Effects of Radiotherapy for Malignancy in Systemic Sclerosis: A Systematic Review

Objective. Concerns regarding offering radiotherapy to patients with systemic sclerosis (SSc) stem from the potential worsening of SSc manifestations and radiotherapy toxicity. We conducted a systematic review to evaluate the effects of radiotherapy on SSc outcomes and radiotherapy-related toxicity. Methods. MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials were searched for SSc and radiotherapy. Inclusion criteria were SSc diagnosis, subsequent cancer development, and radiotherapy exposure. Outcomes were SSc manifestations (cutaneous thickening, pulmonary fibrosis, and SSc flare) and radiotherapy toxicity (acute and late) using Common Terminology Criteria for Adverse Events for grading. Grade 1 and 2 toxicities were categorized as nonsevere and grade 3 to 5 toxicities as severe. Results. Of 121 patients with SSc undergoing radiotherapy (mean age 56.4 years, 83.3% female, median radiotherapy dose 50 Gy), most did not show worsened SSc skin thickening (74.5%) or pulmonary complications (74%) post radiotherapy. In retrospective studies, the average rates of acute adverse effects were 57.3% for nonsevere and 25.8% for severe, whereas the rates of late adverse effects were 32.4% for nonsevere and 24% for severe. Conclusion. Although most patients with SSc do not exhibit significant worsening of SSc manifestations post radiotherapy, there is a variable risk of acute and late toxicity. These findings suggest that although radiotherapy may be a viable option for patients with cancer with SSc, it requires caution.