input: The following are multiple choice questions (with answers) about medical knowledge.   The incidence of colorectal cancer in young patients is increasing. It remains unclear if the disease has unique features in this age group. This was a single-center, retrospective cohort study which included patients diagnosed with colorectal cancer at age ≤40 years in 1997-2013 matched 1:2 by year of diagnosis with consecutive colorectal cancer patients diagnosed at age>50 years during the same period. Patients aged 41-50 years were not included in the study, to accentuate potential age-related differences. Clinicopathological characteristics, treatment, and outcome were compared between groups. The cohort included 330 patients, followed for a median time of 65.9 months (range 4.7-211). Several significant differences were noted. The younger group had a different ethnic composition. They had higher rates of family history of colorectal cancer (p = 0.003), hereditary colorectal cancer syndromes (p < 0.0001), and inflammatory bowel disease (p = 0.007), and a lower rate of polyps (p < 0.0001). They were more likely to present with stage III or IV disease (p = 0.001), angiolymphatic invasion, signet cell ring adenocarcinoma, and rectal tumors (p = 0.02). Younger patients more frequently received treatment. Young patients had a worse estimated 5-year disease-free survival rate (57.6  vs. 70 %, p = 0.039), but this did not retain significance when analyzed by stage (p = 0.092). Estimated 5-year overall survival rates were 59.1 and 62.1 % in the younger and the control group, respectively (p = 0.565).   **Question:** Colorectal cancer in young patients: is it a distinct clinical entity?   (A) Yes   (B) No   (C) Maybe
output: ['(A) Yes <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Yes  (B) No  (C) Maybe <> possible answers', 'The incidence of colorectal cancer in young patients is increasing. It remains unclear if the disease has unique features in this age group. This was a single-center, retrospective cohort study which included patients diagnosed with colorectal cancer at age ≤40\xa0years in 1997-2013 matched 1:2 by year of diagnosis with consecutive colorectal cancer patients diagnosed at age>50\xa0years during the same period. Patients aged 41-50\xa0years were not included in the study, to accentuate potential age-related differences. Clinicopathological characteristics, treatment, and outcome were compared between groups. The cohort included 330 patients, followed for a median time of 65.9\xa0months (range 4.7-211). Several significant differences were noted. The younger group had a different ethnic composition. They had higher rates of family history of colorectal cancer (p\xa0=\xa00.003), hereditary colorectal cancer syndromes (p\xa0<\xa00.0001), and inflammatory bowel disease (p\xa0=\xa00.007), and a lower rate of polyps (p\xa0<\xa00.0001). They were more likely to present with stage III or IV disease (p\xa0=\xa00.001), angiolymphatic invasion, signet cell ring adenocarcinoma, and rectal tumors (p\xa0=\xa00.02). Younger patients more frequently received treatment. Young patients had a worse estimated 5-year disease-free survival rate (57.6\xa0 vs. 70\xa0%, p\xa0=\xa00.039), but this did not retain significance when analyzed by stage (p\xa0=\xa00.092). Estimated 5-year overall survival rates were 59.1 and 62.1\xa0% in the younger and the control group, respectively (p\xa0=\xa00.565). \n   Colorectal cancer in young patients: is it a distinct clinical entity? <> context']