Major Swedish cancer registry misses half of rectal cancer recurrences
A validation study found that Sweden's national rectal cancer registry—used to guide clinical care and research—fails to capture 43% of local recurrences, particularly cases involving metastatic disease. The finding raises questions about data reliability for hospitals, regulators, and researchers who depend on the registry for treatment benchmarking and outcome tracking.
Originaltitel: Validation of the reporting of local recurrence of rectal cancer in the Swedish ColoRectal Cancer Registry (SCRCR)
BACKGROUND AND AIMS: The Swedish ColoRectal Cancer Registry (SCRCR) includes data on patients with rectal cancer in Sweden with a coverage rate of 98.5%. Variables on primary diagnosis and treatment have good validity, but the validation of oncological outcomes such as local recurrence is lacking. Since data from the SCRCR are used widely in research and for clinical evaluation, with local recurrence as an important outcome, this study aimed to validate the registration of local recurrence of rectal cancer in the SCRCR. METHODS: All patients registered with a diagnosis of rectal cancer in 2016 and 2017 who underwent an abdominal resection of the tumor were identified in the SCRCR. Medical records were reviewed and compared to the data registered in the SCRCR. RESULTS: A total of 2828 patients were included, of which 166 patients (5.9%) were diagnosed with local recurrence according to medical records within the study period. Of these, 94/166 (57%) were registered with local recurrence in the SCRCR. Patients with non-reported local recurrence more often had concurrent metastases and/or were treated with palliative intent. There were 17 patients reported with local recurrence in the SCRCR without local recurrence identified in the medical records. CONCLUSION: There was a significant underreporting of local recurrence in the SCRCR. Ambiguities in the definition of local recurrence as well as disregarding patients with concurrent metastatic disease probably contributed to the underreporting. Clarifying the definition of local recurrence and stressing the importance of reporting local recurrence regardless of metastatic disease or palliative treatment may improve data accuracy.