Impact of Different Lines of Palliative Chemotherapy in Patients with Metastatic Breast Cancer

Back ground and objectives: Metastatic breast cancer (MBC) is a heterogeneous disease that exhibits different clinical scenarios, ranging from solitary metastatic lesions to multiple organ involvements. No gold standard treatment exists for MBC and no specific guidelines are available. Although, the improvement in overall survival (OS) observed in the last decades mainly related to the contributions of various therapies, metastatic disease remains the primary cause of death in the majority of patients with breast cancer. This study aims to determine the benefit of different lines of chemotherapy in patients with MBC and to identify patients who have better benefit from the treatment.
Methods: We conducted a retrospective study of 182 MBC patients who received palliative chemotherapy at medical oncology department of South Egypt Cancer Institute (SECI), Assuit University between January, 2012 and December, 2017. A total of 182, 130, 72 and 29 patients received first-, second-, third-, and fourth-line chemotherapy, respectively. Chemotherapy groups were defined according to the principle agents used: anthracycline-, taxane-, capecitabine-, platinum-based and others.
Results: The median progression free survival (mPFS) decreased with the advancing lines of chemotherapy: it was 5 ms for first line versus 4 ms for second line versus 3 ms for third line and 3 ms for fourth line. In addition, we found that OS was significantly correlated with response rate and mPFS of first line of chemotherapy. OS when mPFS of the first line >5 ms was 19 (16.3-21.69) while it was 14 (11.4-16.6) when mPFS ≤ 5 ms p=.008. In addition both CR and RD after first line of chemotherapy were significantly related to longer OS as it was 17 (0-45.8) and 23 (17.08-28.91) respectively P= .016.
Conclusion: Both of overall response rate (ORR) and mPFS decrease with the advancing lines of chemotherapy. In addition, the response rate and mPFS of the first-line therapy are important prognostic factors for OS.