There is a biological distinction between breast cancers that depend on hormones and those that do not, according to research published Friday, April 25th in the open-access journal PLoS Genetics.
Scientists previously thought that hormone dependent breast cancers, which usually require treatment with surgery and anti-hormone drugs, originated from the same biological pathway as hormone independent breast cancers, which are treated with surgery and chemotherapy.
In the largest study of its kind, an international consortium of cancer researchers studied the genetic makeup of over 23,000 breast cancer cases.
Dr. Paul Pharoah, lead author based at the University of Cambridge, said: “We looked at five genetic variants associated with breast cancer to see if they were more likely to be found in hormone dependent or independent breast cancers. One common genetic variant, FGFR2, was strongly associated with hormone dependent breast cancer, but weakly associated with hormone independent cancer. This shows that they have distinct genetic origins, and are different diseases.”
Dr Lesley Walker, Cancer Research UK’s director of cancer information, said: “Scientists were previously unsure how different types of breast cancer developed. Although the findings won’t have any immediate effects on the treatment of women with the disease, they are important in helping to define the next steps in our research on the causes of this major cancer.”
This discovery provides strong evidence that the subtypes originate from separate pathways and could guide future research into prevention and treatments for the cancer types as different diseases. This study was funded by Cancer Research UK.
Citation: Garcia-Closas M, Hall P, Nevanlinna H, Pooley K, Morrison J, et al. (2008) Heterogeneity of Breast Cancer Associations with Five Susceptibility Loci by Clinical and Pathological Characteristics. PLoS Genet 4(4): e1000054. doi:10.1371/journal.pgen.1000054
http://www.plosgenetics.org/doi/pgen.1000054
Source: Public Library of Science
Related stories:
Soy foods aid bone density
Bone loss commonly occurs as we age, especially for women. Until recently, women were routinely prescribed estrogen after menopause to prevent bone loss and fractures.
Breast cancer cells recycle to escape death by hormonal therapy
Many breast cancer cells facing potentially lethal antiestrogen therapy recycle to survive, researchers say.
Colon cancer link to obesity uncovered
A new study reveals the first-ever genetic link between obesity and colon cancer risk, a finding that could lead to greater accuracy in testing for the disease, said a researcher at the University of Alabama at Birmingham (UAB).
Social class dictates cancer risk
Cervical and lung cancer are more common in poor people while rates of breast cancer and melanoma are higher in the wealthy. A detailed analysis of the incidence of these four different kinds of cancer, carried out on more than 300,000 English cancer patients and published today in the open access journal
BMC Cancer, describes the effects of socioeconomic group, region and age.
New predictive tool can help determine treatment of breast cancer patients
A new predictive measurement, called a PEPI score, could bring good news to many women diagnosed with early stage breast cancer — a low PEPI (preoperative endocrine prognostic index) score could show that they have little risk of relapse and can safely avoid chemotherapy after surgery.
The dietary supplement genistein can undermine breast cancer treatment
Women taking aromatase inhibitors to treat breast cancer or prevent its recurrence should think twice before also taking a soy-based dietary supplement, researchers report.
Breast cancer survivors have high quality of life up to 15 years after lumpectomy/radiation
Women with breast cancer who are treated with lumpectomy and radiation report a high level of overall quality of life several years after treatment that is comparable to a general sampling of the adult women U.S. population according to a survey conducted by physicians at Fox Chase Cancer Center.
Calculating how breast cancers will respond to tamoxifen
A discovery by Australian scientists could help clinicians decide which women with breast cancer will make good candidates for anti-oestrogen therapies, such as tamoxifen, and which will not.