Oral cancer incidence in Shanghai ---- a temporal trend analysis from 2003 to 2012

Oral cancer is a serious problem owing to its poor prognosis and destruction of patients' eating ability as well as facial appearance. Epidemiological studies can provide aetiological clues for prevention. The prevalence of oral cancer in densely populated cities in eastern China is unclear. The aim of the study is to analyse the incidence rates of oral cancer in Shanghai over the period 2003-2012 and estimate the temporal trends.

Cases of oral cancer were retrieved from the Shanghai Cancer Registry system in the Shanghai Municipal Center for Disease Control & Prevention for the years 2003 to 2012. Information on the corresponding population was obtained from the Shanghai Municipal Bureau of Public Security. Age-standardised incidence rates were directly calculated according to the world standard population. An annual percent change model was employed to analyse the temporal trends of cancer incidence.

A total of 3860 oral cancer cases were reported, representing 0.69% of all malignancies in Shanghai during the 10-year study period. The mean age at diagnosis was 64 years. The age-standardised incidence rate was 1.34 per 100,000 person-years, with a male-to-female ratio of 1.41. Annually, the incidence rates increased by 3.83 and 2.54% for men and women, respectively. The increase was most noticeable in males aged 45-64 years.

In Shanghai, the oral cancer incidence is relatively low. However, it is continuously increasing, especially among middle-aged males. This finding urges further investigations on the risk factors of oral cancer in this population, especially on changes in living patterns, such as the smoking, drinking, and dietary habits.