New study is first to show that risk of childhood obesity may be reduced by treating pregnant woman for gestational diabetes

New study confirms link between breast cancer and hormone therapy

New Study Finds Breast Cancer Survivors Don’t Need to Increase Fruits and Vegetables beyond National Guidelines

Kaiser Permanente’s Center for Health Research 2007 Saward Lecture

Kaiser Permanente’s Center for Health Research Wins $2.76 Million Award to Study Long-Term Oxygen Treatment for Patients with COPD

National Study Shows Patients with Chronic Obstructive Pulmonary Disease and Asthma Receive Only Half of Recommended Care

Kaiser Permanente Study Shows Flu Vaccine Safe for Young Children

Kaiser Permanente’s Center for Health Research Launches Two New Smoking Cessation Studies

OHSU, Kaiser Permanente Northwest Partner to Win $55 Million Grant to Transform Medical Research

Using Safety Alerts in Electronic Medical Records Reduces Rates of Potentially Dangerous Medication Interactions

Kaiser Permanente of Georgia to merge research program

Making longer-term lifestyle changes lowers rates of high blood pressure and risk of heart disease

What's New - Breast Cancer Risks

Preventive Removal of Both Breasts Reduces Chance of Breast Cancer in Women at Elevated Risk

(PORTLAND, Ore.) -  Women with a moderately elevated risk of breast cancer who underwent surgery to have both breasts removed reduced their risk of getting the disease by about 95 percent. Women with a personal history of breast cancer were excluded from the study. The study, conducted by scientists at six health plans, is published in the March 14, 2005, edition of the Archives of Internal Medicine.

It is possible for breast cancer to occur after removal of both breasts because small amounts of breast tissue can sometimes remain even after breast surgery.

"Prophylactic mastectomy appears to be very effective in preventing breast cancer, said Emily L. Harris, PhD, one of the co-authors of the study and a senior investigator at Kaiser Permanente's Center for Health Research in Portland. "However, choosing to have this surgery is a difficult and complex decision. Prophylactic mastectomy prevents breast cancer, but it also carries a risk of complications and may impact a woman's psychosocial health. A woman who is considering this procedure should talk to her doctor, family and friends, and get genetic counseling to help her understand her risk of breast cancer and learn about all her options. Rather than choosing surgical removal of her breasts, women may choose to manage their risk with tamoxifen, prophylactic ovarian surgery, regular mammograms, or possibly MRI."

The study's patients were female members from multiple health plans who were 18 to 80 years of age between Jan. 1, 1979, and Dec. 31, 1998. Each had at least one breast cancer risk factor. This means that these women's chance of getting breast cancer in the next 10 years was about double that of women the same age who were at average risk of breast cancer. The most often noted risk factors were having a family history of breast cancer, a personal history of atypical hyperplasia (a potentially pre-cancerous condition), and one or more benign breast biopsies.

"The vast majority of women in this study had not had genetic testing for breast cancer risk because it was not available at the time they had their breasts removed," Harris noted. "So our study does not address the use of prophylactic mastectomy in women who have a breast cancer susceptibility gene. However, other studies suggest that this surgery prevents most breast cancers in women who have a genetic susceptibility."

The multicenter study was performed at the six plans of the National Cancer Institute-funded Cancer Research Network: Group Health Cooperative, Washington; Harvard Pilgrim Health Care, Massachusetts; HealthPartners, Minnesota; and Kaiser Permanente's Northwest, and Northern and Southern California Regions. The Cancer Research Network is a consortium of integrated healthcare delivery systems that uses its large populations and data resources to conduct research that transforms cancer prevention and care.

In addition to Harris, the other authors are Ann M. Geiger, PhD, Research and Evaluation Department, Southern California Permanente Medical Group, Pasadena; Onchee Yu, MS, Group Health Cooperative Center for Health Studies, Seattle; Lisa J. Herrinton, PhD, Division of Research, Permanente Medical Group, Oakland; Sharon Rolnick, PhD, Health Partners Research, Minneapolis; Mary B. Barton, MD, and Suzanne W. Fletcher, MD, Msc, Department of Ambulatory Care and Prevention, Harvard Pilgrim Health Care, Boston; and William E. Barlow, PhD, and Joann G. Elmore, MD, Departments of Biostatistics and Medicine, University of Washington, Seattle.

Kaiser Permanente's Center for Health Research, founded in 1964, is a non-profit research institution whose mission is advancing knowledge to improve health. Kaiser Permanente Northwest is a group practice health care organization founded in 1945 and serving the health care needs of more than 460,000 people in Oregon and Southwest Washington.For more infomation contact: