High risk of recurrence after CR gives the reasonable weight to adjuvant therapy for DBDC. However, when LN metastasis absent, the role of adjuvant chemotherapy after surgery is still controversial. Thus, we aimed to analyze risk factors for recurrence of DBDC without LN metastasis after CR and identify high-risk groups, which would be the candidates for adjuvant chemotherapy. We retrospectively analyzed the clinicopathologic data of the patients who underwent surgical resection for lymph node (LN)-negative distal bile duct cancer (DBDC) at Yonsei University Severance hospital from January 2010 to June 2019. In a total of 393 patients who underwent curative resection (CR) for DBDC, 62.8% (247 cases) were pathologically confirmed to be free from LN metastasis. During the follow-up, recurrence in surgical bed (local recurrence) and/or distant metastasis was reported in 115 cases (46.6%). The mean recurrence-free survival was 594.59 days. In terms of recurrence pattern, local recurrence was 46, distant metastasis was 54 and recurrence both in local and distant sites was 15 cases. In terms of the factors for recurrence, R1 resection, presence of lymphovascular invasion (LVI), and perineural invasion (PNI), and advanced T stage based on AJCC 7th edition were statistically meaningful. The Cox proportional hazards model showed LVI (OR 2.250, 95% CI 1.400-3.617, p=0.001) or PNI (1.977, 95% CI 1.153-3.389, p=0.013) were associated with recurrence after CR in LN-negative DBDC. Overall risk of recurrence after CR in LN-negative DBDC was high enough to give attention. Especially, the risk of recurrence was significantly increased in conditions of the presence of LVI or PNI. Based on the above, adjuvant treatment for LN-negative DBDC should be considered. And more studies are warranted to find the effective therapy in adjuvant setting.
