Scientists identify avoidable breast cancer risk factors

January 18, 2011, Helmholtz Association of German Research Centres

Many risk factors for breast cancer are well studied and documented. Thus, scientists are sure by now that early first menstrual period, late onset of menopause and a family history of breast cancer are associated with an increased breast cancer risk.

However, neither an individual woman nor medicine can influence whether family members develop or at what age starts - these are risk factors on which we have no influence. Scientists of the German Cancer Research Center in the team of Associate Professor (PD) Dr. Karen Steindorf and Professor Dr. Jenny Chang-Claude, jointly with Professor Dr. Dieter Flesch-Janys of Hamburg Eppendorf University Hospitals, have been searching for risk factors which can be influenced by changes in lifestyle and behavior.

"58,000 women in Germany are diagnosed with breast cancer each year," says Jenny Chang-Claude."Therefore, a key question is whether there are behavioral changes that might help to lower the disease risk. Our study aims to determine the percentage of cases where these avoidable risk factors are responsible."

The researchers focused on aspects such as taking hormones for relief of menopausal symptoms (), physical activity, overweight and alcohol consumption. All these have been identified in prior studies as possible risk factors for the development of breast cancer.

In their current MARIE study, which is supported by Deutsche Krebshilfe (German Cancer Aid), the epidemiologists studied 6,386 female controls along with 3,074 patients who had been diagnosed with breast cancer after the onset of menopause. On the basis of these data, the scientists calculated the percentage of cancer cases that is attributable to a particular risk factor (or a particular combination of several risk factors).

Of the modifiable lifestyle factors, it is primarily hormone replacement therapy and a lack of physical activity which increase a woman's risk of developing breast cancer. and overweight were found to have less influence on . Thus, 19.4 percent of invasive postmenopausal breast cancer are attributed to hormone replacement therapy; 12.8 percent to a lack of physical activity. Both factors together are responsible for 29.8 percent of breast cancer cases. When the investigators took a separate look at the group of patients whose tumors have receptors for sex hormones (hormone receptor-positive breast tumors), they determined an even higher value of 37.9 percent. The study leaders emphasize that these results reflect the situation in Germany with our typical lifestyle and may differ in countries with other lifestyles.

Non-modifiable factors such as family history or age at first and last menstrual period account for 37.2 percent in total of all malignant postmenopausal breast cancers. "That means that two factors which each woman has in her own hands are responsible for a similar number of postmenopausal breast cancer cases as the non-modifiable factors," Karen Steindorf says. "If behavioral changes in these two areas could be brought about, almost 30 percent of breast cancers after menopause could be prevented." Therefore, the DKFZ researchers recommend women to take more exercise and to refrain from hormone replacement therapy, unless it is absolutely necessary.

More information: Population attributable risk of invasive postmenopausal breast cancer and breast cancer subtypes for modifiable and non-modifiable risk factors. Benjamin B.E. Barnes, Karen Steindorf, Rebecca Hein, Dieter Flesch-Janys and Jenny Chang-Claude: Cancer Epidemiology 2010, DOI: 10.1016/j.canep.2010.11.003

Related Stories

Recommended for you

New approach attacks 'undruggable' cancers from the outside in

January 23, 2018
Cancer researchers have made great strides in developing targeted therapies that treat the specific genetic mutations underlying a patient's cancer. However, many of the most common cancer-causing genes are so central to ...

Study: Cells of three advanced cancers die with drug-like compounds that reverse chemo failure

January 23, 2018
Researchers at Southern Methodist University have discovered three drug-like compounds that successfully reverse chemotherapy failure in three of the most commonly aggressive cancers—ovarian, prostate and breast.

'Hijacker' drives cancer in some patients with high-risk neuroblastoma

January 23, 2018
Researchers have identified mechanisms that drive about 10 percent of high-risk neuroblastoma cases and have used a new approach to show how the cancer genome "hijacks" DNA that regulates other genes. The resulting insights ...

Enzyme inhibitor combined with chemotherapy delays glioblastoma growth

January 23, 2018
In animal experiments, a human-derived glioblastoma significantly regressed when treated with the combination of an experimental enzyme inhibitor and the standard glioblastoma chemotherapy drug, temozolomide.

Researchers identify a protein that keeps metastatic breast cancer cells dormant

January 23, 2018
A study headed by ICREA researcher Roger Gomis at the Institute for Research in Biomedicine (IRB Barcelona) has identified the genes involved in the latent asymptomatic state of breast cancer metastases. The work sheds light ...

Scientists block the siren call of two aggressive cancers

January 23, 2018
Aggressive cancers like glioblastoma and metastatic breast cancer have in common a siren call that beckons the bone marrow to send along whatever the tumors need to survive and thrive.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.