The Prognostic Impact of Early Change in Standardized Uptake Value of 18F-fluorodeoxy-glucose Positron Emission Tomography after Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer Patients

Standardized uptake value (SUV), which is an indicator of the degree of glucose uptake in 18Ffluorodeoxy-glucose positron emission tomography (18FDG-PET), can be applied as a prognostic factor in various malignant tumors. We investigated the prognostic impact of early changes in 18FDG-PET uptake in patients with locally advanced breast cancer who received neoadjuvant chemotherapy (NAC). Methods: We retrospectively identified 87 patients who were treated with NAC followed by surgery for locally advanced breast cancer. All patients underwent 18FDG-PET at baseline and after three cycles of NAC and the maximum SUV (SUVmax) of primary tumor mass were assessed in each scan. Pathologic slides were retrospectively reviewed and residual cancer burden (RCB) index was calculated to estimate pathologic response. RCB-0 is referred to no residual disease (RD) and patients with RD is categorized into three classes: RCB-I (minimal RD), RCB-II (moderate RD), and RCB-III (extensive RD). Results: There was a negative correlation between reduction rate of SUVmax (ΔSUVmax) and RCB index (correlation coefficient = -0.408; p<0.001). In multivariate analyses, ΔSUVmax were significant independent prognostic factor for recurrence-free survival (RFS) and overall survival (OS), and corresponding adjusted hazard ratios were 0.31 (95% CI: 0.12-0.77, p=0.011) and 0.20 (95% CI: 0.260.71, p=0.013), respectively. When patients were classified into four groups according to pathologic response (RCB index ≤1 vs. ≥2) and metabolic response (ΔSUVmax ≤66.4% vs. >66.4%), metabolic responders presented significantly better RFS and OS than metabolic non-responders within poor pathologic response patients. In contrast, within metabolic responders, there was no survival difference according to pathologic response. Conclusions: The early change in SUVmax of 18FDG-PET after 3rd cycle NAC is an independent and good prognostic marker beyond pathologic response in locally advanced breast cancer patients. We suggest that by on November 7, 2017. For personal use only. jnm.snmjournals.org Downloaded from