Feasibility, safety, and adequacy of research biopsies for cancer clinical trials at an academic medical center

Abstract

Objective: Research biopsies are an essential component of cancer clinical trials for studying drug efficacy and identifying biomarkers. Site-level clinical investigators, however, do not have access to results on the adequacy of research biopsies for histological or molecular assays, because samples are sent to central labs and the test results are seldom reported back to site-level investigators unless requested. We evaluated the feasibility, safety, and adequacy of research biopsies performed at an academic medical center.

Materials and methods: We retrospectively reviewed the data on 122 research biopsy sessions conducted in 99 patients via percutaneous core needle biopsy for 39 clinical trials from January 2017 to February 2018 at a single institute. We asked the sponsors of each clinical trial for the adequacy of the biopsy samples for histological or molecular assays.

Results: The biopsy success rate was 93.4% (113/122), with nine samples categorized as inadequate for obtaining pathologic diagnosis. Post-biopsy complications occurred in 9.8% (12/122) of biopsies, all of which were mild and completely recovered by the day after the biopsy. The sponsors of clinical trials provided feedbacks on the adequacy of 76 biopsy samples, and noted that a total of 8 biopsy samples from 7 patients were inadequate for analysis, resulting in an adequacy rate of 89.5% (68/76): the reasons for inadequacy were insufficient tumor content for immunohistochemistry (n = 3) and low RNA yield for sequencing (n = 5).

Conclusion: Research biopsies performed at an experienced, multidisciplinary center had acceptable safety for patients as well as practicality in terms of obtaining adequate tissue samples for molecular studies.

Fig 1. Patient flow diagram.

Footnote: *The pre-screening failure cases were samples obtained from patients who met the eligibility criteria, signed an informed consent, underwent biopsy, but failed to start the study treatments.