Abstract P1-13-08: A prospective non-randomized clinical trial of adjuvant carboplatin chemotherapy in triple negative breast cancer

Background: The addition of carboplatin in the neoadjuvant setting has demonstrated improved outcomes in patients with triple negative breast cancer (TNBC). Carboplatin in the adjuvant setting has not been demonstrated to be an accepted regimen to date. This trial addresses this issue. Methods: The primary objectives of this study were to assess the toxicity of an adjuvant carboplatin-containing regimen for early stage TNBC patients, and to correlate outcomes with molecular markers including Spy-1. Secondary objectives included determination of progression free (PFS) and overall survival (OS), and comparing these to our institutional historical controls. Patients received the backbone of a dose dense anthracycline, taxane, cyclophosphamide (DD ACT), with the addition of carboplatin. Results: Ninety patients with stage I to III patients with triple negative breast cancer were accrued to this trial between Jan 2011 and June 2017. We discovered that DD ACT with carboplatin with an AUC of 5 given on the second and last paclitaxel was well tolerated. Chemotherapy delays were minimized when the parameters for administration of the carboplatin was to allow chemotherapy to proceed if the platelet count was >/= 70,000 x10^9/L and dose adjustment of paclitaxel was allowed based on neuropathy. There were no grade 4 adverse events. 4% of patients had grade 3 peripheral neuropathy (PN), 28% had grade 2 PN and 45% had grade 1 PN. Results of molecular profiles will be reported. Univariate analysis are reported, and were found to be very promising. Using log-rank statistic, a trend to improvement in overall survival was found when compared to historical controls (p=0.089). Median follow-up is 24 months. Longer follow-up is necessary to determine PFS and overall survival benefit. Conclusion: If considering an adjuvant regimen for triple negative breast cancer patients DDAC/TC with the carboplatin administered with an AUC of 5 on the second and fourth taxol of DDACT is a well-tolerated regimen. Citation Format: Hamm C, Kulkarni S, Gupta R, Mathews J, Amin K, Hussein A, Porter L. A prospective non-randomized clinical trial of adjuvant carboplatin chemotherapy in triple negative 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 P1-13-08.