A prospective prostate cancer screening programme for men with pathogenic variants in mismatch repair genes (IMPACT): initial results from an international prospective study.

Funder: Victorian Cancer Agency ; Funder: NIHR Manchester Biomedical Research Centre ; Funder: Cancer Research UK ; Funder: Cancer Council Tasmania ; Funder: Instituto de Salud Carlos III ; Funder: Cancer Australia ; Funder: NIHR Oxford Biomedical Research Centre ; Funder: Fundación Científica de la Asociación Española Contra el Cáncer ; Funder: Cancer Council South Australia ; Funder: Swedish Cancer Society ; Funder: NIHR Cambridge Biomedical Research Centre ; Funder: Institut Català de la Salut ; Funder: Cancer Council Victoria ; Funder: Prostate Cancer Foundation of Australia ; Funder: National Institutes of Health ; BACKGROUND: Lynch syndrome is a rare familial cancer syndrome caused by pathogenic variants in the mismatch repair genes MLH1, MSH2, MSH6, or PMS2, that cause predisposition to various cancers, predominantly colorectal and endometrial cancer. Data are emerging that pathogenic variants in mismatch repair genes increase the risk of early-onset aggressive prostate cancer. The IMPACT study is prospectively assessing prostate-specific antigen (PSA) screening in men with germline mismatch repair pathogenic variants. Here, we report the usefulness of PSA screening, prostate cancer incidence, and tumour characteristics after the first screening round in men with and without these germline pathogenic variants. METHODS: The IMPACT study is an international, prospective study. Men aged 40-69 years without a previous prostate cancer diagnosis and with a known germline pathogenic variant in the MLH1, MSH2, or MSH6 gene, and age-matched male controls who tested negative for a familial pathogenic variant in these genes were recruited from 34 genetic and urology clinics in eight countries, and underwent a baseline PSA screening. Men who had a PSA level higher than 3·0 ng/mL were offered a transrectal, ultrasound-guided, prostate biopsy and a histopathological analysis was done. All participants are undergoing a minimum of 5 years' annual screening. The primary endpoint was to determine the incidence, stage, and ...