The following is a summary of “Evaluating CA-125 and PET/CT for cancer detection in idiopathic inflammatory myopathies,” published in the September 2024 issue of Rheumatology by Wang et al.
Researchers conducted a retrospective study to assess the effectiveness of CA-125 and PET/CT in diagnosing cancer among adult patients with idiopathic inflammatory myopathy (IIM).
They reviewed adult patients with IIM enrolled between 2003 and 2020. The patients were introduced to CA-125 and PET/CT tests within 5 years of symptom onset—data from electronic records captured true-positive, false-positive, true-negative, and false-negative results.
The results showed that out of 1,432 patients with IIM, 250 CA-125 tests on 205 patients showed a 3.1% false-positive rate and 14.3% false-negative rate. Most false positives were linked to endometriosis or fibroids. For PET/CT, 149 tests on 139 patients resulted in 5.5% false positives and 28.6% false negatives. Lymphadenopathy and lung nodules were predominant causes of false positives, mainly missing melanoma, low-stage breast, and prostate cancers.
Investigators concluded that false positives and negatives were common in CA-125 and PET/CT tests for newly diagnosed patients with IIM. Recognizing the inaccuracies helps clinicians make better decisions when managing patient care.
Source: academic.oup.com/rheumatology/advance-article-abstract/doi/10.1093/rheumatology/keae470/7747834
