国际英语新闻:Colorectal cancers rising in U.S. young people: study

NEW YORK, Feb. 28 (Xinhua) -- There has been a sharp rise in colorectal cancers in adults as young as in their 20s and 30s in the U.S., found a new study from the American Cancer Society (ACS).

The vast majority of colorectal cancers are still found in older people, with nearly 90 percent of all cases diagnosed in people over 50, colorectal cancer rates, which had dropped steadily for people born between 1890 and 1950, have been increasing for every generation born since 1950, said the study published on Tuesday.

"Age-specific colorectal cancers risk has escalated back to the level of those born circa 1890 for contemporary birth cohorts, underscoring the need for increased awareness among clinicians and the general public, as well as etiologic research to elucidate causes for the trend," concluded the study.

"Further, as nearly one-third of rectal cancer patients are younger than age 55 years, screening initiation before age 50 years should be considered," it said.

The study, based on the analysis of the incidence patterns of colorectal cancer in the country from 1974-2013, found that in adults ages 20 to 39, colon cancer rates have increased by 1 percent to 2.4 percent a year since the mid 1980s, while rates declined overall among those 55 and older. Rates among adults 40 to 54 increased by 0.5 percent to 1.3 percent a year since the mid-1990s.