Abstract 808: Analysis of 1151 prospective research biopsies: Factors influencing tumor yield across patients and biopsy cores

• Published in: Cancer research (Chicago, Ill.) Ill.), 2020-08, Vol.80 (16_Supplement), p.808-808
• Main Authors: Bhamidipati, Deepak, Verma, Anuj, Maru, Dipen M., Sui, Dawen, Mathew, Grace, Lang, Wenhua, Posadas, Juan F., Hein, Joshua P., Kopetz, Scott, Futreal, Andrew, Wistuba, Ignacio I., Lee, J. Jack, Overman, Michael J., Tam, Alda L.
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2020-808

Background: While important for the initial diagnosis and treatment of malignancies, biopsies have an increasing role in clinical trials for correlative science to improve the molecular understanding of cancer. However, research biopsy specimens can be insufficient for analysis and their scientific impact on drug development and treatment has been questioned. The purpose of our study was to identify which inter- and intrapatient factors predict research biopsy tissue quantity and adequacy. Methods: Biopsies were obtained from patients enrolled in clinical trials across multiple cancer histologies as part of the Adaptive Patient-Oriented Longitudinal Learning and Optimization (APOLLO) program at MD Anderson Cancer Center. For each trial, enrolled patients typically underwent a pre-treatment biopsy, with 60% undergoing on/post treatment biopsies. Biopsy cores were either paraffin embedded or flash frozen and sent for pathology review to determine tumor area (core length times core width multiplied by proportion of core area occupied by tumor cells) as well as percentage of tumor contained in the core (fraction of core containing cellular components of tumor, including malignant and peri-tumor non-malignant cells, reported as a percentage). Results: A total of 1151 research biopsies were performed on 661 patients from which 5126 cores were evaluated (median 5 cores per biopsy). 5 or more cores were sent for pathology review in 753 biopsies (65.4%) with 4 sent in 232 cases (20.2%). Tumor area decreased across increasing core position (p