Colorectal cancer under the age of 50 years in U.S. Department of Veterans Affairs: Is there a role of early screening?

Abstract

4072 Background: While the overall incidence of colorectal cancer (CRC) is decreasing, the rate has increased in population under 50, with higher stages at diagnosis and a greater proportion of African Americans (AA). Hence, there is an ongoing debate about the age of CRC screening. These trends have not been studied in the VA population. Methods: ICD-10 codes C18-C20 were used to identify the cases of colon and rectal cancer in National VA Cancer Cube Registry. 43,544 cases of colon cancer, 1,278 below and 42,254 above age 50, and 19,815 cases of rectal cancer, 862 below and 18,948 above age 50 were identified between 2003-17. Younger age group was defined as patients less than 50 years old. IRB approval was obtained. Results: Our data comprised > 97% of male patients. In younger group, in the 5 year periods, 2003-07, 2008-12 and 2013-17, colon cancer rate increased from 2.59% to 2.79% to 3.59%, while for rectal cancer it increased from 3.5% to 4.3% to 5.3% (p < .0001). Blacks comprise 31.6% cases of colon cancer and 27.15% cases of rectal cancer in under 50 group, compared to 18.5% and 15.9% of cases in above 50 group respectively (p < .0001). For under 50 group, 48.6% cases of colon and 42.2% cases of rectal cancer were diagnosed in stage III or IV compared to 35.7% and 34.05% cases in above 50 group respectively (p < .0001). For colon cancer, 51.87% of patients in the younger group have a < 5 year survival, worse compared to 45.05% in 50-60 group (p < .0001) and similar to 49.3% in 60-70 group (p = .08). For rectal cancer, 5 year survival showed no difference between these groups. Stage specific survival shows no difference for either colon or rectal cancer across < 50, 50-60 and 60-70 age groups. Conclusions: Rate of CRC is rising in < 50 age group with more advanced stage at diagnosis and higher proportion of African Americans. For colon cancer, < 50 group has a worse 5 year survival as compared to 50-60 age group likely due to increased proportion of patients in stage III or IV, as there is no difference in stage specific survival. For rectal cancer, the 5 year survival or stage specific survival shows no difference in < 50, 50-60 and 60-70 groups. These results add to our understanding of the trends of CRC and should be accounted for in the screening guidelines.