Safety and utility of image-guided research\ud biopsies in relapsed high-grade serous\ud ovarian carcinoma—experience of the\ud BriTROC consortium

Background: Investigating tumour evolution and acquired chemotherapy resistance requires analysis of sequential tumour\ud material. We describe the feasibility of obtaining research biopsies in women with relapsed ovarian high-grade serous carcinoma\ud (HGSC).\ud Methods: Women with relapsed ovarian HGSC underwent either image-guided biopsy or intra-operative biopsy during\ud secondary debulking, and samples were fixed in methanol-based fixative. Tagged-amplicon sequencing was performed on biopsy\ud DNA.\ud Results: We screened 519 patients in order to enrol 220. Two hundred and two patients underwent successful biopsy, 118 of which\ud were image-guided. There were 22 study-related adverse events (AE) in the image-guided biopsies, all grades 1 and 2; pain was\ud the commonest AE. There were pre-specified significant AE in 3/118 biopsies (2.5%). 87% biopsies were fit-for-purpose for\ud genomic analyses. Median DNA yield was 2.87 mg, and was higher in biopsies utilising 14 G or 16 G needles compared to 18 G.\ud TP53 mutations were identified in 94.4% patients.\ud Conclusions: Obtaining tumour biopsies for research in relapsed HGSC is safe and feasible. Adverse events are rare. The large\ud majority of biopsies yield sufficient DNA for genomic analyses—we recommend use of larger gauge needles and methanol\ud fixation for such biopsies, as DNA yields are higher but with no increase in AEs.