Background

There is an increased incidence of malignancy in patients with dermatomyositis. It is unknown if the risk differs between the subtypes of dermatomyositis.

Objective

To (1) compare the prevalence of malignancy-associated dermatomyositis between patients with classic and clinically amyopathic disease and (2) determine factors associated with an increased risk of malignancy-associated disease.

Methods

Retrospective cohort study of 201 patients with adult-onset dermatomyositis prospectively enrolled in a longitudinal dermatomyositis database between July 2008 and April 2018 at an outpatient dermatology urban tertiary referral center. The main outcome measure was a diagnosis of malignancy, excluding nonmelanoma skin cancer.

Results

There were 201 patients with adult-onset dermatomyositis: 142 (71%) classic and 59 (29%) clinically amyopathic. Within 2 years of diagnosis, the prevalences of malignancy-associated classic and clinically amyopathic dermatomyositis were 9.9% and 1.7%, respectively. In this time period, patients who were older at dermatomyositis diagnosis (P = .01) and had the classic subtype (P = .04) were significantly more likely to have an underlying malignancy on multivariable regression analysis.

Limitations

This was a retrospective study of prospectively collected data at a single tertiary referral center.

Conclusion

Older age and classic dermatomyositis are independent risk factors for malignancy-associated dermatomyositis within 2 years of disease onset.

中文翻译：

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皮肌炎恶性肿瘤：对宾夕法尼亚大学 201 名患者进行的回顾性研究。

 背景

皮肌炎患者的恶性肿瘤发病率增加。目前尚不清楚皮肌炎亚型之间的风险是否不同。

 客观的

目的 (1) 比较经典无肌病患者和临床无肌病患者之间恶性肿瘤相关皮肌炎的患病率，以及 (2) 确定与恶性肿瘤相关疾病风险增加相关的因素。

 方法

回顾性队列研究对 2008 年 7 月至 2018 年 4 月期间在城市三级转诊中心门诊皮肤科前瞻性纳入纵向皮肌炎数据库的 201 名成人发病的皮肌炎患者进行了回顾性队列研究。主要结果指标是恶性肿瘤的诊断，不包括非黑色素瘤皮肤癌。

 结果

共有 201 名成人发病的皮肌炎患者：142 名（71%）为典型皮肌炎，59 名（29%）为临床无肌炎。诊断后 2 年内，恶性肿瘤相关的经典型和临床无肌病性皮肌炎的患病率分别为 9.9% 和 1.7%。在此期间，多变量回归分析显示，皮肌炎诊断时年龄较大 ( P = .01) 且具有经典亚型 ( P = .04) 的患者明显更有可能患有潜在恶性肿瘤。

 局限性

这是对在单个三级转诊中心前瞻性收集的数据进行的回顾性研究。

 结论

年龄较大和经典皮肌炎是发病 2 年内发生恶性肿瘤相关皮肌炎的独立危险因素。