EDMONTON - Researchers who examined cancer rates in a small aboriginal community near the oilsands in northern Alberta have found more cases than expected.

But Dr. Tony Fields, a senior official with Alberta Health Services, said Friday the higher numbers shouldn't have people jumping to conclusions about a possible link to the environment.

Some communities downstream from oilsands plants have expressed concerns that industrial pollution is responsible for cancers and other health problems.

Aboriginal leaders and health officials said the latest study has done little to determine why people in their communities are dying of cancer.

"The question we have is what is causing this outbreak of cancer in our community, yet no one has come to us with an answer," said Roxanne Marcel, chief of the Mikisew Cree First Nation.

Alberta Cancer Board researchers examined information gathered from 47 residents of Fort Chipewyan who were diagnosed with cancer between 1995 and 2006.

Fields said the study found evidence of 51 cancers of varying types, including some relatively rare ones.

Researchers had expected to find 39 cancers.

They noted in the study that there were three cases of bile duct-related cancer and two cases of soft tissue cancer, which was higher than anticipated.

There were also eight cases of blood and lymphatic cancer, more than double what they expected to see.

But Fields said the study didn't address risk factors for those cancers, including possible links to environmental causes.

"These could be due to chance, they could be due to increased detection of cancers, they could be due to increased risk in the community. Our investigation can't go any farther in distinguishing these," Field said.

He suggested cancer cases in the aboriginal community about 600 kilometres north of Edmonton should be closely monitored to see whether any cancer trends emerge in the future.

"What we would recommend is we should keep a close eye on this population," he said. "We should look and see what do the next five to 10 years bring."

Alberta Liberal Leader David Swann, a former medical officer of health, said urgent action is required and suggested it isn't happening because of the location of the problem.

"I guess if this development was upstream of Calgary, we'd know a lot more about what was going on in the environment, in the food, in the air, and what people are consuming on a daily basis, than we do today," he said.

"This is the largest development on the planet, we need to know a lot more about what's happening there, and respecting the rights and protecting the health of the communities up there."

But Alberta Health Minister Ron Liepert called the study "quite conclusive."

"There are some issues that have been identified that, clearly, we want to address going forward, and beyond that I think that some of the other findings in the report put to rest some of the concerns that have been expressed over the past number of years," he said.

"People are always expecting black and white, and I don't know if you can necessarily ever come to black and white."

The report's author, Dr. Yiqun Chen, wrote in the report the study's limitations "prevented any conclusions being reached about whether the cancer rates (in Fort Chipewyan) are related to living near the oilsands."

She concluded that it's still not clear whether people living in the community have an increased risk of developing cancer and noted the study didn't investigate any potential links with environmental exposures.

But she pointed out there's a need to continue to study people in the community.

"Health concerns voiced by the Fort Chipewyan community, the existing evidence about the potential environmental contaminants in the area, along with an absence of a general increase in cancer rates in comparison communities justify further investigations," she wrote.

Those investigations would include potential risk factors such as lifestyle, family history, occupational and environmental exposures, Chen added.

The study was peer reviewed by experts in Australia, New Zealand and the U.S.

"The overall findings show no cause for alarm. They do however point to the need for some further investigation," Fields said.

Marcel and two senior officials with the Nunee Health Board Society in the region, Claudia Simpson and Steve Courtoreille, were heavily critical of the study.

Simpson said the study was flawed in several ways, particularly because people with cancer who once lived in Fort Chipewyan but have moved away weren't counted in the study.

They also blasted their community's lack of involvement in the study and slammed health officials for not giving them an advance look at the complicated report before it was publicly released.

"We need our own experts to review it and say what more we need to get done and what recommendations they have in relation to this study," said Marcel from Slave Lake, Alta., where the trio were attending a Treaty 8 First Nations health meeting.

Field's conclusion that no one in the tiny aboriginal community should be alarmed by the study's findings did not come as a surprise to its leaders.

"This is expected. No one is going to want to take responsibility for ill health downstream from an industry, absolutely not, so one would expect that this is the way things would go," Simpson said.

"It's very frustrating. We've been studied to death by everybody and we're not anywhere near to finding out what are the causes," said Courtoreille.

Aboriginal leaders will be meeting in the near future to determine what kind of steps the community should take next, he said.

"We're not saying it's all industry's fault. We're wondering what it is. Let's get to the bottom of it."