Researchers probe gene possibly linked to breast cancer

<br>WASHINGTON (AP) _ Researchers investigating a gene that they suspect helps spur breast cancer found an unusual racial disparity: The gene appears active more often in the tumors of black women than

Monday, April 21st 2003, 12:00 am

By: News On 6

WASHINGTON (AP) _ Researchers investigating a gene that they suspect helps spur breast cancer found an unusual racial disparity: The gene appears active more often in the tumors of black women than white women.

Breast cancer isn't as common among black women as white women, yet black patients are more likely to die of their disease. Only part of the problem is socioeconomic. Specialists now agree that breast cancer seems more aggressive in black women, although they can't explain why.

The new study of the gene called BP1 provides a promising lead, said chief researcher Dr. Patricia Berg of George Washington University Medical Center, whose findings will be published Tuesday by the journal Breast Cancer Research.

Berg first discovered that BP1 was active in numerous patients with a type of leukemia. Her research suggested that when the gene is switched on, it interferes with cell regulation in a way that helps cancerous cells survive.

Wondering if BP1 played a role in other malignancies, she tested breast cancer tissue from 46 patients. Berg found BP1 activity in 89 percent of the tumors from black women, compared with 57 percent of the white women's tumors.

Berg found BP1 expression in only one of seven samples of normal breast tissue.

Another surprise: BP1 was active in 100 percent of tumors that are hard to treat because they are not affected by estrogen, compared with three-fourths of estrogen-sensitive tumors.

Other cancer specialists called the findings intriguing, but cautioned that the study was far too small to determine if BP1 really plays a role in breast cancer, particularly the racial disparity.

``This may be a tip-off, but it's too early to tell,'' said Dr. Herman Kattlove of the American Cancer Society.

Another question is just what role BP1 plays in overall cancer development, said Dr. Joseph Fontana of Wayne State University _ noting that Berg also found BP1 activity in two benign breast tumors.

Berg plans additional testing to see how often BP1 activity is detected in non-cancerous breast tissue, and is working to develop a blood test.