TPS588 Background: The possibility of improving the survival of stage IV breast cancer patients by primary tumor resection (PTR) has been reported by several retrospective studies; however, these studies essentially suffer from biases such as arbitrary patient selection, diverse timing of surgery or various regimens of systemic therapy. Five prospective randomized trials including our trial have evaluated the efficacy of PTR for them. Two have reported final results, but those results were inconsistent. Therefore, this subject still remains a hotly debated topic at major breast conferences. Methods: Our trial is being conducted to confirm the superiority of PTR plus systemic therapy over systemic therapy alone in stage IV pts who are sensitive to primary systemic therapy (PST) in this study. The inclusion criteria are untreated pts with histologically confirmed invasive breast cancer with one or more measurable distant metastatic lesions diagnosed by radiological examination.All pts receive PST according to the ER and HER2 status of the primary breast cancer after the first registration. After three months, the pts who are sensitive to PST are randomized to the PTR plus systemic therapy arm or the systemic therapy alone arm. After randomization and surgery in the former arm, or after randomization in the latter arm, the same systemic therapies are continued until progression of diseases and next appropriate regimens are started after that. The primary endpoint is the overall survival, and the secondary endpoints are proportion of pts without tumor progression at the metastatic sites, yearly local recurrence-free survival, proportion of local ulcer/local bleeding, yearly primary tumor resection-free survival, adverse events (AEs) of chemotherapy, operative morbidity, and serious AEs. Sample size for randomized pts was determined to attain at least 80% of power to detect a 6 months difference with one-sided alpha of 0.05.The pts accrual was started in May 2011. Enrollment of 410 pts for randomization is planned over a 7-year accrual period. 307 pts have been randomized until Jan 2017. This trial was registered at UMIN-CTR[umin.ac.jp/ctr/] as UMIN000005586. Clinical trial information: UMIN000005586.
The eligibility of primary tumor resection for de novo stage IV breast cancer patients