Colorectal cancer (CRC) is the fourth most commonly diagnosed cancer among adults in the U.S. and the second leading cause of cancer-related deaths. Recent studies have shown an increased incidence of CRC in younger patients, leading to increasing interest in identifying patient populations who might be at increased risk of developing CRC for researchers.
The U.S. Multi-Society Task Force on Colorectal Cancer recommends that CRC screening should begin at age 50 in average-risk persons. However, recently the American Cancer Society (ACS) published its own recommendations to begin CRC screening at age 45 in the average-risk patient population. These recommendations were primarily based on modeling studies since there is little outcomes data in younger age groups in regards to prevention and detection of CRC.
Despite these new recommendations from the ACS, there is limited direct evidence to support CRC screening at a younger age. In our study, we have evaluated the predictors of increased prevalence of adenomas in the 40 to 49-year-old individuals undergoing colonoscopy.
The results of our study, presented at the recent annual meeting for the American Gastroenterology Society, show that in addition to family history of colorectal carcinoma, the patient’s age, male gender, body mass index, and chronic kidney disease are independent predictors of increased prevalence of adenomas in patients between 40 to 49 years of age. Our study suggests that rather than performing an early colonoscopy on everyone, a select group of individuals—obese males with chronic kidney disease—might benefit from early colonoscopic institution of colon cancer screening.
Colorectal carcinoma is usually developed through the “adenoma-carcinoma” pathway. This means that adenomatous polyps are precursors to carcinoma. Our study raises the question that increased incidence of colorectal carcinoma in younger patients is perhaps not related to the adenoma-carcinoma pathway. Therefore, identifying a higher-risk “select group” of individuals who might benefit from early colonoscopic screening in this younger population might be more cost effective and feasible strategy.
Despite these results, our study is a single center retrospective study and further large multi-center prospective studies are needed to validate these finding. In the meantime, we must not stop efforts to continue to improve colon cancer screening rates in average-risk patients at 50 years of age.
Dr. Mohammad Bilal, MD is an internist based in Texas.