Tumor stage at diagnosis as an indicator of cancer screening efficacy in diverse populations.

Abstract

e13805 Background: Efficacy of cancer screening depends on effective communication of its benefits and on low threshold access. Screening program acceptance may be influenced by cultural and socio-economic factors relating to health literacy. The City of Berlin with its former east-west division and multicultural population offers a special opportunity to study screening efficacy in diverse populations. Methods: As a measure of screening efficacy, the distribution of cancer stage at diagnosis reported to the regional cancer registry between 2008 and 2014 was assessed in a population-based epidemiological study. Three common cancer entities were chosen for this analysis, namely breast cancer (BC, high acceptance of screening by invitation), colon cancer (CC, low acceptance of screening), and lung cancer (LC, no screening program). Cancer stage at diagnosis was mapped to postal code micro-areas. Map visualization was used to assess spatial distribution, and logistic regression analysis to examine the association of regional socioeconomic data with stage. Results: The number of reported cases was 12.176 for BC, 5.038 for CC and 12.023 LC. BC stages were heterogenously distributed throughout the city. Specifically, a significantly higher proportion of stage I was observed in more affluent areas of the southwest, predominance of stage II in the east, and higher frequency of advanced stages in socially deprived areas with a high proportion of migratory background in the northwest, with a trend towards migratory background in the population as the stongest determinant for higher stage. No heterogeneity was detected for CC and LC, although multivariate analysis revealed significantly higher CC stages in socially deprived areas. There was no effect of health insurance status or density of primary physicians and stage. Conclusions: Even within a health care system with high access to health insurance and systematic invitation for breast cancer screening, there was a significant impact of migratory background and socioeconomic factors associated with higher initial breast cancer stage. Furthermore, the association of CC stage and socio-economic status suggests a lower tendency to seek medical workup for early signs of CC in socially deprived populations. Both findings suggest health literacy as an important factor for success of early cancer detection. Future design of educational programs tailored to specific populations may be helpful. Acknowledgement for providing case data and helpful discussion: Martin STRIK, Jochem POTENBERG, Harald MATTHES, Matthias PROSS, acknowledgement for statistical analysis: Genka TZOLOVA-MÜLLER, Verena MATERNA.