NEW YORK (Reuters Health) - Early-onset colorectal cancer (CRC) rates are rising in young people, particularly non-Hispanic Blacks and Hispanics, with advanced-stage cancers accounting for increasing proportions of diagnoses, an analysis of SEER cancer registry data reveals.
"We were expecting to see an increasing burden of distant-stage disease, but the degree to which distant stages rates are rising and the proportion (percentage of all cancer stages) that are distant-stage disease in younger patients were much higher than we anticipated," Dr. Jordan Karlitz of the Denver Health Medical Center in Colorado told Reuters Health by email.
"Given the rising rates of metastatic disease we are seeing in young patients... average-risk screening needs to begin on time at age 45," he said. "For those younger than age 45 who are not eligible for average-risk screening, we need to be vigilant about promptly evaluating concerning symptoms and taking cancer family histories to help stratify patients for earlier testing. We also need to focus in on even higher risk subgroups, including the youngest non-Hispanic Blacks and Hispanics."
As reported in Cancer Epidemiology, Biomarkers and Prevention, Dr. Karlitz and colleagues analyzed annual incidence data from the US SEER 18 cancer registry from 2000-2016, which included close to 104,000 CRC patients. They stratified incidence rates (IRs) by disease stage, subsite, patient age and racial/ethnic group.
Comparing 2000-2002 with 2014-2016, the steepest percent increases were in distant-stage cancers.
Colon-only distant adenocarcinoma increased most in 30-39-year-olds (49%).
Rectal-only distant-stage increases were greatest in 20-29-year-olds (133%), followed by 30-39-year-olds (97%) and 40-49-year-olds (48%).
Comparing the same time periods, distant-stage proportions increased for colon-only and rectal-only subsites in young patients, with the largest increases for rectal-only in 20-29-year-olds (18%-31%) and 30-39-year-olds (20%-29%).
By race/ethnicity, distant-stage proportion increases were largest for rectal-only in 20-29-year-old non-Hispanic Blacks (0%-46%) and Hispanics (28%-41%). Distant colon-only proportions increased most in 20-29-year-old non-Hispanic Blacks (20%-34%).
Dr. Karlitz said, "There are often long delays between symptom onset and cancer diagnosis in young patients, which can increase the chance of younger patients presenting with distant-stage disease. However further studies are required to better understand why the proportion of distant-stage disease has been actually increasing over time."
Dr. Jeffery Nelson, Surgical Director of Mercy's Center for Inflammatory Bowel and Colorectal Diseases in Baltimore, commented in an email to Reuters Health, "This is an interesting statistical exercise looking at much younger age groups than usual. It confirms what we already know, and that is that CRC incidence is increasing in younger people. This is why the screening recommendation for everyone dropped from 50 to 45 in 2018 for those at average risk."
"In addition, it shows that younger people are presenting with more advanced disease than older age groups," he said. "At Mercy, about 70% of all rectal cancers seen in the last two years were between 50 and 59 years old."
However, he noted, "It's a retrospective study of SEER data, which can be problematic, so firm conclusions are hard to reach. More study is necessary."
SOURCE: https://bit.ly/3ANf9Md Cancer Epidemiology, Biomarkers and Prevention, online January 26, 2022.
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