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Screening colonoscopies have reduced the overall colorectal cancer (CRC) incidence rates over the past few decades. However, reverse trends have been noted in those younger than age 50 (early-onset CRC; EO-CRC) -- possibly related to changes in behavioral factors over time.

In a comprehensive review in this year's , Rebecca Siegel and co-authors provided a compelling argument for changing the age of screening for CRC to 45. They noted that the changing epidemiological trends suggest increased rates of EO-CRC for left-sided tumors among non-Hispanic whites and for advanced stages.

Emerging data suggest that EO-CRC may be a distinct molecular entity with upregulation of certain pathways and higher incidence of microsatellite instability. While managing these patients, due attention must be paid to the unique challenges they face including those related to fertility, sexuality, survivorship, and financial toxicities.

Given the higher morbidity and mortality associated with EO-CRC, the authors supported, with a plethora of data, the change in the American Cancer Society's recommendation to lower the age for screening colonoscopy in the average-risk population from 50 to 45. Those at higher risk such as those with family history or Lynch syndrome should continue to have colonoscopies at an earlier age per established guidelines. Siegel et al. further appropriately recommended periodic revision of such screening guidelines based on continued epidemiological trends.

N. Arvind Dasari, MD, is associate professor in the Department of Gastrointestinal Medical Oncology at the University of Texas MD Anderson Cancer Center in Houston.

Read the study abstract here and an interview about it here.