A pilot study investigating feasibility of mainstreaming germline BRCA1 and BRCA2 testing in high-risk patients with breast and/or ovarian cancer in three tertiary Cancer Centres in Ireland

Abstract

In the Republic of Ireland (ROI), BRCA1/BRCA2 genetic testing has been traditionally undertaken in eligible individuals, after pre-test counselling by a Clinical Geneticist/Genetic Counsellor. Clinical Genetics services in ROI are poorly resourced, with routine waiting times for appointments at the time of this pilot often extending beyond a year. The consequent prolonged waiting times are unacceptable where therapeutic decision-making depends on the patient's BRCA status. "Mainstreaming" BRCA1/BRCA2 testing through routine oncology/surgical clinics has been implemented successfully in other centres in the UK and internationally. We aimed to pilot this pathway in three Irish tertiary centres. A service evaluation project was undertaken over a 6-month period between January and July 2017. Eligible patients, fulfilling pathology and age-based inclusion criteria defined by TGL clinical, were identified, and offered constitutional BRCA1/BRCA2 testing after pre-test counselling by treating clinicians. Tests were undertaken by TGL Clinical. Results were returned to clinicians by secure email. Onward referrals of patients with uncertain/pathogenic results, or suspicious family histories, to Clinical Genetics were made by the treating team. Surveys assessing patient and clinician satisfaction were sent to participating clinicians and a sample of participating patients. Data was collected with respect to diagnostic yield, turnaround time, onward referral rates, and patient and clinician feedback. A total of 101 patients underwent diagnostic germline BRCA1/BRCA2 tests through this pathway. Pathogenic variants were identified in 12 patients (12%). All patients in whom variants were identified were appropriately referred to Clinical Genetics. At least 12 additional patients with uninformative BRCA1/BRCA2 tests were also referred for formal assessment by Clinical Geneticist or Genetic Counsellor. Issues were noted in terms of time pressures and communication of results to patients. Results from a representative sample of participants completing the satisfaction survey indicated that the pathway was acceptable to patients and clinicians. Mainstreaming of constitutional BRCA1/BRCA2 testing guided by age- and pathology-based criteria is potentially feasible for patients with breast cancer as well as patients with ovarian cancer in Ireland.

Keywords: BRCA1; BRCA2; Breast cancer; Cancer genetics; Cancer genomics; Hereditary Breast and Ovarian cancer; King syndrome; Mainstreaming; Oncogenetics; Ovarian cancer.