The Breast and Prostate Cancer Cohort Consortium (BPC3) was established in 2003 to pool data and biospecimens from nine large prospective cohorts to conduct research on gene-environment interactions in cancer etiology. The BPC3 initially focused on the association of >70 candidate genes in the Steroid Hormone Metabolism and IGF pathways with risk of breast and prostate cancer. The Consortium's work expanded in 2007 to include genome-wide association studies of estrogen receptor negative (ER-) breast cancer and aggressive prostate cancer. ER- breast cancers have specific epidemiologic characteristics and greater lethality, suggesting ER- breast cancer has a different etiology than ER+ breast cancer. Similarly, aggressive forms of prostate cancer, characterized by extraprostatic extension (Stage C/D) or high histologic grade (Gleason score 8+), differ epidemiologically from the vastly more common indolent forms of prostate cancer and are of the greatest clinical importance. By restricting cases to these specific subtypes, the BPC3 GWAS increased power to detect loci associated with ER- and aggressive prostate cancer (Kraft P and Haiman CA, Nature Genetics 2010 Oct;42:819-20, <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=Nature+Genetics+2010+Oct%3B42%3A819-20/html/">PMID: 20877320</a> ). The BPC3 GWAS includes the following cohorts: the American Cancer Society Cancer Prevention Study-II (CPS-II); the European Prospective Investigation of Cancer (EPIC); the Physician's Health Study (PHS); the Nurses' Health Studies I and II (NHS and NHSII); the Health Professionals Follow-up Study (HPFS); the Multiethnic Cohort (MEC); the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial; and the Alpha-Tocopherol, Beta-Carotene (ATBC) Study. For the GWAS of ER- cancer, the BPC3 was expanded to include the Polish Breast Cancer Study (PBCS), a population-based case-control study.

The Breast and Prostate Cancer Cohort Consortium (BPC3) GWAS of Aggressive Prostate Cancer and ER- Breast Cancer

A meta-analysis of genome-wide association studies of breast cancer identifies two novel susceptibility loci at 6q14 and 20q11.

Established breast cancer risk factors by clinically important tumour characteristics