Substantial resources are dedicated to long-term follow-up within cancer registries; however, the completeness of these data is poorly characterized. Our objectives were to quantify long-term cancer follow-up data completeness and the effort required to collect these data using the National Cancer Database (NCDB).
To quantify data completeness, patients diagnosed with cancer in 1989 were identified in the NCDB and loss to follow-up rates were assessed for 25 years after diagnosis. To quantify data collection effort, patients diagnosed from 1989 to 2014 who were alive and eligible for follow-up in 2014 were identified and the effort to perform patient follow-up was obtained via a survey of tumor registrars. The effort to perform follow-up beyond various intervals after diagnosis was calculated.
In total, 484,201 patients at 958 hospitals were diagnosed with cancer in 1989. After 5 years, 6.5% of patients were lost to follow-up (13.1% of living patients), 50.3% were deceased, and 43.2% had ongoing follow-up. After 15 years, 22.9% were lost to follow-up (68.7% of living patients), 66.7% were deceased, and 10.5% had ongoing follow-up. By 25 years, loss to follow-up increased to 28.6% (93.7% of living patients), 69.5% were deceased, and 1.9% had ongoing follow-up. In 2014, 522,838 h were spent performing follow-up for 2,091,353 patients at 1456 hospitals who were >15 years from their initial cancer diagnosis.
While 5-year follow-up is excellent in the NCDB, loss to follow-up increases over time. The impact of curtailing data collection is under investigation and follow-up duration requirements will be re-evaluated.