Using Science to Reduce the Burden of Cancer

CDC conducts studies and supports public health research designed to help the cancer community reduce the burden of cancer and eliminate health disparities. CDC also evaluates the feasibility and effectiveness of strategies designed to prevent and control cancer.

The cancer community has made extraordinary progress during the past two decades in developing and using cancer prevention strategies, early detection interventions, and cancer treatments. Nonetheless, cancer remains the second leading cause of death in the United States, claiming the lives of more than half a million Americans every year.¹

CDC conducts and supports studies, often in collaboration with partners, to develop and apply sound science to reduce the burden of cancer and eliminate health disparities. This research uses many different areas of expertise (behavioral science, economics, epidemiology, health services, medicine, and statistics) to address the public health research needs of CDC programs, health care providers, people affected by cancer, and the larger comprehensive cancer control community.

Annual Report to the Nation on the Status of Cancer

CDC has collaborated with the American Cancer Society, the North American Association of Central Cancer Registries, and the National Cancer Institute since 1998 to create this annual report. It provides an update of cancer incidence (new cases) and death rates and trends in these rates in the United States, as well as an in-depth analysis of a selected topic.

According to the most recent report, published in March, 2012, death rates from all cancers combined for men, women, and children continued to decrease in the United States between 2004 and 2008. The overall rate of new cancer cases, also known as incidence, among men decreased by an average of 0.6% per year between 2004 and 2008.

A special feature section of the report explains how being overweight and not getting enough physical activity increase cancer risk. The following six cancers are associated with being overweight: breast cancer among postmenopausal women, colorectal cancer, endometrial cancer, esophageal adenocarcinoma, and cancers of the kidney and pancreas. Several of these cancers also are associated with not getting enough physical activity.²

Vital Signs: Colorectal Cancer Screening, Incidence, and Mortality

Colorectal (colon) cancer incidence decreased by 3.4% per year, and the colorectal cancer death rate decreased by 3.0% per year from 2003 through 2007 in the United States. These decreases represent about 66,000 fewer new cases and 32,000 fewer deaths than expected from 2003 to 2007, compared with 2002.

About half of the improvement in death rates can be attributed to more people getting screened for colorectal cancer, about one-third to reductions in risk factors such as smoking and obesity, and one-eighth to improved treatment. For incidence rates, about half of the decrease can be attributed to screening, and the other half to reductions in risk factors.

According to the 2010 Behavioral Risk Factor Surveillance System, about 65.4% of people who are 50–75 years old are up-to-date with colorectal cancer screening, which is a substantial improvement in the past decade; only 40.9% of U.S. residents reported up-to-date with colorectal cancer screening in 1997. But about 22 million people in this age group have never been screened for colorectal cancer.³

Cancer Screening—United States, 2010

Each year, about 350,000 people are diagnosed with breast, cervical, or colorectal cancer in the United States, and nearly 100,000 die from these diseases. The U.S. Preventive Services Task Force (USPSTF) recommends screening tests for these cancers. This study looked at responses to the 2010 National Health Interview Survey to see if people are following USPSTF screening guidelines.

• The USPSTF recommends that women who are 50–74 years old get screened for breast cancer with a mammogram every two years; about 72% of women surveyed said they followed this recommendation.
• The USPSTF recommends that women who are 21–65 years old and have a cervix get screened for cervical cancer and precancerous lesions with a Pap test every three years; about 83% of women surveyed said they followed this recommendation.
• The USPSTF recommends that men and women who are 50–75 years old get screened for colorectal cancer; about 59% of adults surveyed said they were up-to-date with colorectal cancer screening.⁴

Demographic Characteristics and Health Behaviors Among Adult Cancer Survivors

A cancer survivor is anyone who has been diagnosed with cancer, from the time of diagnosis through the end of his or her life. To determine cancer survivors' health behaviors, the authors looked at data from CDC's 2009 Behavioral Risk Factor Surveillance System. They found—

• About 15.1% of cancer survivors aged 18 or older were current cigarette smokers, ranging from 10.3% in California to 23.9% in Oklahoma.
• About 27.5% of cancer survivors were obese, ranging from 15.7% in Colorado to 33.8% in Missouri.
• About 31.5% of cancer survivors had no leisure-time physical activity, ranging from 21.4% in Oregon to 42.3% in West Virginia.

The number of cancer survivors will continue to increase due to a growing aging population, the ability to find cancer earlier, better ways to diagnose cancer, more effective treatment, and improved follow-up after treatment. Healthy lifestyle behaviors will lead to longer and more productive lives for cancer survivors.⁵

Research Nominated for the Charles C. Shepard Science Award

The Charles C. Shepard Science Award is presented to the best manuscript on original research published by a CDC or ATSDR scientist in a reputable, peer-reviewed journal. CDC's Division of Cancer Prevention and Control submitted the following three papers for consideration.

Time and Distance Barriers to Mammography Facilities in the Atlanta Metropolitan Area

This study analyzed travel times from the centers of 282 census tracts in Dekalb and Fulton counties to the nearest facility that offered mammograms via public transportation, taking into consideration bus and rail routes, bus and rail stops, transfers, walk times, and wait times. The study found that the median public transportation time was almost 51 minutes.

The authors also examined public transportation travel times by levels of household access to a private vehicle. Residents in tracts with the lowest household access to a private vehicle had the shortest travel times, suggesting that facilities were favorably located for women who have to use public transportation. However, census tracts with majority non-Hispanic black populations had the longest travel times for all levels of vehicle availability.

The authors concluded that addressing the transportation barriers at a population level would increase access to health care services, including mammograms, at an individual level.⁶

Estimated Effects of the National Breast and Cervical Cancer Early Detection Program on Breast Cancer Mortality

CDC's National Breast and Cervical Cancer Early Detection Program (NBCCEDP) provides breast cancer screening to medically underserved, low-income women aged 40–64 years. This study estimates life-years saved by NBCCEDP breast cancer screening (referred to as Program) compared with screening in the absence of NBCCEDP (referred to as No Program), and with no screening (referred to as No Screening).

• Among 1.8 million women who were screened between 1991 and 2006, the Program saved 100,800 life-years compared with No Program and 369,000 life-years compared with No Screening.
• Per woman screened, the Program saved 0.056 life-years compared with No Program and 0.206 life-years compared with No Screening.
• Per woman with invasive breast cancer and screen-detected invasive cancer, the Program saved 0.41 and 0.71 life-years, respectively, compared with No Program.

The authors concluded that mammograms offered through the NBCCEDP have reduced death from breast cancer for uninsured and underinsured low-income women.⁷

Human Papillomavirus and Papanicolaou Tests Screening Interval Recommendations in the United States

Guidelines recommend that when the human papillomavirus (HPV) and Papanicolaou (Pap) tests are used together for routine cervical cancer screening, women can wait three years to be screened again. This study looked at whether doctors order HPV tests in addition to Pap tests, and if so, how often they recommend their patients get Pap tests.

About half of doctors ordered the HPV test in addition to the Pap test. Less than 15% of doctors who ordered the HPV test recommend that women with normal HPV test results and a normal Pap screening history wait three years for their next Pap test. The authors concluded that doctors continue to recommend cervical cancer screening every year, even though the new guidelines say the frequency should be based on each woman's screening history and HPV test results.⁸

References

1. Xu J, Kochanek KD, Murphy SL, Tejada-Vera B. Deaths: Final data for 2007. [PDF-555KB] National Vital Statistics Reports 2010;58(19).
2. Eheman C, Henley SJ, Ballard-Barbash R, Jacobs EJ, Schymura MJ, Noone AM, Pan L, Anderson, RN, Fulton JE, Kohler BA, Jemal A, Ward E, Plescia M, Ries LAG, Edwards BK. Annual report to the nation on the status of cancer, 1975–2008, featuring cancers associated with excess weight and lack of sufficient physical activity. Cancer March 28, 2012. [DOI: 10.1002/cncr.27514]
3. Centers for Disease Control and Prevention (CDC). Vital signs: Colorectal cancer screening, incidence, and mortality—United States, 2002–2010. MMWR 2011;60(26):884–889.
4. Centers for Disease Control and Prevention (CDC). Cancer screening—United States, 2010. MMWR 2012;61(3):41–45.
5. Underwood JM, Townsend JS, Stewart SL, Buchannan N, Ekwueme DU, Hawkins NA, Li J, Peaker B, Pollack LA, Richards TB, Rim SH, Rohan EA, Sabatino SA, Smith JL, Tai E, Townsend GA, White A, Fairley TL. Surveillance of demographic characteristics and health behaviors among adult cancer survivors—Behavioral Risk Factor Surveillance System, United States, 2009. MMWR Surveillance Summaries 2012;61(1):1–23.
6. Peipins LA, Graham S, Young R, Lewis B, Foster S, Flanagan B, Dent A. Time and distance barriers to mammography facilities in the Atlanta metropolitan area. Journal of Community Health 2011;36(4):675–683.
7. Hoerger TJ, Ekwueme DU, Miller JW, Uzunangelov V, Hall IJ, Segel J, Royalty J, Gardner JG, Smith JL, Li C. Estimated effects of the National Breast and Cervical Cancer Early Detection Program on breast cancer mortality. American Journal of Preventive Medicine 2011;40(4):397–404.
8. Roland KB, Soman A, Benard VB, Saraiya M. Human papillomavirus and Papanicolaou tests screening interval recommendations in the United States. American Journal of Obstetrics and Gynecology 2011;205(5):447.e1–8.

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