ABSTRACT
Background: This study examined the spatial pattern of the colorectal cancer (CRC) in the 18 municipalities that compose the Regional Health Department of Barretos (RHD-V), which is in the northeast of the state of São Paulo, Brazil. Methods: All incident cases and deaths from CRC between 2002 and 2016 were included. Age-standardized rates (ASR) for incidence and mortality per 100,000 person-years were used to evaluate the spatial distribution for the total and five-year periods. The lethality rates were also assessed. Excess risk maps compared the observed and expected events. Age-standardized net survival was used to evaluate CRC survival. Results: For CRC incidence, the ASR value for the general population over the entire period (2002-2016) was 17.7 (95% CI: 16.7, 18.6), ranging from 16.7 (95% CI: 14.9, 18.4) (2002-2006) to 20.0 (95% CI: 18.3, 21.7) (2012-2016) per 100,000. When males and females were compared, the ASR was 20.1 (95% CI: 18.6, 21.6) and 15.7 (95% CI: 14.5, 17.0) per 100,000, respectively. For CRC mortality (2002-2016), the ASR was 8.2 (95% CI: 7.6, 8.9), ranging from 9.0 (95% CI: 7.8, 10.3) (2002-2006) to 8.2 (95% CI: 7.2, 9.3) (2012-2016) per 100,000. Overall, the excess risk up to 2.0 was more frequent. In terms of survival, municipalities with large port populations had lower survival in comparison with medium port. Conclusions: This study showed a variation in CRC incidence and mortality, with differences considering five-year periods and gender, being the incidence higher in males than females in the entire period, with mortality equivalent to half the incidence. The survival was lower in municipalities with large port populations in comparison with medium port. Knowing spatial patterns of incidence, mortality, lethality, and survival can be necessary to support policymakers to advance or implement effective cancer control programs.
ABSTRACT
Population-based cancer registries (PBCR) are the primary source of cancer incidence and survival statistics. The loss to follow-up of these patients is concerning since it reduces the reliability of any statistical analysis. The linkage techniques have been increasingly used to improve data quality in various information systems. The linkage was performed between the databases of the PBCR-Barretos and the mortality database of the state of São Paulo. To evaluate the improvement in the follow-up time of patients, the comparability of the two databases, pre- and post linkage, was made. Three analyses were performed: a comparative analysis of the absolute number of deaths, a comparative analysis of the follow-up time of patients and the survival analysis. After linkage, there was an increase of 813 deaths. The follow-up time of patients was extended and observed in most types of tumours. The comparability of the survival analyses at both time points also showed a decrease in survival probabilities for all tumour types. Deterministic linkage is effective in updating the vital status of registered patients, improving patient follow-up time, and maintaining good quality data from PBCRs, consequently producing more reliable rates, as seen for the survival analyses.
