TOPLINE:

The new Scoring system for Cancer Risk in idiopathic Inflammatory Myositis (SCRIM), which incorporated age, sex, smoking status, dermatomyositis, anti‑transcriptional intermediary factor 1‑gamma (anti-TIF1-gamma) positivity, and other clinical factors, showed excellent performance in predicting and stratifying the risk for cancer in patients with idiopathic inflammatory myopathy.

METHODOLOGY:

• Researchers used data from a large multicenter cohort of patients with idiopathic inflammatory myopathy to identify risk factors for cancer, develop a prediction model, and derive a clinically applicable SCRIM score for precise cancer risk stratification.
• They analyzed data of 481 patients (mean age at diagnosis, 53.2 years; 30.6% men) with idiopathic inflammatory myopathies across four independent cohorts in the Republic of Korea; diagnoses were confirmed using established criteria.
• The analysis utilized 24 clinical variables as potential covariates, which included age and sex; subtypes of idiopathic inflammatory myopathy; clinical features such as refractoriness to the initial treatment, dysphagia, cutaneous ulcers, Raynaud phenomenon, arthritis, and interstitial lung disease; and the presence of myositis-specific or myositis-associated autoantibodies.
• The key outcome was myositis-associated cancer, defined as cancer occurring within 3 years before or after the diagnosis of idiopathic inflammatory myopathy.

TAKEAWAY:

• Among the study population, 12.9% developed myositis-associated cancer, and lung cancer was the most common type.
• Older age, male sex, current smoking, dermatomyositis, and anti-TIF1-gamma positivity were identified as high-risk factors; however, antisynthetase syndrome, overlap myositis, inflammatory arthritis, and interstitial lung disease were associated with a lower risk for cancer.
• The SCRIM score incorporating these nine parameters demonstrated excellent performance in predicting the risk for cancer, with an area under the receiver operating characteristic curve of 0.852 (95% CI, 0.796-0.907).
• Patients with final scores of 2 or less were classified as the low‑risk group, those with scores of 3-7 were classified as the intermediate‑risk group, and those with scores of 8 or more were classified as the high‑risk group; those in the low‑risk group had an incidence of cancer comparable to that of the general population, whereas those in the intermediate‑ and high‑risk groups had higher incidences.

IN PRACTICE:

“This approach significantly improved the accuracy of predicting myosi­tis-associated malignancy and could enable more precise recommendations for cancer screening. For example, patients classified as the low-risk group based on SCRIM score encompassed approximately 40% of the study pop­ulation, and their cancer incidence rate was comparable to that of the general population,” the authors wrote.

SOURCE:

The study was led by Yun Kyu Kim, MD, and Jung Yoon Pyo, MD, Seoul National University Hospital in Seoul, South Korea. It was published online on November 4, 2025, in Arthritis Research & Therapy.

LIMITATIONS: 

Although the model demonstrated acceptable discriminative performance in internal validation, external validation across diverse populations is still needed. Not all patients had completed 3 years of follow-up after myopathy diagnosis. The lack of standardized cancer screening strategy in this population led to heterogeneous screening approaches. 

DISCLOSURES:

The study was supported by the National Research Foundation of Korea grant funded by the Korean government, with additional funding provided by Seoul National University. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.