Low testing rates and high prevalence: Poly (ADP-ribose) polymerase inhibitor use in Middle East /homologous recombination deficiency-positive cancer patients.

BACKGROUND

Poly (ADP-ribose) polymerase inhibitors (PARPis) are approved as first-line therapies for breast cancer gene ()-positive, human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer. They are also effective for new and recurrent ovarian cancers that are - or homologous recombination deficiency (HRD)-positive. However, data on these mutations and PARPi use in the Middle East are limited.

AIM

To assess /HRD prevalence and PARPi use in patients in the Middle East with breast/ovarian cancer.

METHODS

This was a single-center retrospective study of 57 of 472 breast cancer patients tested for mutations, and 25 of 65 ovarian cancer patients tested for HRD. These adult patients participated in at least four visits to the oncology service at our center between August 2021 and May 2023. Data were summarized using descriptive statistics and compared using counts and percentages. Response to treatment was assessed using Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Among the 472 breast cancer patients, 12.1% underwent testing, and 38.5% of 65 ovarian cancer patients received HRD testing. Pathogenic mutations were found in 25.6% of the tested patients: 26.3% breast cancers had germline () mutations and 24.0% ovarian cancers showed HRD. Notably, 40.0% of -positive breast cancers and 66.0% of HRD-positive ovarian cancers were Middle Eastern and Asian patients, respectively. PARPi treatment was used in 5 (33.3%) -positive breast cancer patients as first-line therapy ( = 1; 7-months progression-free), for maintenance ( = 2; > 15-months progression-free), or at later stages due to compliance issues ( = 2). Four patients (66.6%) with HRD-positive ovarian cancer received PARPi and all remained progression-free.

CONCLUSION

Lower testing rates but higher mutations in breast cancer were found. Ethnicity reflected United Arab Emirates demographics, with breast cancer in Middle Eastern and ovarian cancer in Asian patients.