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efficacy trials are designed to determine the potential for chemoprevention methods and regimens to reduce cancer incidence in the aggregate as well as influence the incidence of specific cancers, the rate of regression and/or progression of preneoplastic changes, and changes in cellular or biochemical parameters associated with tumor regression or progression. participants are varied and include volunteers from the general population; populations at high risk for cancer because of occupation, lifestyle, or place of residence; persons with preneoplastic lesions, and/or persons with previously treated cancer. A number of these trials are intermediate endpoint studies and are testing biological and biochemical parameters which may serve as surrogate markers for cancer endpoints in chemoprevention trials.

Several ongoing trials focus upon those at high risk for lung cancer. One such trial has been initiated to determine whether markers of early lung carcinoma can be identified and whether beta-carotene can modify either their frequency and/or

progression.

In another trial, participants will receive the vitamin A derivative 13-cis retinoic acid or a placebo and be evaluated for decreases in bronchial squamous

metaplasia/dysplasia, a possible precursor lesion of lung cancer.

Nutrition and Cancer Studies

Because as much as 25 to 35 percent of cancer mortality could be related to diet, nutrition studies seek to establish an association between dietary intake of fiber, micro- and macronutrients, vitamins, minerals or other food stuffs and the prevention or development of cancer.

The diet and cancer component of the Cancer Prevention Research Program combines the results of the chemoprevention studies along with epidemiological research to test the role of the diet and nutrition interventions in the prevention of cancer. A number of intervention studies have been initiated in three broad areas, including etiologic studies, clinical nutrition studies, and prevention trials. These projects represent collaborative efforts in investigating dietary, nutritional, and constitutional factors relating to cancer prevention and involve NCI researchers in the United States and abroad. Furthermore, nutrition intervention studies testing the efficacy of multiple vitamins and minerals in the prevention of esophageal cancer mortality are continuing in an NCI-sponsored study of 34,000 subjects in China. In Finland beta-carotene and vitamin E are being tested as lung cancer chemopreventive agents among 29,000 male smokers. In the United States a synthetic derivative of vitamin A, 13-cis retinoic acid, is being used in a clinical trial in this country to prevent recurrence of basal cell skin cancers among approximately 1,000 persons with previous tumors.

Dietary Intervention to Prevent Cancer Among Women

The NCI has designed a dietary intervention trial to test whether a low-fat diet can reduce the incidence of breast and other cancers as well as mortality from all causes. Prior to launching this trial, the NCI will conduct a feasibility study to test the methods for dietary change among a broad cross-section of

the American population including minority populations, as well as those less-educated, and the poor. The feasibility phase is scheduled to be completed in three years, and if the trial is proved feasible, NCI expects to proceed with the large-scale intervention trial. The long-range objective of the full trial, termed the Women's Health Trial, is to determine whether a low-fat dietary pattern, designed to reduce total fat and saturated fat, and to increase the intake of fruits, vegetables, and grain products, can decrease the incidence of cancer in postmenopausal women. Primary objectives are to determine whether adoption of a low-fat dietary pattern will reduce breast cancer incidence, reduce combined breast cancer and colo-rectal cancer incidence, and reduce mortality from all causes including coronary heart disease.

State and Local Health Departments

State and local health departments form a national infrastructure through which cancer prevention and control efforts may be addressed. They have the statutory responsibility for the health of the community, provide direct health service to a significant part of the population, have a particular orientation to the health needs of underserved populations who may have a higher than average cancer risk and poorer experience, and are experienced in working with a broad range of community groups and agencies.

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Since 1987, NCI has funded 21 states plus Los Angeles County and the District of Columbia to build their cancer control capacity or utilize existing data resources to develop a state cancer plan and to initiate interventions based on that plan. addition, NCI staff have provided technical assistance in such areas as planning, program development, and data and registry improvement. Monthly mailings of materials related to cancer prevention and control are sent to each of the 50 state health departments and the District of Columbia. In addition, NCI staff collaborate with representatives from states across the country to produce reports for guiding public health agency activities, and for developing state tobacco prevention and control plans, and for promoting screening mammography. The resulting reports have been disseminated to key cancer control individuals in every state.

Community Intervention Trial for Smoking Cessation (COMMIT)

Results from intervention research trials have suggested that community-based and sustained programs produce larger, more costeffective treatment results. Therefore, in 1988, the Community Intervention Trial for Smoking Cessation (COMMIT) began the evaluation of a four-year community-based intervention protocol integrating all previous trial results. The trial design includes 11 pairs of communities located in western Washington, western Oregon, northern California, New Mexico, Iowa, North Carolina, upstate New York, metropolitan New York, New Jersey, and Massachusetts in the United States and in western Ontario in Canada. Following the baseline survey in early 1988, one

community from each pair was selected randomly as the intervention site.

Across the eleven intervention communities, COMMIT involves more than two million people with particular emphasis on the heavy smokers (25 or more cigarettes a day) due to their greater cancer risk and their difficulty in quitting. The four-year intervention effort has involved more than 1,000 doctors, 700 dentists, 1,400 worksites, 1,000 community organizations, 250 media outlets, 400 schools, 60 cessation service providers, and almost 200,000 smokers.

The American Stop Smoking Intervention Study (ASSIST)

While significant progress was made in the 1980's in tobacco control, the major reduction in tobacco use targeted by both NCI and the Public Health Service will not be reached without an accelerated effort. Recognizing this need, NCI has initiated the American Stop Smoking Intervention Study for Cancer Prevention (ASSIST). ASSIST is a large-scale demonstration project conducted through and in collaboration with health departments serving states or large metropolitan areas, and with the American Cancer Society (ACS). In each of the selected states or large metropolitan areas, comprehensive smoking prevention and control programs are planned for implementation in 1992 to disseminate the best available tobacco control technologies currently available. The potential impact of ASSIST will depend upon the size and number of award sites. The upper estimates for the program are that up to 97 million Americans, including 27 million smokers, could be reached by ASSIST. Up to 20 sites will be funded for a 24 month planning period beginning in July of 1991.

Cancer and Minorities

The reduction of disproportionately high cancer death rates found in minority and medically underserved groups continues to be a major focus of the NCI. These populations include Black Americans, Hispanics, and Native Americans (American Indians, Alaska Natives and Native Hawaiians) as well as low-income groups. I have personally re-emphasized NCI's support in addressing this issue in various forums, including testimony before both the House and the Senate Subcommittees on Appropriations.

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Lifestyle factors have been hypothesized by experts as contributing heavily to the disproportionate rate of deaths from cancer in minority and medically underserved populations. Some of the factors implicated are tobacco use both smoking and smokeless forms of tobacco, alcohol, diets high in fat and low in fiber, occupational risks, and patterns of care related to early detection, diagnosis, and treatment. It is important to stress that many of the issues discussed here are linked to poverty and the special circumstances posed by poverty-driven lifestyles. For example, young people from diverse minority and underserved groups may be more prone to begin smoking and to continue to do so for a lifetime.

NCI supports programs targeting special high-risk populations which experience excessive cancer rates and are under-served in terms of cancer prevention and control programs. These special high-risk population groups include Black Americans, Hispanics, Native Americans (American Indians, Alaskan Natives, Native

Hawaiians), Asian-Americans, under-served/low-income groups and blue-collar workers. Members of these groups have unique

circumstances which serve as barriers to receiving quality health care services.

Early Detection

The goal of early detection research is to increase the impact of early detection on cancer morbidity and mortality. Emphasis is also placed on efforts to achieve application of early cancer detection in medical practice and to evaluate the impact of such practices. Research initiatives on new methods and approaches in early detection are undertaken with the goal of extending this research to comparative trials in high-risk groups, and in other defined populations. New evaluation endpoints, the surveillance of trends in the use of early detection methods, and the development of strategies for clinical education are ongoing goals of the program.

Recent findings from genetic studies have opened up the possibility of identifying high-risk groups and developing surveillance strategies for the early detection of disease, most notably in the area of colo-rectal cancer. Genetic and biochemical markers, for example, the use of the marker CA125 to detect ovarian cancer, enhance the possibilities of early detection in cancers previously resistant to such efforts. Success in the standardization of nomenclature in the reporting of test results, as in the widely accepted Bethesda System of Pap Smear reporting, will result in more accurate early detection and

treatment.

Community Clinical Oncology

The Community Clinical Oncology Program (CCOP) is a network of community cancer specialists, primary care physicians, and other health care professionals who conduct both clinical treatment research and cancer prevention and control research studies in the areas of early detection and screening, chemoprevention, smoking, patient management, continuing care, and rehabilitation.

In June 1990, 51 community programs in 29 states were funded through the CCOP with awards varying in length from three to five years. The current program involves over three hundred hospitals and 2,100 physicians. Approximately 5,000 patients per year are entered onto treatment clinical trials through the CCOP Program, which represents about one-third of the Phase III annual accrual to NCI-approved randomized clinical trials. In addition, the CCOP contributes substantially to the NCI's effort to increase accrual to high priority intervention trials. The development of cancer prevention and control research in the CCOP network has been increasing steadily since funding for this effort was begun in 1987, with approximately 7,000 patients/subjects enrolled annually in cancer prevention and control studies.

Minority-Based Community Clinical Oncology Program

Since the CCOP model is an effective mechanism for linking investigators and their institutions with the clinical trials network, a Minority-Based CCOP (MBCCOP) was initiated to provide minority cancer patients with access to state-of-the-art cancer treatment and control technology. Twelve programs with greater than 50 percent of new cancer patients from minority populations were funded for three years, beginning in 1990. Through this effort, NCI aims to meet a need of minority cancer patients and individuals at risk for cancer by establishing a system of oncology programs for participation in research trials through the NCI network.

The Surveillance Program

Using its Surveillance, Epidemiology and End Results (SEER) database, NCI's Surveillance Program tracks cancer incidence and survival rates throughout the country to identify regions where progress has been made as well as areas where problems remain. This tracking system provides the information necessary for program planning not only for the Institute but for the Nation as a whole.

Equally as important, SEER has proven to be an important tool for the collection and analysis of data specific to minority populations. NCI has significantly expanded its efforts and improved its ability to monitor cancer incidence, mortality, and survival among Black Americans, Hispanics, and rural populations. For example, the 1992 Cancer Control Supplement to the National Health Interview Survey (NHIS) is an additional sampling of Hispanics. These data will provide a more precise estimate of cancer screening knowledge and practices, dietary intake, smoking habits and attitudes, and medical care for approximately 5,000 Hispanic adults. Coupled with comparable data from the 1987 NHIS Cancer Control Supplement, the Nation will have information with which to measure change in the prevalence of cancer risk factors for this population subgroup.

CANCER AND DIET

Question. Past NCI Director Arthur Upton said in 1979 that up to 50 percent of human cancer may be associated with dietary factors. Does NCI still subscribe to the estimate? If not, what percentage of cancers are linked with diet? Does NCI's degree of support for nutrition related research match the current scientific estimate of the important role of nutrition and cancer?

Answer. Evidence began accumulating in the 60's and 70's strongly suggesting that diet was strongly implicated in certain cancers. Dr. Upton made his estimate in 1979, but in 1981 a now widely referenced study hypothesized that from 10 to 70 percent of cancer deaths could be attributed to diet, with a "best estimate" of 35 percent. Not all scientists accept this estimate, but a relationship of diet to cancer is well-established. If accurate, the effect of diet is roughly the same as the impact of cigarette smoking, and potentially an even larger effect.

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