Endometrial cancer is the most common gynecologic cancer in the U.S., with more than 40,000 new cases per year(1). Since older age and high body mass index (BMI) are major risk factors, the growing number of older women and high prevalence of obesity are likely to lead to increased numbers of women diagnosed in the coming years. As for many other diseases, little is known about the role of genetic variation or interactions between genes and environmental exposures. Although steroid hormones are clearly important in the etiology of endometrial cancer(2-4), the potential role of genetic variation in genes related to hormone biosynthesis and metabolism has not been defined. Research funding in the U.S. per case and per death for this disease has historically been low relative to breast, ovarian, or cervical cancer; however, several studies with substantial numbers of participants have recently been completed or are nearing completion and cohort studies are identifying larger numbers of affected women as their participants age. Individually, these studies face challenges because of relatively low statistical power, particularly for study of interactions, narrow range of exposures for several risk factors, and homogeneous ethnic background. To overcome these challenges, the Epidemiology of Endometrial Cancer Consortium (E2C2) was formed in 2006 by an international group of investigators. The overall objective of E2C2 is to build on resources from existing studies funded by the National Cancer Institute (NCI) and other sources by combining data across studies in order to advance our understanding of the etiology of this disease. This commentary presents the progress and challenges of the consortium to date and the current projects addressing etiologic questions.
The consortium was born at a September, 2005, meeting on Understudied Rare Cancers sponsored by the NCI's Epidemiology and Genetics Research Program (EGRP). At that meeting, a group of investigators with special interests in endometrial cancer summarized the state of the science and the gaps that could be addressed by combining resources from funded studies. Subsequently, a Planning Committee, including representatives from EGRP, met regularly by teleconference. We compiled lists of epidemiologic studies of endometrial cancer, both case-control and cohort, that had been published on endometrial cancer risk or that had the resources to do so in the future. Our goal was to be as inclusive as possible. We contacted individual investigators from each of these studies to determine their interest in the new consortium. More than 30 investigators responded positively, agreed to join, and sent detailed information about their studies. E2C2 includes studies conducted outside the US, including studies in Europe, Australia, and China.
E2C2 became a formally designated NCI consortium in June 2006. This official NCI recognition provides sponsorship for some meetings and a web portal. The portal serves as a central hub, with email ready lists of all consortium members; E2C2 policies; descriptions and status of ongoing projects; schedules and minutes for conference calls and meetings; descriptions of and questionnaires used in individual studies; and a list of “core” and other variables for the joint dataset. Four meetings open to all interested investigators have been held, coordinated with meetings of the American Association for Cancer Research.