The reverse side of the victory: Flare up of symptoms after discontinuation of sunitinib or sorafenib in renal cell cancer patients. A report of three cases

activation of psoriasis and spontaneous regression of metastases. Similar observation has recently been reported in a patient with rheumatoid arthritis and marginal zone B cell lymphoma treated with infliximab and methotrexate [8]. In that case spontaneous remission was noted after the withdrawal of infliximab and methotrexate. Allogeneic hematopoietic stem cell transplantation may be viewed as adoptive immunotherapy, and is frequently accompanied by graftversus-host disease. A case of graft-versus-host disease manifesting as with psoriatic skin lesions has been described [9]. We can only speculate about the mechanism(s) of association between the course of psoriasis and metastatic RCC in the present patient. T lymphocytes isolated from psoriatic lesions exhibit cross reactivity to microbial and self antigens [7]. It is possible that similar cross reactivity exists between the putative tumor antigens responsible for tumor rejection and autoantigens in the skin, but this hypothesis remains speculative. The risk of cancer may be increased in patients with psoriasis, possibly as the result of therapy [10], but increased incidence of RCC has not been observed and RCC is a rare event in patients with psoriasis. In conclusion, this case report presents further indication that immune response may play a role in spontaneous regression of RCC metastases after nephrectomy.