No standard chemotherapy regimen has been established for unresectable or recurrent small bowel adenocarcinoma (SBA).

Clinical courses of 132 patients with unresectable or recurrent SBA who received chemotherapy at 41 institutions in Japan were reviewed retrospectively. Patients were classified into five groups according to first-line chemotherapy regimens: fluoropyrimidine monotherapy (group A), fluoropyrimidine-cisplatin (group B), fluoropyrimidine-oxaliplatin (group C), fluoropyrimidine-irinotecan (group D), and other regimens (group E).

The number of patients in each group was as follows: groups A, 60 patients; group B, 17 patients; group C, 22 patients; group D, 11 patients; and group E, 22 patients. Median progression-free survival (PFS) times were as follows: group A, 5.4 months; group B, 3.8 months; group C, 8.2 months; group D, 5.6 months; and group E, 3.4 months. Median overall survival (OS) times were as follows: group A, 13.9 months; group B, 12.6 months; group C, 22.2 months; group D, 9.4 months; and group D, 8.1 months. Patients in group C achieved significantly longer PFS times and substantially (but not significantly) longer OS times than patients in group A. After adjusting for clinical background characteristics, fluoropyrimidine-oxaliplatin therapy was a significant positive prognostic factor for PFS and OS times.

The results suggest that fluoropyrimidine-oxaliplatin combination therapy is the most promising first-line chemotherapy regimen for unresectable or recurrent SBA.