Abstract P3-01-05: Circulating tumor cell detection predicts early recurrence in patients with non-metastatic breast cancer

Abstract

Abstract Background: Our group and others have shown that CTCs are identified in 20-25% of non-metastatic breast cancer patients. Recent data suggests that circulating tumor cell (CTC) detection at 5 years follow-up predicts late recurrence for non-metastatic, estrogen receptor positive, HER2/neu negative (ER+/HER2-) breast cancer patients. The aim of this study was to determine if CTC detection at time of surgery in ER+/HER2- predicts early (less than or equal to 5 years) recurrence, and to compare the median recurrence-free survival (RFS) to triple negative (TN) patients. Methods: We performed CTC enumeration on 506 patients with non-metastatic breast cancer just prior to surgical resection as part of an IRB approved study. CTCs (per 7.5 ml blood) were identified using the Cell SearchSystem (Menarini Silicon Biosystems). The presence of one or more CTC meeting morphological criteria for malignancy was considered a positive result. Patients with inflammatory breast cancer were excluded from our analysis. Log-rank test and Cox regression analysis were applied to establish the association of CTCs with RFS. Results: Median follow-up was 68 months and mean age was 53 years. Eighty-four percent of patients (417/498) had T1/T2 tumors, 63% (307/487) had grade 1 or 2 tumors, and 58% (292/501) had negative lymph nodes. Eighty-three percent (419/506) had ER+/HER2- tumors, and 17% (87/506) were TN. One or more CTC was identified in 22% (91/419) ER+/HER2- patients, and in 28% (24/87) of TN patients. Nine percent (45/506) of patients recurred within 5 years of CTC assessment. Of the 45 patients who relapsed, detection of one or more CTCs predicted shortened RFS. Median RFS for CTC-positive patients was 1.2 years, vs. 2.5 years for CTC-negative patients, irrespective of ER+/HER2- or TN subtype (log-rank P<0.001, HR = 2.71, 95% CI, 1.50 to 4.87). Conclusions: One or more CTCs identified at surgical resection predicted shortened RFS, irrespective of subtype, in non-metastatic breast cancer patients. This data warrants larger studies to determine if CTC positivity can be used to stratify both ER+ and TN patients who are at increased risk for early recurrence. Citation Format: Hall C, Meas S, Bowman Bauldry J, Kuerer H, Lucci A. Circulating tumor cell detection predicts early recurrence in patients with non-metastatic breast cancer [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 P3-01-05.