Association between biopsy method and development of peritoneal metastases in perihilar cholangiocarcinoma

Abstract

Presenter: Crisanta Ilagan MD | National Institutes of Health Background: In patients with perihilar cholangiocarcinoma (PHC), there is concern that transperitoneal (TP) biopsy may seed tumor in the peritoneal cavity, leading to an increased risk of peritoneal metastases (PM), however, definitive studies are lacking. We aimed to identify any association between biopsy type and development of PM in a cohort of resected patients. Methods: A retrospective review of patients undergoing surgery for PHC (1991- 2014) was performed. The clinicopathologic characteristics and incidence of PM in patients who did and did not undergo TP biopsy were compared. Cumulative incidence of PM was estimated using competing risks methods and compared between subgroups using Gray’s test. Results: Among 262 patients who underwent surgery, 37 had undergone prior TP biopsy, and 225 had undergone intraluminal biopsy or had not undergone biopsy. No differences in demographic or clinicopathologic characteristics were noted between groups. The incidence of PM found at surgery was not significantly different between TP and non-TP patients (5.4% v 7.6%, p>0.9). Among the 243 patients who did not have PM at surgery, the cumulative incidence of PM between TP and non-TP at one year (11.4%, 95%CI 3.5-24.4 v. 10.8% 95%CI 7.0-15.5) and two years (20.3%, 95%CI 8.7-35.2 v. 20.1%, 95%CI 14.9-25.9) was not different (p = 0.7; Figure 1). Cumulative incidence of PM did not differ between patients with positive and negative TP biopsies, positive and negative intraluminal biopsies, and no biopsy performed (p = 0.4). Conclusion: PM occurs at a significant rate in patients with PHC. TP biopsy is not associated with a higher incidence of PM at surgery or cumulative incidence of PM at one or two years after surgery. The risk of peritoneal seeding from TP biopsies may not be as high as case studies suggest, and patients who undergo TP biopsies should be considered candidates for the same treatment modalities as those who do not.