A new study of Alaska Natives and cancer shows a significant and sustained increase in rates since the 1960s especially among women and especially of lung and digestive-tract cancers. The report says Native women are now more likely to suffer cancer than other women nationwide, with rates continuing to climb. The report, written by the U.S. Indian Health Service, documents a trend that public health agencies in Alaska have watched for several years the emergence of cancer as a major health problem among Alaska's indigenous people.
Cancer is now the leading cause of death among Alaska Native women and is surpassed only by heart disease and injuries as a killer of Native men.
The new report focuses on increases in cancer between 1969 and 1988. The information is based on records of Alaska Natives diagnosed by government and private physicians and clinics in Alaska and the Seattle area. It's thought to be the most complete survey ever done on Native cancer rates in Alaska, counting 2,300 cancer cases over the 20-year period. The Native population statewide is about 90,000.
Cancer is thought to have been rare historically among Alaska Natives. It continued to be fairly uncommon into the 1950s. But the rates for a number of different kinds of cancers among Alaska Natives have skyrocketed over the past 30 years, and Natives are now more likely to suffer several types of cancers than are other Americans.
The overall cancer rate for Alaska Native women, for example, is now 30 percent higher than both white and black women nationwide. That's largely because of big jumps in lung cancer , the report says.
The rate of lung cancer among Alaska Native women rose dramatically during the 1980s, and they are now about twice as likely to contract lung cancer as other American women, the study says. Native women also have unusually high rates of cancers of the colon, rectum and cervix.
The overall cancer rate for Native men while somewhat lower than the national rate for men is significantly higher than the rate for Native women. Lung cancer is by far the most common kind of cancer among Native men, the report says, with rates that began rising sharply during the 1960s. By the mid-1980s, lung cancer among Native men had surpassed the national rate and continues to climb, the report says.
TOBACCO'S ROLE
"A huge part of these dramatic increases are directly related to tobacco use," said Anne Lanier, an epidemiologist with the Anchorage office of the Indian Health Service and a primary author of the report.
Up to a third of the Native cancer deaths statewide are believed to be tobacco-related, according to estimates by the IHS and the state Division of Public Health. Alaskans of all races are in the midst of what state epidemiologist John Middaugh has a described as an epidemic of smoking-related cancer and heart disease, responsible for as many as 300 deaths a year.
Among all Alaskans, cancer is now the leading cause of death, according to the state Department of Health and Social Services.
As much as 90 percent of lung cancer cases stem from long-term inhalation of cigarette smoke, according to the National Cancer Institute. Tobacco use is thought to increase the risk for a variety of other forms of cancer as well, including mouth, esophagus, stomach and kidneycancer . Rates for all four cancers are higher among Alaska Natives than the overall U.S. population.
Surveys in rural Alaska have suggested that 40 percent or more of Native adults smoke cigarettes twice the percentage in the rest of the country. One survey of children in northwest Alaska in the late 1980s found that as many as one in seven village 5-year-olds both boys and girls chew smokeless tobacco, and that it becomes more popular as children grow older.
Statistics like that, combined with the high cancer rates, have led regional Native health agencies to launch a variety of anti-tobacco programs over the past few years and to beef up screening for other forms of cancer .
"You look at the statistics and they're pretty stunning," said Paul Hansen, an official with the Maniilaq Association, the health agency for 11 Inupiat villages in the Kotzebue region. "It's clear that the biggest thing we can do to prevent cancer has to do with tobacco, and I'm not sure that it's really hit home with a lot of people in the villages."
The growth of tobacco-related cancers among Alaska Natives parallels the national trend with a big time lag. Lung cancer rates for men nationwide began rising rapidly in the middle part of this century, and researchers think the big reason is that cigarettes became widely marketed in the United States after World War I. Lung cancer among women rose later, as smoking became more acceptable for women.
The same thing happened in Alaska, only later. People familiar with Native cancer trends think it's largely because cigarettes didn't become common throughout the Bush until after World War II.
"It appears the male Native cancer rates started going up earlier than the female rates," said Lanier, the IHS epidemiologist. "That's exactly what happened in the rest of the United States. Men started using tobacco earlier than women (in the rest of the U.S.), and we presume the same thing happened with Natives."
Nationally, lung cancer rates have begun to level off for men but are still rising for women as they are for both Alaska Native men and women.
OTHER CAUSES
Tobacco use isn't the only reason for the rising rates. Some of the increases, such as for colon and rectum cancer , are thought to be associated with lifestyle changes that include more westernized diets.
And doctors and researchers simply don't know what causes many cancers. Few cancers are known to have the direct cause-and-effect connection as tobacco and lung cancer . Because of that, public health agencies tend to concentrate much of their prevention efforts on tobacco use, reasoning it is the most preventable form of cancer .
But many people in rural Alaska suspect other causes for the rises in cancer rates. They have criticized the IHS and other agencies for not doing more to study those risks.
Villagers on the North Slope and northwest Alaska, for example, have long suspected a link between atmospheric nuclear tests in the Russian Far East in the 1950s and 1960s and rising cancer rates. They believe radioactive fallout contaminated arctic soil and became part of the food chain. Residents of coastal villages are concerned that the marine mammals they hunt are being contaminated with heavy metals and other toxins.
Government doctors and researchers respond that it's difficult to find direct links between environmental factors and high cancer rates. Epidemiologists such as Lanier and Middaugh have tended to downplay such risks, saying that because tobacco is such a clear culprit much more so than environmental factors that efforts should be aimed at reducing smoking.
That message has been largely embraced by the Native-run regional health agencies. But people in the villages, who have seen cancerbecome increasingly common among their neighbors, have their doubts.
"People talk about it a lot," said June Childress of Wainwright, an Inupiat village on the Arctic coast. "A lot of Native people do smoke, but then you see people who you know have never smoked in their whole life who come down with cancer . People wonder about that."
Childress, who is chairwoman of the North Slope Borough's Health Board, said many village cancer cases are so far along by the time they are diagnosed that often there's little chance for recovery. She thinks there needs to be better screening at the village level, as well as more of an effort to identify risk factors in addition to tobacco use.
"I don't think anybody's really dismissing tobacco use as an important factor, but there's a crisis of credibility with the IHS at the village level," said Steve Conn, director of the Alaska Public Interest Research Group.
The Anchorage-based activist organization began working with northwest Alaska villagers after they learned two years ago that the federal government buried radioactive material near Point Hope in the 1960s. Conn thinks agencies haven't taken radiation and other potential environmental problems seriously enough, and because of that, many villagers don't trust the agency, which is responsible for providing health care to Native Americans.
Two years ago, the North Slope Borough hired its own epidemiologist to look at cancer rates in the region. The doctor, Ron Bowerman, is still analyzing data, but said it's clear tobacco use is a major problem. Still, he said, smoking and chewing doesn't explain all of the increases. He's not sure what to blame. He noted that the rising rates and increasing number of cancer deaths have been a shock in many communities.
"You're looking at a population where cancer was virtually unknown at the turn of the century," he said. "Now you have rates that are very similar to the Lower 48, or even higher. I think it's been very alarming for communities to suddenly find out they have a problem with cancer."
Officials with the IHS argue that it's difficult, if not impossible, to establish connections between rising cancer rates in the villages and environmental or other factors, largely because the Native population is small.
"It's been very hard for people to deal with in the villages," said Jim Berner, a family practitioner who is director of community health services for the IHS in Alaska. "A third of the population in the rest of the country gets cancer sometime. Twenty percent of the population dies from it. That's been true for a while in the Lower 48, and people understand that. But it's never been true in our Alaska Native communities until now, and people understandably are very upset.
"And on top of everything else, it's just not possible to say that there is not a unique environmental factor, or for that matter unique genetic factors, that make them more vulnerable," Berner said.
Among the study's other findings:
* While overall cancer rates of Natives are now similar to the nation as a whole, rates for specific kinds of cancer vary widely, with some cancers more common among Natives but others still rare. For example, Natives are at increased risk of cancer of the stomach, cervix, colon and rectum, salivary gland, esophagus, liver, gallbladder and kidney. Rates for leukemia among Natives, though, are about half the national average. Breast cancer , while rising, is also below the national rate, as are cancers of the prostate, bladder, uterus, brain and larynx and lymphoma.
* The Native population has a higher proportion of cancers with poor survival rates, such as lung cancer , than the general population.
* One type of cancer seen increasingly in Natives nasopharynx, which occurs near the nasal cavity is virtually unheard of among Caucasian people in the rest of the country. Doctors don't know why, but some evidence suggests there may a genetic factor. This cancer also has been linked to a virus that has become especially common in rural Alaska. Rates are also high for this cancer among Canadian Eskimos and Chinese, including Chinese Americans. Even so, it's relatively rare among Natives compared with other cancers, with a total of 65 cases recorded statewide during the 20 years of the study.
The actual number of cancer cases increased dramatically from 1969 to 1988, according to the study. In the five years between 1969 and 1973, 394 Native cancer cases were diagnosed, the study says. Between 1984 and 1988, 829 were reported.
There are two reasons for the big jump in cases. The first is that the cancer rates for Natives the likelihood of someone getting cancer in their lifetime are rising. The second is that the Native population is getting older, with more and more people living past age 60. As people age, the chances increase that they will get cancer .
The cancer rates in the study are adjusted to take age differences into account, allowing the Native statistics to be measured against the general population.
At current rates, the number of Native cancer cases will double again within 20 or 30 years, according to Lanier.
Statistics like that make the people who run Alaska's hospitals and health agencies nervous.
"The number of people with chronic disease, not just cancer but heart disease and so on, is growing far more rapidly than our in-patient facilities to care for them," said Berner. "That's the message we've been trying to take the tribal leaders around the state: It's absolutely critical that we develop the ability to care for some of these people in our own regions."
Now, most Native cancer patients are treated at central hospitals in Anchorage, Fairbanks, Sitka or even Outside.
The new cancer study is based on an Alaska Native cancer registry maintained by the IHS in Anchorage. Funding was cut for five years in the 1980s, and one reason the data now only goes through 1988 is that researchers have spent the past several years filling in information from those years, Lanier said.
Information through 1992 is expected to be compiled by the end of this year.