Prevalence of clinically significant incidental findings by whole-body fludeoxyglucose F 18 positron emission tomography/computed tomography scanning in moderate-to-severe psoriasis patients participating in clinical trials.

BACKGROUND

There has been an increase in the number of psoriasis treatments being investigated in clinical trials. Patients may have undiagnosed issues at the start of a study which may become identified during follow-up as incident medicinal conditions. The prevalence of incidental findings in patients with moderate-to-severe psoriasis presenting for clinical trials is unknown.

OBJECTIVE

Determine the prevalence of incidentalomas and rate of malignancy identified by fludeoxyglucose F 18 (FDG) positron emission tomography/computed tomography (PET/CT) imaging in clinical trial patients with moderate-to-severe psoriasis.

METHODS

A cross-sectional secondary analysis of patients with moderate-to-severe psoriasis who underwent FDG PET/CT scans at the baseline visit, before randomization, for 3 phase 4 clinical trials on vascular inflammation in psoriasis. Only patients without active infection, malignancy, or uncontrolled comorbidities were eligible for the clinical trials.

RESULTS

A total of 259 healthy patients with moderate-to-severe psoriasis underwent an FDG PET/CT scan as part of the study procedures. In all, 31 patients (11.97%) (95% confidence interval [CI], 8.28-16.56) had clinically significant incidentalomas on the baseline FDG PET/CT scan. Univariate logistic regression demonstrated that with every increase of 10 years of age, there was an approximate 30% increased risk of discovery of an incidentaloma (odds ratio, 1.30; 95% CI, 1.01-1.68). Of those patients with findings suggestive of malignancy (n = 28), 6 were confirmed to have cancer, resulting in a 2.31% (95% CI, 0.9-5.0) prevalence of malignancy. The positive predictive value of a true cancer was 31.58% (range, 21%-54%).

LIMITATIONS

Generalizability and lost to follow-up.

CONCLUSION

Incidentalomas on FDG PET/CT imaging are common in otherwise healthy, asymptomatic patients with moderate-to-severe psoriasis in clinical trials. Our results can help inform interpretation of clinical trial safety data and emphasize the importance of compliance with cancer screening recommendations.