Analysis of Double Cancer Detected by FDG-PET and Esophagogastroduodenoscopy in Oral Cancer Patients

Abstract

We investigated the frequency of double primary cancers in association with oral and maxillofacial regions and also studied the modality for detection of the lesions in 108 patients with primary oral squamous cell carcinoma referred to the Department of Oral and Maxillofacial Surgery at Nagasaki University Hospital from January 2008 to December 2011. Ninety nine of the 108 patients were examined by 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and/or esophagogastroduodenoscopy (EGD). Six patients (6.6%, 6/99) with 8 double cancers were detected. Five patients (8.2%, 5/61) with 6 double cancers were detected by EGD and 4 patients (5.3%, 4/75) with 5 double cancers were detected by FDG-PET. EGD was superior to FDG-PET in sensitivity, but FDG-PET was superior to EGD in specificity. While EGD could diagnose cancer in the upper digestive tract, distant metastasis and colon cancer were detected by FDG-PET scan alone. FDG-PET was suggested to be an effective diagnostic tool for distant metastasis and colon cancer. These results suggest that FDG-PET and EGD are equally suitable diagnostic tools for the detection of double cancers.