Background: The prevalence of esophageal cancer accompanied by hypopharyngeal cancer (HPC) is high and increasing rapidly in Asia. The purpose of this prospective study was to evaluate the prevalence of esophageal cancer during the pretreatment of HPC patients who were routinely examined using esophagogastroduodenoscopy (EGD) and 18F-fluorodeoxyglucose/computed tomography (FDG-PET/CT) and to discuss the utility of these examinations.
Material and methods: Between September 2005 and September 2010, 33 patients with newly diagnosed HPC (all with squamous cell carcinoma) underwent EGD (after a conventional endoscopy, iodine staining was performed) and FDG-PET/CT examinations. We evaluated the prevalence of esophageal cancer among HPC patients according to the EGD findings and determined the sensitivity of FDG-PET/CT for the detection of esophageal primary tumors for each clinical T classification.
Results: In 17 of the 33 patients (51.5%), 29 biopsy-proven esophageal squamous cell carcinomas were diagnosed using EGD. In eight of the 17 (47.1%) patients, two or more esophageal cancer lesions were diagnosed. Twenty-four of the 29 (82.8%) lesions were superficial esophageal cancers, and the remaining five (17.2%) lesions were advanced esophageal cancers. In six of the 29 (20.7%) esophageal cancer lesions that were detected using FDG-PET/CT, only one of the 29 (3.4%) lesions was evaluated as being equivocal; the remaining 22 (75.9%) lesions were not detected. The distribution of the clinical T classifications detected using FDG-PET/CT was as follows: T1a, 0/21 (0%); T1b, 1/3 (33%); and T3, 5/5 (100%).
Conclusions: The prevalence of esophageal cancer during the pretreatment of HPC patients was 51.5%; this prevalence was higher than that in previous reports. We believe that the increasing proportion of superficial lesions (82.8%) detected using iodine staining and EGD may have led to the relatively high prevalence. FDG-PET/CT detected only 20.7% of the esophageal cancers, although FDG-PET/CT is capable of detecting unexpected primary malignant tumors other than esophageal cancer.