Clinical outcomes of resectable small bowel adenocarcinoma treated by surgery alone: Case series in a Japanese single institution.

Abstract

372 Background: Small bowel adenocarcinoma (SBA) is known as a poor prognostic cancer even in surgically resected cases. Its five-year survival rates were reported as 65%, 48%, and 35% in stage I, II, and III SBA, respectively. However, clinical outcomes of curatively resected SBA, especially without peri-operative adjuvant chemotherapy, are still unknown in Japanese population. Methods: We retrospectively reviewed medical records of patients who were diagnosed as Stage I, II, and III SBA after curative surgery between July 1994 and June 2014 at National Cancer Center Hospital. Overall survival (OS) and relapse-free survival (RFS) were calculated by Kaplan-Meier method. Cox proportional-hazards analysis was performed to identify the prognostic factors. Results: From a total of 76 patients with SBA received surgical resection, 56 were selected in this study who underwent curative resection with histological confirmation and did not receive adjuvant chemotherapy. The median age was 64 years (range: 20-85). Thirty-five patients (61%) were male. Forty-five patients (80%) had tumors in duodenum, 6 (11%) in jejunum and 5 (9%) in ileum. Pathological T stage were pT1a/T1b/T2/T3/T4 in 9/2/4/14/27 patients, and pathological N stage (pN) were pN0/N1/N2 in 29/16/11. The 1/3/5-year OS in all patients were 92.5/77.5/71.6%, and 1/3/5-year RFS were 76.5/68.9/61.6%. The 5-year RFS of pN0 (stage I/IIA/IIB) / N1 (stage IIIA) /N2 (stage IIIB) were 81.2/51.6/20.8%, and 5-year OS were 88.2/71.6/26.7%, respectively. Univariate analysis demonstrated that pN, presence of lymphatic and venous invasion were associated with poor OS. In multivariate analysis, pN was a significant predictor of poor OS (HR: 5.39 [N0 vs N1], 21.74 [N0 vs N2], 4.03 [N1 vs N2], p = 0.042). These findings were also seen in RFS. Conclusions: This study showed survival outcome of curatively resected SBA was better compared with previous reports, and pN was a significant prognostic factor of RFS and OS.