Customization of treatment for patients with esophageal adenocarcinoma (EAC) who achieve clinical complete response (cCR) after chemoradiation using initial standardized uptake value (iSUV) of 18f-fluorodeoxyglucose PET.

Abstract

4069 Background: Patients with localized esophageal adenocarcinoma (EAC) receive preoperative chemoradiation followed by surgery (trimodality [TM] therapy) or definitive chemoradiotherapy (bimodality [BM] therapy) based on comorbidities and tumor geography. However, we cannot individualize recommendations beyond these parameters. We hypothesized that iSUV could customize therapy. Methods: Data source was our prospective database of fully staged EAC patients (2002-2010). All patients had a cCR (post-chemoradiation negative biopsy and post-chemoradiation physiologic uptake on PET). iSUV cut-point was derived by recursive partitioning. Results: For 323 cCR patients, the median follow-up was 40.8 months. 206 (63.8%) patients had TM and 117 (36.2%) had BM therapy. Median OS of TM patients and BM patients were 94.8 months (95 % CI; NA-NA) and 36.5 months (95% CI; 30.5-42.4; p<0.001), respectively. Similar differences were observed in RFS (p<0.001). The median iSUV was 9.4 (range, 0-58.0). Intriguingly, TM patients with iSUV of >6 had a better OS (94.8 months; 95% CI; 39.1-150.5) and RFS (94.8 months; 95% CI; 18.2-171.4) compared to BM patients with iSUV of >6 OS (31.4 months; 95% CI; 21.0-41.9; p=<0.001) and RFS (17.2 months; 95% CI; 14.5-19.8; p<0.001). However, the prognosis of TM and BM cCR patients with iSUV <6 was similar (OS, p=0.62 and RFS, p=0.46). The pathological CR (pathCR) rate in TM patients was similar irrespective of iSUV of ≥6 (27.1%) vs. iSUV <6 (28.6%; p=0.85). Conclusions: Our unique data provide an insight into the fate of cCR EAC patients by iSUV. Patient with iSUV ≥6 dramatically benefit from surgery and TM therapy is encouraged. iSUV and pathCR do not correlate. iSUV can customize therapy of localized EAC patients.