Colorectal cancer in young patients: a retrospective cohort study in a single institution

Young onset colorectal cancer is on the rise, with a disproportionate increase in incidence among young people, both in Australia and internationally. Current national guidelines for bowel cancer screening in average risk individuals include only patients greater than 50 years of age. It is well recognized that colorectal cancer is a highly treatable malignancy when detected at an early stage, and timely diagnosis yields a greater than 90% chance of cure and survival. The aims of this study were to define the clinical presentations leading to colonoscopy in young patients and assess the incidence of malignancy in this group.

This is a retrospective cohort study including all patients ≤35 years of age without any baseline indication for early bowel cancer surveillance that underwent colonoscopy at Caboolture Hospital from January 2017 to April 2018.

A total of 224 patients underwent colonoscopy in the study period. A total of 210 (93.8%) had symptoms including rectal bleeding (51.7%), altered bowel habit (25.9%), abdominal pain (10.3%) and symptomatic anaemia (6.7%) prior to colonoscopy. Two cases of invasive adenocarcinoma were identified (0.89%, P < 0.01), both of which were symptomatic and were defined as stage IIIB disease on histopathology.

In a theoretically low-risk population, the incidence of malignancy was nearly 1%. More advanced disease at diagnosis may be due to a delay in investigating these patients due to an overall low suspicion of cancer in young individuals. As such, investigation should be offered early to young patients presenting with any warning symptoms.