Oncological Outcome After Diagnostic Biopsies in Gastrointestinal Stromal Tumors: A Retrospective Cohort Study.

Objective: To analyze whether the route of preoperative biopsy influences oncological outcome in GIST patients.

Summary Of Background Data: Preoperative biopsies are widely used for diagnosing GIST. Little is known about the risk of tumor seeding after different routes of biopsy.

Methods: Patients who underwent resection of a primary GIST between 1996 and 2014 were identified from 2 databases from 2 tertiary referral centers. Survival data were obtained using the Kaplan-Meier method. Possible confounders were identified using Cox regression analysis. The primary endpoint was local recurrence free survival (RFS) and the secondary endpoint was DSS.

Results: A total of 228 patients were included, with a median age of 62 years (range 17-86) and a median follow-up time of 53 months (range 1-204). From these patients, 42 patients did not have a biopsy (18%), 70 underwent a transcutaneous biopsy (31%), and 116 a transluminal biopsy (51%). A total of 42 patients (19.0%) had a local and/or distant recurrence. From the 70 patients with a transcutaneous biopsy, only 1 patient developed a needle tract recurrence (1.4%). Local RFS and DSS were both significantly shorter in the transcutaneous biopsy group on univariate analysis compared to the other groups; however, in multivariate analysis the route of biopsy did not influence local RFS (P = 0.128) or DSS (P = 0.096).

Conclusions: Transluminal or transcutaneous biopsies for diagnosing GIST do not significantly alter the risk of local recurrent disease or DSS in multivariate Cox regressions. The risk of needle tract seeding after transcutaneous biopsy was low.