[Effective therapeutic regimens for patients with triple-negative (ER/PgR/HER2-negative) metastatic breast cancer]

The so-called triple-negative (TN) metastatic breast cancer (MBC), that is, MBC expressing no hormone receptors or HER2 protein, has attracted attention because of its low response rate to drug therapy and poor prognosis after recurrence. Of 423 MBC patients in our hospital in and after 2001, 54 had TN tumors. The median survival time (MST) of TN patients (25 months) was shorter than the MSTs of HR (+)/HER2 (-), HR (+)/HER2 (+), and HR (-)/HER2 (+) patients (69, 58, and 39 months, respectively). A retrospective analysis of responses to 162 regimens in 54 TN-MBC patients showed that anthracycline regimens produced a response rate of 18. 8% (a PR or higher response in 3 of 16 patients), whereas a taxane regimen yielded a very low response rate of 8. 1% (3/37). A similar low response was observed in monotherapy with MTX, CPT-11, VNR, gemcitabine, or S-1. Of particular note were the high response rate (46. 2%, 12/26) of DMpC therapy (oral 5'-DFUR, MPA, and CPA) and that (28%, 7/25) of MFL-P therapy (MTX, 5-FU, leucovorin, and CDDP), although these were not standard therapies. In addition, the molecular-targeted drug bevacizumab or cetuximab was concomitantly used with chemotherapeutic agents in 3 patients, and 1 each treated with either therapy achieved a PR. Thus, in the future, we can expect further advances in molecular-targeted therapy while using DMpC and MFL-P for the treatment of TN-MBC as an early-line therapy.