The study was aimed to investigate the role of radiotherapy (RT) as a risk factor for reactivation or worsening of symptoms in patients affected by rheumatoid arthritis (RA) PATIENTS AND METHODS: This is a single-center retrospective observational study on RA patients who developed cancer requiring RT during the course of the disease. The control group consisted of RA patients with cancer who did not undergo RT. In both groups, the disease activity was evaluated at baseline and at 6 and 12 months through the DAS28 index. A relapse was defined as an increase of >20% in DAS28. A radiotherapist evaluated total and daily doses and timing of radiation. Acute and late toxicity was defined as events occurring within 90 days from the start and more than 90 days after the completion of RT, respectively.
Seventy-two RA patients (38F/34M; mean age: 70±9 years; mean disease duration: 13±9 years), 29 (40.2%) of whom received radiotherapy (mean age 72.9±9 years), were enrolled. The most frequent malignancies were breast (27.2%), thyroid (9.8%), and skin (7%). Between radio-treated and non-radio-treated patients, no significant differences in RA reactivation (6/29 vs. 17/43; p=0.12) or mean exacerbation time (6.7 ± 4.9 months compared to 6.4 ± 4.1 months; p=0.78) were found. Overall, RT was well tolerated with low rates of both acute and late toxicity.
In RA patients, RT was well tolerated and not associated with an increased risk of articular flares. Properly designed prospective clinical studies with a larger number of patients should be performed to confirm these data.