The repertoire of germline variants in patients with early-onset rectal cancer

The incidence of rectal cancer has increased in patients younger than age 50 during the last decade. The etiology and risk factors for young-onset rectal cancer remain unclear. Herein, we described the spectrum of germline variants in 71 young adults with rectal cancer. A hereditary cancer syndrome was confirmed in 13 patients, seven had pathogenic variants in MMR genes (Lynch Syndrome), two in APC, and two exhibited biallelic variants in the MUTYH gene. Clinical criteria for Lynch Syndrome was found in 21 patients, of which 13 carried variants in DNA repair genes. Patients harboring variants in any DNA repair gene presented unfavorable outcomes. The discovery of germline variants in young rectal cancer patients impacts diagnosis, clinical management, and treatment reinforcing that screening tests could be helpful to reverse the morbidity disease-associated.