Abstract P3-07-22: Predictors of neoadjuvant chemotherapy use in women with breast cancer: A review of 169,329 patients from the American College of Surgeons' National Cancer Database

Abstract

Abstract Background: Randomized controlled trials have demonstrated that neoadjuvant chemotherapy (NAC) offers equivalent long-term outcomes when compared to adjuvant chemotherapy while improving rates of breast conservation therapy (BCT). We sought to evaluate the national use of NAC and the patient, tumor, and provider characteristics associated with its use among women with stage I-III breast cancer. We hypothesize that younger women with larger tumors and HER-2+ or triple negative disease are more likely to receive NAC than their older counterparts with ER+ disease, and that use of NAC varies by region and practice setting. Methods: Using the American College of Surgeons National Cancer Database, which captures data on approximately 70% of new cancer diagnoses in the U.S., we identified women with diagnosed with stage I-III invasive cancer between 2008-2013. Women treated with both surgery and chemotherapy were included in the study. Demographic and clinical factors including race, ethnicity, income, insurance type, region of treatment facility, treatment facility type, tumor size, hormone receptor status, HER-2 status and Charlson Comorbidity score were analyzed to determine predictors associated with receipt of NAC. Utilization of preoperative chemotherapy and rates of breast conserving therapy (BCT) were evaluated as outcomes. Results: 169,329 women with stage I-III breast cancer underwent treatment with chemotherapy and surgery during the study period. Of these, 81.0% were White, 14.4% were Black, 4.6% were classified as Other Race. 28.7% were 18-49, 46.8% were 50-64 and 24.5% were >65 years. 64.4% had private insurance while 35.6% had public insurance (Medicaid, Medicare and VA), and 71.4% were treated at Community-Based Clinics while 28.6% were treated at Academic Medical Centers. Patients with larger tumors (p<0.0001) and triple negative disease were significantly more likely to be treated with NAC than those with ER+ or HER2+ disease (p<0.0001). Among women who received NAC, the median age was 54 as compared to 57 in those receiving adjuvant chemotherapy (p<0.0001). Treatment facility type impacted rates of NAC use, with academic centers being more likely than community-based practices to give chemotherapy preoperatively (12.1% vs. 9.8%, p<0.0001) and urban vs. rural settings (10.4% vs 8.2%, p<0.0001). Rates of NAC utilization differed regionally with the highest rate being 14.0% and the lowest rate 7.9% (p<0.0001). The overall % of BCT following NAC was 36.1% compared to 59.0% for those receiving adjuvant chemotherapy. The proportion of BCT following NAC differed significantly by subtype, 54.6% for ER+, 54.5% for Her2 +, and 59.7% for triple negative breast cancer (TNBC) (p <0.0001). Conclusions: In the treatment of stage I-III breast cancer across the US, variations in the utilization of neoadjuvant chemotherapy exist across the country suggesting clinical uncertainty about its use. Further research about the use of NAC therapy and the relationship to clinical outcomes can identify patient subsets who might obtain greatest clinical benefit from preoperative systemic therapy. Citation Format: Lynn J Howie, Rachel Greenup, Kevin Houck, Julie A Sosa, E Shelley Hwang, Jeffrey M Peppercorn. Predictors of neoadjuvant chemotherapy use in women with breast cancer: A review of 169,329 patients from the American College of Surgeons' National Cancer Database [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-07-22.