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Human epidemiologic studies of EMFs and cancer have been inconsistent and inconclusive. Findings from studies in Colorado and Sweden, which suggested a small increase of cancer in children and adults living near high-voltage transmission lines, were not confirmed in similar studies from Rhode Island, Washington State, and England. More recent studies in Denver and Los Angeles suggest an increase of childhood leukemia associated with living near high voltage power lines. However, the associations were with wire code configurations (diagrams showing increasing levels of current-carrying capacity) as a surrogate for EMF exposure levels. No consistent risk for childhood leukemia was seen in homes where actual EMF measurements were made.
Thus, it has been very difficult to evaluate reliably the health effects of exposure to electromagnetic fields. The studies conducted to date have been conflicting and inconclusive, and a connection between electromagnetic fields and cancer has not been established. One problem is the great difficulty in estimating an individual's exposure to electromagnetic fields.
Question. What is the status of my request that a health effects study be conducted included in my letter to you of February 13, 1991?
Answer. Childhood leukemia is the health condition most often related to exposure to electromagnetic fields from power transmission lines. Because of this NCI is conducting a national, multicenter study in collaboration with the Children's Cancer Study Group to determine whether electromagnetic fields might be causally related to childhood leukemia. Leading hospitals and cancer centers in Pennsylvania are included in the study. These large referral centers would treat most of the cases of childhood leukemia diagnosed in the state, including Scranton. The centers include the Children's Hospital of Philadelphia, the Children's Hospital of Pittsburgh, and the Hershey Medical Center.
CANCER INCIDENCE AND MORTALITY AMONG MINORITIES
Question. Dr. Broder, I understand that there is an alarmingly high incidence and mortality of cancer among minorities, particularly. What are the reasons for this disparity?
Answer. The extent to which Blacks experience higher cancer mortality than whites is striking--especially among Black males, where the risk of dying of cancer is 38 percent higher than for white males. The difference among Black and white males stems from both higher cancer incidence as well as poorer survival among Blacks. Although the cancer incidence rate for Black females is slightly less than the rate for white females, the large difference in survival leads to a considerably larger mortality rate among Black females than among white females--indeed, 14 percent higher mortality. Overall differences in cancer experience between Blacks and whites are summarized in the following table.
Differences in Cancer Incidence, Mortality and Survival
1(Note: Incidence and mortality rates are per 100,000 and are age-adjusted to the 1970 U.S. standard population.)
With respect to cancer trends, for Blacks, the age-adjusted incidence rate for all sites combined and both sexes has increased from 347.5 per 100,000 in 1973-4 to 404.2 in 1987-8, a relative increase of 16.3 percent. For whites, the increase of the corresponding rates has been from 325.6 in 1973-4 to 380.2 in 1987-8, a relative increase of 16.7 percent. Of particular interest is the fact that the rate for Blacks in 1987-8 is six percent larger than the rate for whites. The fact that part of the difference in the incidence rates between Blacks and whites is due to smoking-related cancers suggests that the potential exists for reducing the cancer burden in Blacks by appropriate targeting of cancer control programs.
The trend among Blacks in cancer mortality differs from that among whites. Among whites the rate increased from 159.8 to 168.3 from 1973-4 to 1987-8, a total increase of 5.1 percent. For Blacks, however, the rates increased from 195.3 to 214.0 over the same period, an increase of 9.5 percent.
Of the ten combined cancer sites, the five-year survival rates for Blacks are lower for six cancer sites for all stages combined, colon and rectum, lung and bronchus, female breast, cervix uteri, corpus uteri, prostate gland, and urinary bladder and for all cancer sites combined. Black males had a five-year survival rate 29 percent lower than white males and Black females had a five-year relative survival rate 23 percent lower than that of the white females. Few significant survival differences are noted by stage of disease except within the regional stage for colon and rectum, lung and bronchus, female breast, and cervix uteri, distant stage for urinary bladder among males and local stage for females with cancer of the urinary bladder. Black females have a significantly poorer survival within each stage for cancer of the corpus uteri.
Being diagnosed in a more severe stage of disease greatly reduces the effectiveness of therapy and the chances for escaping death due to cancer. Blacks have a tendency to be diagnosed in a more advanced stage of disease at diagnosis than whites. of the ten cancer sites, Blacks, in general, are detected in a later stage than whites for seven cancer sites--colon and rectum, lung and bronchus, female breast, cervix uteri, corpus uteri, prostate, and urinary bladder.
There is some evidence that differences in socio-cultural and perhaps biological factors may explain part of the survival differences observed between Blacks and whites. We know, for example, for cancer as well as other diseases, that low income and under-educated persons have a poorer survivorship than upper income and better educated persons. Some of the reasons revolve around the lifestyle associated with living in a poor environment such as: the ability to pay for health care without comprehensive medical insurance; a knowledge of and recognition of cancer signs and symptoms; delay in seeking and receiving definitive medical care; the existence of other medical problems; and compliance with treatment regimens.
In four primary cancer sites--female breast, colon, corpus uteri, and urinary bladder, the NCI is conducting a case-control study to assess the extent to which lifestyle, care seeking, compliance to treatment regimens and other factors influence the Black-white differences in cancer patient survival. Patient accrual is from three urban areas and was complete as of December, 1987. It is too early in this study to perform definitive analyses, because the patients are still being followed for the assessment of their vital status. It is expected that survival analyses will commence within the next two to three years and that this trial will provide some insightful information into the reasons for some of the observed Black-white differences in cancer patient survivorship.
Question. this problem?
What action is the Institute taking to address
Answer. The National Cancer Institute has formulated an intervention research program to identify and test, in community settings, interventions to reduce the cancer rates in minority populations. The initial focus was on Black populations but has more recently expanded into additional efforts for the Hispanic and Native American populations of American Indian, Alaska Native, and Native Hawaiian.
Many initiatives have been directed to specific populations. Specifically, for the Black population, eight contracts for intervention research specific to cancer in Black populations have been implemented. This research program is currently comprised of two components: studies to reduce avoidable mortality and studies to prevent the onset of smoking and/or to effect widespread smoking cessation. These projects are in their fifth year of support.
The formulation, approval, funding and award of a number of grants for intervention research specific to cancer in Blacks and other minority populations, including low-income groups, have also been initiated.
Initiatives to reduce avoidable mortality have been implemented. These projects seek to identify key factors that contribute to avoidable mortality from specific cancer sites, implement interventions to reduce mortality from the identified sites, evaluate the effectiveness of such interventions in a defined population, and identify prototype approaches to the reduction of avoidable mortality for widespread dissemination
through the National Cancer Program. There are five projects funded through this initiative, with a primary focus on the Black population.
The goal of a Primary Prevention of Cancer in Black Populations initiative is to develop innovative smoking prevention or cessation intervention programs and determine the long-term effectiveness of these programs in the Black population, Knowledge, practice, and attitudes are being addressed also.
The NCI has effected two interagency agreements with the Indian Health Service (IHS) during 1989 directed at Native Americans. One provides for the surveillance of the cancer burden, incidence, survival, and mortality of Alaska Natives, which may lead to the formulation of intervention research. This project will also allow for continued surveillance and monitoring of the effects of intervention strategies.
The goal of the second project is to describe the cancer incidence and/or mortality patterns in American Indians and Alaska Natives and perform studies of the patterns of care, treatment and risk factors, as well as cultural and behavioral barriers, to early detection and treatment and to develop intervention research hypotheses addressing correctable deficiencies. It is expected that both of these projects will lead to data-based intervention activities. Additionally, two Requests For Applications (RFA) have been released, one for Avoidable Mortality and another for Primary Prevention among Native American populations. Eight applications received from these RFA's have been funded in FY 1990 targeting American Indians, Alaska Native and Hawaiian Native populations.
The goal of the avoidable mortality initiative is to identify and remedy key factors that contribute to avoidable mortality from specific cancer sites. Knowledge, attitudes, and practices are also being addressed. The goal of the primary prevention initiative is to develop innovative tobacco use prevention or cessation intervention programs and determine the long-term effectiveness of these programs on the prevention and cessation of tobacco use among Native Americans.
A Hispanic Cancer Control Program has been established. Projects have been funded during FY 1990 to address the cancer control research needs of the growing Hispanic population in the United States.
Although large in number, Hispanics do not currently experience excessive cancer rates to the same degree noted in other special populations. However, due to a number of factors including assimilation, it is anticipated that Hispanic subpopulations will reach parity and may exceed cancer rates in the general population in the near future. Along with cancer surveillance, therefore, targeted intervention research becomes important for monitoring and addressing the cancer needs in this population.
This fall three breast and cervical cancer screening research projects were funded. The projects target areas of high concentration of Mexican Americans and newly arrived Central and
South Americans in Colorado, San Diego, California, and south Texas. The Texas project will coordinate the effort of multiple academic, state, and local institutions to deliver community-wide cancer control nutrition and screening interventions to two largely Hispanic counties. The Colorado project will evaluate methods for improving cancer screening compliance among Hispanics in six counties in Colorado. This project features extensive collaboration between the State Health Department and various Hispanic organizations and health care providers to effectively network into the community. The San Diego project will evaluate the effectiveness of a program designed to promote cardiac health, the Por La Vida model, in the area of cancer prevention and control. Each project pays attention to preserving positive health behaviors associated with the Hispanic culture while simultaneously developing interventions to address their barriers to effective cancer control.
The NCI has established several minority focused research networks. A National Hispanic Cancer Control Research Network has been established to work cooperatively with the Hispanic Cancer Control Program to identify Hispanic researchers and increase the number of Hispanic investigators involved in cancer prevention and control studies. The Network will provide advice and recommendations on efforts to promote early detection of cancer, innovative strategies and methodologies to circumvent barriers to cancer screening as well as advise on state-of-the-art treatment modalities culturally sensitive to Hispanics.
The Cancer Control Science Program initiated the Network for Cancer Control Research among American Indians and Alaska Native Populations on April 19, 1990. The purpose of this Network is to reduce preventable cancer morbidity and mortality to the lowest possible levels and improve cancer survival to the highest possible level. This Network's Steering Committee met four times between April and September in Washington D.C.; Oklahoma City, OK; Oakland, CA; and Albuquerque, NM.
The Network Steering Committee is comprised of eighteen active participants and six ex-officio members including people from different U.S. geographical regions; males and females; representatives from reservations, tribal communities, and urban areas; and, service providers, academicians, and clinic directors. Eleven of the active members are Native American.
To date, the Network has identified long range goals, objectives, and tasks; formed working sub-committees within the Network and suggested activities for NCI to undertake to raise "cancer" on the Native American health agenda. Those suggested activities include, but are not limited to, developing a culturally specific Cancer Exhibit, developing culturally specific cancer prevention promotional materials (e.g., bookmarks and tote bags), and developing culturally and regionally sensitive cancer prevention educational materials.
A series of meetings between NCI staff and community leaders, health care delivery personnel, and state and local government representatives has recently been held. The goal was to formalize the Hawaiian Native Cancer Control Network which will be able to