Late-Stage Incidence Rates Support CRC Screening From Age 45

Findings From 2000 to 2020

During 2000-2020 period, 26,887 CRCs were diagnosed in adults aged 46-49 years (54.5% in men).

As of 2020, the localized adenocarcinoma IR decreased to 7.7 of 100,000, but regional adenocarcinoma IR increased to 13.4 of 100,000 and distant adenocarcinoma IR increased to 9.0 of 100,000.

Regional adenocarcinoma IR remained the highest of all stages in 2000-2020. From 2014 to 2020, distant IRs became similar to localized IRs, except in 2017 when distant IRs were significantly higher than localized.
 

Why the CRC Uptick?

“It remains an enigma at this time as to why we’re seeing this shift,” Dr. Montminy said, noting that etiologies from the colonic microbiome to cellphones have been postulated. “To date, no theory has substantially provided causality. But whatever the source is, it is affecting Western countries in unison with data demonstrating a birth cohort effect as well,” he added. “We additionally know, based on the current epidemiologic data, that current screening practices are failing, and a unified discussion must occur in order to prevent young patients from developing advanced colon cancer.”

Offering his perspective on the findings, Joshua Meyer, MD, vice chair of translational research in the Department of Radiation Oncology at Fox Chase Cancer Center in Philadelphia, said the findings reinforce the practice of offering screening to average-risk individuals starting at age 45 years, the threshold at his institution. “There are previously published data demonstrating an increase in advanced stage at the time of screening initiation, and these data support that,” said Dr. Meyer, who was not involved in the present analysis.

More research needs to be done, he continued, not just on optimal age but also on the effect of multiple other factors impacting risk. “These may include family history and genetic risk as well as the role of blood- and stool-based screening assays in an integrated strategy to screen for colorectal cancer.”

There are multiple screening tests, and while colonoscopy, the gold standard, is very safe, it is not completely without risks, Dr. Meyer added. “And the question of the appropriate allocation of limited societal resources continues to be discussed on a broader level and largely explains the difference between the two guidelines.”

This study received no specific funding. Co-author Jordan J. Karlitz, MD, reported personal fees from GRAIL (senior medical director) and an equity position from Gastro Girl/GI On Demand outside f the submitted work. Dr. Meyer disclosed no conflicts of interest relevant to his comments.