G-DOC breast cancer pilot studies are primarily focused on the problem of defining prognostic signatures for Tamoxifen resistance in breast cancer. Approximately 70% of women diagnosed with breast cancer each year are estrogen receptor-positive (ER+) meaning that the cancer cells use estrogen as a signal to grow. ER+ breast cancer can be treated using anti-estrogen therapies such as Tamoxifen to prevent estrogen from binding. The resulting estrogen deprivation typically leads to cell death however; approximately 50 percent of women treated with anti-estrogen therapies develop a resistance to the drug resulting in disease progression or future recurrence.

While a large amount of public gene expression data was available for breast cancer, to ensure full comparability a number of filters were designed and implemented, at considerable effort. The resulting data sets allowed the analysis group to very effectively re-mine these public data sets.

Breast cancer as a focus for G-DOC pilot study activity is based, in part, on the very substantial strength that Georgetown University Medical Center has in this research area.  Georgetown is one of the most prolific institutes for breast cancer research, as measure by publications per year. Georgetown Lombardi Comprehensive Cancer Center is ranked 8th for the number of breast cancer related publications per year.

In addition, breast cancer is one of the top three causes of cancer-related deaths in North America, responsible for more than 40,000 deaths per year making it a problem deserving extensive, aggressive, and ongoing attention on the part of the research community. Tremendous interest in this research area and the relative ease of obtaining tumor tissue samples, owing to frequent surgical treatment for this disease, allows G-DOC researchers to collect a significant amount of patient information at the outset of the project.