Integration of Imaging in the Management of Breast Cancer

Advances in imaging have the potential to significantly impact how woman with breast cancer are treated. This issue of the Journal of Clinical Oncology Special Series has three papers on imaging in which three modalities are discussed. First, Koomen et al discuss opportunities to improve the accuracy and effectiveness of mammography. Next, Dr Hylton presents the current and future roles that magnetic resonance imaging (MRI) can potentially play in the management of breast cancer. Finally, Drs Quon and Gambir discuss the increasing and evolving role of positron emission tomography (PET) in the diagnosis and management of breast cancer. They conclude by discussing new radiopharmaceuticals and the potential to target and/ or monitor specific metabolic pathways. Mammography is still a critical component of breast cancer screening and diagnosis. It is still the only screening imaging modality that has been shown to decrease mortality from breast cancer. However, the performance of mammography needs to be optimized. Digital mammography will increase the ability to store and reliably retrieve images and separate the acquisition of the images from the interpretation. Koomen et al present the current results of trials that compare standard mammography with digital mammography for screening. At present, it does not appear that digital mammography is more effective than film screen mammography, but it is too early to make a determination, so the results of large ongoing prospective trials are eagerly awaited. However, the routine acquisition of digitized images has enabled the development of other technologies that may improve accuracy, such as mammogram tomography and computer-aided detection. The authors also introduce the concept that breast cancer screening strategies can be better tailored to an individual woman’s risk so that resources are concentrated on those who will have the most to benefit. It is critical to remember that there is a great deal of benefit for those who can safely avoid screening and the attendant false-positive biopsies. That shifts the focus of research to use emerging technology to develop breast cancer risk stratification. One such technology already accepted and used to stratify risk is genetic testing, or the sequencing of BRCA1 and BRCA2 to look for a cancer-causing mutation. We normally do not screen women under the age of 40 years for breast cancer. However, young women with a known mutation are told to get routine mammography starting at age 30, or 10 years prior to the earliest onset of cancer in an affected relative. Recent studies suggest that both MRI and mammography play an important role in screening. Other emerging technologies that may play a role in risk stratification include single nucleotide polymorphisms and proteomics. Time will tell if such information will be sufficient to direct screening using breast imaging. MRI is rapidly becoming a part of breast imaging. While MRI is probably the most sensitive tool to evaluate a known cancer, assess extent of disease, and screen young women with BRCA mutations, the attendant lack of specificity can cause problems. Many clinicians are struggling with MRI images of uncertain significance and the lack of generally available targeted biopsy tools. Thus it is imperative that we thoughtfully deploy the technology to optimize the information it can provide. MRI of the breast allows us to evaluate the extent and pattern of tumor in the breast and thus it is being evaluated for measuring response to therapy in a very quantitative manner, before surgery. If successful, MRI could catalyze a change in the approach to evaluating the impact of current systemic therapies and targeted biologic agents. MRI may also provide a tool for the evaluation of high-risk women including those with ductal carcinoma-in-situ of the breast, and to help us find quicker and more efficient ways to test prevention strategies. The challenge, of course, is to develop methods to minimize false positives, to more easily VOLUME 23 d NUMBER 8 d MARCH 1