Navigation Links
Breast cancer risk varies among different progestins used in hormone replacement therapy
Date:8/10/2010

COLUMBIA, Mo. Progestins are used in hormone replacement therapies to counteract the negative effects of estrogen on the uterus and reduce the risk of uterine cancer. However, evidence in recent studies and clinical trials has demonstrated that progestins increase the risk of breast cancer. Now, University of Missouri researchers have compared four types of progestins used in hormone replacement therapies and found significantly different outcomes on the progression of breast cancer in an animal model depending on the type of progestins used.

"Synthetic progestins have different biological effects, due to differences in their structure, stability and how they interact in the body," said Salman Hyder, the Zalk Endowed Professor in Tumor Angiogenesis and professor of biomedical sciences in the College of Veterinary Medicine and the Dalton Cardiovascular Research Center. "Clinical use of progestins requires caution. These powerful steroids should only be prescribed when a person has no latent, or dormant, cancer and does not have a family history of cancer. However, it is difficult to diagnose latent tumor cells in women since there are no symptoms."

In the study, researchers compared the effects of four clinically relevant progestins on breast cancer tumors in an animal model. The progestins used in the study were the synthetic progestin medroxporgresterone acetate (MPA), norgesterel (N-EL), norethindrone (N-ONE) and megestrol acetate (MGA). In the United States, most women on hormone replacement therapy are treated with MPA, the progestin in Prempro, Hyder said.

"Although previous studies using an animal model for breast cancer found that MPA functions as a tumor promoter, this study show that N-EL and N-One, when administrated using the same protocol as used for MPA, strongly inhibited tumor development," Hyder said. "Thus progestins seem to have tumor-stage specific effects, which determine whether these will function as tumor promoters or tumor suppressors. Progestins, such as N-EL and N-ONE, may have potential as preventive agents in women with no history of breast disease or family history of breast cancer. These progestins may also have a preventive role in post-menopausal women who are at an increased risk for developing breast cancer due to ingestion of combined estrogen/progestin (MPA) hormone replacement therapy and may have early stage disease."

The chart below shows the tumor latency and tumor incidence for the four types of progestins. Tumor latency is the period from when the animal model is first exposed to tumor cells to the first signs of cancer.


'/>"/>

Contact: Steven Adams
adamsST@missouri.edu
573-882-8353
University of Missouri-Columbia
Source:Eurekalert

Related medicine news :

1. Paxil Blocks Tamoxifen, Lowers Survival Odds Against Breast Cancer
2. Low forms of cyclin E reduce breast cancer drugs effectiveness
3. Racial disparities persist in the diagnosis of advanced breast cancer and colon cancer in the U.S.
4. For Some Breast Cancer Patients, Shorter Radiation Works Well
5. Short-term radiation therapy successful on breast cancer
6. Few Women at High Risk for Breast Cancer Take Tamoxifen
7. Hormone May Prevent Aggressive Breast Cancer
8. MSU researcher linking breast cancer patients with alternative therapies
9. MRI May Not Add Value to Routine Breast Cancer Care
10. Breast Cancer Stats Differ Racially Despite Similar Mammogram Rates
11. Businesses Rally Big Efforts to Benefit the Susan G. Komen Phoenix Affiliates Fight Against Breast Cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/9/2016)... ... 09, 2016 , ... The Pennsylvania Athletic Trainers’ Society (PATS) ... summer of 2016. The program was made possible by a Pennsylvania Department of ... Health and Human Services Administration. The broadcast, Use Your Head: Properly Managing ...
(Date:12/8/2016)... (PRWEB) , ... December 08, 2016 , ... ... Compensation Research Institute (WCRI) officially opened registration today for its 33rd Annual ... in Boston, MA . , The theme of the conference is “Persistent Challenges ...
(Date:12/8/2016)... PLAINS, N.Y., and JENNERSVILLE, Pa. (PRWEB) , ... ... ... to announce that Penn Medicine Southern Chester County, a Property owned by an ... The $23 million, 72,000 square foot Penn Medicine Southern Chester County ambulatory care ...
(Date:12/8/2016)... , ... December 08, 2016 , ... With the increasing ... the “What’s In Your Mouth?” (WIYM) campaign to inform dentists and patients about the ... the dental implant and prosthetic market in the U.S. is projected to reach $6.4 ...
(Date:12/8/2016)... Tampa, Fla (PRWEB) , ... December 08, 2016 ... ... offering smarter modes of access for customers and employees that are both engaging ... ChangeGear 7 with Service Smart Technology, the software company revealed today its plans ...
Breaking Medicine News(10 mins):
(Date:12/8/2016)... 8, 2016  Eli Lilly and Company (NYSE: ... phase 3 EXPEDITION3 trial at the 9 th ... disclosed, solanezumab did not meet the primary endpoint in ... in people with mild dementia due to Alzheimer,s disease ... solanezumab for the treatment of mild dementia due to ...
(Date:12/8/2016)... Bodycad announced it has been awarded ... reproducibility and speed for 3D constructs via MRI ... orthopaedic applications. These patents are critical to the ... based on each patient,s distinct anatomy. ... the world,s first suite of orthopaedic CAD/CAM software. ...
(Date:12/8/2016)... , Dec. 8, 2016  EIP Pharma, ... has obtained proof-of-mechanism for neflamapimod (previously code named ... Phase 2a clinical trials that demonstrated significant Alzheimer,s ... 302 (12-week treatment) and Study 303 (6-week treatment) ... Trials in Alzheimer,s Disease (CTAD) scientific conference in ...
Breaking Medicine Technology: