Medical Research: What is the background for this study? What are the main findings?
Dr. Zell: Colorectal cancer incidence (CRC) has been declining in the U.S. since 1975, due largely to screening for premalignant polyps. Screening in the U.S. begins at age 50 for average risk individuals, and so the vast majority of Young Adults in the U.S. (defined as age 20-39 in our study) are unscreened. Recently, several studies have reported an increased risk of colorectal cancer among U.S. individuals under age 50. In our analysis of 231,544 CRC cases in California over a 22 year period, we identified 5617 cases among Young Adults (age 20-39). As expected, the overall risk of colorectal cancer in Young Adults is low. However, colorectal cancer is increasing among Young Adults as observed in this population-based study, and certain groups remain at particularly high risk. For example, Hispanic Females age 20-29 were observed to have nearly a 16% increase in colorectal cancer risk when comparing the Biannual Percent Change over the course of the study period. Also concerning was the observation that Young Adults were more likely to be diagnosed with colorectal cancer at an advanced stage than adults in the “screened population” (ie, those age 50 and over).
Medical Research: What should clinicians and patients take away from your report?
Dr. Zell: While the overall risk of colorectal cancer among Young Adults in the U.S. remains low, the risk is increasing- which is in direct contrast to what is seen in the “screened population” (ie, those age 50 and over). Physicians and patients need to be aware of this trend, and recognize the changing epidemiology of the disease.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Zell: Further research is needed to determine how patients with young-onset colorectal cancer differ from young people without colorectal cancer.