Context: Lynch syndrome is an inherited cause of colorectal cancer caused by mutations of DNA mismatch repair (MMR) genes. A number of extracolonic tumors have been associated with the disorder, including pancreatic cancer; however, the risk of pancreatic cancer in Lynch syndrome is uncertain and not quantified.
Objective: To estimate pancreatic cancer risk in families with germline MMR gene mutations.
Design, setting, and patients: Cancer histories of probands and their relatives were evaluated in MMR gene mutation carriers in the familial cancer registries of the Dana-Farber Cancer Institute (n = 80), Boston, Massachusetts, and University of Michigan Comprehensive Cancer Center (n = 67), Ann Arbor, Michigan. Families enrolled before the study start date (June 2008) were eligible. Age-specific cumulative risks and hazard ratio estimates of pancreatic cancer risk were calculated and compared with the general population using modified segregation analysis, with correction for ascertainment.
Main outcome measures: Age-specific cumulative risks and hazard ratio estimates of pancreatic cancer risk.
Results: Data on 6342 individuals from 147 families with MMR gene mutations were analyzed. Thirty-one families (21.1%) reported at least 1 case of pancreatic cancer. Forty-seven pancreatic cancers were reported (21 men and 26 women), with no sex-related difference in age of diagnosis (51.5 vs 56.5 years for men and women, respectively). The cumulative risk of pancreatic cancer in these families with gene mutations was 1.31% (95% confidence interval [CI], 0.31%-2.32%) up to age 50 years and 3.68% (95% CI, 1.45%-5.88%) up to age 70 years, which represents an 8.6-fold increase (95% CI, 4.7-15.7) compared with the general population.
Conclusions: Among 147 families with germline MMR gene mutations, the risk of pancreatic cancer was increased compared with the US population. Individuals with MMR gene mutations and a family history of pancreatic cancer are appropriate to include in studies to further define the risk of premalignant and malignant pancreatic neoplasms and potential benefits and limitations of surveillance.