Early Detection: Improving Survival
Earlier detection of breast cancer is today the best means of reducing breast cancer mortality. Work completed in 1997 includes research exploring new technologies for the detection of breast cancer, as well as research into access and use of existing services by different populations of women.
Research Conclusions
Dr. Erik R. Wisner, at the University of California, Davis, through his study Novel Agent for Lymph Node Imaging & Targeted Gene Therapy has demonstrated a proofofprinciple in the development of a combined diagnostic imaging and therapeutic agent for breast cancer diagnosis and therapy. He developed a prototype diagnostic and therapeutic agent by binding conventional magnetic resonance (MR) contrast materials to lipid microspheres, or liposomes (i.e., microscopically small membrane-enclosed sacs made in the laboratory) that, in preliminary imaging studies significantly improved the visibility of regional lymph nodes on MR images after subcutaneous injection. In addition, they demonstrated significant uptake and expression of marker DNA material in cell cultures exposed to the agent after incorporating the marker into the core of the liposome component.
Dr. Phillip Gardiner at the Northern California Cancer Center, in his study (False-Positive Mammograms: A Barrier to Annual Screening?) found that, contrary to expectations, women who experienced a false positive mammogram slightly increased adherence to screening guidelines. This finding is based on actual screening behavior in the aftermath of a stressful health-related event, and suggests that tailored interventions to prevent these women from being lost to further screening are not necessary.
Dr. Annette E. Maxwell at the University of California, Los Angeles, undertook to better understand factors influencing Filipino women with respect to breast cancer mammography screening (Understanding Breast Cancer Screening in Filipino Women). Her findings with respect to barriers to screening suggest that strategies to increase screening among Filpino-American women should include: Filipino health professionals in interventions; information in Tagalog at local centers and in take-home brochures; involvement of children or other relatives in intervention programs; and providing mammography screening on weekends. Dr. Maxwell, using the data gathered in this study, has obtained a major research grant from the NCI to test an intervention based on her CBCRP study.
Research in Progress
Developing and improving imaging technologies: better and easier detection
Earlier detection of breast cancer is at present the best means of reducing breast cancer mortality. Work on various technologies to detect breast cancer as early as possible is proceeding. Dr. John Boone at the University of California, Davis is working on improving x-ray detection by changing the design of the detector. Using a thick honeycomb-like structure may enable a greater capture of X rays (and thus more scintillated light to make the image) while simultaneously reducing the blurring associated with thicker layers of X ray absorption material. Dr. Michael Buonocore at the University at the California, Davis is attempting to improve the ability of magnetic resonance imaging (MRI) to distinguish between benign and cancerous lesions (thus reducing the need for biopsies) by modifying the generation and detection of the MR signal. Preliminary results of this IDEA grant have been promising, enabling Dr. Buonocore to obtain a larger grant from the Department of Defense to continue and expand on this work. Dr. Edward Hoffman at the University of California, Los Angeles is attempting to use the potential benefits of nuclear imaging scintillation cameras to distinguish between benign and cancerous lesions in the breast. These cameras are typically very large and, while suitable for whole body work, are ill-adapted to breast imaging. A small, hand-held prototype (using photo-multiplier tubes) able to image portions of the breast has been developed with imaging performance superior to standard cameras; a second, solid state version prototype is now being developed. Clinical studies using the first prototype are now beginning.
Biomarkers and novel screening aproaches: unmasking the hidden signs
Dr. Susan Hawkes at the University of California, San Francisco is finding that a marker called TIMP-3 is present in cancerous tissues but not in normal or benign tissues. TIMP-3 can be detected in the basement membrane of all of the ductal carcinoma in situ (pre-cancers) examined to date, making it an excellent candidate for an early marker of breast cancer. Dr. Christina Niemeyer of The Burnham Institute has found that when a protein called Cripto is present in elevated levels in otherwise normal cells, abnormal outgrowths form. Her experiments show that Cripto does not appear to be involved in the early stages of tumor development but may be involved in tumor progression.
Improving access to screening: reaching every woman
Regardless of the technologies available, women need to make decisions to participate in breast cancer screening efforts. Dr. Jacqueline O'Connor at the University of California, Davis looked at psychological characteristics that motivate breast cancer early detection practices (Benign Breast Biopsy & Cancer Preventive Self-Care). She found that women who had undergone immediate core biopsy of low-suspicion breast lesions detected by mammogram and those that had six-month mammographic follow-up reported greater attention to, and compliance with, recommended breast screening practices, even in the face of increased feelings of vulnerability. Interestingly, those who underwent biopsy reported greater stress levels than those who underwent six-month follow-up, this finding challenging the expectation that the uncertainty attending an extended period of surveillance would result in a higher stress level.
Recently Initiated Research
In 1997, CBCRP awarded seven new grants to develop better methods to detect breast cancer, including testing ways to increase use of screening by underserved populations, testing possible markers for cancer in breast tissue, and developing new technologies to improve or replace mammograms. CBCRP funded one project to use databases of digitized mammograms to reduce the need for biopsies of non-cancerous tissue. Two projects focus on developing other, non-ionizing detection methods. Another project explores the potential of a biological marker to serve as a diagnostic tool.
