Exploratory Study on the Correlation Between HRD Score and PARPi Efficacy Based on Chinese Ovarian Cancer Patients

Although most advanced ovarian cancers achieve clinical remission after conventional initial treatment, the recurrence rate is still high in clinics. Poly ADP-ribose polymerase inhibitor (PARPi) is widely used in the maintenance treatment of ovarian cancer after chemotherapy to prolong the time to recurrence, and its main mechanism is to inhibit the repair of single-stranded DNA damage in tumour cells, which is synthetically lethal in the tumour cells with mutations in the BRCA1/2 gene. Numerous studies have shown that homologous recombination deficiency (HRD) exists in about 50% of epithelial ovarian cancer patients, and has been confirmed to be a predictor of ovarian cancer patients' response to PARPi therapy. However, up to now, there is still no uniform scoring and threshold standard for HRD detection in China. With the increasing attention of HRD detection in clinical diagnosis and treatment, acknowledged standards of HRD scoring algorithms and thresholds are essential. Using a retrospective. Thus, this observational and retrospective study intends to enroll 470 patients with epithelial ovarian, fallopian tube or primary peritoneal cancers who were treated with PARPi maintenance therapy in the hospital from 2018.01 to 2024.01. All patients included would be scored by the proprietary HRD ADx-GSS® algorithm with the detecting results of the three genomic statuses including heterozygous omission (LOH), telomere allelic imbalance (TAI), and large-segment translocation (LST). Finally, the correlation between the HRD scores and the prognosis of Chinese ovarian cancer patients and the efficacy of using PARPi as maintenance treatment would be explored.

Inclusion criteria

• Patients with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer initially diagnosed after January 2015 or platinum-sensitive recurrent patients diagnosed with advanced epithelial ovarian, fallopian tube, and primary peritoneal cancers, and are treated with PARPi maintenance therapy by January 2024 after chemotherapy or Platinum-sensitive recurrent patients diagnosed with advanced epithelial ovarian, fallopian tube, and primary peritoneal cancers, and are treated with PARPi maintenance therapy by January 2024 after chemotherapy;
• Age ≥ 18 years, female;
• Stable CA125 level, ECOG: 0-2 points, and appropriate cardiac, liver and renal function before using PARPi.

Exclusion criteria

• other malignancies combined within 5 years;
• poor underlying condition, one of the following: ECOG PS score >2, KPS score <60, cardiac insufficiency (Class III-IV), hepatic insufficiency (Child-Pugh Class C), renal insufficiency (Stage 4-5);
• patients whose sample residuals and quality do not support the need for testing;
• conditions that, in the judgement of the investigator, may affect the conduct of the clinical study and the determination of the study results.