Is Duodenal Invasion a Relevant Prognosticator in Patients Undergoing Adjuvant Chemoradiotherapy for Distal Common Bile Duct Cancer?

Purpose: To analyze the outcome of adjuvant chemoradiotherapy for patients with distal common bile duct (CBD) cancer who underwent curative surgery, and to identify the prognostic factors for these patients. Methods and Materials: Between January 1991 and December 2002, 38 patients with adenocarcinoma of the distal CBD underwent curative resection followed by adjuvant chemoradiotherapy. There were 27 men and 11 women, and the median age was 60 years (range, 34-73). Adjuvant radiotherapy was delivered to the tumor bed and regional lymph nodes up to 40 Gy at 2 Gy/fraction with a 2-week planned rest. Intravenous 5-fluorouracil (500mg/m²/day) was given on day 1 to day 3 of each split course. The median follow-up period was 39 months. Results: The 5-year overall survival rate of all patients was 49.1%. On univariate analysis, only histologic differentiation (p = 0.0005) was associated with overall survival. Tumor size (≤2cm vs. >2cm) had a marginally significant impact on the treatment outcome (p = 0.0624). However, there was no difference in overall survival rates between T3 and T4 tumors (p = 0.6189), for which the main determinants were pancreatic and duodenal invasion, respectively. On multivariate analysis, histologic differentiation (p = 0.0092) and tumor size (p = 0.0046) were independent risk factors for overall survival. Conclusions: Long-term survival can be expected in patients with distal CBD cancer undergoing curative surgery and adjuvant chemoradiotherapy. Histologic differentiation and tumor size were significant prognostic factors predicting overall survival, whereas duodenal invasion was not. This finding suggests the need for further refinement in tumor staging.