Frequent mismatch-repair defects link prostate cancer to Lynch syndrome | BMC Urology | Full Text

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 Background

Lynch syndrome is a multi-tumor syndrome with the highest risks for colorectal cancer and endometrial cancer though a number of other tumor types, e.g. cancer of the urinary tract, the small bowel and the ventricle, ovarian cancer, brain tumors and skin tumors develop at increased incidence [1, 2]. Other tumor types assumed to represent sporadic tumors in families with hereditary cancer, e.g. breast cancer, pancreatic cancer and sarcoma may indeed develop as part of the syndrome. This is suggested based on identification of mismatch repair (MMR) defective tumors of these subtypes and demonstration of an increased risk of these tumor types in mutation carriers [3–10].

Prostate cancer is the most common tumor type in men in the Western world with an estimated lifetime risk of 18 % and a median age at diagnosis of 67 years [1]. Worldwide, prostate cancer is the sixth common tumor with more than 250,000 deaths annually [11]. In Denmark, prostate cancer constitutes 23 % of all male cancers with an estimated risk of 10 % for disease development before age 75 [12]. The role of prostate cancer in Lynch syndrome is unresolved though molecular investigations and epidemiologic studies have suggested a potential link to the syndrome [1, 8, 13]. The MMR system has been suggested to influence prostate carcinogenesis e.g. through an increased risk of prostate cancer linked to single nucleotide polymorphisms in MLH1 and MSH3, and a role for complex structural rearrangements in MSH2 and MSH6 as a mechanism underlying the hypermutation in aggressive prostate cancer [14–20]. We assessed the role of prostate cancer in the Danish Lynch syndrome cohort with characterization of MMR status and risk estimates.....

 Conclusions

The Danish Lynch syndrome cohort contains 28 prostate cancers that developed at a median age of 63 years, showed high Gleason scores and frequent TILs. The tumors were predominantly linked to MSH2 mutations. Frequent MMR defects consistent with the underlying germline defects suggest that prostate cancer is included in Lynch syndrome tumor spectrum and should be considered during genetic counseling.