Esophageal carcinoma is a significant worldwide health problem and the incidence is increasing faster than that of any other malignancy. 18F-2-deoxy-D-glucose (FDG)-positron emission tomography/computed tomography (PET/CT) is important in the management of patients with potentially resectable esophageal cancer and is useful in initial staging of locally advanced cancer and after neoadjuvant therapy. The purpose of this study is to determine the utility of FDG-PET/CT in the clinical staging of early-stage esophageal cancer.
Subjects in this retrospective study were 79 consecutive patients with cTisN0 (high-grade dysplasia) and cT1N0 primary esophageal adenocarcinoma diagnosed by endoscopy and endoscopic ultrasound biopsy that were evaluated with preoperative FDG-PET/CT and had not received neoadjuvant therapy. Seventh edition American Joint Committee on Cancer cTNM and FDG-PET/CT were compared with postoperative pTNM staging. pT1 was subdivided into intramucosal cancers with lamina propria or muscularis mucosa invasion (pT1a) and submucosal cancers (pT1b).
In pT staging, the frequency of FDG uptake increased with increasing pT, from pT1a 21 of 39 (53.8%) to pT1b 19 of 22 (55.8%). pTis was three of five (60.0%). Similarly, the maximum standardized uptake value of FDG-avid lesions increased with increasing pT, with median values of 3.7 for pTis, 3.8 for pT1a and 4.2 for T1b. In cN staging, FDG-PET/CT was negative in 76 patients and positive in three patients. All three patients with FDG-avid nodes on FDG-PET/CT were negative for metastatic disease on biopsy. In 12 patients with pN1 and in one patient with N2, FDG-PET/CT was falsely negative. Sensitivity and positive predictive value for pN disease were 0% and accuracy was 82%. There were no distant metastases. In cM staging, FDG-PET/CT was falsely positive in five patients (FDG avid nodules n = 3, distant nodal metastasis n = 2) and resulted in unwarranted biopsy in four patients.
FDG-PET/CT is not useful in the TNM staging of primary adenocarcinoma of the esophagus when endoscopy and biopsy indicate cTis and cT1. In fact, FDGPET/CT can be detrimental to patient management. Because regional nodal metastases are uncommon and distant metastases rare, and as FDG-PET/CT can result in inappropriate clinical care, FDG-PET/CT should not be performed in the evaluation of early-stage esophageal cancer.