AT ACR 2022
PHILADELPHIA – The first consensus screening guidelines for patients with idiopathic inflammatory myopathy (IIM) provide recommendations on risk stratification for individuals, basic and enhanced screening protocols, and screening frequency.
The recommendations, issued by the International Myositis Assessment and Clinical Studies Group (IMACS), stratify cancer risk for individual patients into low, intermediate, or high categories based on the IIM disease subtype, autoantibody status, and clinical features, reported Alexander Oldroyd, PhD, MSc, MBChB of the University of Manchester, England.
“There’s a big unmet need for cancer screening. One in four adults with myositis has cancer, either 3 years before or after a diagnosis of myositis. It’s one of the leading causes of death in these patients, and they’re overwhelmingly diagnosed at a late stage, so we need standardized approaches to get early diagnosis,” he said in an interview at the annual meeting of the American College of Rheumatology.
Sharon Kolasinski, MD, of the University of Pennsylvania in Philadelphia, said in an interview that the guideline is a welcome development for rheumatologists. Dr. Kolasinski moderated the session where Dr. Oldroyd described the guideline, but she was not involved in its formulation.
“I think that we all have wondered for a very long time: What is the optimal cancer screening for myositis patients? We all worry that the onset of their diseases is associated with a coincident cancer, or that they will develop it soon,” she said.
Dr. Oldroyd emphasized that all patients with myositis have elevated risk for cancer compared with the general population and that the guideline categories of low, intermediate, and high are relative only to patients with IIM.
The data on which the recommendations are based come from aby Dr. Oldroyd and colleagues of 69 studies on cancer risk factors and 9 on IIM-specific cancer screening.
The authors of that paper found that the dermatomyositis subtype, older age, male sex, dysphagia, cutaneous ulceration and antitranscriptional intermediary factor-1 gamma (anti-TIF1-gamma) positivity were associated with significantly increased risk of cancer.
In contrast, polymyositis and clinically amyopathic dermatomyositis subtypes, Raynaud’s phenomenon, interstitial lung disease, very high serum creatine kinase or lactate dehydrogenase levels, and positivity for anti-Jo1 or anti-EJ antibodies were associated with significantly reduced risk of cancer.
The consensus recommendations were developed with anonymous contributions from 75 expert participants in 22 countries, with additional input from 3 patient partners.
The guideline lists 18 recommendations, of which 13 are strong and 5 are conditional.
An example of a strong recommendation is number 3, based on a moderate level of evidences:
“All adult IIM patients, irrespective of cancer risk, should continue to participate in country/region-specific age and sex appropriate cancer screening programs,” the guideline recommends.
Patients with verified inclusion body myositis or juvenile-onset IIM do not, however, require routine screening for myositis-associated cancer, the guideline says (recommendations 1 and 2).
There are also recommendations that all adults with new-onset IIM be tested for myositis-specific and myositis-associated autoantibodies to assist in stratifying patients by risk category.
The guideline divides screening recommendations into basic and enhanced. The basic screening should include a comprehensive history and physical exam, complete blood count, liver functions tests, erythrocyte sedimentation rates/plasma viscosity, serum protein electrophoresis, urinalysis, and chest x-ray.
Adults with IIM who are determined to be at low risk for IIM-related cancer should have basic cancer screening at the time of IIM diagnosis. Adults with intermediate risk should undergo both basic and enhanced screening at the time of IIM diagnosis, and those with high risk should undergo enhanced screening at the time of myositis diagnosis, with basic screening annually for 3 years, the recommendations say.