Objective:

To characterize the ordering patterns of paraneoplastic antibody panels in all medical practitioners in Calgary, Alberta, Canada and implement quality improvement initiatives to improve ordering adherence to the 2021 Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.

Background:

Paraneoplastic neurologic syndromes (PNS) are inflammatory disorders of the nervous system triggered by an underlying malignancy. Neuronal antibody testing is an essential diagnostic tool for PNS. However, over-reliance on autoantibody testing with inconsistent clinical presentations can result in false positive test results. Incomplete autoantibody testing between CSF and serum samples and incomplete malignancy screening can lead to diagnostic uncertainty and missed diagnoses.

Design/Methods:

Electronic medical records (EMR) were screened for adult patients in Calgary who had paraneoplastic antibody panels sent from December 2024 - June 2025. Charts were reviewed for presentation type, paired serum/CSF testing, malignancy screening, and false positive rates based on the 2021 paraneoplastic diagnostic guidelines. Interventions to improve adherence to guidelines included education rounds to neurologists and oncologists and EMR ordering requirements. Analysis of a 6-month period after these interventions is ongoing.

Results:

Pre-intervention analysis shows that 262 patients had paraneoplastic antibody tests sent from December 2024 - June 2025. 14.9% (39/262) of patients had a presentation-type that was consistent with a high- or intermediate-risk PNS presentations. 38.1% (100/262) had paired serum-CSF testing. 20.2% (53/262) had complete malignancy screening. 10.3% (27/262) of patients had positive antibody testing, of which 88.9% (24/27) were false positives.

Conclusions:

The ordering patterns for paraneoplastic antibody testing in Calgary, Alberta shows that a low percentage of patients being tested have a consistent paraneoplastic presentation type resulting in a high false-positive rate. When these panels are being sent there is incomplete testing of serum/CSF paired samples and malignancy screening. Paraneoplastic antibody testing requires ongoing quality improvement to improve adherence rate to published guidelines. Further analysis post-quality improvement interventions is ongoing.