Breast And Ovarian Cancer Share Genetic Similarities
September 24, 2012

Cancer Genome Atlas Finds Shared Genomic Features That Could Aid Treatments

Alan McStravick for — Your Universe Online

With the exhaustive amounts of research that have been focused on breast cancer over the past 2 decades, researchers have been able to recognize 4 subtypes of the cancer. Using data generated under The Cancer Genome Atlas (TCGA), the team was able to obtain new insights into the four standard molecular subtypes of breast cancer.

"TCGA's comprehensive characterization of their high-quality samples allows researchers an unprecedented look at these breast cancer subgroups," said National Institutes of Health (NIH) Director Francis S. Collins, M.D., Ph.D., in a statement. It was the TCGA Research Network that was able to uncover these marked genomic similarities between the Basal-like subtype and serous ovarian cancers. The mutation spectrum, or types and frequencies of genomic mutations, shared many similarities in both cancer types.

One particular subtype of breast cancer, it has been learned, shares many of the same genetic features with high-grade serous ovarian cancer.  This form of ovarian cancer has traditionally been exceptionally difficult to treat, according to researchers supported by the NIH. The suggestion is that this finding links the two cancers to a similar molecular origin. This knowledge may facilitate the comparison of therapeutic data for subtypes of breast and ovarian cancers.

Their findings, part of a collaborative effort that received funding from the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), both under the NIH, were published online yesterday and will appear in print, in the October 4 issue of Nature.

The implications from this discovery are very positive for women who are diagnosed with high-grade serous ovarian cancer, once an exceptionally dire diagnosis. This is because, as it shares genetic similarities with a form of breast cancer that has established treatment protocols, doctors will now be able to target this form of ovarian cancer in much the same way.

In fact, computational analyses have been completed that show that the Basal-like breast and serous ovarian cancers could exhibit susceptibility to treatments that would inhibit blood vessel growth. One such therapy, a chemotherapy drug called cisplatin, performs in this manner, effectively cutting off blood supply to the tumor.

"The molecular similarity of one of the principal subtypes of breast cancer to that found in ovarian cancer gives us additional leverage to compare treatments and outcomes across these two cancers," noted Harold Varmus, M.D., NCI director, in a statement. "This treasure trove of genetic information will need to be examined in great detail to identify how we can use it functionally and clinically."

Statistics provided by the World Health Organization show that each year there are approximately 1.3 million new cases of breast cancer, with 450,000 fatalities resultant from that diagnosis.  Breast cancer, while not exclusively a female condition, (men account for 1% of breast cancer cases), is the most common cancer among women. The majority of these diagnoses are what are called sporadic, which negates familial history as a cause. There are genetic diagnoses, as well.

Dr. Eric D. Green, MD, PhD, director of the NHGRI commented, “The data generated by the TCGA program comprise a vast resource that investigators will be analyzing for years to come. The resource of information about breast cancer genomes will undoubtedly fuel myriad discoveries by the cancer research community.”