Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia

Johannes C Nossent; Helen Keen; David Preen; Charles Inderjeeth

doi:10.3899/jrheum.2023-1044

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia

J Rheumatol. 2024 Apr 1;51(4):396-402. doi: 10.3899/jrheum.2023-1044.

Authors

Johannes C Nossent¹, Helen Keen², David Preen³, Charles Inderjeeth⁴

Affiliations

¹ J.C. Nossent, MD, PhD, C. Inderjeeth, MBBS, MPH Rheumatology Group, University of Western Australia Medical School, and Department of Rheumatology, Sir Charles Gairdner Hospital; johannes.nossent@uwa.edu.au.
² H. Keen, MBBS, PhD, Rheumatology Group, University of Western Australia Medical School, and Department of Rheumatology, Fiona Stanley Hospital.
³ D. Preen, PhD, School of Population and Global Health, University of Western Australia, Perth, Australia.
⁴ J.C. Nossent, MD, PhD, C. Inderjeeth, MBBS, MPH Rheumatology Group, University of Western Australia Medical School, and Department of Rheumatology, Sir Charles Gairdner Hospital.

PMID: 38302176
DOI: 10.3899/jrheum.2023-1044

Abstract

Objective: To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population.

Methods: Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates.

Results: The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM.

Conclusion: Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

Keywords: cancer; idiopathic myositis; incidence; mortality; site.

MeSH terms

Dermatomyositis* / diagnosis
Dermatomyositis* / epidemiology
Female
Humans
Lung Neoplasms*
Male
Middle Aged
Myositis* / diagnosis
Myositis* / epidemiology
Polymyositis* / diagnosis
Polymyositis* / epidemiology
Western Australia / epidemiology