Empfehlungen zur Früherkennung, Risikoreduktion, Überwachung und Therapie bei Patienten mit Lynch-Syndrom

Introduction Lynch syndrome (LS) is the most common hereditary colorectal cancer syndrome and accounts for ∼3% of all CRCs. This autosomal dominant disorder is caused by germline mutations in DNA mismatch repair genes (MLH1, MSH2, MSH6, PMS2, and EPCAM). One in 300 individuals of the general population are considered to be mutation carriers (300000 individuals/Germany). Mutation carriers are at a high CRC risk of 15-46% till the age of 75 years. LS also includes a variety of extracolonic malignancies such as endometrial, small bowel, gastric, urothelial, and other cancers. Methods The German Consortium for Familial Intestinal Cancer consists of 14 university centers in Germany. The aim of the consortium is to develop and evaluate surveillance programs and to further translate the results in clinical care. We have revisited and updated the clinical management guidelines for LS patients in Germany. Results A surveillance colonoscopy should be performed every 12-24 months starting at the age of 25 years. At diagnosis of first colorectal cancer, an oncological resection is advised, an extended resection (colectomy with ileorectal anastomosis) has to be discussed with the patient. The lifetime risk for gastric cancer is 0.2-13%. Gastric cancers detected during surveillance have a lower tumor stage compared to symptom-driven detection. The lifetime risk for small bowel cancer is 4-8%. About half of small bowel cancer is located in the duodenum and occurs before the age of 35 years in 10% of all cases. Accordingly, patients are advised to undergo an esophagogastroduodenoscopy every 12-36 months starting by the age of 25 years. Conclusion LS colonic and extracolonic clinical management, surveillance and therapy are complex and several aspects remain unclear. In the future, surveillance and clinical management need to be more tailored to gene and gender. Future prospective trials are needed.