Pancreatic Ductal Carcinoma Risk Associated With Hereditary Cancer-Risk Genes.

BACKGROUND: Although several hereditary cancer predisposition genes have been implicated in pancreatic ductal adenocarcinoma (PDAC) susceptibility, gene-specific risks are not well defined and are potentially biased because of the design of previous studies. More precise and unbiased risk estimates can result in screening and prevention better tailored to genetic findings. METHODS: This is a retrospective analysis of 676 667 individuals, 2445 of whom had a personal diagnosis of PDAC, who received multigene panel testing between 2013 and 2020 from a single laboratory. Clinical data were obtained from test requisition forms. Multivariable logistic regression models determined the increased risk of PDAC because of pathogenic variants (PVs) in various genes as adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Multivariable odds ratios were adjusted for age, personal and/or family cancer history, and ancestry. RESULTS: Overall, 11.1% of patients with PDAC had a PV. Statistically significantly elevated PDAC risk (2-sided P < .05) was observed for CDK2NA (p16INK4a) (OR = 8.69, 95% CI = 4.69 to 16.12), ATM (OR = 3.44, 95% CI = 2.58 to 4.60), MSH2 (OR = 3.17, 95% CI = 1.70 to 5.91), PALB2 (OR = 3.09, 95% CI = 2.02 to 4.74), BRCA2 (OR = 2.55, 95% CI = 1.99 to 3.27), and BRCA1 (OR = 1.62, 95% CI = 1.07 to 2.43). CONCLUSIONS: This study provides PDAC risk estimates for 6 genes commonly included in multigene panel testing for hereditary cancer risk. These estimates are lower than those from previous studies, possibly because of adjustment for family history, and support current recommendations for germline testing in all PDAC patients, regardless of a personal or family history of cancer.

Targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers: results from the initial screening round of the IMPACT study.

BACKGROUND: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls) is an international consortium of 62 centres in 20 countries evaluating the use of targeted PCa screening in men with BRCA1/2 mutations. OBJECTIVE: To report the first year's screening results for all men at enrollment in the study. DESIGN, SETTING AND PARTICIPANTS: We recruited men aged 40-69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrollment, and those men with PSA >3 ng/ml were offered prostate biopsy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types. RESULTS AND LIMITATIONS: We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%-double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups. CONCLUSIONS: The IMPACT screening network will be useful for targeted PCa screening studies in men with germline genetic risk variants as they are discovered. These preliminary results support the use of targeted PSA screening based on BRCA genotype and show that this screening yields a high proportion of aggressive disease. PATIENT SUMMARY: In this report, we demonstrate that germline genetic markers can be used to identify men at higher risk of prostate cancer. Targeting screening at these men resulted in the identification of tumours that were more likely to require treatment.

Familial prostate cancer: the damage done and lessons learnt.

BACKGROUND: A 51-year-old French Canadian man presented to his family physician owing to an extensive family history of prostate cancer in five brothers, his father and two paternal uncles. His serum PSA level was 4.9 ng/ml and a six-core biopsy revealed the presence of a prostate adenocarcinoma with a Gleason score of 7 (3+4). He was treated with radical prostatectomy. Repeat PSA tests revealed a gradual rise in PSA levels despite androgen deprivation therapy with bicalutamide and goserelin over the course of 3 years. Genetic evaluation was undertaken in view of his personal and family history. The proband died at the age of 58 years of widespread metastasis. INVESTIGATIONS: PSA testing, six-core biopsy, genetic counselling and mutation analysis for French Canadian founder mutations in the BRCA1 and BRCA2 genes, histopathological review of tumour tissue from family members, examination of loss of heterozygosity at the BRCA2 gene locus, immunohistochemistry to determine the expression of the ERG nuclear oncoprotein in prostate tumours, genotyping with eight selected risk-associated single nucleotide polymorphisms, Doppler ultrasonography of the leg, CT of the abdomen and pelvis with intravenous and oral contrast, chest CT with intravenous contrast for the assessment of metastatic prostate cancer, genetic testing for the G84E variant in the HOXB13 gene. DIAGNOSIS: Early-onset and aggressive prostate cancer associated with a nonsense French Canadian BRCA2 founder mutation, c.5857G>T (p.Glu1953(*)). MANAGEMENT: Radical prostatectomy, hormone therapy with bicalutamide and goserelin, palliative chemotherapy initially with docetaxel plus prednisone then with mitoxantrone plus prednisone, as well as genetic counselling and testing for the proband and his family members.