Cachin F et al. (2006) Powerful prognostic stratification by [18F]fluorodeoxyglucose positron emission tomography in patients with metastatic breast cancer treated with high-dose chemotherapy. J Clin Oncol 24: 3026–3031

A single 18F-fluorodeoxyglucose (FDG)-PET scan performed following high-dose chemotherapy (HDC) is a powerful independent predictor of survival in patients with metastatic breast cancer (MBC), according to Cachin et al.'s recent study.

In this study, 47 patients with MBC received a maximum of three consecutive cycles of HDC with autologous stem cell transplantation. Therapeutic response was assessed 1 month after the last cycle of HDC using a range of conventional imaging techniques (CImg; including CT and ultrasound) and FDG-PET. Overall, complete responses following HDC were seen in 37% of patients using CImg and 72% using FDG-PET. At a median follow-up of 87 months, analysis showed that the FDG-PET result was the most powerful independent predictor of survival. Patients with a negative post-treatment FDG-PET result had a significantly longer median survival than those with a positive FDG-PET result (24 months vs 10 months; P <0.001), and FDG-PET positivity was associated with a fivefold increased risk of death. Other factors associated with increased risk of death on multivariate analysis were prior anthracycline treatment (relative risk 3.3) and visceral metastasis (relative risk 2.4). Therapeutic response according to CImg did not predict for significantly improved long-term survival.

The authors call for larger prospective studies of FDG-PET in patients undergoing conventional-dose therapy for MBC.