Survival after diagnosis of cancer of the oral cavity.

In this retrospective study we analysed the survival in 470 patients with oral cancer. Patients who attended five university hospitals in Tehran, Iran, during the period 1996-2002 were included. Data were obtained from a combination of sources including patients' records, telephone calls, and deaths registered by the Ministry of Health. Survival curves were generated using Kaplan-Maier curves. Univariate and multivariate analyses of the relations between survival and age, sex, site of primary tumour, stage, and histopathological type were made using the log-rank test and Cox's regression analysis. Sex and age were not associated with survival. Treatment and stage of tumour at the time of diagnosis were related to survival. The overall survival rates were higher in patients with stages I or II cancer than those in stages III (OR=2.8, 95% CI=1.8 to 4.4) or IV (OR=4.6, 95% CI=3.1 to 6.8) at the time of diagnosis. Patients treated with radiotherapy had lower survival than those who had been operated on and had radiotherapy or operation alone (OR=2.8, 95% CI=1.7 to 4.5). There was no difference in survival depending on the histological type of tumour. To achieve higher survival, early detection and diagnosis of oral cancers should be emphasised in oral health programmes to improve public awareness and preventive activities among dentists in Iran.