[Long-Term Survival of a Patient with Stage IV Breast Cancer and An Intrathoracic Space-Occupying Metastatic Lesion].

A 50-year old woman noticed left axillary lymph node swelling and presented at our hospital. CNB showed adenocarcinoma( pap-tub, ER+, PgR+, HER2 3+). CT revealed a right lung metastatic nodule and swollen lymph nodes above the left collarbone and left axilla. However, no breast tumor was found at that time. We diagnosed occult breast cancer, TxN3bM1 (lung), Stage IV . FEC(100), paclitaxel, letrozole, anastrozole, exemestane plus trastuzumab, tegafur/uracil plus trastuzumab, and lapatinib plus capecitabine were sequentially administered. Five years and 9 months after the treatment started, CT revealed a right intrathoracic lesion that had gradually increased in size. Subsequently, trastuzumab plus pertuzumab plus docetaxel, bevacizumab plus paclitaxel, trastuzumab emtansine, trastuzumab plus fulvestrant, and doxifluridine plus medroxyprogesterone acetate plus cyclophosphamide(DMpC therapy)were sequentially administered. At this time, 8 years after the treatment started, trastuzumab plus pertuzumab plus vinorelbine were also administered. An intrathoracic space-occupying lesion due to breast cancer is rare, and anti-HER2 chemotherapy was effective for this patient.