Abstract P2-14-01: The impact of local therapy on locoregional recurrence in women with high risk breast cancer in the neoadjuvant I-SPY2 TRIAL

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 P2-07-03: Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden

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.

Abstract P1-15-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Schwab R, Clark A, Yau C, Wolf D, Chien AJ, Majure M, Ewing C, Wallace A, Roesch E, Helsten T, Forero A, Stringer-Reasor E, Vaklavas C, Nanda R, Jaskowiak N, Boughey J, Haddad T, Han H, Lee C, Albain K, Isaacs C, Elias A, Ellis E, Shah P, Lang J, Lu J, Tripathy D, Kemmer K, Yee D, Haley B, Korde L, Edmiston K, Northfelt D, Viscusi R, Khan Q, I-SPY 2 Consortium, Symmans WF, Perlmutter J, Hylton N, Rugo H, Melisko M, Wilson A, Singhrao R, Asare S, van't Veer L, DeMichele A, Berry D, Esserman L. Withdrawn [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 P1-15-02.

Abstract P1-07-15: Detection of molecular alterations in breast cancer through next generation sequencing of both tumor tissue and circulating tumor DNA: The UC San Diego Moores Cancer Center experience

Background: Next generation sequencing (NGS) analysis of actionable molecular alterations has the potential to guide cancer treatment, especially for patients with advanced cancer who have progressed on standard treatment. In this study, we analyzed tumor biopsies and peripheral blood from 62 patients with advanced breast cancer by two different NGS clinical-grade assays for molecular alterations in tumor tissue or in circulating tumor DNA (ctDNA). We used these results to determine if these specimens have potentially “actionable” alterations that could guide cancer therapy.

Methods: From 2014 to 2016, 62 patients with advanced breast cancer had plasma sent for ctDNA analysis (Guardant360 assay; 54 to 70 genes) Thirty-eight of these patients (61%) also had tumor biopsies evaluated by NGS (FoundationOne®; 182 to 315 genes). Alterations were defined as mutations, insertions, deletions, truncations, or rearrangements or amplifications/copy number variations. Patients that harbored multiple alterations in the same gene were not counted as having separate alterations; however, if a gene amplification and an alteration were found in the same gene these were counted as separate events. Variants of unknown significance (VUS) and synonymous mutations were excluded from both assays. Data were collected and analyzed according to a UCSD Institutional Review Board approved protocol.

Results: The median age of our patients at the time of ctDNA analysis was 55 years (range, 44 to 84 years); the median age at the time of tissue biopsy for NGS was 52 years (range, 39 to 82 years). One patient was male. The most common receptor status was estrogen receptor (ER) and progesterone receptor (PR) positive, human epidermal growth factor receptor 2 (HER2) non-amplified or negative (neg)(N=44; 71%), followed by triple negative breast cancer (ERnegPRnegHer2neg) (N=10, 16%), triple positive (N=6, 1%) and finally ERnegPRnegHER2positive (N=2, 0.03%). One patient of 38 (2%) had no tumor alteration detected and 19 of 62 had no ctDNA alterations (31%). In 38 breast cancer patients with tumor NGS results, alterations were detected in 79 unique genes, with the most frequent being TP53 (37% of patients), PIK3CA (24%) and GATA3 (24%) genes. In the 62 patients with ctDNA analysis, 31 unique genes had at least one alteration, with the most frequent being TP53 (36% of patients) and PIK3CA (23%) and EGFR amplification (11%) (GATA3 was not analyzed in the ctDNA assay). Both assays had a high rate of detection for potentially actionable mutations: 41 out of 62 patients (66%) by ctDNA and 34 out of 38 (89%) by tumor NGS. No two patients harbored identical genomic profiles by either tumor NGS or plasma ctDNA analysis except for 1 patient who had no alterations detected by either assay.

Conclusions: Plasma and tissue NGS analysis appear to be complementary assays that yield a high percentage of potentially actionable alterations in patients with advanced breast cancer. Studies of the clinical impact of NGS-guided therapy in breast cancer are warranted.

Citation Format: Shatsky RA, Parker BA, Schwab R, Helsten T, Boles SG, Subramanian R, Piccioni D, Kurzrock R. Detection of molecular alterations in breast cancer through next generation sequencing of both tumor tissue and circulating tumor DNA: The UC San Diego Moores Cancer Center experience [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 P1-07-15.

Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics

Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients.

Measurement of DKK1 and FRP in breast and prostate cancer patients with bone metastases: Impact of zoledronic acid (ZA)

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Background: Bone metastases produce an imbalance in osteoblast and osteoclast activity. While metastases from prostate cancer are osteoblastic, metastases from breast cancer may be osteolytic, osteoblastic or mixed. The wnt/frizzled pathway is involved in maturation of osteoblasts and in adult bone homeostasis. We explored the wnt antagonists dickkopf (DKK1) and frizzled related protein (FRP) as potential biomarkers in bone metastasis after ZA treatment. Methods: This is a pilot cohort study in bisphosphonate naive breast and prostate cancer patients with bone metastases. Cancer therapy was not specified. Patients received 2 monthly doses of ZA 4 mg IV. Pre- and post-treatment (day 60) sera were collected for measurement of FRP and DKK1, along with IL-6, calcium, creatinine and bone-specific alkaline phosphatase (BAP, a marker of osteoblast activity). Primary endpoint: mean change in FRP and DKK1; Secondary endpoints: correlation of biomarkers with each other and comparison of breast vs. prostate cancer patients. Biomarkers were measured using standard ELISA assays. Statistics: comparison of means = student t-test, correlation coefficients = Pearson. Results: Mature data from 14 patients are reported here, 9 with breast and 5 with prostate cancer. Mean age = 61 years (range 42–89). Two breast cancer patients were premenopausal. One prostate and 3 breast cancer patients received chemotherapy; all others were treated hormonally. After ZA, calcium decreased in all patients (p = 0.09). BAP decreased in all but 1 breast and 1 prostate cancer patient (mean decrease 20.0, p = 0.16). IL-6 was undetectable in most patients. FRP decreased in all but 4 patients (mean decrease 6.2, p = 0.13). There was no discernable pattern for DKK1. Pre-treatment DKK1 correlated with FRP (p = 0.01, r2 = 0.39), but there was no correlation post-treatment. Post-treatment DKK1 correlated with both serum calcium (p = 0.04, r2 = 0.49) and BAP (p = 0.005, r2 = 0.65). There was no difference between breast and prostate cancer patients. Conclusions: It is feasible to measure DKK1 and FRP in patients with malignant bone disease. Treatment with ZA has measurable effects upon these and other serum markers. Further studies with more patients are needed to evaluate their potential as biomarkers.

No significant financial relationships to disclose.