Platinum-based chemotherapy regimens are frequently used in patients with triple-negative breast cancer (TNBC). The aim of the current study was to assess whether or not platinum-based chemotherapy is associated with an increased time to progression when compared with non-platinum-based regimens in TNBC and non-TNBC. A retrospective analysis was conducted within a cohort of patients with metastatic breast cancer who received platinum-based chemotherapy at a single institution. Data were collected for up to three lines of treatment for metastatic disease. Time to progression was determined for platinum-based chemotherapy and non-platinum-based regimens for each line of treatment. Adjusted hazard ratios (HRs), together with 95% confidence intervals (CIs) were estimated comparing the time to progression associated with the use of platinum-based chemotherapy versus non-platinum-based regimens. A total of 159 patients were included in the analysis, with 58 diagnosed with TNBC. Among the patients with TNBC, compared with non-platinum-based chemotherapy, no correlation was identified between platinum-based chemotherapy and an improved time to progression [first line: HR, 0.97 (95% CI, 0.40-2.35); second line: HR, 0.91 (95% CI, 0.42-2.01); and third line: HR, 2.83 (95% CI, 0.73-11.03)]. By contrast, patients with non-TNBC appeared to improve with non-platinum-based chemotherapy [first line: HR, 2.57 (95% CI, 1.11-5.99); second line: HR, 1.91 (95% CI, 1.00-3.63); and third line: HR, 1.08 (95% CI, 0.53-2.18)]. Although the present study was limited by the sample size and its observational nature, the results indicated that platinum-based chemotherapy does not offer a discernible or distinct advantage compared with standard regimens in patients with TNBC, and is perhaps less efficacious in patients with non-TNBC.
Keywords: metastatic breast cancer; platinum; time to progression; triple-negative breast cancer.