29.0°

ANCHORAGE - The unexplained increase in breast cancer rates among Alaska Native women may finally be leveling off, but doctors say there's no sign of a decline just yet.

Breast cancer rates have been rising among Alaska Natives for three decades, tripling between 1969 and 1998. The disease was once relatively rare among Alaska Native women, but now matches the rate for white women nationwide. It also exceeds by half the rate for American Indians and Alaska Natives who live in the Lower 48.

"I think you'd be hard-pressed to say there's anything (like a decline) going on yet," said Janet Kelly, an epidemiologist with the Alaska Native Tribal Health Consortium. She was speaking at a Mayo Clinic-led cancer conference at the Alaska Native Medical Center.

The incidence of breast cancer rose sharply among Alaska Native women toward the end of the 20th century from 40 cases per 100,000 in the early 1970s to 138 cases per 100,000 in the mid 1990s.

The rate fell slightly to 132 cases from 1999 to 2004.

Some of the chief risk factors for breast cancer include obesity, lack of exercise, excessive alcohol consumption and hormone therapies, said Dr. Sandhya Bruthi, a pathologist at the Mayo Clinic in Rochester, Minn.

No single lifestyle change has been shown to prevent breast cancer, Bruthi said, but controlling weight through diet and exercise reduces the risk, especially among women age 50 and older.