Young-onset rectal cancers on the rise in U.S.

Last Updated: 2020-07-29

By Reuters Staff

NEW YORK (Reuters Health) - The incidence of regional and distal rectal cancer among people under 45 is on the rise in the U.S., a new analysis confirms.

"We found that rectal cancer is increasing at about 2.3% annually (P<0.001). The significant rise in the incidence of rectal cancer represents a growing public health threat," Dr. Douglas G. Adler of the University of Utah School of Medicine in Salt Lake City and colleagues write.

The incidence of advanced rectal cancer is growing among people under 50, but few clinical studies have looked at treatment and survival outcomes in younger patients, the authors note in the Journal of Clinical Gastroenterology.

To investigate, they analyzed 2000-2016 data from the Surveillance, Epidemiology, and End Results Registry (SEER) on more than 10,000 patients diagnosed with cancer before age 45, 54.7% of whom were male. Eighty percent of patients received chemotherapy and surgery, 7.1% radiation and surgery, 1.2% radiation and chemo, and one-third of patients had all three therapies.

Overall, the age-adjusted incidence of rectal cancer was 1.24 per 100,000 per year. Incidence increased by about 2.29% annually during the study period. Patients aged 40-44 had the highest rectal-cancer incidence. Cause-specific survival was 93% at one year and 72% at five years.

Mortality was higher in patients with localized cancer who received chemotherapy (hazard ratio, 2.88). Chemotherapy was associated with reduced mortality in patients with distant cancers (HR, 0.62), largely among those 35 and older, but the reduction in patients with regional cancers was not significant (HR, 0.89; P=0.116).

Survival for patients with regional and distant cancers was worse for patients younger than 45 compared with older ones, the researchers found.

"Future risk-adapted screening methodologies should be able to selectively screen younger individuals at high risk of rectal cancer. Our study urges clinicians to be aware of these trends and the impact of different therapeutic approaches on survival outcomes," Dr. Adler and colleagues write.

"Further prospective studies are needed to elucidate the cause for these trends, identify potential preventive and early-detection strategies, and optimal therapeutic interventions," they conclude.

Dr. Adler was not available for an interview by press time.

SOURCE: https://bit.ly/3f1SeQz Journal of Clinical Gastroenterology, online July 3, 2020.