Epidemiological and histopathological characteristics of head and neck cancers in Bhutan from 2011 to 2017: a retrospective descriptive study.

Background: Head and neck cancers are among the commonest cancers in the developing world. Personal habits, such as the use of tobacco, betel nut and alcohol are strongly associated with the development of head and neck cancers at certain sites. Therefore, they are among the preventable cancers. In Bhutan, there has not yet been a study conducted on head and neck cancers.

Objective: To describe baseline epidemiological and histopathological characteristics of head and neck cancers in Bhutan.

Methods: This is a 7-year descriptive study of all cases of head and neck cancers presented at the Jigme Dorji Wangchuk National Referral Hospital from 2011 to 2017. The data were collected from the hospital's medical records section, histopathology records, patient referral unit and some treatment centres in India. Prior approval was sought from the Research and Ethics Board for Health, the Ministry of Health and the hospital management.

Results: There were a total of 515 cases of head and neck cancers from 2011 to 2017. The crude incidence rate was 10 per 100,000 and the overall age adjusted rate was 12.3 (95% CI 9.5-15.1) per 100,000 population. The prevalence during this 7-year period was 69.1 per 100,000 population. The commonest cancers are thyroid, oral cavity, hypopharyngeal, laryngeal and nasopharyngeal cancer in decreasing order. Head and neck cancers are more common in males than females in the majority of sites except thyroid, salivary gland and sinonasal malignancies. Thyroid cancers and nasopharyngeal cancers are found to affect younger age groups. Tashigang (48) followed by Paro (43) recorded the highest number of cases. Squamous cell carcinoma is the commonest histopathology type in almost all the cases, while papillary carcinoma is the commonest among thyroid cancers. Personal habits, such as smoking, chewing tobacco, betel nut and alcohol consumption, were found to be more common among patients suffering from oral cavity, laryngeal, hypopharyngeal and oropharyngeal cancers.

Conclusion: Head and neck cancers are the third most common cancer in Bhutan after stomach cancer and cervical cancer. Thyroid, oral cavity and hypopharynx are the top three anatomical sites for head and neck cancers in Bhutan. The current epidemiological and histopathological profile of head and neck cancers will form a baseline of information and basis for further research on head and neck cancers in Bhutan.