Reappraisal of the incidence, various types and risk factors of malignancies in patients with dermatomyositis and polymyositis in Taiwan

Abstract

Our study aimed to investigate the incidence, risk factors and time to occurrence of malignancy in patients with dermatomyositis (DM) and polymyositis (PM). The electronic medical records of 1100 patients with DM and 1164 patients with PM were studied between January 2001 and May 2019. Malignancies after myositis were diagnosed in 61 (5.55%) patients with DM and 38 (3.26%) patients with PM. The cumulative incidence of malignancies in patients with DM were significantly higher than patients with PM (hazard ratio = 1.78, log-rank p = 0.004). Patients with DM had a greater risk of developing malignancy than those with PM at 40–59 years old (p = 0.01). Most malignancies occurred within 1 year after the initial diagnosis of DM (n = 35; 57.38%). Nasopharyngeal cancer (NPC) was the most common type of malignancy in patients with DM (22.95%), followed by lung, and breast cancers. In patients with PM, colorectal, lung and hepatic malignancies were the top three types of malignancy. The risk factors for malignancy included old age (≥ 45 years old) and low serum levels of creatine phosphokinase (CPK) for patients with DM and male sex and low serum levels of CPK for patients with PM. Low serum levels of CPK in patients with myositis with malignancy represented a low degree of muscle destruction/inflammation, which might be attributed to activation of the PD-L1 pathway by tumor cells, thus inducing T-cell dysfunction mediating immune responses in myofibers. A treatment and follow-up algorithm should explore the occurrence of malignancy in different tissues and organs and suggested annual follow-ups for at least 5.5 years to cover the 80% cumulative incidence of malignancy in patients with DM and PM.

Autoantibody Markers of Increased Risk of Malignancy in Patients with Dermatomyositis

“…The increased risk of cancer is associated with both dermatomyositis and other types of autoimmune myopathies. However, it is significantly higher in dermatomyositis with the incidence of malignancy ranging from 5.5 to 42% [ 20 , 21 ]. A recent meta-analysis of 5 studies involving 4538 patients showed that the risk of cancer increased 4.66-fold in patients with the disease compared to the general population [ 17 ].…”

“…According to the analysis of 2 large cohorts of patients with dermatomyositis, the most frequently reported malignancies were breast cancer (24.5%), hematologic malignancies (17.0%), colorectal cancers (9.4%), and prostate cancer (9.4%) [ 23 ]. Studies conducted in the Asian population showed that the nasopharynx was the most common location of malignancy with the incidence of 22.5–62.5% of all cancers [ 24 , 25 ] (Table 1 ).…”

“…Studies conducted in the Asian population showed that the nasopharynx was the most common location of malignancy with the incidence of 22.5–62.5% of all cancers [ 24 , 25 ] (Table 1 ).…”

Diagnosis and Management of Cutaneous Manifestations of Autoimmune Connective Tissue Diseases

“… 79 , 80 For women, cancers with the greatest risk include breast, ovarian, and uterine cancer. 81 In a nationwide cohort study in Taiwan, cancers with the greatest risk associated with DM included nasopharyngeal carcinoma, followed by lung and breast cancers. 82 Universally accepted screening guidelines are lacking, but age appropriately cancer screening is recommended along with obtaining a complete blood count, liver function tests, urinalysis, fecal occult blood test and chest radiograph.…”

“…• Mechanic's hands 86 • Disease phenotypes vary by anti-ARS antibody, with those against non-Jo-1 ARS associated with earlier and more severe ILD and poor prognosis 87 • Association with anti-synthetase syndrome 67,81 Up to 20%…”