Professor Rebecca Grainger presents two studies that provide reassuring answers to important patient care questions in systemic sclerosis.
Among the hundreds of posters at ACR Convergence 2023 were two in particular that caught the eye of Professor Rebecca Grainger.
Both covered cancer in patients with systemic sclerosis: one looked at the reliability of mammograms, and the other at adverse effects of radiotherapy.
Speaking at Dermatology Republic’s sister publication Rheumatology Republic’s webinar, The ACR abstracts that will change practice, Professor Grainger, of the University of Otago in Wellington NZ, told the audience they interested her “because there was research work done based on an actual question for patient care”.
The first was research from Mt Sinai Hospital in New York, which looked at whether systemic sclerosis affects the interpretation of mammograms (poster 0616).
The study authors point out that patients with systemic sclerosis often have cutaneous cutis, the deposition of insoluble calcium salts in the skin and subcutaneous tissues. Meanwhile, around 10% of patients in the general population have abnormal mammograms with areas of calcification, which may indicate malignancy.
But to date, there’s been no formal study of patients with systemic sclerosis.
“Am I going to get more abnormalities because my skin is a bit different and I have calcinosis? The short answer is no,” said Professor Grainger.
Using the hospital’s electronic records, the researchers identified patients with systemic sclerosis who’d had mammograms done. They analysed the results of the mammogram and subsequent bioposy results and compared them with age-matched controls. The primary outcome was frequency of false positives.
Of the 152 systemic sclerosis patients, 19% had abnormal mammograms and were referred for biopsy. Around one-third of those biopsied (34.5%) were diagnosed with breast cancer, with two-thirds (65.5%) being false positive. This was comparable to the controls, with 67% false positives.
“So there’s no increase in false positives in people with systemic sclerosis,” said Professor Grainger. “It’s one centre, one study, but these are the only data I’m aware of that addressed this particular question.”
The other poster reported on a systematic review of research into the safety of radiotherapy in patients with systemic sclerosis (poster 0631).
“The American College of Radiology lists systemic sclerosis as a relative contraindication to radiotherapy because perhaps it worsens the scleroderma or there’s an increased rate of complications,” said Professor Grainger.
The authors found 25 papers, ranging from individual case reports to small studies, covering 121 systemic sclerosis patients who’d received radiotherapy.
“The bottom line is it did not appear to make skin or lung disease worse. Over 90% of patients did not get worse skin or lung disease after radiotherapy, they were stable,” Professor Grainger told the audience, which included a number of Australian dermatologists.
However, she pointed out, 15-24% of people in cohort studies had chronic or late severe sequelae of radiotherapy, with the study authors suggesting close monitoring during and after radiotherapy is needed.
“Some caveats here: there’s risk of bias and reporting. We probably need some prospective controlled data, but I liked this because someone’s done something to try and address a very practical question,” said Professor Grainger.
The post-ACR webinar, The abstracts that will change practice was held on 21 November, featuring Professor Peter Nash, Dr Claire Owen, Professor Rebecca Grainger and Dr David Liew. You can register here to watch a recording.
