Decline in Breast Cancer Diagnoses Follows Decline in Hormone Therapy Use, Recent Data Confirms
Posted on: Wednesday, 6 December 2006, 21:00 CST
OAKLAND, Calif., Dec. 6 /PRNewswire/ -- Research scientists at the Northern California Cancer Center and Kaiser Permanente's Division of Research have found significant reductions in both the use of hormone replacement therapies and the incidence of breast cancer in California in the years following the release of the 2002 Women's Health Initiative (WHI) trial results. The data appear in the November 20 issue of the Journal of Clinical Oncology.
Previous studies have shown that long-term use of hormone therapy is linked to increased risk of breast cancer. For example, the WHI randomized trial and other studies discovered that estrogen plus progestin hormone therapy use increased a woman's risk of breast cancer.
This new analysis, the first to use the most recent 2004 California Cancer Registry data, supports the theory that women who discontinue hormone therapy use may reduce their chances of being diagnosed with breast cancer.
"Hormone therapy use dropped 68 percent between 2001 and 2003, and shortly thereafter we saw breast cancer rates drop by 10 to 11 percent. This drop was sustained in 2004, which tells us that the decline wasn't just a fluke," notes Dr. Christina A. Clarke, the Northern California Cancer Center scientist who led the study.
In the current study, researchers examined yearly prevalence of hormone therapy use and breast cancer incidence from 1994 to 2003 for women ages 50 to 74 in Kaiser Permanente's Northern California Region and in the 2004 California Cancer Registry. They found consistent evidence of corresponding trends in decline in both hormone therapy use and breast cancer incidence. "We can't say that changes in hormone therapy use caused the decline in breast cancer, because these data don't link hormone users directly to breast cancer diagnoses, but they are certainly suggestive," adds Dr. Lisa Herrinton from Kaiser Permanente's Division of Research. "If it holds up over time, a 10 percent decline in breast cancer incidence is really striking. It amounts to an annual reduction of about 10,000 breast cancer cases in women aged 50 to 74."
Similar studies on the decline of breast cancer incidence in the United States will be presented by different researchers at the San Antonio Breast Cancer Symposium next week, though only data from 2003 is presented. The Northern California Cancer Center/Kaiser Permanente study includes data through 2004, and it provides information on hormone therapy for the same population.
From their analysis, researchers maintain that breast cancer incidence trends need to be monitored closely in regard to patterns of hormone therapy use. "Based upon what we know about the biology of hormone therapy, the declines make a lot of sense, and we want to continue to track these parallel trends," says Clarke.
The Northern California Cancer Center (http://www.nccc.org/) is an established, nationally recognized leader dedicated to understanding the causes and prevention of cancer and to improve the quality of life for individuals living with cancer. NCCC has been working with scientists, educators, patients, clinicians, and community leaders successfully since 1974, and is an active partner with Stanford University's Comprehensive Cancer Center. NCCC is a 501(c)3 nonprofit with over 160 employees and a $15 million operating budget.
The Kaiser Permanente Division of Research conducts, publishes, and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well-being and to improve the quality and cost-effectiveness of health care. Currently, DOR's 400-plus staff is working on more than 250 epidemiological and health services research projects.
Kaiser Permanente
CONTACT: Desiree Aquino of Northern California Cancer Center,+1-510-608-5160, or daquino@nccc.org; or Maureen McInaney of KaiserPermanente, +1-510-987-4779, or Maureen.McInaney@kp.org
Web site: http://www.kaiserpermanente.org/http://www.nccc.org/
Source: PRNewswire
Related Articles
- Up and Down Reductions In Breast Cancer Suggest Hormone Therapy To Blame
- Kaiser Permanente Study Finds Drinking Wine May Lower Risk of Barrett's Esophagus, Precursor to Nation's Fastest Growing Cancer, Esophageal Cancer
- Kaiser Permanente Bellflower Medical Center Welcomes Quadruplets
- Kaiser Permanente Honored for Improving Cancer Care Through Clinical Research
- Kaiser Permanente Colorado Opens Center for Health Dissemination and Implementation Research
- New Study Confirms Link Between Breast Cancer and Hormone Therapy
- Hormone Therapy Linked to Increased Incidence of Ovarian Cancer
- Wizzard Software, MedivoxRx Technologies Announce Kaiser Permanente Now Offering Rex-The Talking Prescription Bottle in Northern California
- Kaiser Permanente Fresno Medical Center Selects Dragon NaturallySpeaking Medical 8 From Nuance
- Cancer Link with Hormone Therapy Known Since 1930s, say Researchers
 |
 |
User Comments (0)
RSS Feeds