Impact of Linkage to the Social Security Administration on Follow-up Completeness and Cancer Relative Survival Estimates in 2 New SEER Registries: 2000-2016 Diagnosis Years.

The Social Security Administration Service to Epidemiological Researchers (SSA-SER) can help central cancer registries meet the contractual follow-up requirements of the Surveillance, Epidemiology, and End Results (SEER) Program and improve survival estimate accuracy. We evaluated the impact of first-time SSA-SER linkage on follow-up rates and survival estimates for 2 SEER registries. Methods: In May 2019, cancer registries in Idaho (Cancer Data Registry of Idaho [CDRI]) and New York (New York State Cancer Registry [NYSCR]) used results from an SSA-SER linkage to update date of last contact and vital status for patients with a SEER-reportable tumor diagnosed during 2000-2016. We compared follow-up completeness through 2017 between pre-SSA-SER linkage and post-SSA-SER linkage data. Among individuals with a first primary tumor diagnosed during 2009-2015, we calculated 60-month age-standardized all sites and site-specific relative survival ratio (RSR) estimates via the presumed alive method using pre-SSA linkage data, and survival time calculated from last known date of contact using post-SSA linkage data. Results: SSA-SER linkage improved overall followup completeness from 79.0% to 97.4% and 55.7% to 92.6% for CDRI and NYSCR, respectively. Follow-up completeness improved most for laboratory-only reported tumors, in situ tumors, melanomas of the skin, prostate cancers, and benign and borderline brain and other central nervous system tumors. Post-SSA linkage RSRs were lower than pre-SSA presumed alive RSRs by an average -0.47% and -2.16% for Idaho and New York, respectively. Conclusions: SSA-SER linkage greatly and efficiently improved follow-up completeness for the 2 participating registries and revealed small difference in survival estimates by method. Use of the SSA-SER by all US registries would standardize and improve US survival estimates.