PET N (-) is a good candidate for surgical treatment in patients with T1-3 esophageal squamous cell carcinoma.

Objectives Surgery alone can provide good survival rate for patients with esophageal squamous cell carcinoma (SCC) who have none or few lymph node metastases. The aim of this study was to investigate the quality of positron emission tomography with 18F-fluorodeoxy glucose (FDG-PET) in detecting nodal metastasis, the ability to predict the prognosis after surgery, and to establish new criterion to identify good candidates for surgical treatment.

Methods Sixty-four patients with potentially operable (T1-3) esophageal SCC underwent FDG-PET before surgical resection to evaluate PET-N findings, number of pathological nodal metastasis, and postoperative survival.

Results Forty-nine patients had no PET-positive nodal metastases (PET N(-) group). Among this group, 20 patients were pathologically metastasis-positive, but the number of metastasis was less than three. Fifteen patients had PET-positive lymph node site (PET N (+) group). All 15 patients of this group had pathologically positive node, in which 12 patients had four or more. The sensitivity and specificity of PET were 42.9% and 100%. PET N (-) group demonstrated a significantly higher 5-year cause-specific survival rate (83.8%) compared with 26.7% in PET N (+) group (p=0.0003). Univariate Cox regression analyses identified PET N (+) or (-) as the significant preoperative prognostic factor (p=0.0006).

Conclusions FDG-PET is not sensitive in detecting lymph node metastasis of esophageal SCC, wherein PET N (-) does not always mean pathological N0. However, it suggests that metastasis is limited and indicates good survival after surgery. PET N (-) is suspected to be a good candidate for surgery.