Evaluation of prognostic factors and treatment in advanced small bowel adenocarcinoma: report of a multi-institutional experience of Anatolian Society of Medical Oncology (ASMO).

Purpose: Small bowel adenocarcinoma (SBA) is a rare tumor of the gastrointestinal system with poor prognosis. Since these are rarely encountered tumors, there are limited numbers of studies investigating systemic treatment in advanced SBA. The purpose of this study was to evaluate the prognostic factors and systemic treatments in patients with advance SBA.

Methods: Seventy-one patients from 18 Centers with advanced SBA were included in the study. Fifty-six patients received one of the four different chemotherapy regimens as first-line therapy and 15 patients were treated with best supportive care (BSC).

Results: Of the 71 patients, 42 (59%) were male and 29 (41%) female with a median age of 56 years. Median follow- up duration was 14.3 months. The median progression free survival (PFS) and overall survival (OS) were 7 and 13 months, respectively (N=71). In patients treated with FOLFOX (N=18), FOLFIRI (N=11), cisplatin-5-fluorouracil/ 5-FU (N=17) and gemcitabine alone (N=10), median PFS was 7, 8, 8 and 5 months, respectively, while median OS was 15, 16, 15 and 11 months, respectively. No significant differences between chemotherapy groups were noticed in terms of PFS and OS. Univariate analysis revealed that chemotherapy administration, de novo metastatic disease, ECOG PS 0 and 1, and overall response to therapy were significantly related to improved outcome. Only overall response to treatment was found to be significantly prognostic in multivariate analysis (p=0.001).

Conclusions: In this study, overall response to chemotherapy emerged as the single significant prognostic factor for advanced SBAs. Platin and irinotecan based regimens achieved similar survival outcomes in advanced SBA patients.