Survival from head and neck cancer in Mumbai (Bombay), India

Head and neck cancers, among the 10 most frequent cancers in the world, are common in regions with a high prevalence of tobacco and alcohol habits. They account for one-fourth of male and one-tenth of female cancers in India. The authors report and discuss the survival from these cancers in Mumbai (Bombay), India.

Follow-up information on 6311 head and neck cancer patients registered in the Bombay Population-Based Cancer Registry for the period 1987-1991 was obtained by a variety of methods, including matching with death certificates from the Bombay vital statistics registration system, postal/telephone enquiries, home visits, and scrutiny of medical records. The survival for each case was determined as the duration between the date of incidence and the date of death or date of loss to follow-up or the closing date of the study (December 31, 1996). Cumulative observed and relative survival were calculated by the Hakulinen method. For comparison of results with other populations, age-standardized relative survival (ASRS) was calculated by directly standardizing age specific relative survival to the specific age distributions of the estimated global incidence of major cancers in 1985. The log rank test was used in univariate analysis to identify the potentially important prognostic variables. The variables showing statistical significance in univariate analysis were introduced stepwise into a Cox regression model to identify the independent predictors of survival.

The 5-year relative survival rates were 74.5% for the lip, 42.7% for the anterior tongue, 25.5% for the posterior tongue, 45.1% for the mouth, 29.7% for the oropharynx, 38.7% for the nasopharynx, 29.1% for the hypopharynx, and 41.2% for the larynx. Age, marital status, religion, and site and clinical extent of disease emerged as independent predictors of survival. Age specific 5-year relative survival declined with advancing age. Single patients had a 20% excess risk of death compared with married patients. Those with cancers of the lip, mouth, nasopharynx, and larynx had a better prognosis than those with cancer at other sites. Those with regional spread of disease experienced a threefold increased risk of death, and those with distant metastasis experienced a sixfold excess risk. Less than one-fourth of cancers were localized in the organ of origin at diagnosis; 5-year survival for localized cancers ranged from 52.9% to 80.2% depending on the subsite.

There were significant variations in survival from cancer at individual sites within the head and neck region. Comparison with other populations revealed variations that seemed to be related to differences in detection and treatment. Tobacco and alcohol control measures and early detection linked with treatment are important measures to reduce mortality from head and neck cancer.