Corporate Banner
Satellite Banner
Genomics
Scientific Community
 
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
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 2,500+ scientific posters on ePosters
  • More than 3,700+ 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

Cellular Factors that Shape the 3D Landscape of the Genome Identified
Researchers have identified 50 cellular factors required for the proper 3D positioning of genes by using novel large-scale imaging technology.
Tuesday, August 18, 2015
Nuclear Process in the Brain That May Affect Disease Uncovered
Scientists have shown that the passage of molecules through the nucleus of a star-shaped brain cell, called an astrocyte, may play a critical role in health and disease.
Tuesday, August 18, 2015
Tell-tale Biomarker Detects Early Breast Cancer in NIH-funded Study
The study published online in the issue of Nature Communications.
Thursday, August 13, 2015
Scientists Adopt New Strategy to Find Huntington’s Disease Therapies
Large, international NIH-supported study uses precision medicine to tackle neurological disorders.
Tuesday, August 11, 2015
Study Shows Promise of Precision Medicine for Most Common Type of Lymphoma
The study appeared online July 20, 2015, in Nature Medicine.
Tuesday, July 21, 2015
NIH Study Identifies Gene Variant Linked to Compulsive Drinking
Mice carrying the Met68BDNF gene variant would consume excessive amounts of alcohol.
Tuesday, July 21, 2015
In Blinding Eye Disease, Trash-Collecting Cells Go Awry, Accelerate Damage
NIH research points to microglia as potential therapeutic target in retinitis pigmentosa.
Friday, July 03, 2015
Potential Therapeutic for Blinding Eye Disease
NIH research points to microglia as potential therapeutic target in retinitis pigmentosa.
Thursday, July 02, 2015
NCI-MATCH Trial will Link Targeted Cancer Drugs to Gene Abnormalities
Precision medicine trial will open to patient enrollment in July.
Tuesday, June 09, 2015
A New Role for Zebrafish: Larger Scale Gene Function Studies
A relatively new method of targeting specific DNA sequences in zebrafish could dramatically accelerate the discovery of gene function and the identification of disease genes in humans.
Monday, June 08, 2015
NIH Researchers Pilot Predictive Medicine by Studying Healthy People’s DNA
New study sequence the genomes of healthy participants to find “putative,” or presumed, mutations.
Friday, June 05, 2015
Linking Targeted Cancer Drugs to Gene Abnormalities
Investigators at the NIH have announced a series of clinical trials that will study drugs or drug combinations that target specific genetic mutations.
Wednesday, June 03, 2015
Scientists Create Mice with a Major Genetic Cause of ALS and FTD
NIH-funded study provides new platform for testing treatments for several neurodegenerative disorders.
Friday, May 22, 2015
Mice With a Major Genetic Cause of ALS and FTD Created
NIH-funded study provides new platform for testing treatments for several neurodegenerative disorders.
Thursday, May 21, 2015
New Insights into How DNA Differences Influence Gene Activity, Disease Susceptibility
NIH-funded pilot study provides a new resource about variants across the human genome.
Friday, May 08, 2015
Scientific News
Poor Survival Rates in Leukemia Linked to Persistent Genetic Mutations
For patients with an often-deadly form of leukemia, new research suggests that lingering cancer-related mutations – detected after initial treatment with chemotherapy – are associated with an increased risk of relapse and poor survival.
Searching Big Data Faster
Theoretical analysis could expand applications of accelerated searching in biology, other fields.
Growing Hepatitis C in the Lab
Recent discovery allows study of naturally occurring forms of hepatitis C virus (HCV) in the lab.
Inciting an Immune Attack on Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
Reprogramming Cancer Cells
Researchers on Mayo Clinic’s Florida campus have discovered a way to potentially reprogram cancer cells back to normalcy.
Genetic Overlapping in Multiple Autoimmune Diseases May Suggest Common Therapies
CHOP genomics expert leads analysis of genetic architecture, with eye on repurposing existing drugs.
Surprising Mechanism Behind Antibiotic-Resistant Bacteria Uncovered
Now, scientists at TSRI have discovered that the important human pathogen Staphylococcus aureus, develops resistance to this drug by “switching on” a previously uncharacterized set of genes.
How DNA ‘Proofreader’ Proteins Pick and Edit Their Reading Material
Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have discovered how two important proofreader proteins know where to look for errors during DNA replication and how they work together to signal the body’s repair mechanism.
Fat in the Family?
Study could lead to therapeutics that boost metabolism.
Tissue Bank Pays Dividends for Brain Cancer Research
Checking what’s in the bank – the Brisbane Breast Bank, that is – has paid dividends for UQ cancer researchers.
Skyscraper Banner

Skyscraper Banner
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
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!