Volume 15, Issue 4, Fall 2003
Current CHS breast cancer studies
Work continues on several major CHS studies related to breast cancer, including the following:
Breast Cancer Surveillance in a Defined Population
Principal Investigator: Diana S. M. Buist, PhD
Co-Principal Co-investigators: Carolyn M. Rutter, PhD; Emily J. White, PhD, Fred Hutchinson Cancer Research Center; Peggy L. Porter, MD, Fred Hutchinson Cancer Research Center; Joann G. Elmore, MD, MPH, and Constance D. Lehman, MD, PhD, University of Washington
Group Health currently maintains independent automated clinical systems tracking mammography, pathology, cost, and breast cancer risk factors among more than 90,000 women, aged 35 and older, who get mammograms at the Co-op. The researchers can link mammogram results to cancer risk factors, clinical breast exams, and pathology specimens—as well as cancer outcomes from the Seattle–Puget Sound Surveillance, Epidemiology and End Results (SEER) registry. This study is funded by the NCI with $7 million to CHS over nine years.
Statistical Coordinating Center for the Breast Cancer Surveillance Consortium (BCSC)
Principal Investigator: William E. Barlow, PhD
Co-Principal Investigator: Diana L. Miglioretti, PhD
Group Health is among eight institutions nationwide participating in the comprehensive Breast Cancer Surveillance Consortium (BCSC) funded by the NCI. CHS' portion of the funding is $3 million over five years. This project, begun in 1994, transcends conventional cancer surveillance systems, which typically track how many people get a disease, how many survive, and how many die. In contrast, this system characterizes women who get mammograms at the participating institutions—and links the mammogram interpretations with cancer outcomes. By studying such a large population, investigators learn how to make breast cancer screening more effective and affordable. Group Health makes a unique contribution to this surveillance system by being able to monitor all women in a broad population and identify whether they're getting mammography, clinical breast exams, and diagnostic procedures. CHS also hosts the Statistical Coordinating Center (SCC), which coordinates data for the entire BCSC, helping to organize and standardize the data submission process and leading analyses of pooled data. The SCC is developing and implementing new statistical methods to characterize the process of mammography. It's also providing scientific guidance in the development of BCSC-based publications.
The Effect of HRT Cessation on the Recall Rates for Screening Mammography
Principal Investigator: Diana S. M. Buist, PhD, MPH
Co-Principal Investigators: Katherine M. Newton, PhD and Susan D. Reed, UW Department of Obstetrics and GynecologySeveral factors affect the accuracy of
mammograms to screen for breast cancer. For instance, as women age and their breasts become less dense and more fatty, accuracy increases. Conversely, for women who take HRT for menopause, this treatment tends make their breasts denser. This, in turn, makes their mammograms harder to read, thus lowering accuracy and leading to more false positives as well as cases missed until late-stage cancer. This randomized controlled trial tests whether it is worthwhile for women to stop taking HRT for one or two months before screening mammography. If this short-term intervention is effective, it will significantly lower the number of women who are unnecessarily called back for additional mammograms. The U.S. Department of Defense is funding the study with a grant of $900,000 over three years.
Breast and Bone Density: Impact of Colonic Environment
Principal Investigator: Johanna W. Lampe, Fred Hutchinson Cancer Research Center
Lead Group Health Co-Investigator: Katherine M. Newton, PhD
This project is designed to test the hypothesis that differences between individual women's intestinal bacteria may change the amounts, forms, or both of circulating estrogens, thus influencing the risk of breast cancer. To do so, the researchers are exploring women's ability to produce a chemical known as equol from the soy isoflavone called daidzein. Only a third of people have this ability, thanks to having the right bacterial species in their gut. The scientists will see whether there is any link between this ability, which may help prevent breast cancer, and the density of a woman's breasts and bones. These densities have been proposed as markers for cumulative exposure to estrogen. The National Cancer Institute funds this four-year study, with more than $800,000 to CHS.
Optimizing Breast Cancer Outcomes
Principal Investigator: Diana S. M. Buist, PhD
The American Cancer Society (ACS) has awarded CHS a three-year, $430,000 grant for two observational studies of factors associated with breast cancer recurrence and death from breast cancer. One study concerns the relationship between body mass index (BMI) and the risk of recurrence and death. The second focuses on medical information about women with early-stage breast cancer, comparing the treatment they receive with current clinical guidelines.
Understanding Variability in Community Mammography
Principal Investigator: Joann G. Elmore, MD, MPH, Harborview Medical Center, University of Washington (UW) School of Medicine
Principal Group Health Co-investigator: William E. Barlow, PhD
This study is measuring the extent of several possible sources for variability in the interpretation of 500,000 screening and diagnostic mammograms, reviewing the work of individual radiology staff at 91 health care facilities in three geographic regions (Washington, New Hampshire, and Colorado). The researchers are paying special attention to staff members' fiscal incentives, legal factors, and personal characteristics, as well as to each facility's fiscal, legal, and community practice environments. The Agency for Healthcare Research and Quality (AHRQ) is funding this study for three years at $400,000.
Breast Cancer Treatment Effectiveness in Older Women
Principal Investigator: Rebecca A. Silliman, MD, PhD, Boston University
Principal Group Health Co-investigator: Diana S. M. Buist, PhD
While deaths from breast cancer have declined among women younger than 70, they remain stable among those in their 70s and are actually rising in women aged 80 and older. Older women may receive less than standard therapy. Using the CRN, the researchers are conducting a historical cohort study of women aged 65 and older who were newly diagnosed with early-stage breast cancer between 1990 and 1994. This study compares the effectiveness of standard primary tumor therapy with any treatment other than standard in reducing the risk of recurrence. It aims to determine how additional systemic adjuvant therapy—for instance, with tamoxifen—modifies the effectiveness of treatment in reducing breast cancer recurrences. The NCI provides CHS with $500,000 over four years for its part in this study.