PET: An effective method to predict breast cancer survival?

Reston, VA – While early detection and new drug therapies have contributed significantly to the battle against breast cancer, doctors continue to search for better methods to improve patients' odds of survival. Higher-risk forms of cancer, such as locally advanced breast cancer (LABC), are often treated with chemotherapy prior to surgery in order to enhance the probability of surgical success. Predicting the effectiveness of this pre-surgery chemotherapy can spare patients exposure to ineffective treatment and save money in the long run.

Recently, a team of University of Washington researchers conducted a study to determine if 18F-FDG and 15O-water PET can accurately predict patient response to neoadjuvant chemotherapy and disease-free survival (DFS). The study, published in the November 2003 issue of The Journal of Nuclear Medicine, used PET to monitor changes in glucose metabolism and tumor blood flow in 35 patients with LABC. While patients with decreased metabolism after two months of treatment had a trend towards improved survival, the effect was not statistically significant. Results did show, however, that decreased tumor blood flow correlated significantly with survival in this preliminary analysis.

These results back the researchers' conclusion that tumor biology should be an important factor in considering patient response to neoadjuvant chemotherapy, rather than relying only on decreases in tumor size as evidence of therapeutic success.

In an invited commentary, Hans J. Biersack, MD, and Holger Palmedo, MD, of University Hospital Bonn discuss the application of PET in predicting response to chemotherapy treatment. Although Biersack and Palmedo support PET use, they found discrepancies between the findings of Mankoff and his colleagues and other researchers. As a result, Biersack and Palmedo believe more clinical trials and research are necessary, a conclusion with which Mankoff and colleagues concur.

"Changes in Blood Flow and Metabolism in Locally Advanced Breast Cancer Treated with Neoadjuvant Chemotherapy" was written by David A. Mankoff, MD, PhD, Lisa K. Dunnwald, BS, Jeffrey Tseng, MD, and Erin K. Schubert, BA, from the Division of Nuclear Medicine; Julie R. Gralow, MD, Georgiana K. Ellis, MD, Hannah M. Linden, MD, and Robert B. Livingston, MD, from the Division of Medical Oncology; and Thomas J. Lawton, MD, from the Department of Pathology, all from the University of Washington, Seattle, Washington.

Copies of the article and images related to the study are available to media upon request to Kimberly A. Bennett. Current and past issues of The Journal of Nuclear Medicine can be found online at jnm.snmjournals.org. Print copies can be obtained at $15 per copy by contacting the SNM Service Center, Society of Nuclear Medicine, 1850 Samuel Morse Drive, Reston, VA 20190-5315; phone: (703) 326-1186; fax: (703) 708-9015; email: servicecenter@snm.org. A yearly subscription to the journal is $210 for individuals and $318 for institutions. A subscription is a Society of Nuclear Medicine member benefit.

The Society of Nuclear Medicine is an international scientific and professional organization of more than 14,000 members dedicated to promoting the science, technology, and practical applications of nuclear medicine. The SNM is based in Reston, VA.

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