Prognostic significance of microsatellite instability in curatively resected adenocarcinoma of the small intestine

Adenocarcinoma of the small intestine (ACSI) is a rare condition with few studies addressing follow-up and prognosis. Tumors of 35 patients with curative resection of an ACSI were retrospectively analyzed by immunohistochemistry: p53, hMLH1, hMSH2 and hMSH6 and microsatellite instability (MSI): BAT-26, BAX, TGF-beta RII. With a median follow up of 6.1 years, the median cancer-specific survival (CSS) was 36.2 months. Patients who were highly instable (MSI-H) (n = 10) had a CSS of 49.6 months in contrast to patients with stable tumors (23.2 months) (P = 0.010). Additionally, a low tumor stage according to UICC and MSI-H were shown to be independent factors (P = 0.005 and P < 0.001) for an increased survival in multivariate analysis. Therefore, it is suggested that analysis of the MSI status might prove useful in discerning prognosis within cancers of the same stage. (C) 2003 Elsevier Ireland Ltd. All rights reserved.