The ratio between metastatic and examined lymph nodes is an independent prognostic factor for patients with resectable middle and distal bile duct carcinoma

Abstract Background The lymph node ratio, defined as the ratio between the number of lymph node metastasis and the total number of lymph nodes examined, has been reported to be an important prognostic factor in other gastrointestinal carcinomas except middle and distal bile duct carcinomas. Methods Between 1991 and 2004, 62 consecutive patients who underwent surgery for middle and distal bile duct carcinoma were retrospectively analyzed concerning prognostic factors. Results The median number of lymph nodes examined was 12 (range 5 to 38). The overall 5-year survival rates of patients with lymph node ratio of 0, lymph node ratio of 0 to .2, and lymph node ratio >.2 were 62%, 41%, and 0%, respectively. A multivariate analysis revealed that a lymph node ratio >.2 and perineural invasion were independent predictive factors for survival. Conclusions Lymph node ratio >.2 is an important factor to predict survival after resected middle and distal bile duct carcinoma.