Standardized Prevalence Ratios of Cancer in Idiopathic Inflammatory Myositis

Christopher Mecoli¹, Takeru Igusa², Mengkun Chen³, XingYao Wang², Jemima Albayda², Julie Paik², Eleni Tiniakou², Brittany Adler², Carrie Richardson⁴, William Kelly², Sonye Danoff⁵, Andrew Mammen⁶, Elizabeth Platz³, Antony Rosen², Lisa Christopher-Stine², Livia Casciola-Rosen⁷ and Ami Shah⁸, ¹Johns Hopkins University School of Medicine, Baltimore, MD, ²Johns Hopkins University, Baltimore, MD, ³Johns Hopkins School of Public Health, Baltimore, MD, ⁴Rush University Medical Center, Chicago, IL, ⁵Johns Hopkins Medicine, Baltimore, MD, ⁶National Institutes of Health, Bethesda, MD, ⁷Johns Hopkins, Baltimore, MD, ⁸Johns Hopkins Rheumatology, Baltimore, MD

Meeting: ACR Convergence 2021

Keywords: Cancer, dermatomyositis, Myositis

Session Information

Date: Sunday, November 7, 2021

Title: Muscle Biology, Myositis & Myopathies Poster (0683–0722)

Session Type: Poster Session B

Session Time: 8:30AM-10:30AM

Background/Purpose: Whether the likelihood of a cancer diagnosis in idiopathic inflammatory myopathy (IIM) patients differs by autoantibody type is not fully characterized. To inform cancer surveillance in IIM patients, in a large, tertiary referral IIM cohort, we determined whether cancer occurrence differs by autoantibody type from that expected based on the general US population.

Methods: Patients enrolled in our myositis cohort was retrospectively reviewed from 2007-2020 for adult patients who met one of these criteria: (i) Probable or definite DM/PM by Peter and Bohan, (ii) IMNM by the 2003 ENMC Criteria, (iii) Classic DM rash (Gottron’s/heliotrope) and consistent histopathology on skin biopsy. Myositis specific and associated autoantibodies were determined systematically in our research lab using Euroimmun line blot (16 Ag IgG), ELISA (Mi2 and TIF1ƴ by MBL, HMGCR by INOVA Diagnostics), and in-house immunoprecipitation (NXP2). Three time windows were analyzed: cohort enrollment onward, IIM symptom-onset onward, and within 3 years of IIM symptom onset (-3 to +3 years). The Surveillance, Epidemiology, and End Results (SEER) registry was used to compare the observed number of cancers to the expected number of cancers in the general population, adjusted for calendar year, age, sex, and race. Standardized prevalence ratios of cancer (SPR) – the observed/expected prevalence of cancer over an interval of time – were determined.

Results: 1174 patients, including 201 (17%) with a history of cancer, were studied. Median (IQR) time from IIM symptom onset to enrollment was 1.68 (0.75-3.8) yrs. From enrollment onward (5.21 [2.64-8.64] yrs; 89 diagnosed with cancer), patients with TIF1ƴ autoantibodies ( >6 units) had higher than expected cancer period prevalence (SPR=1.73, 95%CI 1.12-2.56), whereas patients negative for anti-TIF1ƴ did not (SPR=1.04, 95%CI 0.68-1.51) [Table 1]. From IIM symptom onset onward (7.95 [4.92-11.86] yrs; 131 diagnosed with cancer, 25.2% within 0-1 yr, 28.2% >1-3 yrs, 14.5% >3-5 yrs, 32.1% >5 yrs), patients with anti-TIF1ƴ had higher than expected period prevalence of cancer, mainly breast (SPR=2.95, 95%CI 1.69-4.70) and ovarian (SPR=16.63, 95%CI 6.10-36.19). Patients with anti-SAE also had higher than expected cancer period prevalence (SPR=4.04, 95%CI 1.48-8.79). Patients with anti-Mi2 had higher than expected period prevalence of gastrointestinal cancers (SPR=6.03, 95%CI 1.24-17.61) [Table 2]. Within 3 yrs of IIM symptom onset (93 diagnosed with cancer), patients with anti-TIF1ƴ had higher than expected period prevalence of breast and ovarian cancer [Table 3]. Patients with DM autoantibodies (Mi2, SAE, or NXP2) had higher than expected cancer period prevalence.

Conclusion: In this tertiary referral center cohort, anti-TIF1ƴ was associated with higher occurrence of breast and ovarian cancers. Other DM-specific autoantibodies (Mi2, SAE, or NXP2) were associated with higher cancer occurrence. No cancer association (positive or negative) was observed for antisynthetase antibodies. These data suggest that intensive cancer surveillance is not needed in all IIM patients, and that autoantibody type may inform cancer occurrence, site and timing. Funded in part by NIAMS K23AR075898.

Table 1. Number of IIM patients, person-years of follow-up, and cancer standardized prevalence ratio in each autoantibody stratum. Time period is from cohort enrollment, median 1.6 (IQR 0.75_3.8) years after IIM-symptom onset. TIF1ƴ was considered positive by two different MBL thresholds: >32 units per manufacturer, and >6 units (4 standard deviations above healthy control cohort mean).

Table 2. Number of IIM patients, person-years of follow-up, and cancer standardized prevalence ratio in each autoantibody stratum. Time period is from IIM symptom onset onwards. TIF1ƴ was considered positive by two different MBL thresholds: >32 units per manufacturer, and >6 units (4 standard deviations above healthy control cohort mean).

Table 3. Number of IIM patients, person-years of follow-up, and cancer standardized prevalence ratio in each autoantibody stratum. Time period is _3 to +3 years surrounding IIM symptom onset. TIF1ƴ was considered positive by two different MBL thresholds: >32 units per manufacturer, and >6 units (4 standard deviations above healthy control cohort mean).

Disclosures: C. Mecoli, None; T. Igusa, None; M. Chen, None; X. Wang, None; J. Albayda, None; J. Paik, Pfizer Inc, 5; E. Tiniakou, None; B. Adler, None; C. Richardson, None; W. Kelly, None; S. Danoff, None; A. Mammen, None; E. Platz, None; A. Rosen, Celgene, 9, Inova, 9; L. Christopher-Stine, None; L. Casciola-Rosen, None; A. Shah, None.

To cite this abstract in AMA style:

Mecoli C, Igusa T, Chen M, Wang X, Albayda J, Paik J, Tiniakou E, Adler B, Richardson C, Kelly W, Danoff S, Mammen A, Platz E, Rosen A, Christopher-Stine L, Casciola-Rosen L, Shah A. Standardized Prevalence Ratios of Cancer in Idiopathic Inflammatory Myositis [abstract]. Arthritis Rheumatol. 2021; 73 (suppl 9). https://acrabstracts.org/abstract/standardized-prevalence-ratios-of-cancer-in-idiopathic-inflammatory-myositis/. Accessed .

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