Genome Project ties some forms of TNBC to ovarian cancer

Basal-like breast cancers, many of which are triple-negative,  bear a molecular similarity to ovarian cancers, which can ultimately lead us to targeted therapies, according to researchers at The Cancer Genome Atlas program in research published in the September 23, 2012 online edition of the journal Nature.  And it's possible that this could eventually lead to less-toxic chemotherapy treatments.

Charles Perou, PhD, corresponding author of the paper, says, "Through the use of multiple different technologies, we were able to collect the most complete picture of breast cancer diversity ever. These studies have important implications for all breast cancer patients and confirm a large number of our previous findings. In particular, we now have a much better picture of the genetic causes of the most common form of breast cancer, namely estrogen-receptor positive/Luminal A disease. We also found a stunning similarity between basal-like breast cancers and ovarian cancers."

[NOTE:  Some news stories I have read equate TNBC with basal-like tumors, which is not accurate.  There is a correlation between TNBC and basal-like cancers, but not all TNBC tumors are basal-like, and not all basal-like tumors are TNBC.  In fact, some researchers break TNBC into three subtypes, including basal-like and non-basal-like.  And, of course, some outlets, such as The New York Times, use terms such as "particularly deadly," for TNBC, when the fact remains that most women survive it.]

According to the genome research, basal-like breast tumors share molecular similarities with high-grade ovarian tumors, meaning the likelihood of a related origin and similar therapeutic opportunities. Interestingly, basal-like breast cancer was more similar to ovarian cancer than to ER-positive breast cancer.

Matthew Ellis of the Washington University School of Medicine in St. Louis offered on intriguing possibility:  that women with TNBC might do better on the standard chemotherapy regimen for ovarian cancer, which is less toxic.  He suggests clinical trials using these drugs,  which typically combine a platinum-based agent such as carboplatin (Paraplatin) or cisplatin with a taxane such as paclitaxel (Taxol) or docetaxel (Taxotere). Currently, breast cancer patients are treated with the more toxic anthracyclines, such as Adriamycin and Epirubicin. 

Katherine Hoadley, PhD, study co-author, says that basal-like breast cancer should be studied as distinct from other breast cancers: "Our ability to compare and integrate data from RNA, microRNA, mutations, protein, DNA methylation, and DNA copy number gave us a multitude of insights about breast cancer. In particular, highlighting how distinct basal-like breast cancers are from all other breast cancers on all data types. These findings suggest that basal-like breast cancer, while arising in the same anatomical location, is potentially a completely different disease."