Purpose: To report the genotype and phenotype of a cohort of unselected uveal melanoma (UM) patients who had germline multi-gene panel genetic testing, including the BAP1 gene, from a large multi-ethnic cancer centre. We describe the central role of the medical genetics clinic in collaboration with oncologists in a mainstreaming model to facilitate genetic testing, counselling and streamlining of patients with hereditary cancer predisposition.
Methods: A retrospective chart review of clinical and genetic findings of unselected UM patients who had germline genetic testing between December 2019 and October 2021 was conducted. Extracted DNA from peripheral blood samples were analyzed with a multi-gene panel that included at least six genes associated with hereditary melanoma. The correlation between the genotype and the phenotype of the cohort was evaluated. Statistical analysis comprised descriptive and comparative statistics with significance assigned at p < .05. The genetics clinic streamlined patients among the relevant oncology clinics for cancer screening in germline BAP1 positive individuals.
Results: In unselected UM patients, 3.5% (4/114) tested positive for a BAP1 pathogenic variant. Germline BAP1 status was associated with a family history of mesothelioma (p = .0015) and metastatic disease (p = .017). There were no other significant associations between the patient- or tumour-related characteristics and germline BAP1 results.
Conclusion: A germline BAP1 mutation was detected in 3.5% of unselected UM patients. The oncologist-initiated and genetics-led mainstreaming model is a straightforward process and can be utilized for offering genetic testing to all UM patients.
Keywords: BAP1; Uveal melanoma; genetic counselling; hereditary cancer; mainstreaming; service delivery.