Quality and safety of research biopsies in oncology clinical trials

The scientific benefits gained from studying research biopsies in oncology clinical trials depend on sample quality, and there are concerns that participant risks might outweigh any benefits. We conducted this study to determine the safety and quality of research biopsies conducted in the context of oncology clinical studies.

This is a retrospective cohort study of patients with solid cancers participating in oncology clinical trials at a single institution who underwent a biopsy procedure between January 2017 and December 2020. Complications were retrieved from medical records, and tumour content (TC) was extracted from pathology reports. Rates of complications, determinants of safety, and quality of research biopsies were investigated.

The study included 3104 research biopsy procedures from 1983 patients. Any grade complications occurred in 462(15%) procedures and major complications (≥G3) in 28(0.9%). A total of 6805 tissue samples (2.2 samples/procedure) were obtained. Median TC was 70% (95% CI:70-70) with 68% showing high-quality (>50% TC). In multivariate models, image-guided methods (ultrasound OR=2.48, 95% CI:1.88-3.27, P < 0.001, and computed tomography OR=1.56, 95% CI:1.07-2.29, P = 0.02) and collecting multiple samples per procedure (OR=1.71, 95% CI:1.43-2.05, P < 0.001) were determinants of high-quality biopsies. Biopsies of visceral organs (OR=9.09, 95% CI:3.23-31.3, P < 0.001) and collected after screening/baseline timepoints (OR=2.61, 95% CI:1.22-5.52, P = 0.014) increased the risk of major complications, while the use of ultrasound (OR=0.31, 95% CI:0.12-0.81, P = 0.01) was independently associated with a lower risk of procedure-related major adverse events.

By identifying factors that affect the safety and quality of research biopsies, our data may allow investigators to minimise participant risk and maximise biopsy quality for meaningful correlative science.