What Is the Association Between Pharyngeal Lugol-Voiding Lesions and Esophageal Cancer Risk After Treatment for Superficial Head and Neck Cancer?

Background Iodine staining in endoscopic examinations detects multiple Lugol-voiding lesions (LVLs) and is linked to secondary primary lesions in other organs. However, few studies have evaluated the risk of esophageal squamous cell carcinoma (ESCC) based on pharyngeal LVL grade. This study aimed to investigate esophageal cancer risk in patients treated for superficial head and neck squamous cell carcinoma (HNC). Methods We analyzed 66 cases underwent endoscopic resection for HNC at our institution (January 2020–December 2023). Cases with non-SCC histology, prior esophageal cancer treatment, or synchronous esophageal cancer were excluded. Data on patient characteristics and endoscopic findings were collected. Esophageal LVL grading followed Katada’s criteria: A (no unstained areas), B (between A and C), and C (≥10 unstained areas). Pharyngeal LVL was defined as follows: A (no unstained areas), B (between A and C-1), C-1 (≥10), and C-2 (≥20). ESCC events were defined as newly detected cases more than one year after HNC treatment and analyzed by pharyngeal LVL grade. Results The follow-up period was 27 months (±13.7 SD). Esophageal LVL grade was A:B:C = 2:23:41 and pharyngeal LVL grade was A:B:C-1:C-2 = 1:10:33:22. The concordance rate between pharyngeal LVL grade and esophageal LVL grade was higher in C-1/C (64%) and C-2/C (82%). There were no ESCC events in grade A and B cases of pharyngeal LVL. 3/33 (9.1%) patients in the C-1 group developed ESCC, compared to 7/22 (31.8%) in the C-2 group (p = 0.07). Conclusion Patients with pharyngeal LVL grade C-2 were at higher risk of ESCC. Post-treatment surveillance of HNC cases should focus on monitoring the likelihood of ESCC development, especially in cases with higher pharyngeal LVL grades.