Paraneoplastic myalgias and myositis.

Area of Science:

• Neurology
• Oncology
• Immunology

Background:

• Paraneoplastic myopathies (PMs) are rare disorders where muscle inflammation is associated with an underlying cancer.
• Dermatomyositis (DM) carries a very high cancer risk, while polymyositis (PM) has a mildly increased risk.
• The onset of myositis often precedes cancer diagnosis by up to one year, with elevated risk persisting for five years.

Purpose of the Study:

• To summarize key observations regarding paraneoplastic myopathies and their association with cancer.
• To highlight clinical features, screening strategies, and autoantibody associations in cancer-associated myositis (CAM).

Main Methods:

• Review of clinical observations and literature on paraneoplastic myopathies.
• Analysis of cancer types associated with DM and PM.
• Correlation of clinical features and autoantibodies with CAM risk.

Main Results:

• DM is linked to adenocarcinomas (lung, ovarian, etc.) and lymphoma; PM is strongly associated with lymphoma.
• Clinical presentation of myopathy often mirrors cancer progression; severe symptoms like muscle weakness and dysphagia indicate CAM.
• Specific autoantibodies (e.g., anti-p155) increase CAM risk, while others (antisynthetase) decrease it.

Conclusions:

• Cancer screening for PMs should be tailored to patient demographics and risk factors, potentially including advanced imaging.
• Understanding the link between myositis and antitumor immune responses may elucidate CAM pathogenesis.
• Early detection and management of paraneoplastic myopathies are crucial for improved patient outcomes.