Following Medical Services Advisory Committee support in March 2023, a new Medicare Benefits Schedule item for homologous recombination deficiency (HRD) testing in newly diagnosed, high-grade epithelial ovarian, fallopian tube or primary peritoneal cancer came into effect in January 2024, to guide Pharmaceutical Benefits Scheme-funded PARP inhibitor (PARPi) maintenance therapy after first-line platinum chemotherapy. Here we report on the first 2 years of NATA-accredited HRD testing at the Peter MacCallum Cancer Centre between January 2024 and November 2025. The SOPHiA Genetics HRD Solution assay was requested for 1756 tumours with results reported on 1377 (21.6% failed). The most common reason for sample failure was insufficient specimen or specimen purity (14.2%). Of reported samples, 1344 (97.6%) and 1353 (98.3%) underwent BRCA1/2 and Genomic Integrity Index (GII) testing, respectively. This showed that 528 tumours (38.3%) were GII-positive indicating HRD, of which 188 (35.6%) were BRCA1/2 -positive. Thus, combined GII + BRCA1/2 testing retrieves 180% more PARPi-eligible patients than BRCA1/2 testing alone. Among non- BRCA drivers, CCNE1 amplification was seen in 140 mostly HRD-negative cases. RAD51D , RAD51C and PALB2 were mutated in nine, four and four HRD tumours, respectively. BRIP1 was mutated in ten HRD-negative and seven HRD-positive tumours, suggesting a lack of association with genomic instability.
Boratav et al. (Sun,) studied this question.