In this study, the investigators compared and evaluated the clinicopathological and oncological characteristics of sporadic colorectal cancer (CRC) in young adults without genetic mutations associated with hereditary CRC syndrome and sporadic CRC in elderly individuals.

The ambiguity in the findings among several previous studies might be because of the difference in the age of the study population, yCRC and eCRC. The family history of CRC and cancer due to Crohn's disease or ulcerative colitis were also not excluded in such previous studies. Most importantly, those studies did not rule out the risk of hereditary cancer through the genetic testing in yCRC. Since hereditary CRC accounts for approximately 34% of those under the age of 35 years, it is necessary to exclude it to accurately compare the clinicopathological characteristics of sporadic cancer developed in yCRC and eCRC.

Inclusion Criteria:

• Histologically confirmed cases of adenocarcinoma in the colon and rectum
• The age at the time of diagnosis should be ≤ 40 years (for yCRC) or ≥ 70 years (for eCRC)
• Genetic testing confirmation of non-hereditary cancer.

Exclusion Criteria:

• Inflammatory bowel disease
• A family history of CRC
• A history of other cancers
• Underwent any emergency operation or palliative surgery
• The Amsterdam criteria with mutations in genes associated with APC, MLH1, MSH2, MSH6

Three tertiary referral hospitals between January 2010 to December 2017