Regular screening plays a key role in early detection of cancer and is credited with helping to reduce the number of advanced cancers diagnosed in the United States. Nevertheless, a new study has found a decline in the frequency of screening for common cancers among large segments of the population.

Led by Tainya C. Clarke, MPH, of the Department of Epidemiology and Public Health at the Miller School of Medicine in Miami, a team of researchers analyzed data collected between 1999 and 2010 in the National Health Interview Survey, a program at the Centers for Disease Control and Prevention that collects demographic and health information from a sample of the US population annually. Subjects included 119,374 working adults with no cancer history and 7,528 working adult cancer survivors. Information on the frequency of Pap tests, prostate-specific antigen (PSA) tests, colorectal cancer screening, mammography, and manual breast examination was evaluated against the “Healthy People” objectives established by the US Department of Health and Human Services.

“There is a great need for increased cancer prevention efforts in the US, especially for screening, as it is considered one of the most important preventive behaviors and helps decrease the burden of this disease on society in terms of quality of life, the number of lives lost and insurance costs,” Clarke said. “But despite this, our research has shown that adherence rates for cancer screenings have generally declined, with severe implications for the health outlook of our society.”

The rate of screening for colorectal cancer increased by 16.6% during the study period and the Healthy People 2010 goal of screening 50% of individuals over age 50 years was met. The trends were less promising, however, for other cancers. Rates for mammography changed little, although the average proportion of women who had received a mammogram within the past 2 years was 69.7%, close to the Healthy People goal of 70%. The rate of Pap testing declined by 3.7% from 1999 to 2010, and in 2010, 85.5% of eligible women reported receiving a Pap test in the previous 2 years, short of the goal of 90%. The most striking decline in cancer screening occurred among men—the proportion of those who reported having had a PSA test declined from 64.6% in 1999 to 46.0% in 2010, reflecting an average annual decline of 3.6%.

One important sector of the population—cancer survivors—adhered more closely than the general population to cancer screening recommendations, meeting screening goals for colorectal, breast, and prostate cancer, but not for cervical cancer. Breast and cervical cancer screening rates declined in this group while colorectal and prostate cancer screening rates rose. The researchers noted a downward trend for screening rates among this group for the final 3 years of the study.

As in the general population, screening rates among working cancer survivors rose for colorectal cancer but declined for breast, cervical, and prostate cancer. White-collar workers had higher screening rates than blue-collar workers for all four cancers and higher screening rates compared to service workers for colorectal, breast, and prostate cancers.

The researchers speculated that ongoing disagreements among the US Preventive Services Task Force, the American Cancer Society, and others over screening guidelines and the decrease in the number of workers who have health insurance may have contributed to the decline in screening rates. The declining rates of cancer screening, especially among cancer survivors, may portend higher mortality rates from these common cancers.