PET-Uptake Reduction into Lymph Nodes After Neoadjuvant Therapy is Highly Predictive of Prognosis for Patients Who have Thoracic Esophageal Squamous Cell Carcinoma Treated with Chemoradiotherapy Plus Esophagectomy.

BACKGROUND

Patients with F-fluorodeoxyglucose-positron emission tomography (FDG-PET)-positive lymph nodes before treatment have a poor prognosis after esophagectomy. This study investigated whether FDG uptake into lymph nodes on FDG-PET (PET-N) during the pre- or posttreatment stage is more predictive of survival for thoracic esophageal squamous cell carcinoma (TESCC) patients who received neoadjuvant chemoradiotherapy (NACRT) followed by esophagectomy.

METHODS

Of 129 TESCC patients with clinical lymphatic metastasis who underwent curative-intent esophagectomy after NACRT between 2010 and 2018, 97 who received PET before and after NACRT were enrolled in the study. The study defined lymph nodes with a maximum standardized uptake value (SUV) greater than 2.5 on FDG-PET before NACRT as cPET-N(+) and after NACRT as CRT-cPET-N(+). Both the cPET-N(+) and CRT-cPET-N(-) patients were defined as PET-N responders. Survival was analyzed using the Kaplan-Meier method and Cox proportional hazard models.

RESULTS

No significant difference in survival was detected between the cPET-N(+) and cPET-N(-) patients. However, the CRT-cPET-N(-) patients had significantly better 5-year overall survival (OS) and disease-specific survival (DSS) than the CRT-cPET-N (+) patients. The PET-N responders had significantly better 5-year OS and DSS than the PET-N non-responders, and PET-N response was an independent prognostic factor for 5-year DSS.

CONCLUSION

The PET-N response is a highly predictive prognostic marker for TESCC patients who undergo NACRT followed by esophagectomy. The PET-N response may help clinicians to establish a strategy for perioperative treatments that improves survival for patients with lymph node metastasis in TESCC.