemotherapy, regardless of resolution of invasive disease. Further work is needed to determine whether residual DCIS should drive locoregional therapy decisions after neoadjuvant chemotherapy for invasive breast cancer. Citation Format: Marie Osdoit, Christina Yau, W. Fraser Symmans, Judy C. Boughey, Smita M. Asare, Ron Balassanian, Jodi M. Carter, Yunn-Yi Chen, Kimberly Cole, Laila Khazai, Molly Klein, Dina Kokh, Gregor Krings, Sunati Sahoo, Gretchen Ahrendt, Akiko Chiba, Cheryl Ewing, Constantine Godellas, Nora Jaskowiak, Brigid Killelea, Helen Krontiras, Rachael Lancaster, Julie Lang, M. Catherine Lee, Arpana Naik, Roshni Rao, Julia Tchou, Shannon Tierney, Eleni Tousimis, Tod Tuttle, Anne Wallace, I-SPY 2 TRIAL Consortium, Bev Parker, Laura J. Esserman, Rita A. Mukhtar. The impact of residual ductal carcinoma in situ on breast cancer recurrence in the neoadjuvant I-SPY2 TRIAL [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 P3-08-16.

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.