The silent progression of metastatic malignancy during the treatment with soluble tumor necrosis factor receptor.

Etanercept is singular among anti-tumor necrosis factor alpha (TNF-alpha) agents, for being a soluble antibody to both TNF and lymphtoxin-alpha. The long-term neutralization of two cachexins by etanercept would theoretically compromise early detection of malignancy. This case reports a patient who was treated by etanercept for 21 months due to ankylosing spondylitis. Metastatic malignancy of unknown origin developed, and silently led the patient to lethal hepatic rupture. With an example of a malignancy masking effect of soluble TNF receptor, this article questions a need for vigilant attention to de novo carcinoma during the therapy, and calls for refined strategies in modulating autoimmune diseases.