Radiation therapy may be used with caution in scleroderma

25% of patients saw side effects months after treatment by Patricia Inácio, PhD | August 6, 2024

Scleroderma patients who have cancer may be treated with radiotherapy without a notable risk of skin and pulmonary worsening, a review study suggests, but around 25% of patients saw severe acute and late toxicities, that is, side effects months after radiation therapy.

As such, “individualized assessment, close collaboration between radiation oncologists and rheumatologists, use of high precision radiotherapy techniques to minimize dose to organs at risk, and vigilant monitoring are key to optimizing the risk-benefit balance,” scientists wrote in the review, “Effects of Radiotherapy for Malignancy in Systemic Sclerosis. A Systematic Review,” in The Journal of Rheumatology.

Studies have shown that having scleroderma increases the risk for developing cancer, especially lung, blood and head and neck cancers.

While radiotherapy is a cornerstone of cancer treatment, its use in scleroderma patients has raised concerns about causing severe skin thickening and localized scleroderma in people without prior disease. In fact, the American College of Radiology considers scleroderma and related disorders as contraindications for treatment to remove an area of cancer from the breast.
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Evidence in scleroderma is scarce, however, leading researchers from Canada and Saudi Arabia to review 26 studies published across four databases to better understand safety and outcomes of radiotherapy in scleroderma. Half the studies analyzed were case reports and most were from the U.S. The studies were published between 1987 and 2021, and taken together they reported on 121 scleroderma patients treated with radiotherapy. The patients’ mean age was 56.4 and 83.3% were female.

How radiotherapy is used in scleroderma
Radiotherapy was used as a curative treatment in 88.5% of the cases and as palliative in the remaining ones. Palliative care is intended to provide relief from pain and other symptoms of a serious disease. The median radiotherapy dose was 50 Gray.

In 45% of the cases, radiotherapy was given as an add-on treatment. In 5%, it was given as a neoadjuvant treatment, meaning before the main treatment (usually surgery) with the goal of shrinking tumors and helping to improve outcomes. The remaining 50% had radiotherapy as definitive therapy, which means the best possible approach among all considered.

Indications included breast (46 patients), intrathoracic (seven), head and neck (four), genitourinary, that is, affecting the reproductive and urinary tract (four), colorectal (three), and brain tumors (one). Eleven studies reported the outcomes of 41 scleroderma patients (33.8%) following radiotherapy.

Most patients didn’t show worsening skin thickening (92.7%) or pulmonary complications (90.3%) after radiotherapy. Rare instances of skin thickening or lung scarring were reported, however.

Among other types of complications, one patient developed dysfunction of the esophagus, which is the muscular tube that passes food and liquid from the throat to the stomach, and two others developed acroosteolysis, a rare condition marked by resorption of the small bones in the fingers or toes.

Acute adverse reactions were reported in 21 studies that encompassed 77 patients. Four patients had severe adverse reactions, which included diarrhea and acute kidney injury. Late adverse reactions to radiotherapy were reported in 25 studies with 95 patients. Examples included scarring of the skin, trouble swallowing, and bowel obstruction.
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The study suggests “that although most [scleroderma] patients do not exhibit significant exacerbation of cutaneous or pulmonary manifestations post-radiotherapy, there is a variable risk of acute and late adverse effects that cannot be overlooked,” the researchers wrote.