Lynch syndrome
LS is the most common cause of hereditary nonpolyposis CRC. The second most frequent type of cancer among LS patients is endometrial cancer in women, followed by ovarian and urinary tract cancers.
LS is caused by pathogenic germline mutations in DNA mismatch repair genes known as "mismatch repair" or MMR genes. Depending on which gene is mutated, there is an increased risk for a specific type of cancer. For example, mutations in MLH1 and MSH2 increase the predisposition to nonpolyposis colorectal cancer, whereas the incidence of colorectal cancer in carriers of PMS2 variants is lower and the disease is usually less severe.
Symptoms
Lynch syndrome increases predisposition to CRC and other tumors such as ovarian, stomach, small intestine, urinary tract, biliary tract, brain, sebaceous skin tumors, pancreas and prostate. Not all people carrying Lynch syndrome-related mutations develop cancer, although they are at increased risk, which usually increases with age and may be influenced by other factors.
Disease management
Periodic colonoscopies, approximately every 1-2 years, are usually recommended in individuals diagnosed with LS.
Hysterectomy and prophylactic salpingo-oophorectomy, in women affected by the syndrome, can sometimes be used to prevent endometrial and ovarian cancer. Individualized counseling should be provided on the need for surgery, the risk involved, and the optimal timing of surgery.
There are several pharmacological treatments that can be used to try to reduce the risk of CRC and other LS-related tumors such as high-dose aspirin and estrogen therapy. Additionally, supplementation with vitamin complexes may be recommended.
Risk factors that may influence the development of CRC and other neoplasms should also be controlled, such as reducing overweight, avoiding smoking, minimizing or eliminating alcohol consumption, preventing type 2 diabetes, and controlling cholesterol and triglyceride levels.
Genes analyzed
Bibliography
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