The emergence of oral cavity cancer and the stabilization of oropharyngeal cancer: Recent contrasting epidemics in the South Korean population.

Abstract

By analyzing the recent epidemiologic trajectory of head and neck squamous cell carcinoma (HNSCC) in South Korea, we tracked 2 findings that have been reported recently in other countries: the stabilization of human papillomavirus (HPV)-related HNSCC incidence and the acceleration of oral cavity cancer incidence. We analyzed data from the comprehensive population-based Korean Central Cancer Registry for the period 1999 to 2017. The age-standardized incidence rate (ASR), annual percent change (APC), and relative survival were calculated. The ASR of total HNSCC decreased from 1999 to 2017 (APC, -0.2 [95% CI, -0.3 to -0.0]), as did the ASR of HPV-unrelated HNSCC (APC, -0.6 [95% CI, -0.8 to -0.5]); however, the ASR of HPV-related HNSCC increased (APC, 2.9 [95% CI, 2.5 to 3.2]). The rapidly increasing incidence of tonsil squamous cell carcinoma, which was the main subsite of HPV-related HNSCC, stabilized after 2011 (APC pre-2011, 6.8 [95% CI, 5.0 to 8.3]; APC post-2011, 1.6 [95% CI, -2.1 to 5.5]), and the difference was significant (P = .017). In contrast, oral cavity cancer incidence demonstrated the only increase among HPV-unrelated subsites, with the increase occurring after 2006 (APC pre-2006, 1.6 [95% CI, 0.3 to 2.8]; APC post-2006, 2.8 [95% CI, 2.2 to 3.5]); the main cause of this change was an increase in the ASR of tongue cancer. This study demonstrates the recent stabilization of tonsil cancer incidence and the contrasting increase in oral cavity cancer incidence, unlike other HPV-unrelated cancers. These trends require further surveillance and understanding in terms of tumor biology and prevention.