[A Case of Hormone Receptor‒Positive HER2‒Negative Advanced/Recurrent Breast Cancer with 1.5 Years Withdrawal Period of Palbociclib Showed a Good Response Treated by Abemaciclib and Fulvestrant].

A 58‒year‒post‒menoposal woman was presented with left chest pain and shortness of breath because her breast cancer metastasized to the skin, lung, and pleural dissemination. In late‒line treatment for hormone receptor‒positive HER2‒negative advanced/recurrent breast cancer, we experienced a patient with tumor shrinkage leading to pain relief who was treated with a second combination of a CDK4/6 inhibitor and fulvestrant. Due to her poor performance status, she was treated with combined therapy to avoid severe adverse events. The CDK4/6 inhibitor was reintroduced after 1.5 years withdrawal period of endocrine therapy during anticancer drugs and radiation treatment. It has also been reported that withdrawal of CDK4/6 inhibitors might restore susceptibility related to the inhibitory signal. Rather than sequentially administering combined endocrine therapy with a CDK4/6 inhibitor, the withdrawal strategy of endocrine therapy continuing to administer anticancer drugs should be considered in case of reintroduction of CDK4/6 inhibitor.

[Long-term survival of a patient with giant liver metastatic breast cancer treated with trastuzumab].

We report the long-term survival of a patient with metastatic breast cancer treated with trastuzumab and chemoendocrine therapy. The patient was a 60-year-old female. She underwent right mastectomy with axillary lymphadenectomy I c for advanced right breast cancer in 1999. In 2007, she consulted our hospital for treatment of recurrent giant liver metastasis. A giant liver metastasis up to 15 cm in diameter was detected by CT upon arrival. After 4 years of trastuzumab and chemoendocrine therapy, she was diagnosed as in progressive remission with good quality of life. Breast cancer with liver metastasis often can be life-threatening. Therefore, an optimal chemotherapy should be applied as soon as possible. Trastuzumab and chemoendocrine therapy showed efficacy for the treatment of a HER2-positive breast cancer with recurrent giant liver metastasis.