A Comprehensive Approach to Cancer Prevention and Control:
A Vision for the Future

Opportunities in Cancer Control

• Primary, Secondary, and Tertiary Prevention
  
  
• Essential Strategies and Interventions

Primary, Secondary, and Tertiary Prevention
Many factors that contribute to cancer deaths are preventable. It has been estimated that from 50% to 70% of cancer deaths are attributable to preventable risk behaviors;⁷ 30% of cancer deaths can be attributed to tobacco use and more than 30% to poor nutrition.⁸ Obviously, state and local programs need to focus on such preventable risk factors.

Cancer prevention can be divided into three stages: primary, secondary, and tertiary. Primary prevention refers to the complete prevention of disease, often through methods that inhibit exposure to risk factors. The four most important risk factors for cancer are tobacco use, lack of physical activity, exposure to ultraviolet light, and poor nutrition. Primary prevention is often used synonymously with prevention.

Secondary prevention activities detect disease early and limit disease effects after diagnosis. Outcomes for patients with breast cancer, for example, can be dramatically improved through early detection followed by appropriate treatment.

Tertiary prevention involves preventing further disability and restoring a higher level of functioning in someone with a disease. Like secondary prevention, tertiary prevention can involve treatment; however, it also includes rehabilitation and pain control. Even though cancer pain can be relieved through proper therapies, the National Cancer Institute suggests that the undertreatment of pain is a serious and neglected public health problem.⁹ To help alleviate this problem, programs should work with medical partners to ensure that cancer patients receive effective pain relief.

Local programs that are adopting a comprehensive cancer approach need to work with partners to ensure that patients with cancer receive appropriate tertiary care. Prevention opportunities offered through a particular intervention will vary depending on the risk factor or stage of disease at which the intervention is directed and the type of cancer being addressed.

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Essential Strategies and Interventions

Programmatic Interventions
Cancer prevention and control interventions can be directed at individuals, at health care providers or systems, or at organizations such as religious institutions or employers. Rates of cancer-related illness and death can be lowered by increasing public awareness about cancer and its risk factors, promoting behavior that decreases people’s cancer risk, and providing people with better access to cancer-related health care services.

Environmental and policy actions affect communities, work places, homes, and schools, influencing lifestyle choices that people make. Environmental factors, defined broadly to include smoking, diet, and infectious disease, as well as some chemicals and radiation, are associated with perhaps three-quarters of all cancer deaths in the United States.¹ Strong regulatory controls and promotion of safe occupational practices, in combination with healthier individual lifestyle choices, can be effective in reducing cancer incidence and mortality rates. Policy and environmental interventions specific to cancer risk factors, such as those that encourage physical activity, good nutritional choices, or tobacco use cessation, are especially useful in supporting behavioral change among individuals. (See Chapter 4 on physical activity and nutrition and Chapter 5 on tobacco use.)

Interventions important for the prevention and early detection of cancer include those designed to reduce the prevalence of smoking, reduce people’s consumption of fat and increase their consumption of fiber, increase people’s level of physical activity, increase the percentage of women who undergo regular breast cancer screening and Pap testing, increase the proportion of the population over 50 years of age who are screened for colorectal cancer, decrease people’s level of ultraviolet radiation exposure, and encourage the use of appropriate state-of-the-art cancer treatment.

In The Guide to Community Preventive Services (also called The Community Guide; available at www.thecommunityguide.org), the Task Force on Community Preventive Services recommends specific evidence-based interventions for promoting breast, cervical, and colorectal cancer screening; preventing sun exposure and promoting skin protection; and helping people make informed decisions about screening for cancers. It also identifies areas for future prevention research and programming and includes chapters related to tobacco control and physical activity. When choosing or designing interventions, decision makers should consider these evidence-based recommendations as they examine their own needs, goals, resources, and constraints.

The North Carolina example below provides a clear model for how individual site-specific and risk-factor-specific interventions can be coordinated within a framework that integrates surveillance, communications, policy, and evaluation. Currently, interventions implemented through cancer prevention and control programs often overlap with those implemented through other programs. A comprehensive cancer control approach would foster collaboration among such overlapping programs and, as a result, potentially provide more effective interventions at a lower cost.

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Using Data and Research Results to Design Interventions
Accurate and complete data and solid research form the underpinnings for comprehensive cancer control. They help planners to understand the extent of the cancer burden and the existing infrastructure to address that burden. Data and research help ensure that politically popular strategies are also sound.

Because a major goal of public health is to translate research into effective practice, partners should be encouraged to participate in the data review process, reviewing data that document the burden of cancer and its costs in human and monetary terms.

Information useful in assessing and addressing (through interventions) cancer burden include data derived from basic and applied research; data on the relevance, efficacy, and cost-effectiveness of possible intervention strategies; and data on the existing or developing capacity to implement effective interventions. Such data should help programs select relevant and affordable intervention strategies that they can tailor to priority populations and implement successfully. When incorporated into an organization’s comprehensive cancer control plan, these strategies will provide all stakeholders with a blueprint for action to address the cancer burden.

Evaluation data, the means by which the effectiveness of programs are measured, provide feedback for ongoing refinement of the program planning and implementation process. Core evaluation activities include surveillance (i.e., identifying and monitoring cancer and risk factor trends in the general population and cancer-burden disparities among groups of people) and the collection of data measuring the process and outcomes of program activities.

A comprehensive cancer control plan should be reviewed on a specified, routine basis to determine whether its objectives are being met and whether program activities should be redirected. Supervising officials should ensure that evaluation activities are useful, feasible, accurate, and ethical. A detailed discussion of how to conduct program evaluations can be found in “Framework for program evaluation in public health.” ¹⁰ This document can be accessed at www.cdc.gov/eval/framework.htm.

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Opportunities for the Prevention and Control of Selected Cancers
Five cancers have been chosen for discussion because of 1) their importance in new cancer cases and cancer deaths (breast, colorectal, and prostate), 2) the ability to detect them early through screening (breast, cervical, and colorectal), 3) their increasing prevalence (melanoma), and 4) their potential for 5-year survival with early diagnosis (cervical and prostate).

Breast Cancer Interventions
Breast cancer is the most common type of nondermatologic cancer among women in the United States. Because opportunities for the primary prevention of breast cancer are limited, we encourage public health practitioners to focus on secondary prevention (i.e., on early detection and appropriate treatment). Regular use of screening mammograms can help reduce the risk of dying of breast cancer. For women aged 50–69, strong evidence indicates that screening lowers this risk by 30%. For women in their 40s, the risk can be reduced by about 17%.⁷ The 5-year survival rate for women with localized, early-stage breast cancer is excellent—97%.¹

A number of states have state- and CDC-funded programs to encourage breast cancer screening. An example of a nationwide program is the CDC-funded National Breast and Cervical Cancer Early Detection Program (NBCCEDP; information is available at www.cdc.gov/cancer/nbccedp/index.htm). Through this program, CDC and its partners in state, tribal, and territorial health agencies provide low-income, uninsured, or underinsured women free or low-cost breast and cervical cancer screening. The program operates in all 50 states, the District of Columbia, 6 U.S. territories, and 14 American Indian/Alaska Native tribal organizations.

Cancer support groups, such as the American Cancer Society’s Reach to Recovery program, are often a valuable resource for women being treated for breast cancer, as well as for their families and friends.

Cervical Cancer Interventions
Cervical cancer is not common in the United States. Although the incidence rate has leveled off in the last few years, until then incidence and mortality rates had both decreased steadily for 50 years. A major reason for these decreases is the widespread use of screening for cervical cancer with the Pap test. As a result, preinvasive lesions of the cervix are detected more frequently than invasive cancer.¹

The annual cervical cancer incidence rate among African American women is still substantially higher than that among white women (13.9 versus 8.8 per 100,000 in 1999).¹¹ Health officials should institute screening programs and, to reduce this disparity, behavioral change interventions that target underserved African American populations. Behaviors to be promoted include limiting one’s number of sex partners, delaying sexual intercourse, using condoms, and avoiding tobacco products.

Cervical cancer screening is often offered through programs that provide both breast and cervical cancer education and screening services. The NBCCEDP, discussed in the previous section, is an example of a nationwide screening program that addresses cervical cancer. A goal of the NBCCEDP is to identify those women who have not had a Pap test in at least 5 years. Sixty percent of women diagnosed with cervical cancer are in this group, and many of them have a poor prognosis; however, women whose cervical cancer is diagnosed and treated early have a 5-year survival rate of 92%.¹

Colorectal Cancer Interventions
Colorectal cancer is the second most common nondermatologic cancer in the United States. Definite risk factors for colorectal cancer include a personal or family history of colorectal cancer, colon polyps, or inflammatory bowel disease. Other potential risk factors include smoking, physical inactivity, a high-fat and/or low-fiber diet, alcohol consumption, and low intake of fruits and vegetables.

The number of deaths from colorectal cancer and the incidence of the disease can both be reduced by detecting and removing precancerous polyps and by detecting and treating the cancer in its early stages. Precancerous polyps can be present in the colon for years before invasive cancer develops. The 5-year survival rate for patients with colorectal cancer (all stages) is 62%.¹

One way to promote colorectal cancer screening nationwide is by educating health care providers and the public about the benefits of screening, the availability of screening procedures, and current screening guidelines.

Prostate Cancer Interventions
Other than skin cancer, prostate cancer is the most commonly diagnosed form of cancer among men in the United States and is second only to lung cancer as a cause of cancer-related death among men. Age, race, ethnicity, and family history are all significantly associated with risk for prostate cancer. The incidence of prostate cancer is substantially higher among African American men than among white men (229.3 versus 152.3 per 100,000 in 1999).¹¹

Medical and public health experts agree that every man needs balanced information on the pros and cons of prostate cancer screening to help him make an informed decision. Balanced information is important because medical experts disagree about whether men should be screened regularly for prostate cancer.

Those who encourage regular screening believe current scientific evidence shows that finding and treating prostate cancer early, when treatment might be more effective, may save lives. They recommend that all men who have a life expectancy of at least 10 years should be offered the prostate-specific antigen blood test and digital rectal examination annually beginning at age 50. They also recommend offering screening tests earlier to men at higher risk for prostate cancer, specifically African American men and men who have a father or brother with prostate cancer. They do not recommend routine screening, but instead using a form of shared decision-making.

Those who do not recommend regular screening want convincing evidence that finding early-stage prostate cancer and treating it is beneficial. They believe that some of these cancers detected by screening may never affect a man’s health and that treating them could cause temporary or long-lasting side effects such as impotence and incontinence. Because they believe it is unclear if the potential benefits of screening outweigh the known side effects of screening and treatment, they recommend that all men be given information on the pros and cons of screening before making their own screening decision.

Results from clinical trials that are currently underway are expected in 5 to 10 years, and these results will help to clarify guidance about prostate screening. Each man must make his own decision about prostate cancer screening in consultation with his physician. This decision should be based on an understanding of his own risk factors and the risks and benefits of screening and the alternatives.

Skin Cancer Interventions
Among Americans, more than 1 million cases of the highly curable basal cell or squamous cell cancers are diagnosed each year. The American Cancer Society estimates that melanoma, the most serious form of skin cancer, will be diagnosed in over 54,000 people in 2003.¹ However, even melanoma is treatable if detected early: the 5-year survival rate of patients with localized melanoma is 96%.¹

Risk factors for skin cancer include excessive exposure to ultraviolet radiation, fair complexion, occupational exposure to certain chemicals, a family history of skin cancer, and multiple or atypical moles. Strategies to help prevent skin cancer include limiting or avoiding exposure to the sun during the midday hours, covering the skin when outdoors, and using a sunscreen with a sun protection factor (SPF) of 15 or greater. Because of the possible link between severe sunburns during childhood and risk for melanoma in later life, children, in particular, should be encouraged to avoid excessive sun exposure.

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