Severe toxic effects from hypofractionated radiotherapy were low among patients with cancer and comorbid collagen vascular disease (CVD), indicating these patients may be eligible to receive this therapy. These findings were published in JAMA Network Open.
Collagen vascular disease is a group of disorders characterized by the presence of autoantibodies and a dysregulated immune system. These diseases can produce widespread inflammation associated with injury to connective tissues. In addition, patients with CVD are at greater risk of developing site-specific cancers.
At least half of patients with cancer will be treated with radiation therapy; however, many oncologists feel CVD is a contraindication to radiation therapy because of concerns about severe treatment-associated toxic effects. This retrospective cohort study compared acute and late toxic effects of dose-fractionated radiotherapy in patients with cancer and comorbid CVD.
In the study, researchers analyzed electronic medical records from 197 patients with cancer and CVD treated at University of California, Los Angeles between 2007 and 2019 for toxic effects and clinical outcomes, with a median follow-up of 23 months.
Patients were mean age 69 years (standard deviation [SD], 12); 68.0% were women; 75.6% were White; and 37.6% had rheumatoid arthritis, 27.4% psoriasis, 17.3% systemic lupus erythematosus, and 4.1% scleroderma.
Conventional fractionation (CF) radiotherapy was administered to 40.6% of patients, moderate hypofractionation (MH) radiotherapy to 27.9%, and ultrahypofractionation (UH) radiotherapy to 31.5%. On the basis of therapy, patient groups differed significantly for age (P =.02), gender (P <.001), CVD medication (P =.01), and cancer type (P <.001).
Among all patients, no grade 4 or 5 acute toxic events were observed. Rates of severe toxic events (grade 3) were 5.4% in patients treated with CF, 7.4% with MH, and 1.7% with UH. Most common acute events were dermatitis (20.4%), pain (14.1%), and fatigue (13.1%).
No grade 5 late toxic events were observed. Rates of severe late toxic events were 8.3% in those treated with CF, 0% with MH, and 2.2% with UH. Most common late toxic events were pain (10.2%), skin hyperpigmentation (6.3%), and superficial soft tissue fibrosis (4.6%).
CVD symptom flare occurred in 23.8% of patients treated with CF, 27.3% with MH, and 16.1% with UF.
This study may have been limited by the fact that toxic effects are often underestimated.
These data suggested high dose radiation may be administered to patients with cancer and comorbid CVD with little risk for toxic effects and modest risk for CVD symptom flare.
Disclosure: One author declared affiliations with and receiving funds from the pharmaceutical industry. Please refer to the original article for a full list of disclosures.
Yoon SM, Chu FI, Ruan D, et al. Assessment of toxic effects associated with dose-fractionated radiotherapy among patients with cancer and comorbid collagen vascular disease. JAMA Netw Open. 2021;4(2):e2034074. doi:10.1001/jamanetworkopen.2020.34074.