Younger age as an independent factor for second primary head and neck cancer in esophageal squamous cell carcinoma patients after curative esophagectomy: A two-center retrospective study

Background: Postoperative survival of esophageal cancer patients has improved with advances in technology and treatment modalities. However, squamous cell carcinoma (SCC) often affects the esophagus together with the head and neck regions, with second primary head and neck cancer (SPHNC) adversely influencing the patients' quality of life. Therefore, patients with esophageal squamous cell carcinoma (ESCC) should be carefully followed up postoperatively. This study evaluated the risk of developing SPHNCs after an esophagectomy for ESCC. Methods: Patients with ESCC who underwent curative esophagectomy from January 2008 to December 2017 from two tertiary medical centers, Taipei Veteran General Hospital and Kaohsiung Veteran General Hospital, were retrospectively reviewed. SPHNC development was documented according to the anatomic region and the cumulative incidence rate and risk factors were analyzed. Results: The median follow-up period of the 435 patients included in our study was 48.5 months [interquartile range (IQR) 16.7–92.4 months]. Among the ESCC patients after curative esophagectomy, younger age <50 [hazard ratio 4.13, 95% CI: 2.53–6.75, p < 0.001) was the only independent factor for developing SPHNCs in the multivariable analysis. The cumulative incidence rate of SPHNCs of patients aged <50 years old was 14.3%, 22.1%, and 34.2% after 3, 5, and 10 years, respectively. Conclusions: There was a high risk of secondary cancer after ESCC in the upper aerodigestive tract, especially the head and neck regions; therefore, active surveillance is strongly recommended, especially in younger patients.