Colorectal cancer mortality rates have decreased since 1970 in black individuals 20 to 54 years of age, but have increased in white individuals since 1995 among those ages 30 to 39 years and since 2005 among those 40 to 54 years of age following decades of decline, according to a study published by JAMA.

Colorectal cancer (CRC) incidence has been increasing in the United States among adults younger than 55 years since at least the mid-1990s, with the increase mainly among white men and women.

Although CRC mortality is declining overall, trends for all ages combined mask patterns in young adults, which have not been comprehensively examined.

Rebecca L. Siegel, M.P.H., of the American Cancer Society, Atlanta, and colleagues analysed CRC mortality among persons ages 20 to 54 years by race from 1970 through 2014.

The researchers found that CRC mortality rates per 100,000 population for this age group declined from 6.3 in 1970 to 3.9 in 2004, then increased by 1 percent annually.

The increase was confined to white individuals, among whom mortality rates increased by 1.4 percent annually.

Among black individuals, mortality rates declined by 0.4 percent annually to 1.1 percent annually.

Among other races combined, mortality rates declined from 1970-2006 and were stable thereafter.

In age-stratified analyses, mortality trends in white individuals during the most recent period were stable for those ages 20 to 29 years from 1988-2014, but increased by 1.6 percent annually for those 30 to 39 years of age from 1995-2014, by 1.9 percent annually for those ages 40 to 49 years, and by 0.9 percent annually for those ages 50 to 54 years from 2005-2014.

In contrast, rates in black individuals decreased over the entire study period among those ages 20 to 49 and since 1993 among those ages 50 to 54 years.

The authors note that disparate racial patterns conflict with trends in major CRC risk factors like obesity, which are similar in white and black individuals.

This study is limited by its inaccuracies in about 5 percent of all death certificates listing CRC as the underlying cause of death.

"Escalating mortality rates in young and middle-aged adults highlight the need for earlier CRC detection through age-appropriate screening and more timely follow-up of symptoms," the researchers write.

Source: JAMA