Randomized phase III study of observation versus adjuvant capecitabine and oxaliplatin in curatively resected small bowel adenocarcinoma: A Japan Clinical Oncology Group study (JCOG1502C).

Abstract

TPS539 Background: Small bowel adenocarcinoma (SBA) is extremely rare tumor. Surgery is broadly applied as a standard treatment for localized SBA. However, the patients with localized SBA have poor prognosis even after curative resection (5-year survival: 40-65%), and most of them experience relapse. To prevent relapse, postoperative therapies are considered as most promising. However, there is no prospective study of postoperative therapies for curatively resected SBA patients and which regimens improve prognoses is unknown. For metastatic SBA, fluoropyrimidine and oxaliplatin is now regarded as global standard chemotherapy. Therefore, Japan Clinical Oncology Group (JCOG) planned a multicenter randomized phase III trial to confirm the superiority of postoperative capecitabine and oxaliplatin (CAPOX) to observation for curatively resected SBA under the Advanced Medical Care System of the Ministry of Health, Labour and Welfare, Japan. This study is a counterpart trial of BALLAD trial conducted in International Rare Cancer Initiative (IRCI) (clinical trials gov; NCT02502370), and the integrated analysis of BALLAD trial and JCOG1502C is planned. Methods: Eligibility criteria include histologically proven adenocarcinoma located in the duodenum (except Ampulla of Vater) / jejunum / ileum, curatively resected with regional lymph nodes dissection, pathological stage I (T1b-2N0M0) / stage II / stage III. Eligible patients are randomized into observation arm or CAPOX arm. CAPOX (130 mg/m2 of oxaliplatin on day 1, and 1000 mg/m2 of capecitabine twice a day for 14 days) is repeated every 3 weeks for 6 months (total 8 courses). The primary endpoint is RFS. The 3-year RFS of observation arm is assumed to be 70% and expected a 10% increase in CAPOX arm. The sample size was calculated as 150 (75 per arm) with a one-sided alpha level of 10%, a statistical power of 70%, an accrual period of 6.5 years. This study has been registered in the UMIN Clinical Trials Registry (UMIN000027280). This trial was activated in 9 May 2017, and no patients was enrolled as of Sep 2017. We will increase the number of participating sites up to 20 throughout Japan. Clinical trial information: UMIN000027280.