Epidemiological review of laryngeal cancer: An Indian perspective

BACKGROUND: Laryngeal cancer is one of the 10 leading causes of cancer in Indian men. The association of laryngeal cancer and tobacco smoking is well-established, but the peculiarities such as wide variation of disease distribution and survival, role of tobacco chewing, indoor air pollution, and dietary factors in laryngeal cancer causation needs to be understood. In this study, we review the descriptive and observational epidemiology of laryngeal cancer in India. MATERIALS AND METHODS: MEDLINE and Web of science electronic database was searched from January 1995 to December 2013, using the using keywords “laryngeal cancer, laryngeal cancer outcome, epidemiology, etiological factor and their corresponding Mesh terms were used in combination like OR, AND.” Two authors independently selected studies published in English and conducted in India. A total of 15 studies were found to be relevant and eligible for this review. RESULTS: In India, laryngeal cancer contributes to approximately 3-6% of all cancers in men. The age-adjusted incidence rate of cancer larynx in males varies widely among registries, highest is 8.18 per 100,000 in Kamprup Urban District and the lowest is 1.26 per 100,000 in Nagaland. The 5-year survival for laryngeal cancer in India is approximately 28%. Indian studies show tobacco, alcohol, long-term exposure to indoor air pollution, spicy food, and nonvegetarian diet as risk factors for laryngeal cancer. CONCLUSION: There is wide regional variation in the incidence of laryngeal cancer in India. Survival rates of laryngeal carcinoma are much lower as compared to other Asian countries. Studies conducted in India to identify important risk factors of laryngeal cancer are very limited, especially on diet and indoor air pollution. Hence, more research is required for identifying the etiological factors and development of scientifically sound laryngeal cancer prevention programs.