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. 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 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 discussed 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.

SOURCE:
The Journal of Nuclear Medicine, November 2003