PS02.110: PREDICTION OF PROGNOSIS BY EVALUATING RELATIVE CHANGE IN FDG-UPTAKE OF THE METASTATIC LYMPH NODES AFTER NEOADJUVANT CHEMOTHERAPY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract

Abstract Background Prognosis of patients with esophageal squamous cell carcinoma (ESCC) can be significantly improved by neoadjuvant chemotherapy (NAC). The current best clinical method to predict pathologic response of chemotherapy is the maximum standardized uptake value (SUVmax) in 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). However, most of the FDG-PET evaluation has been focused on the primary tumors, but not on other metastatic lesions. The aim of this study was to determine the predictive value of FDG-uptake measured prior and after NAC both in the primary tumors and in the metastatic lymph modes (mLN) in ESCC. Methods Forty-five consecutive potentially resectable ESCC patients treated with NAC, which consisted of 2 courses of continuous infusion of 5-FU for days 1–5 and CDDP on day 1, between 2009 and 2016 were evaluated. FDG-uptake was measured at baseline and after chemotherapy in the primary tumors and in the mLN, and all patients underwent esophagectomy with R0 resection. The predictive values of FDG-PET and clinicopathological characteristics were determined with univariate and multivariate analyses. Results The median age was 66 years, with 35 males and 9 females. Pretreatment clinical classification of tumor depth was T1 in 9, T2 in 10, T3 in 26, respectively, and that of lymph modes metastases was N0 in 9, N1 in 12, N2 in 18, N3 in 6, respectively. The average SUVmax before and after NAC in the primary tumors was 13.9 and 7.9, respectively, and the average SUVmax reduction was 39.8% after chemotherapy. Pathological response was found to correlate well with the SUVmax reduction in the primary tumors, however, relative change in FDG uptake after chemotherapy was not associated with overall survival (OS). The average SUVmax before and after NAC in the mLN was 6.9 and 3.3, respectively, and the average SUVmax reduction was 46.2% after chemotherapy. Univariate and multivariate analyses revealed that both of the SUVmax and relative change in FDG uptake after chemotherapy in the mLN were well correlated with OS. Conclusion Post-NAC SUVmax and relative change in FDG uptake after chemotherapy in the mLN are valuable independent preoperative predictor of prognosis for patients with ESCC who received chemotherapy before surgery. Disclosure All authors have declared no conflicts of interest.