A phase II study of 5-FU/l-LV/oxaliplatin (mFOLFOX6) in patients with metastatic or unresectable small bowel adenocarcinoma: A post hoc analysis.

430 Background: Small bowel adenocarcinoma (SBA) is a rare disease. Previous studies suggested several prognostic factors of unresectable SBA, including age, performance status (PS), primary site, resection of primary tumor, histology, and tumor marker (CEA and CA19–9) levels. However, prognostic factors of the patients treated with oxaliplatin–fluoropyrimidine combination therapy were unknown, while these drugs were reported as a promising chemotherapy regimen for SBA. Methods: Previously untreated SBA patients were treated with an mFOLFOX6 regimen, and a post hoc analyses for prognostic factors were performed. Results: Between April 2010 and November 2012, 24 patients were included in this study. The overall response rate was 45% (9/20). The median progression-free survival and overall survival (OS) were 5.4 months (95% CI, 4.8–6.0) and 17.3 months (95% CI, 11.7–19.0), respectively. Univariate analysis revealed that lower PS (HR= 0.27; 95% CI, 0.10–0.77; p= 0.014), primary disease of the jejunum (HR= 0.35; 95% CI, 0.11–1.12; p=0.077), and serum CEA in the normal range (HR= 0.40; 95% CI, 0.14–1.11; p= 0.079) were potential prognostic factors of longer OS (threshold, p< 0.10). Although resection of the primary tumor was not a predictive factor of survival in this study, 54% and 21% of the patients needed surgery (primary resection or bypass) because of stenosis before and during chemotherapy, respectively. It is considered that bowel obstruction should be addressed before and during treatment. Conclusions: PS, primary site, and serum CEA levels are potential prognostic factors of unresectable SBA. There is a higher incidence of bowel stenosis or obstruction caused by the primary tumor before and during the treatment of SBA.