Decoding Cancer Registry Data: Are We All on the Same Page?
"A New Look at How Race, Ethnicity, and Cancer Type Are Recorded and Why It Matters for Everyone."
Cancer registries are vital tools for tracking disease trends, informing public health initiatives, and allocating resources effectively. These databases rely on accurate information regarding cancer type, race, and ethnicity. But how consistent is the information in these registries with what individuals report about themselves? This question is at the heart of ensuring equitable healthcare and driving meaningful improvements in cancer outcomes.
Self-reported data, on the other hand, plays a critical role in research, influencing how we understand lived experiences and tailor interventions. National surveys and studies often depend on individuals accurately reporting their medical history and background. When discrepancies arise between registry data and self-reports, it raises questions about the reliability of both sources and the implications for our broader understanding of health.
A recent study by Layne, Ferrucci, Jones, Smith, Gonsalves & Cartmel (2018) delves into this issue, examining the consistency between cancer registry data and self-reported information from participants in the American Cancer Society's Studies of Cancer Survivors (SCS). The study highlights areas of strong agreement and significant variation, shedding light on the challenges of accurately capturing race and ethnicity data and what it means for addressing cancer disparities.
Cancer Registry vs. Self-Report: What Did the Study Find?
The study, encompassing 6,306 survivors in SCS-I and 9,170 in SCS-II, assessed several key factors to measure the agreement between registry and self-reported data. Kappa statistics, which quantify the level of agreement beyond chance, were used to evaluate the concordance for cancer type, race, and Hispanic ethnicity. Sensitivity, specificity, and positive predictive value were also calculated to provide a comprehensive view of the data's accuracy.
- Breast and Prostate Cancer: Showed the strongest concordance, with sensitivity consistently above 0.98 in both SCS-I and SCS-II. This suggests that registries are highly accurate in recording these common cancer types.
- Race: Kappa scores were 0.85 in SCS-I and 0.93 in SCS-II. While these scores indicate good agreement, the study found significant variations among different racial groups.
- White and Black Survivors: Demonstrated strong concordance, with sensitivity around 0.95 and 0.99, respectively. This suggests that registries are generally accurate in recording these racial categories.
- American Indian/Alaska Native Survivors: Displayed weak concordance, with sensitivity as low as 0.23 and 0.19 in SCS-I and SCS-II, respectively. This indicates significant misclassification in registry data for this group.
- Asian/Pacific Islander Survivors: Showed variable concordance, with sensitivity at 0.43 in SCS-I and 0.87 in SCS-II. The improvement in SCS-II suggests potential changes in data collection or reporting practices over time.
- Hispanic Ethnicity: Agreement was moderate, with Kappa scores of 0.73 and 0.71 in SCS-I and SCS-II, respectively. Sensitivity was 0.74 and 0.76, indicating some level of misclassification.
Why Accurate Data Matters for Cancer Research
Accurate cancer registry data is fundamental for monitoring cancer trends, understanding risk factors, and addressing health disparities. When race and ethnicity data are inconsistently recorded, it can obscure our understanding of how cancer affects different populations, leading to ineffective interventions and policies. By ensuring that cancer registries accurately reflect the diversity of the population, we can better target resources, tailor prevention strategies, and improve outcomes for all cancer survivors.