Long-term hormone replacement therapy increases breast cancer risk

May 28, 2008

Now there is proof for women in Germany, too: If hormone replacement therapy is taken over a period of more than five years, the risk of breast cancer will increase. While this risk is considerably elevated during use of hormone medication, it drops back to the original level within about five years after a woman has stopped taking hormones.

“Are you taking or did you take hormones? If yes, which hormone medication and for how long? When did you stop taking hormone replacement medication?” 3,464 breast cancer patients and 6,657 healthy women between the ages of 50 and 74 years participated in a large survey and elicited detailed information about hormone replacement medications they are taking or used to take for relief of menopausal symptoms.

The survey was prompted by the “MARIE” case-control study carried out by the German Cancer Research Center (DKFZ) and the University Hospitals in Hamburg-Eppendorf, Germany. The goal of this 6-year study, which was financed by the German Cancer Aid (Deutsche Krebshilfe), was to determine the effect of hormones – both on their own and in association with other factors – on breast cancer risk.

Women who have taken menopausal hormone therapy before have a 37 percent higher risk of breast cancer than women who have never taken hormone replacement therapy (HRT). During the actual time of HRT use the risk is even elevated by 73 percent. Within five years after cessation of therapy the risk of breast cancer in former HRT users falls back to the level of women who never used HRT. “These results of the MARIE study confirm findings of two U.S. and U.K. studies (Women’s Health Initiative Study and Million Women Study) that caused a stir in 2002 and 2003,” says Professor Dr. Wilhelm Braendle of Hamburg-Eppendorf University Hospitals, who headed the study.

“It has often been argued that the results of the U.S. study could not be applied to Germany where prescription practices are completely different. Therefore, we captured the various hormone preparations, especially the various progestins, very precisely. We have obtained similar results as the U.S. researchers,” Professor Dr. Jenny Chang-Claude of DKFZ summarizes. “With our new data, we provide physicians in Germany with solid information that will help them to advise their patients about the benefits and risks of hormone replacement therapy.”

The MARIE study also confirms that different hormone preparations have different effects: Compared to the risk of women who have never used HRT, a combined therapy of estrogen and progestin doubles the risk of breast cancer, while use of estrogen alone (estrogen replacement therapy) raises the risk by only 15 percent. However, in both cases the risk increases only if hormones are taken for more than five years.

“Hormone replacement therapy also appears to have a different influence on different types of breast cancer,” Braendle explains. “The risk of developing one of the less common lobular or tubular breast cancers increases twice as much under HRT as the risk of the common type of ductal carcinoma, which constitutes 40 to 75 percent of all malignant tumors of the breast.”

Source: Helmholtz Association of German Research Centres

Explore further: Chronic inflammation linked to 'high-grade' prostate cancer

add to favorites email to friend print save as pdf

Related Stories

Stress gives cells a 'second childhood'

Feb 10, 2014

What doesn't kill cells may make them stronger—or considerably more flexible, at least. New findings from Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe and Charles Vacanti at Brigham ...

Flame retardants in blood drop after state ban

Sep 25, 2013

A class of flame retardants that has been linked to learning difficulties in children has rapidly declined in pregnant women's blood since the chemicals were banned in California a decade ago, according to a study led by ...

At the heart of the circadian clock

Jun 11, 2013

(Phys.org) —Cellular processes in most organisms are regulated by an internal clock, and proteins called cryptochromes are at the core of its central oscillator. The three dimensional structures of cryptochromes ...

UGA research finds sterilized dogs live longer

Apr 17, 2013

Many dog owners have their pets spayed or neutered to help control the pet population, but new research from the University of Georgia suggests the procedure could add to the length of their lives and alter ...

Recommended for you

Unraveling the 'black ribbon' around lung cancer

Apr 17, 2014

It's not uncommon these days to find a colored ribbon representing a disease. A pink ribbon is well known to signify breast cancer. But what color ribbon does one think of with lung cancer?

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.