# Cheap long-term survival follow-up by linking trial participants to registries

Source: https://onco.cc/ideas/idea-tr1-registry-linked-os-followup/  
OnCo record `idea-tr1-registry-linked-os-followup` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Trials often stop following patients once the main result is in, so we never learn whether the drug extended life. Linking participants to national death and cancer registries costs almost nothing and would answer that question.

## Summary

With participant consent at enrolment, trials link identifiers to national death indices and cancer registries so that OS and second-cancer follow-up continues indefinitely at negligible cost after study closure. Regulators require OS reporting at 5 and 10 years for drugs approved on surrogate endpoints, using this linkage. Precedent: registry-linked follow-up in Nordic and UK trials and in US cooperative-group studies via the National Death Index.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Registry-linked follow-up will deliver long-term OS for most surrogate-based approvals at under 1 percent of the original trial cost, and will identify approvals whose survival benefit was not sustained.
- Rationale: Long-term follow-up in trials is expensive because it relies on site visits; registries collect the same outcome routinely. Accelerated approvals frequently lack mature OS years later.
- Proposed test: Retrospectively link participants of five completed surrogate-endpoint trials to registries (with consent provisions permitting) and report the incremental OS information obtained and its cost.
- Maturity: early-clinical
- Actor: regulator

## Sources

- FDA Oncology Center of Excellence: Project Confirm: https://www.fda.gov/about-fda/oncology-center-excellence/project-confirm

## Connected records

- collections: [SEER (Surveillance, Epidemiology, and End Results)](https://onco.cc/collections/seer/)
- terms: [Accelerated approval](https://onco.cc/terms/accelerated-approval/), [Overall survival (OS)](https://onco.cc/terms/os/)
- bottlenecks: [Trial design, endpoints and cost](https://onco.cc/bottlenecks/b-trial-design/), [Weak real-world evidence and registries](https://onco.cc/bottlenecks/b-real-world-evidence/)

---
JSON: https://onco.cc/api/v1/entities/idea-tr1-registry-linked-os-followup.json