Use of Exogenous Progestins and Risk of In Situ and Invasive Breast Cancer
No involved investigator sites defined.
The SHARE II Study (Seattle Area Hormone And Reproductive Epidemiology Breast Cancer Study) is a 6 year grant funded by the Breast Cancer Research Program of the U.S. Department of Defense, to continue the SHARE Study. This is a population-based case-control study, which investigates how menopausal hormone therapy use and other known breast cancer risk factors are related to the risks of invasive lobular, ductal and mixed ductal-lobular carcinomas. Given the rapid increases in lobular, and particularly ductal-lobular, incidence rates, the epidemiologic data suggesting that certain risk factors differ considerably in their associations with lobular vs. ductal tumors (but that require confirmation and enhancement), the differences in these tumors’ molecular features that may reflect differing etiologic pathways, and the more recently emerging data indicating important differences between invasive pure lobular carcinomas (IPLC) and invasive ductal-lobular carcinomas (IDLC), it is clear that distinguishing between different histologic types in observational studies is an important, though underutilized, strategy for gaining insights into breast cancer etiology. To address the need for studies that further our knowledge of IPLC and IDLC, we propose to extend our existing population-based case-control study that enrolled 469 controls, 271 IPLC cases, 330 IDLC, and 442 IDC (invasive ductal carcinoma) cases, with an additional 325 subjects in each of these groups. When the two studies are combined, there will be 794 controls, 596 IPLC, 655 IDLC, and 767 IDC cases. With the addition of more cases we will have sufficient statistical power to address the following new questions: 1. How do known breast cancer risk factors, such as reproductive factors, anthropometric measures, alcohol use, and family history of breast cancer, modify the associations between use of different hormone therapy regimens and risks of lobular, ductal-lobular, and ductal carcinomas? 2. How are known breast cancer risk factors, including reproductive factors, anthropometric measures, alcohol use, and family history of breast cancer, related to risks of lobular, ductal-lobular, and ductal carcinomas, and how do breast cancer risk factors interact with each other to alter these risks? 3. How do ductal-lobular carcinomas differ from lobular and ductal carcinomas in their expression of ER, PR, c-erbB-2, e-cadherin, and Ki-67? 4. How do known breast cancer risk factors, and CHT use in particular, influence the expression of ER, PR, c-erbB-2, e-cadherin, Ki-67, in lobular, ductal-lobular, and ductal carcinomas?
There are currently no biomarkers annotated for this protocol.
No datasets are currently associated with this protocol.