Assessment of Registry-Based Surveillance Statistics Used for Cancer Control in the Dindigul District in South India.

Abstract

Background: Cancer incidence rates from the Dindigul district were lower by 50% than Chennai in Tamil Nadu for most cancers. This study describes the cancer surveillance statistics and provides an assessment of missing cases from routine registration in the Dindigul Ambilikkai Cancer Registry (DACR), covering a predominantly rural population in the Dindigul district.

Method: A total of 21,214 incident cancers in the DACR during 2003-2017 were examined for this study. Cancer registration was carried out by active case-finding following standard international norms. A total of 12,541 incident cancers registered during 2003-2012 and followed through 2014 were used to estimate survival. Data on follow-up were obtained through a mixture of active and passive methods. Survival probability was estimated by actuarial methods. A random survey carried out independently was used to assess the quality of case ascertainment.

Results: The age-standardized rate (ASR) per 100,000 population was higher among women (76.2) than men (61) in 2013-2017, with both sexes reporting a 17% increase compared to 2003-2007. The most common cancers were cervix (ASR,18.5) and female breast (ASR,17.1), with percentage changes of -19% and +46.1%, respectively. Lung cancer (ASR, 5.5) was top among men with an increasing trend (+57.1%). The percent change in ASR of mouth cancer showed opposite trends among men (+24.3%) and women (- 21.4%). The ASR of colorectal cancers almost doubled among men between 2003-2007 and 2013-2017 (3.9; +94.7%). The 5- and 10-year absolute survival for all cancers were 31% and 20%, respectively. Out of 365 incident cancers that occurred during 2003-2010 in the surveyed areas, 310 (84.9%) were already registered in the DACR, while 55 were newly identified from the survey (15.1%). Inadequate coverage of sources outside the Dindigul district was significant (P = .002), with the highest number of missed cases from hospitals under nongovernment sectors (58.3%). Underascertainment was higher among cancer patients living in hilly regions (60%) and border areas (47.4%) than in core regions (P = .05).

Conclusion: Because of an enacted government order making cancer a notifiable disease, the registry-based cancer surveillance could be extended, covering a population of 80 million in a cost-effective manner with enhanced coverage and systematic evaluation of cancer-screening programs.