Colorectal cancer in young African Americans: clinical characteristics and presentations

Colorectal cancer (CRC) is the third most common cancer in the USA, and the incidence in young adults has been increasing over the past decade. We studied the clinical characteristics and presentations of CRC in young African American (AA) adults because available data on how age and ethnicity influence its pattern of presentation is limited.

We conducted a retrospective study of 109 young adults (75 African Americans) below 50 years, who were diagnosed with CRC between 1 January 1997 and 31 December 2016. Proximal CRC was defined as lesions proximal to the splenic flexure. Independent t-tests and χ-test or Fisher's exact test were performed where appropriate to determine the differences between AA and non-AA patients.

The mean age at diagnosis was 42 years (range: 20-49 years). Compared with non-AAs, AAs had more frequent proximal CRC (38.7 vs. 14.7%, P=0.003), lower hemoglobin (10.5 vs. 12.7 g/dl, P<0.001), and more frequent weight loss (21.3 vs. 2.9% P=0.014). Non-AAs presented more frequently with rectal bleeding (52.9 vs. 32.0% P=0.037). There was no statistically significant difference in histology, stage, grade, tumor size, and carcinoembryonic antigen level between groups. When we stratified between proximal and distal disease among patients with CRC, we found larger tumor size in distal disease, which presented more with rectal bleeding and bowel habit changes. Proximal disease presented more as abdominal pain and weight loss.

There should be a higher index of suspicion for CRC in young AA adults presenting with anemia, abdominal pain, and weight loss. Early screening colonoscopy should be advocated in AAs because of the predominance of proximal disease.