title: Temporal relationship between cancer and myositis identifies two distinctive subgroups of cancers: impact on cancer risk and survival in patients with myositis.
abstract: The aim was to compare standardized incidence ratios (SIRs) of cancers temporally related and unrelated to active myositis in patients with myositis.
  
  
  
  Fifty-two cancer cases were identified in 281 myositis patients. SIRs of cancers having temporal overlap with the active phase of myositis [cancers concurrent with active myositis (CAM), n = 30] and cancers not having such temporal overlap [cancers non-concurrent with active myositis (CNM), n = 22] were compared in 281 patients.
  
  
  
  Patients with CAM were older at diagnosis of myositis, had a greater tendency to be male, more frequent dysphagia and less frequent interstitial lung disease than patients with CNM. CAM SIR (95% CI) was 1.78 (1.19, 2.56) and CNM SIR 1.23 (0.75, 1.90). The peak SIR was observed in the seventh decade of life for CAM and in the third decade for CNM. When stratified by myositis-cancer intervals, CAM SIR was 9.94 (6.43, 14.67) within 1 year of myositis diagnosis, whereas no temporal relationship was found for CNM. Elevated SIRs were observed for oesophageal cancer [57.77 (11.91, 168.82)], non-Hodgkin's lymphoma [41.43 (13.45, 96.69)], adenocarcinoma of unknown primary origin [67.6 (18.42, 173.07]), lung cancer [7.27 (1.98, 18.61)] and ovarian cancer [19.15 (2.32, 69.17)] within 3 years of CAM diagnosis. The cancer stage at the time of diagnosis was more advanced in CAM than CNM (P < 0.001), with a correspondingly increased hazard ratio of mortality [4.3 (1.5, 12.7)] in patients with CAM vs CNM.
  
  
  
  A significantly elevated SIR was found for CAM, whereas there was a comparable SIR for CNM relative to the general population. Multiple types of cancers showed elevated SIRs among CAM, but none among CNM. Given that cancer stages in CAM were far advanced at diagnosis, mortality risk was greater in patients with CAM.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam ysong@snu.ac.kr.
authors.forename: Eun Ha
authors.initials: EH
authors.lastname: Kang
authors.affiliation: Division of Rheumatology, Department of Internal Medicine Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, USA.
authors.forename: Dana P
authors.initials: DP
authors.lastname: Ascherman
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam.
authors.forename: Yun Jong
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine.
authors.forename: Eun Bong
authors.initials: EB
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Yeong Wook
authors.initials: YW
authors.lastname: Song
mesh_terms: D017668:Age of Onset; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000150:complications* / Q000401:mortality; D009367:Neoplasm Staging; D009369:Neoplasms / Q000209:etiology* / Q000401:mortality; D011379:Prognosis; D056910:Republic of Korea; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor
keywords: cancer; cancer stage; myositis; standardized incidence ratio