What Is the Appropriate Treatment Strategy for Superficial Esophageal Cancer With Synchronized Head and Neck Cancer?

Background In case of esophageal cancer with synchronized head and neck cancer (HNC), treatment of HNC is generally preferred when the HNC is more advanced. Although prior chemoradiotherapy (CRT) for HNC is expected to have some therapeutic effect on synchronized esophageal cancer, there are few reports on the efficacy and its treatment options in large numbers, and the subsequent course is unclear. We aimed to evaluate the appropriateness of treatment options for superficial esophageal squamous cell carcinoma (SESCC) with synchronized HNC in patients who had previously received CRT for HNC. Methods 26 patients with SESCC and 36 lesions who underwent prior CRT for synchronized HNC from January 2017 to December 2022. We analyzed retrospectively the endpoints, such as treatment response, treatment option and prognosis of SESCC. Results HNCs included hypopharyngeal (20), mesopharyngeal (2), tongue (2), laryngeal (1), and unknown primary lymph node metastasis (1), all treated with cisplatin. The mean age was 62.9 years (23 males, 3 females). SESCCs invasion depth were EP/LPM: 27, MM/SM1: 6, SM2: 3. Endoscopic types were 0-IIa: 3, 0-IIb: 10, 0-IIc: 22, 0-Is: 1. The median time from detection to CRT evaluation was 125 days. CR was achieved in 7 cases, with 3 relapses. Among 28 non-CR/non-PD cases, 21 received additional treatment (ESD: 13, surgery: 4, CRT: 4). The mean follow-up was 679 days. No SESCC-related deaths occurred. Conclusion As a treatment strategy for SESCC with synchronized HNC, it was considered clinically reasonable to perform treatment response assessment and treatment option for SESCC after CRT for HNC. However, appropriate follow-up timing for SESCC is an issue to be considered.