Northfelt, Donald W.

Abstract Purpose: With improvements in breast cancer imaging, there has been a corresponding increase in false-positives and avoidable biopsies. There is a need to better differentiate when a breast biopsy is warranted and determine appropriate follow-up. This study describes the design and clinical performance of a combinatorial proteomic biomarker assay (CPBA), Videssa Breast, in women over age 50 years. Experimental Design: A BI-RADS 3, 4, or 5 assessment was required for clinical trial enrollment. Serum was collected prior to breast biopsy and subjects were followed for 6–12 months and clinically relevant outcomes were recorded. Samples were split into training (70%) and validation (30%) cohorts with an approximate 1:4 case:control ratio in both arms. Results: A CPBA that combines biomarker data with patient clinical data was developed using a training cohort (469 women, cancer incidence: 18.5%), resulting in 94% sensitivity and 97% negative predictive value (NPV). Independent validation of the final algorithm in 194 subjects (breast cancer incidence: 19.6%) demonstrated a sensitivity of 95% and a NPV of 97%. When combined with previously published data for women under age 50, Videssa Breast achieves a comprehensive 93% sensitivity and 98% NPV in a population of women ages 25–75. Had Videssa Breast results been incorporated into the clinical workflow, approximately 45% of biopsies might have been avoided. Conclusions: Videssa Breast combines serum biomarkers with clinical patient characteristics to provide clinicians with additional information for patients with indeterminate breast imaging results, potentially reducing false-positive breast biopsies.

Abstract Background: Although the efficacy of different immunotherapeutic agents varies greatly across tumor types, little is known about the role of different metastatic tumor microenvironments in modulating the expression of immune-checkpoints like PD-L1. Using metastatic breast cancer as a model, this work explored whether metastatic lesions derived from different patients, but colonizing the same host target organ, showed organ-specific immune signatures. Methods: Snap frozen metastatic lesions collected from 30 breast cancer patients enrolled in a prospective phase II multi-omic precision medicine clinical trial (“Side-Out II”) were used for this analysis. Sites of metastasis were: liver (LI) (n=10), skin/chest wall (SC) (n=10), and other lesions (OL) (n=10) [including lymph nodes (LN) (n=4), lung (LU) (n=3), and intra-abdominal lesions (IA) (n=3)]. Pure tumor epithelia were isolated from each specimen via Laser Capture Microdissection (LCM). PD-L1 expression (Antibody Clone E1L3N) was quantitatively measured using the Reverse Phase Protein Microarray (RPPA), a high-throughput, multiplex immunoassay that provides operator-independent quantitative data starting from a small amount of biological material. Proportion of patients with PD-L1 expression above the median and the 75th percentile of the population was compared across metastatic sites. Results: PD-L1 expression had a >5 fold dynamic range across breast cancer-derived metastatic lesions with different distribution across metastatic sites. Specifically, PD-L1 expression of 6/10 LIs, 5/10 OLs (including 2 LU and 3 LN positive lesions), and 4/10 SC metastases was greater than the population median of all metastases combined. LI metastases were the most represented group above the 75th percentile of the population (4/10), followed by OS (2/10) (including 1 LU and 1 LN positive lesions), and SC (1/10). Of the 15 lesions above the population median, 6 were LI (40%), 5 were OS (33%), and 4 were SC (27%); of the 7 metastases above the 75th percentile, 4 were LI (57%), 2 were OS (29%), and 1 was SC (14%). Conclusions: The LCM-RPPA workflow can capture PD-L1 protein expression on a continuous quantitative scale and provide a broader understanding of the dynamic range of expression. Our data suggest that organ specific microenvironments in which metastatic lesions develop may strongly influence overall PD-L1 tumor cell expression. If different metastatic host organs can modulate PD-L1 expression, location of the metastatic lesion should be kept in consideration when selecting patients that are candidates for immunotherapy. Such hypotheses should be further validated in prospective clinical trial where quantitative PD-L1 expression of different metastatic lesions is evaluated along with response to targeted immuno-oncology compounds. Citation Format: Mariaelena Pierobon, K Alex Hodge, Elisa Baldelli, Steven Anthony, Nicholas J. Robert, Donald W. Northfelt, Mohammad J. Jahanzeb, Linda Vocila, Lance A. Liotta, Bryant Dunetz, Emanuel F. Petricoin. PD-L1 expression differs across cancer metastatic sites from breast tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3129.

PurposeBevacizumab improves progression-free survival but not overall survival in patients with metastatic breast cancer. E5103 tested the effect of bevacizumab in the adjuvant setting in patients with human epidermal growth factor receptor 2–negative disease.Patients and MethodsPatients were assigned 1:2:2 to receive placebo with doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (arm A), bevacizumab only during AC and paclitaxel (arm B), or bevacizumab during AC and paclitaxel followed by bevacizumab monotherapy for 10 cycles (arm C). Random assignment was stratified and bevacizumab dose adjusted for choice of AC schedule. Radiation and hormonal therapy were administered concurrently with bevacizumab in arm C. The primary end point was invasive disease–free survival (IDFS).ResultsFour thousand nine hundred ninety-four patients were enrolled. Median age was 52 years; 64% of patients were estrogen receptor positive, 27% were lymph node negative, and 78% received dose-dense AC. Chemotherapy-associated adverse events including myelosuppression and neuropathy were similar across all arms. Grade ≥ 3 hypertension was more common in bevacizumab-treated patients, but thrombosis, proteinuria, and hemorrhage were not. The cumulative incidence of clinical congestive heart failure at 15 months was 1.0%, 1.9%, and 3.0% in arms A, B, and C, respectively. Bevacizumab exposure was less than anticipated, with approximately 24% of patients in arm B and approximately 55% of patients in arm C discontinuing bevacizumab before completing planned therapy. Five-year IDFS was 77% (95% CI, 71% to 81%) in arm A, 76% (95% CI, 72% to 80%) in arm B, and 80% (95% CI, 77% to 83%) in arm C.ConclusionIncorporation of bevacizumab into sequential anthracycline- and taxane-containing adjuvant therapy does not improve IDFS or overall survival in patients with high-risk human epidermal growth factor receptor 2–negative breast cancer. Longer duration bevacizumab therapy is unlikely to be feasible given the high rate of early discontinuation.

Abstract OBJECTIVE: Currently, no study has assessed the performance of contrast-enhanced spectral mammography (CESM) in evaluating tumor response in breast cancer patients undergoing neoadjuvant systemic therapy (NST). This study aims to evaluate whether the accuracy of CESM is comparable to MRI in detection of residual breast cancer following NST. MATERIALS AND METHODS: Retrospective review of CESM cases at our institution between September 2014 and June 2016 identified patients who had both CESM and MRI pre- and post-NST with pathologic assessment after surgical management. Size of residual malignancy (if any) on post-neoadjuvant CESM and MRI was compared to surgical pathology (reference standard). Pathologic complete response (pCR) was documented and compared to Residual Cancer Burden (RCB) score for confirmation. Bland-Altman plots were used to visualize the differences between CESM/MRI and pathologic tumor size. RESULTS: Forty female patients met inclusion criteria. Mean age was 52.3 years (range 35-73). Type of NST included: 34 (85%) chemotherapy and 6 (15%) endocrine therapy. Histological analysis showed invasive ductal carcinoma in 38 (95%), the remaining cases consisted of one invasive lobular carcinoma, and one mixed invasive carcinoma. Mean tumor size after NST was 10.3 mm (range 0-75 mm) for CESM and 9.7 mm (range 0-60 mm) for MRI compared to 15.7 mm (range 0-100 mm) on final surgical pathology. Equivalence tests demonstrated that the mean tumor size measured by CESM or by MRI is equivalent to the mean tumor size measured by pathology within -1 and 1 cm range (p=0.0132 for CESM and p=0.0194 for MRI). Difference in Measurement Post-NST Compared to Pathology Path Tumor Size (mm)CESM Tumor Size (mm)MRI Tumor Size (mm)Mean (SD)15.7 (24.5)10.3 (18.9)9.7 (16.3)Difference Compared with Path (SD); P value -5.4 (12.6); 0.0132-6.0 (11.7); 0.0194 A complete radiologic response was seen in 25 CESM and 22 MRI cases which was confirmed by pathology in 17 and 14, respectively. Alternatively, CESM and MRI demonstrated residual disease in 15 patients and 18 patients respectively and this was confirmed on pathology in 15 and 15, respectively. Accuracy of CESM vs. MRIModalityResidual Disease by Pathology (N=23)Complete Response by Pathology (N=17)SensitivitySpecificityPPVNPVResidual Disease by CESM (N=15)150Complete Response by CESM (N=25)81765.2%100%100%68%Residual Disease by MRI (N=18)153Complete Response by MRI (N=22)81465.2%82.4%83.3%63.6% All patients who achieved a pCR had an RCB score of 0 indicating no residual cancer in lymph nodes. Among patients with residual disease, their mean RCB score was 2.6 (range 0.8-4.18). CONCLUSION: In this study, CESM was comparable to MRI in assessing residual malignancy after completion of NST, thereby offering a potentially faster and less expensive alternative to MRI for monitoring treatment response in the neoadjuvant setting. Citation Format: Hilal T, Covington M, Sugi M, Zhang N, Pockaj B, Northfelt D, Ocal IT, Patel BK. Contrast-enhanced spectral mammography is comparable to MRI in the assessment of residual breast cancer following neoadjuvant systemic therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-11.