Effect of local treatment in patients with oligo-recurrence after surgery of distal bile duct cancer: A bi-institutional study

Background: Distal extrahepatic bile duct (EHBD) cancer is highly recurrent. More than 50% of patients suffer from disease relapse after curative resection. Some patients present with oligo-recurrence which could be a single loco-regional mass or lesions limited to a single solid organ. The aim of this study was to examine the effect of local control (surgical resection or radiofrequency ablation) on survival outcomes in patients with oligo-recurrent distal EHBD cancer. Methods: Data of 1219 patients who underwent surgery for distal EHBD cancer from 2000 to 2018 were retrospectively reviewed. Clinicopathological characteristics and survival outcomes of patients with recurrence were investigated. Post-recurrence survival (PRS) was analyzed according to modalities of re-treatment (local treatment or systemic therapy alone). Results: Among 654 patients with recurrence, 90 patients who had oligo-recurrence showed better recurrence-free and overall survival than patients with non-oligo-recurrent disease. Lymph node ratio and perineural invasion at initial pathology, timing of recurrence, and platelet-to-lymphocyte ratio at recurrence were independent risk factors for PRS in the oligo-recurrent group. Patients with local treatment for oligo-recurrence had better 3- and 5-year PRS than those with systemic treatment alone (38.3% vs. 14.1%, p = 0.04; 28.3% vs. 7.1%, p = 0.04, respectively). Recurrence within 24 months after initial surgery was the only significant factor for PRS in the local treatment group. Conclusion: In patients with oligo-recurrence after resection of distal EHBD cancer, post-recurrence local treatment could improve survival outcomes, particularly for those with recurrence more than 2 years after initial resection.