Radiotherapy Prolongs Biliary Metal Stent Patency in Malignant Pancreatobiliary Obstructions

BACKGROUND/AIMS: Biliary stenting is the most effective decompressive method for treating malignant biliary obstructive jaundice. Although the main cause of stent occlusion is tumor growth, few studies have investigated whether stent patency is affected by the combination of cancer-treatment modalities. The aim of this study was to evaluate the effects of local radiotherapy on metal-stent patency in patients with malignant biliary obstruction. METHODS: Patients who underwent self-expandable biliary metallic stenting for malignant biliary obstruction from 1999 to 2007 were included. Forty patients received chemotherapy and radiation therapy (radiation group, RG), and 31 patients received only chemotherapy (nonradiation group, NRG). RESULTS: The cumulative median stent patency was significantly longer in the RG than in the NRG (17.7 months; 95% confidence interval [CI], 1.8 to 33.6 months vs 8.7 months; 95% CI, 4.9 to 12.5 months; p=0.025). Stent occlusion caused by tumor growth or stent migration occurred in two (5%) and three (7.5%) cases in the RG and in six (19.3%) and two (6.5%) cases in the NRG, respectively. CONCLUSIONS: The patency of biliary metal stents in pancreatobiliary cancer patients who receive chemoradiation therapy is significantly longer than that in patients who do not receive radiotherapy, which suggests that local cancer control significantly affects stent patency.