American Indian Culture and Research Journal

On behalf of myself and the Arizona Cancer Center, I want to extend a warm welcome to all of you and to thank you for participating in this First National Conference on Cancer in Native Americans. Those of us working in the field of cancer research and treatment have been issued two challenges: The first challenge, by the National Cancer Programs, is to address the cancer needs of all United States citizens, regardless of ethnicity or socioeconomic status; the second challenge, set by the National Cancer Institute, is to achieve a 50 percent reduction in cancer mortality by the year 2000. In order to meet these challenges, we need to focus not only on cancer treatment in the Anglo population, but-perhaps more importantly-we also need to address the specific and unique issues related to cancer treatment, prevention, and control in the minority groups in this country. There currently exist over 1.5 million Native Americans on 278 reservations and over 200 Alaska Native villages. Over half of all Native Americans reside in the states of Arizona, California, New Mexico, and Oklahoma. There are 65,000 Alaskan Eskimos and over 200,000 Native Hawaiians and peoples of Hawaiian ancestry. Compared with the general United States population, American Indians have a much higher incidence for cancers of the stomach, cervix uteri, liver, gallbladder, and kidney. They have a higher mortality for cancer of the cervix and gallbladder. The survival rates are poor for all sites combined. American Indians have a high prevalence of smoking. Their use of smokeless tobacco among students in grades 7 to 12 is much higher than among white students in the same grades. Alaska Natives have a high risk for nasopharyngeal, gallbladder, cervix, and kidney cancer. Native Hawaiians have a higher incidence of cancer of the breast, cervix uteri, corpus uteri, and lungs. They have a higher mortality rate for all sites combined. Their smoking prevalence is also higher than in the general population, as is their dietary fat intake.

The first nationwide conference on the problem of cancer in Native American peoples was held in Tucson, Arizona, 26-28 October 1989. The conference was supported through private donations and was sponsored by the Native American Research and Training Center, which is part of the Department of Family and Community Medicine at the University of Arizona College of Medicine. The specific aims of this first nationwide Conference on Cancer in American Indians and Alaska Natives were (1) to share information, published and unpublished, about cancer in American Indians and Alaska Natives; (2) to discuss priorities for further research and program development; and (3) to determine if regional approaches to detection, treatment, prevention, and epidemiology are justified, thus necessitating periodic regional meetings of researchers and health care professionals.

INTRODUCTION It is difficult to profile the American Indian population, because there are 511 federally recognized tribes and villages, each of which has its own unique culture and history. This report must be considered a discussion of the "average American Indian," which of course does not exist, but we are limited by available data sources and space. The 1980 United States census identified a total of 1,364,033 American Indians and 278 American Indian reservations (excluding Alaska Natives) where approximately one-fourth of all American Indians lived in that year. The majority of Indian people (estimated 54 percent) live in urban areas; 46 percent live in rural and reservation areas. The American Indian population residing in historic areas and tribal trust lands of Oklahoma (excluding urban areas) numbered 116,000, comprising 9 percent of the total American Indian population. Generally, American Indians had a significantly lower median family income ($13,768) in 1979 than that for the entire country ($19,917). The income of American Indian families living on reservations ($9,924) was even lower. Twice as many American Indians (27.5 percent compared to 12.4 percent) lived at or below the poverty level in 1980 as the total population. Unemployment rates are very high: In comparison to unemployment rates for the entire country, the rate for all American Indians combined is twice as high, and over four times as high for Indians living on reservations. Fifty-six percent of all American Indians were high school graduates in 1980, as were 43 percent of reservation Indians and 66 percent of the total United States population. The median age of American Indians was 23.4, according to the 1980 census, which is almost seven years younger than the overall United States figure of 30.0. Indians living on reservations were even younger, with a median age of 19.7.

The health of American Indians continues to be poor when compared to that of the general population. Three out of eight American Indians die before their forty-fifth birthday compared to only one out of eight other Americans. Cancer has not always been a major public health problem for American Indians, and its occurrence in this special population has been studied this century only sporadically. At the beginning of the twentieth century, American Indians were described as "never having cancer". The SEER data in mid-century showed American Indians to have the lowest incidence rates among ethnic groups, although they did show the least favorable survival rates. A growing interest in cancer prevention and control, which has emerged from advances in research knowledge of cancer etiology, encompasses the epidemiologic evidence that the way people live can affect their chances of getting cancer. Since more American Indians are living longer, more might be expected to develop cancer, and since many have been assimilated into the larger society, their risks of getting cancer are becoming more comparable. The evidence that cancer is increasing in this population has been demonstrated. Other factors to explain this increase include genetic predisposition, heretofore a protective factor that has been modified by environmental influences that change the patterns of survival.

INTRODUCTION Few published data have addressed the descriptive epidemiology of cancer among various American Indian tribes nationwide, and risk factor information on a site-specific or tribal-specific basis is almost nonexistent in published reports. Nonetheless, with appropriately guided searches, a tenacious researcher of health care information can be directed to specific data sources on cancer among American Indians/Alaska Natives in various parts of the country. In this chapter, we will discuss some of these data sources, their access, and their limitations. METHODOLOGY A study of the descriptive epidemiology of cancer or any other disease generally starts with the calculation of incidence rates, which are based on the number of newly diagnosed cases in a defined population during a specified period of time, or mortality rates, which are based on the number of deaths during a specified period. Crude rates, obtained simply by dividing the number of cases (numerator) that occur during a specified period of time by the total population at risk (denominator), are seldom informative, because they do not take into account any variation in the distributions of ages in the different populations that one wants to compare. Indian groups in the United States tend to have young populations; crude rates for most tribes typically are very low, because the denominators are weighted with relatively large numbers of young persons who have not yet reached the ages at which cancers occur most frequently.

A study of variation in cancer incidence among the Navajo Indians, given their relative racial and environmental homogeneity, could provide important clues to etiology and, ultimately, to cancer control. A family with Lynch syndrome II, which was originally described in a Navajo kindred, has received follow-up eight years later. Three at-risk relatives have had newly diagnosed colorectal cancer. These findings were highly predictable, given knowledge of the natural history and genetics of this autosomal dominantly inherited disorder. This disorder is believed to be the first example of hereditary colorectal cancer of any type among American Indians. Given the ubiquitous nature of hereditary colorectal cancer disorders, it is likely that other, similar, colorectal cancer-prone families exist among the Navajo. Biomolecular technology employing DNA analysis, when it becomes available, should aid in cancer genetic diagnosis. Meanwhile, knowledge of hereditary colon cancer’s natural history, coupled with painstaking compilation of the pedigree, will be mandated for hereditary colorectal cancer syndrome diagnosis.

We have studied the relationship between gallstones and gallbladder cancer in American Indians located in the southwestern United States. As determined in a case-control study, the overall age- and sex-adjusted relative risk for this group was 20.9 (95 percent confidence interval 8.1-54). The corresponding relative risk for non-Indian subjects was significantly less: 4.4 (95 percent confidence interval 2.6-7.3). Indian subjects were more likely to have stones >cm than non-Indian subjects: Age-adjusted odds ratio = 1.5, 95 percent confidence interval 1.2-2.00. Large stones appear to be associated with an increased risk of gallbladder cancer, perhaps because they have been present longer than small stones. Many other Native American populations in the Western Hemisphere ranging from Alaska to South America are also prone to gallbladder cancer. These widely separated groups may share a common genetic factor leading first to obesity and then to gallstones and gallbladder cancer.

The relative distribution of primary cancers as well as incidence rates by type were found to be significantly different between the Oglala Sioux from the Northern Plains and the Tohono O’Odham from the Southwestern desert. The Oglala had higher mortality rates for lung, cervix, and breast cancer, and the Tohono O’Odham had higher mortality rates for gallbladder, breast, and stomach cancer compared to the mortality rates for the same cancers in the all-United States Indians. Multiple myeloma rates were increased for both tribes. Cancer rates among Indian peoples are usually reported by ethnic groups. For American Indians, these groups are usually combined, and rates are reported under the heading Indians. It appears that if regional tumor registries for Native Americans were to be developed, then distinctive patterns might be expected, proving that individual tribal cancer patterns may vary as much as observed patterns for other ethnic groups of European or Asian origin in the United States.

CANCER AND CANCER RISK FACTORS AMONG NORTHERN PLAINS INDIANS A pragmatic definition for epidemiology is the study of diseases and health problems as they affect groups of people. Why do we need epidemiologists in Indian Health Service? The main reason is to provide information for action to media, tribal communities, health professionals, and individuals. This information is used to design and evaluate interventions to improve Indian health to the highest possible level, which is the goal of Indian Health Service (IHS). I will review some of the cancer prevention and control interventions being conducted in the Aberdeen Area Indian Health Service. The Aberdeen Area IHS serves 80,000 Indians who are members of seventeen tribal groups living in four states: North Dakota, South Dakota, Iowa, and Nebraska. It is an isolated area with severe transportation difficulties. Several years ago, I worked on a report for Congress called "Closing the Gap" or "Bridging the Gap," on the differential epidemiology in various areas of the Indian Health Service. We reported on a number of different health conditions, including cancer, utilizing age-adjusted mortality rates. Overall, Indian people are at less of a risk of dying from cancer than United States all races, but there are some areas, notably Alaska, Bemidji, Billings, and Aberdeen, where the rates of death from cancer are higher than the United States all races (figure 1). In Albuquerque, Phoenix, Navajo, Portland, and Oklahoma areas, the age-adjusted cancer mortality rates are considerably lower. In fact, the Navajo have about half the rate of death from cancer as the United States all races.

I would like to begin by sharing with you an excerpt from a poem called ”Knots” by R. D. Laing that will express how some feel about our lack of understanding: There is something I don’t know that I am supposed to know. I don’t know what it is I don’t know, and yet I am supposed to know, and feel I look stupid if I seem both not to know it and not to know what it is I don’t know. . . I feel you know what I am supposed to know but you can’t tell me what it is because you don’t know that I don’t know what it is. We must share with each other, which I hope to do this afternoon, in order to enable us to have a better understanding of Native American culture as it relates to the care of cancer patients. The attitudes and beliefs of Native Americans are as diverse as are the tribes throughout the United States. I have often addressed descriptions of Native Americans based upon modified sociological definitions: traditional, transitional, assimilated, and dualistic. The traditional folks follow their traditional ways and customs. The transitional folks are in the process of accepting the ways of the mainstream culture in which they have relocated. The assimilated folks have become alike or similar to the environment and culture which they have adopted as their new lifestyle. The dualistic folks, which I believe many successful people of ethnicity have found to be most satisfying, live in and adapt to both cultures and consciously adjust to each with flexibility.