Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

More Evidence Shows Hormone Therapy May Increase Breast Cancer Risk

Published: Tuesday, April 02, 2013
Last Updated: Tuesday, April 02, 2013
Bookmark and Share
In new analysis, researchers found risk highest when used just before menopause.

Women who take hormone therapy that includes estrogen and progestin are at increased risk of developing breast cancer and dying from it, especially if they start taking the therapy just as menopause begins, a new analysis confirms.

Researchers followed nearly 42,000 women, all of whom were past menopause, for an average of more than 11 years. Of those, more than 25,000 did not use hormone therapy and more than 16,000 took estrogen and progestin, also called combined hormone therapy. For this analysis, the researchers did not include estrogen-only therapy, used by women who have had a hysterectomy.

At the end of the follow-up period, more than 2,200 of the women were found to have breast cancer. Compared to non-users, those who took combined therapy were more likely to have breast cancer, said Dr. Rowan Chlebowski, a medical oncologist at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center. Chlebowski led the study, which was published in the March 29 issue of the Journal of the National Cancer Institute.

The link has been found in other studies, but Chlebowski also found the risk was greatest among those who took the hormones closest to menopause. "Women starting within months of menopause had about a threefold greater risk than women starting 10 years after menopause," Chlebowski said.

For the new analysis, Chlebowksi looked at results from the Women's Health Initiative observational study. He compared the findings with those from the Women's Health Initiative randomized clinical trial, in which women were assigned to different treatments.

The Women's Health Initiative included four clinical trials and an observational study. Women were all past menopause and were aged 50 to 79.

Chlebowski said he did the new analysis to resolve what he saw as unanswered questions. In the trial, only about one-third, or 5,000, of the women were in their 50s when they started the study. As that is the typical age for menopause to start, about two-thirds of the women in the trial were in their 60s or beyond, so began to take hormones several years after menopause.

Chlebowski set out to see if the link between breast cancer risk and combined hormone therapy use was influenced by earlier use of hormones.

"We had a substantial number closer to menopause than the clinical trial of [the Women's Health Initiative]," he said.

He found, however, that not only was the risk of breast cancer still increased, but it also increased even more if the women were closer to menopause when they began to take the hormones.

He speculated that women who start the hormone therapy close to menopause still have circulating levels of estrogen high enough to make them exceed some threshold, beyond which it may become hazardous.

Progestin is thought to play a role, too, he added.

Although others have thought that the breast cancers linked with combined hormone therapy are often ones with a somewhat better outlook -- another question Chlebowski thought needed more study -- he did not find that in his new analysis.

The new analysis reinforces the finding that combination hormone therapy is linked with higher breast cancer risk, said Dr. Joanne Mortimer, director of Women's Cancer Programs at the City of Hope Comprehensive Cancer Center in Duarte, Calif.

Although previous research has found some good effects of hormone therapy on the heart, she and Chlebowski said that has to be weighed against the breast cancer risk found in much other research.

The new analysis also suggests that "the time of starting hormone therapy really matters," Mortimer said. Although the analysis found an association between the two, it did not prove a cause-and-effect link.

Mortimer and Chlebowski agreed that women need to discuss the pros and cons of hormone therapy during menopause with their doctors.

Women should seriously consider whether their symptoms, such as hot flashes and night sweats, are limiting enough to warrant taking hormones, Chlebowski said. Although some women are severely bothered by symptoms, he said, others may be less bothered and can avoid hormone therapy.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 4,000+ scientific posters on ePosters
  • More Than 5,300+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Exploring the Genome of the River Blindness Parasite
Researchers have decoded the genome of the parasite that causes the skin and eye infection known as river blindness.
Wednesday, December 07, 2016
Gene-Editing Improves Vision in Blind Rats
Scientists developed a targeted gene-replacement technique that can modify genes in both dividing and non-dividing cells in living animals.
Wednesday, December 07, 2016
Uncovering Cerebral Malaria’s Deadly Agents
NIH scientists film inside mouse brains to uncover biology behind the disease.
Wednesday, December 07, 2016
Study to Assess Shorter-Duration Antibiotics in Children
Physicians plan a clinical trial to evaluate whether short course anti-biotics are effective at treating CAP in children.
Wednesday, November 30, 2016
First New HIV Vaccine Study for Seven Years Begins
South Africa hosts historic clinical trial of experimental HIV vaccine aiming to safely prevent HIV infection.
Wednesday, November 30, 2016
Antibody Protects Mice from Zika Infection
Researchers develop human-derived antibody protected pregnant mice and their developing fetuses from Zika infection.
Wednesday, November 23, 2016
Food Additives Promote Inflammation, Colon Cancer
Dietary emulsifiers promoted colon cancer in a mouse model by altering gut microbes and increasing gut inflammation.
Wednesday, November 23, 2016
Protein-Folding Gene Helps Heal Wounds
Researchers identified a protein that dramatically accelerates wound healing in animal models.
Wednesday, November 23, 2016
More Immunotherapy Options Approved for Lung Cancer
The FDA has approved a new immunotherapy drug for certain patients with non-small cell lung cancer.
Monday, November 21, 2016
Big Data for Infectious Disease Surveillance
NIH-led effort examines use of big data from health records and other digital sources for uses in infectious disease surveillance.
Tuesday, November 15, 2016
Potential Therapies Against Drug-Resistant Bacteria Identified
Researchers create new identification method for drug and drug combinations that may combat resistant infections.
Thursday, November 10, 2016
Testing Zika Vaccine in Humans Begins
The first of five planned clinical trials to test ZPIV vaccine in humans has begun.
Tuesday, November 08, 2016
Genetic Markers Predict Malaria Treatment Failure
By comparing 297 parasite genomes to a reference malaria parasite genome, researchers have identified two genetic markers that are strongly associated with the parasites’ ability to resist piperaquine.
Monday, November 07, 2016
Cannabinoid Receptor Structure Revealed
Scientists provided a detailed view of the primary molecule through which cannabinoids exert their effects on the brain. The findings might help guide the design of more targeted medicines with fewer side effects.
Wednesday, November 02, 2016
NIH Researchers Unveil New Wound-Healing Role for Protein-Folding Gene in Mice
The study found that topical treatment of an Hsp60-containing gel dramatically accelerates wound closure in a diabetic mouse model.
Friday, October 28, 2016
Scientific News
Big Genetics in BC: The American Society for Human Genetics 2016 Meeting
Themes at this year's meeting ranged from the verification, validation, and sharing of data, to the translation of laboratory findings into actionable clinical results.
Stem Cells in Drug Discovery
Potential Source of Unlimited Human Test Cells, but Roadblocks Remain.
Automated Low Volume Dispensing Trends
Gain a better understanding of the current and future market requirements for fully automated LVD systems.
Personality Traits, Psychiatric Disorders Linked to Specific Genomic Locations
Researchers have unearthed genetic correlations between personality traits and psychiatric disorders.
Forensic 3D Documentation of Skin Injuries
In this study, the validity of using photogrammetry for documenting injuries in a pathological context was demonstrated.
3-D Printed Dog’s Nose Improves Vapor Detection
By mimicking how dogs get their whiffs, a team of government and university researchers have demonstrated that “active sniffing” can improve by more than 10 times the performance of current technologies that rely on continuous suction to detect trace amounts of explosives and other contraband.
New Markers for Forensic Body-fluid Identification
University of Bonn researchers have successfully identified specific Micro-RNA signatures to help forensically identify body fluids.
Genetics Control Regenerative Properties Of Stem Cells
Researchers define how genetic factors control regenerative properties of blood-forming stem cells.
Major Neuroscience Initiative Launched
Tianqiao and Chrissy Chen Institute invest $115 million to further expand neuroscience research, while Caltech construct $200 million biosciences complex.
Making It Personal
Cancer vaccine linked to increased immune response against leukemia cells.
Scroll Up
Scroll Down
Skyscraper Banner

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
4,000+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,300+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!