G. Iacono

Hormonal therapy followed by chemotherapy or the reverse sequence as first-line treatment of hormone-responsive, human epidermal growth factor receptor-2 negative metastatic breast cancer patients: results of an observational study

Introduction Although hormonal-therapy is the preferred first-line treatment for hormone-responsive, HER2 negative metastatic breast cancer, no data from clinical trials support the choice between hormonal-therapy and chemotherapy. Methods Patients were divided into two groups according to the treatment: chemotherapy or hormonal-therapy. Outcomes in terms of clinical benefit and median overall survival (OS) were retrospectively evaluated in the two groups. To calculate the time spent in chemotherapy with respect to OS in the two groups, the proportion of patients in chemotherapy relative to those present in either group was computed at every day from the start of therapy. Results From 1999 to 2013, 119 patients received first-line hormonal-therapy (HT-first group) and 100 first-line chemotherapy (CT-first group). Patients in the CT-first group were younger and with poorer prognostic factors as compared to those in HT-first group. Clinical benefit (77 vs 81%) and median OS (50.7 vs 51.1 months) were similar in the two groups. Time spent in chemotherapy was significantly longer during the first 3 years in CT-first group (54-34%) as compared to the HT-first group (11-18%). This difference decreased after the third year and overall was 28% in the CT-first group and 18% in the HT-first group. Conclusions The sequence first-line chemotherapy followed by hormonal-therapy, as compared with the opposite sequence, is associated with a longer time of OS spent in chemotherapy. However, despite the poorer prognostic factors, patients in the CT-first group had a superimposable OS than those in the HT-first group.

PO54 ACTIVITY AND DURATION OF CHEMOTHERAPY IN DIFFERENT BIOLOGIC SUBTYPES (BS) IN METASTATIC BREAST CANCER (MBC) PATIENTS

Background: In MBC patients the benefit of chemotherapy after the first line is poorly defined. We evaluated activity of subsequent line of chemotherapy in different BS of MBC. Methods: MBC patients treated in our center from 2007 to 2012 with ER, PgR and HER2 on primary tumor and at least one line of chemotherapy for MBC were evaluated. Patients were classified as luminal A (ER and/ or PgR +, HER2 -, Ki67 ≤ 14%), luminal B (ER and/or PgR +, HER2 -, Ki67 > 14%), HER2+ (HER2+, any ER/PgR) and triple-negative (ER-, PgRand HER2-). The objectives of our analysis were to estimate number of chemotherapy lines in different BS, to evaluate clinical benefit (CB) defined as RC+RP+SD and overall survival (OS) by chemotherapy line in every BS and to identify possible predictive factors for a greater number of chemotherapy line. Time on chemotherapy was calculated from the start of the first line to the end of the last line. Statistical analyses included Chi-square and Kruskal-Wallis tests, Kaplan-Meier curves and log-rank tests, and multivariate logistic regressions. Results: A total of 326 patients were identified, 50 were excluded because they did not receive any chemotherapy. Median follow-up was 32.3 months. Median number of chemotherapy lines was 2 (range 1-10). Median OS according to BS was 60.5 months in luminal A (58 patients), 50.0 months in luminal B (119 patients), 69.2 in HER2+ (57 patients) and 32.3 in TN (42 patients). The percentages of patients receiving second line, third line and four or more lines of chemotherapy were respectively: 58%, 41%, 22% for luminal A, 59%, 34%, 16% for luminal B, 71%, 52%, 39% for HER2+, and 69%, 43%, 16% for TN. CB was inferior in TN patients as compared with the other ones in first and in second lines (p=.027 and p=.093 respectively in first and second lines). From third line onward all patients showed the same CB independently from BS. Time on chemotherapy related to median OS for every BS was the same (18% in luminal A, 20% in luminal B, 27% in HER2+, 29% in TN). At multivariate analysis the characteristics independently associated with a greater probability of receiving more than four chemotherapy lines were HER2+ (p=.027) and less than three sites of metastasis (p=.05). Conclusions: Our analysis showed that, despite the same time spent on chemotherapy, TN patients received less benefit from first and second chemotherapy lines than other BS. On the other hand, HER2+ patients were more likely to receive multiple lines of chemotherapy with a significant impact on median OS (p=.044). PO55