Simultaneous evaluation of cytokines and their soluble receptor production and serum levels can be helpful in understanding the local and systemic immune response of a tumor-bearing host. In the present study we examined the serum levels of TNF-, IL-6 and their soluble receptors sTNFRp55, sTNFRp75 and sIL-6R compareded with their production by the polymorphonuclear neutrophils (PMN) from cancer patients. Examinations were carried out in patients with adenocarcinoma breast cancer and squamous cell carcinoma of the oral cavity and related to the clinical course and to different phases of therapy. Secretion of IL-6, sTNFRp55 and sTNFRp75 by PMN appeared to be dependent on tumor type, clinical progression of disease as well as on therapy, suggesting a significant role of these cells at different phases of the immune response to cancer associated with these mediators. Changes in values of TNF-alpha, IL-6 and their soluble receptors in sera of both cancer groups, dependent on tumor type, clinical progression and cancer therapy, could have a diagnostic and prognostic role in cancer disease.