Metastatic/recurrent triple-negative breast cancer is a malignant tumor with a poor prognosis. However, metastatic/recurrent triple-negative breast cancer is a cancer type that is highly sensitive to anticancer drugs. The antitumor effect of DNA-damaging anticancer drugs has been confirmed for triple-negative breast cancer.

In addition, the antitumor effect of platinum preparations on triple-negative breast cancer has also been reported. In 2020, our cancer care network compared the response of platinum-containing treatments to the platinum-free treatment for metastatic and recurrent triple-negative breast cancer.

In a randomized phase II trial of preoperative chemotherapy in HER2-negative breast cancer patients, weekly Paclitaxel (PTX) followed by Carboplatin (CBDCA) for 4 cycles prior to CEF therapy＊ was performed.

The results of our clinical trials showed a significant increase in overall pathological complete response (pCR). In particular, high pCR was observed in patients with triple-negative breast cancer. From this clinical trial, the efficacy of platinum drugs has been suggested for patients with triple-negative breast cancer.

From the results of our clinical trials, the strength of medical evidence and the balance between benefits and harms were examined in the treatment of metastatic/recurrent triple-negative breast cancer. As a treatment option for metastatic or recurrent triple-negative breast cancer, platinum preparations are recommended.

However, in Japan, platinum preparations are not covered by insurance for breast cancer. In addition, carboplatin is covered by insurance only for HER2-positive breast cancer, so caution is required in prescribing.

CEF therapy＊: Treatment with a combination of three anticancer drugs: cyclophosphamide, epirubicin and fluorouracil

Disclosure of potential conflicts of interest
The authors declare no potential conflicts of interest.

Data availability and Consent to publish
This manuscript is an editorial and does not contain research data.
Therefore, there is no research data or information to be published or opened.

Acknowledgments
We thank all the medical staffs and co-medical staffs for providing and helping medical research at National Hospital Organization Kyoto Medical Center.

Doctor specializing in cancer medicine 　                                                   JAMA Oncology Published on January 2021. by Kyoto@Takuma H