The prognostic factor and the optimal timing of conversion surgery in unresectable stage IV gastric cancer: A retrospective analysis.

78 Background: Conversion surgery could be an option for unresectable stage IV gastric cancer when distant metastasis (M1) is disappeared by chemotherapy. However, the indication and the optimal timing of conversion surgery in stage IV gastric cancer remain unclear, even if metastatic lesions disappear with chemotherapy. Guideline of National Comprehensive Cancer Network also shows no principle after down-staging. Methods: This retrospective study examined 34 gastric cancer patients who underwent curative conversion surgery at our institute between 2005 and 2014. Clinicopathologic characteristics and patient outcomes were analyzed, with particular focus on the potential to select patients who might benefit from surgical resection. Results: The number of M1 factors was one in 31 patients and two in 3, including metastases to non-regional lymph node in 21, peritoneum in 8, liver in 5, and lung in 3. The regimen of chemotherapy was Docetaxel/CDDP/S-1 in 23 patients, Docetaxel/CDDP/S-1+Trastuzmab in 6, S-1/CD...