Evaluation of Delhi Population Based Cancer Registry and Trends of Tobacco Related Cancers

Background: Tobacco use is the single most important preventable risk factor for cancer. Surveillance of tobacco-related cancers (TRC) is critical for monitoring trends and evaluating tobacco control programmes. We analysed the trends of TRC and evaluated the population-based cancer registry (PBCR) in Delhi for simplicity, comparability, validity, timeliness and representativeness. Materials and Methods: We interviewed key informants, observed registry processes and analysed the PBCR dataset for the period 1988-2009 using the 2009 TRC definition of the International Agency for Research on Cancer. We calculated the percentages of morphologically verified cancers, death certificate-only (DCO) cases, missing values of key variables and the time between cancer diagnosis and registration or publication for the year 2009. Results: The number of new cancer cases increased from 5,854 to 15,244 (160%) during 1988-2009. TRC constituted 58% of all cancers among men and 47% among women in 2009. The age-adjusted incidence rates of TRC per 100,000 population increased from 64.2 to 97.3 among men, and from 66.2 to 69.2 among women during 1988-2009. Data on all cancer cases presenting at all major government and private health facilities are actively collected by the PBCR staff using standard paper-based forms. Data abstraction and coding is conducted manually following ICD-10 classifications. Eighty per cent of cases were morphologically verified and 1% were identified by death certificate only. Less than 1% of key variables had missing values. The median time to registration and publishing was 13 and 32 months, respectively. Conclusions: The burden of TRC in Delhi is high and increasing. The Delhi PBCR is well organized and generates high-quality, representative data. However, data could be published earlier if paper-based data are replaced by electronic data abstraction.