Adjuvant concurrent chemoradiotherapy with low-dose daily cisplatin for extrahepatic bile duct cancer

Purpose We aimed to present the clinical outcomes of adjuvant concurrent chemoradiotherapy (CCRT) with low-dose daily cisplatin regimen compared to the conventional 5-fluorouracil (5-FU)-based regimen for extrahepatic bile duct cancer (EHBDC). Methods From October 1994 to April 2013, 41 patients received adjuvant CCRT with low-dose daily regimen or 5-FU-based regimens. Nineteen patients received low-dose of cisplatin just before every delivery of radiation therapy, and 21 patients received two cycles of 5-FU-based regimen during radiotherapy. We compared the clinical outcomes between two adjuvant CCRT regimens. Results Adjuvant CCRT with low-dose daily cisplatin showed comparable toxicity profiles compared with that of a 5-FU-based regimen. The median follow-up time was 33 months (range, 5-205), and the 5-year overall survival (OS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) were 34.2, 50.8, and 49.7%, respectively. Univariable analyses showed no significant differences in OS, LRRFS, and DMFS between the groups with two regimens. In multivariable analyses, chemotherapeutic regimen was a significant prognostic factor for OS, favoring the low-dose daily cisplatin regimen (HR = 2.491, p = 0.036) over 5-FU-based regimen, though not for LRRFS (p = 0.642) and DMFS (p = 0.756). Conclusions Adjuvant CCRT with low-dose daily cisplatin regimen showed acceptable toxicities and survivals compared to those of the 5-FU-based regimen. Low-dose daily cisplatin can be one of the feasible regimens for adjuvant CCRT for EHBDC.