Optimal criteria of treatment change for advanced gastric cancer patients with nonmeasurable peritoneal metastasis alone.

Abstract

103 Background: Palliative chemotherapy is the mainstay for the treatment of advanced gastric cancer (AGC) patients with peritoneal metastasis. In general, chemotherapy regimen is changed when patients show disease progression on CT scan. However, nearly 40% of these patients have no measurable lesions. It remains uncertain how clinicians can decide the timing of treatment change for AGC patients with non-measurable peritoneal metastasis alone. Methods: There were 217 patients with primary unresectable or recurrent gastric cancer at our institution between April, 2005 and March, 2012. Among them, 50 patients, who had histologically proven non-measurable peritoneal metastasis alone, were retrospectively identified and investigated in this study. They underwent measurements of tumor markers (TM) every month and abdominal CT scan every 2 months. For these 50 patients, chemotherapy regimen was changed based on the following different 2 criteria; 1. elevated TM and/or aggravated clinical symptoms alone (n=21), 2. radiologically confirmed disease progression (n=29). We assessed whether these two different criteria have any impact on overall survival (OS) by univariate and multivariate analyses. Results: Median survival time of all 50 patients was 604 days. Multivariate analysis identified pre-treatment performance status of 0-1 (hazard ratio (HR) 0.211, 95% confidence interval (CI) 0.045–0.998, P=0.049), initial hemoglobin level of 10 mg/dl or more (HR 0.114, 95% CI 0.014–0.936, P=0.043) and the TM / symptom based treatment change (HR 0.124, 95% CI 0.043–0.360, P=0.001) as significant prognostic factors for favorable OS. Conclusions: Early decision making of treatment change based on elevated TM and/or aggravated clinical symptoms alone might contribute to longer OS in AGC patients with non-measurable peritoneal metastasis alone.