Objectives: Cancer recurrence is a meaningful patient outcome that is not captured in population-based cancer surveillance. This project supported National Program of Cancer Registries central cancer registries in five U.S. states to determine the disease course of all breast and colorectal cancer cases. The aims were to assess the feasibility of capturing disease-free (DF) status and subsequent cancer outcomes and to explore analytic approaches for future studies.
Methods: Data were obtained on 11,769 breast and 6033 colorectal cancer cancers diagnosed in 2011. Registry-trained abstractors reviewed medical records from multiple sources for up to 60 months to determine documented DF status, recurrence, progression and residual disease. We described the occurrence of these patient-centered outcomes along with analytic considerations when determining time-to-event outcomes and recurrence-free survival.
Results: Disease-free status was determined on all but 3.8 % of cancer cases. Among 14,458 cases that became DF, 6.1 % of breast and 13.0 % of colorectal cancer cases had a documented recurrence. Recurrence-free survival varied by stage; for stage II-III cancers at 48 months, 83.2 % of female breast and 69.2 % of colorectal cancer patients were alive without recurrence. The ability to distinguish between progression and residual disease among never disease-free patients limited our ability to examine progression as an outcome.
Conclusions: This study demonstrated that population-based registries given intense support and resources can capture recurrence and offer a generalizable picture of cancer outcomes. Further work on refining definitions, sampling strategies, and novel approaches to capture recurrence could advance the ability of a national cancer surveillance system to contribute to patient-centered outcomes research.
Keywords: Breast cancer; Colon cancer; National Program of Cancer Registries; Recurrence.
Published by Elsevier Ltd.