Young-Onset Colorectal Cancer: Earlier Diagnoses or Increasing Disease Burden?

Colorectal cancer (CRC) incidence and mortality in the United States have changed strikingly in recent decades. Overall, CRC incidence decreased by >30% from 1975 (59.5 per 100,000) to 2013 (37.9 per 100,000).1 CRC mortality similarly declined from 28.1 per 100,000 in 1975 to 14.5 per 100,000 in 2013—nearly a 50% decrease. Screen-eligible populations, particularly those over age 65, have experienced the largest declines in incidence and mortality.

In marked contrast with populations >50 years of age, the CRC incidence is increasing in younger adults.4, 5 Starting in the early 1990s, incidence rates have increased in this population (ages 20-49 years), from 8.5 per 100,000 in 1992 to 10.7 per 100,000 in 2013, a 26% increase. The largest absolute increases have occurred in the 40- to 49-year age group, from 18.2 per 100,000 in 1992 to 22.3 per 100,000 in 2013. Mortality rates have remained stable during the same period (around 2.4 per 100,000), ranging from 2.1 per 100,000 in 1998 to 2.7 per 100,000 in 2012.

Age-adjusted (2000 US standard population) incidence (A) and mortality (B) of young-onset colorectal cancer by 10-year age group, Surveillance, Epidemiology, and End Results (SEER) 13, 1992–2013. Colorectal cancer (CRC) incidence and mortality were derived from the National Cancer Institute’s SEER program during 1992–2013. SEER 13 registries include Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle-Puget Sound, Utah, Los Angeles, San Jose-Monterey, Rural Georgia, and Alaska Native Tumor Registry. Age-adjusted incidence and mortality (by using the 2000 US standard population) were obtained by using SEER*Stat version 8.3.2 as rates per 100,000 persons.