The frequency of occult solid malignancy in patients with polymyalgia rheumatica-like symptoms

Aims: We aim to evaluate the clinical usefulness of systematic screening for occult cancer in patients with polymyalgia rheumatic (PMR)-like symptoms in real-life practice. Methods: All patients seen by rheumatologists in Burgundy, France, between March 2016 and December 2018 for new-onset PMR that met the 2012 ACR/EULAR classification criteria were prospectively included. Patients underwent systematic screening including determination of the erythrocyte sedimentation rate, serum C-reactive protein levels, thoracic, abdominal and pelvic computed tomography (CT-TAP) and, in men, serum prostate-specific antigen. The standardized incidence ratio (SIR) for cancers was calculated using 2012 national estimates of cancer incidence. Potential predictive factors for the diagnosis of cancer were then evaluated using univariate and multivariate analyses. Results: Among the 118 patients included, nine cases of cancer were confirmed and diagnosed with CT-TAP: kidney carcinoma (n = 4), lung cancer (n = 2), pancreatic, colon, and ampullary carcinoma (n = 1 each). Among these cancers, five were localized (four kidney, and one ampullary carcinoma) and were treated with complete surgical resection. The expected incidence of cancer in the general population was 1.95, leading to an overall SIR of 4.6 (95% CI 2.4-8.9, p < 0.0001). An additional analysis was performed for the kidney carcinoma, and it showed a highly significant increase in SIR: 80.8 (95% CI 30.3-215.4). In 80% of patients, the PMR-like syndrome regressed during cancer treatment. No other predictive factors for cancer were found. Conclusion: Systematic screening for cancer including CT-TAP in real-life practice revealed occult solid malignancy, mostly early-stage cancer, in a relevant proportion of patients presenting PMR-like symptoms. The high proportion of kidney cancer (40%) is worth highlighting, especially considering that it is not one of the most frequent cancers after 50 years of age.