Fifteen-year experience of all patients (pts) with small bowel adenocarcinoma (SBA), treated in a specialized gastrointestinal (GI) oncology unit: Royal Marsden (RM) experience.

Abstract

316 Background: Small bowel adenocarcinoma (SBA) is a rare tumour with poor prognosis. There is paucity of published literature due to rarity of disease; we conducted this retrospective study to determine the clinical course and outcome along with prognostic factors in both early and later stage SBA. Methods: Clinical characteristics and outcomes of all pts treated consecutively in the GI Unit RM, 1996-2011 were recorded. The study endpoints were relapse free survival (RFS), progression free survival (PFS), and overall survival (OS), in early stage pts (G1) and in pts with advanced disease (presentation or relapse with un-resectable disease=G2). In G2 response rate (RR) to chemotherapy was determined. In both groups association to baseline prognostic factors were sought by performing Cox regression univariate analysis (UVA). Results: Eighty four pts with SBA were treated 1996-2011. A total of 48 presented with early stage disease (G1). In G1 (58.3% males; mean age, 57 years), 44/48 pts underwent R0 resection; 21 received adjuvant chemotherapy. RFS, PFS and OS in this group were 29.6 [95% confidence interval (CI) 3.3-55.9], 31.1 (CI=8.0-54.3) and 42.9 (CI=0-94.9) months (m), with median follow up of 76.4 m. Poor histological differentiation (p=0.025), abnormal CEA at presentation (P=0.082), and lymphovascular invasion (p=0.003) were prognostic of OS. G2 comprised of 36 pts with un-resectable disease along with 23 from G1 who subsequently relapsed [G2 (n=59); 52.5% males; mean age, 59 years]; 54 pts with metastatic and 5 with locally advanced disease; 78% received first-line chemotherapy. Overall RR of pts who received chemotherapy was 50%. OS and PFS were 12.8 (CI =8.4-17.2) and 8.8 (CI=5.5-12.3) m respectively; 1-year survival was 60.9% vs. 27.3% (no chemotherapy) (p=0.042). Abnormal albumin (0.041), platelet count (p=0.007) and CEA (p=0.025) were prognostic of OS in the chemotherapy group; doublet (18/41) versus triplet (23/41) chemotherapy were not prognostic (p=0.185). Conclusions: Pts with SBA and metastatic disease may derive benefit from systemic chemotherapy; prospective clinical trials are required to evaluate this further.