Menopausal estrogen replacement therapy (ERT) also significantly increases the likelihood of the cancer metastasizing to the lymph nodes, according to the study, which will be published in the Nov. 1 issue of Cancer Research.
The study was released online Oct. 19, 2010. Cancer Research, published by the American Association for Cancer Research, is the world's largest circulation medical journal devoted specifically to cancer research.
The effect of ERT was shown in mouse models of estrogen receptor positive(ER+) ovarian cancer, which accounts for about 60 percent of all human ovarian cancer cases. Ovarian cancer is one of the deadliest cancers affecting women. This year alone, nearly 22,000 women will be newly diagnosed with ovarian cancer and an estimated 13,850 women will die from the disease, according to the National Cancer Institute.
"We showed that estrogen replacement substantially increases proliferation and risk of distant lymph node metastasis in ER+ tumors," says Monique Spillman, MD, PhD, the study's lead researcher, a gynecologic oncologist at University of Colorado Hospital and assistant professor at of obstetrics and gynecology at the University of Colorado School of Medicine.
For the first time, Spillman and her team measured ovarian cancer growth in the abdomen of mice using novel techniques for visualizing the cancer. In mice with ER+ ovarian cancer cells, which were tagged with a firefly-like fluorescent protein that allowed them to be tracked, the introduction of estrogen therapy made the tumors grow five times faster than in mice that did not receive the ERT. The risk of the cancer moving to the lymph nodes increased to 26 percent in these mice compared with 6 percent in mice that did not receive ERT.
The team also found that the estrogen-regulated genes in ovarian cancer reacted differently than ER+ genes found in breast cancer, helping to explain why current anti-estrogen therapies used with breast cancer, such as Tamoxifen, are largely ineffective against ovarian cancer.
"Breast cancer and ovarian cancer are often linked when talking about hormone replacement therapy, but we found that only 10 percent of the ER+ genes overlapped," Spillman says. "We were able to identify estrogen-regulated genes specific to ER+ ovarian cancer that are not shared with ER+ breast cancers. We believe these genes can be specifically targeted with new anti-estrogen therapies that could more effectively treat ER+ ovarian cancers."
Spillman and her team now will begin to screen current antiestrogen therapies against the newly identified ovarian cancer genes to identify the pathways and compounds that are more likely to effectively treat ER+ ovarian cancer.
This study looked at the effect of estrogen replacement therapy in mice that already possessed ER+ ovarian cancer cells. It did not test whether the estrogen replacement actually could cause the development of these cancer cells. The study also dealt only with estrogen replacement, which is linked to higher risks of ovarian cancer, not combined estrogen/progesterone therapy that is used with women who retain their uteruses.
This research is too early to draw implications for use of estrogen replacement therapy in women, Spillman cautions. "We cannot make clinical recommendations based on what is happening in mice," says Spillman, one of just eight gynecological oncologists in Colorado. "Every woman is different and needs to talk to her doctor about the decision to use hormone replacement therapy."
The study was funded by a Gynecologic Cancer Foundation Career Development Award and the Liz Tilberis Scholars Award from the Ovarian Cancer Research Foundation. This competitive award, a $450,000 three-year grant, is given to early-career researchers who are developing techniques for early diagnosis and improved care for women with ovarian cancer.
About the University of Colorado Cancer Center
The University of Colorado Cancer Center is the Rocky Mountain region's only National Cancer Institute-designated comprehensive cancer center. NCI has given only 40 cancer centers this designation, deeming membership as "the best of the best." Headquartered on the University of Colorado Denver Anschutz Medical Campus, UCCC is a consortium of three state universities (Colorado State University, University of Colorado at Boulder and University of Colorado Denver) and five institutions (The Children's Hospital, Denver Health, Denver VA Medical Center, National Jewish Health and University of Colorado Hospital). Together, our 440+ members are working to ease the cancer burden through cancer care, research, education and prevention and control.
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
21.09.2017 | Physics and Astronomy
21.09.2017 | Life Sciences
21.09.2017 | Health and Medicine