In cancer, the extent to which the disease has spread is probably the most important factor in determining patient prognosis. Hence practical and non-invasive methods are needed to identify disease stage. In a previous paper we showed how diagnostic and prognostic indices for disease progression could be defined by evaluating parameters in peripheral blood. The aim of this study was to identify further serum parameters that could be used. Serum levels of interferon (IFN) gamma, interleukin (IL)4, IL8, IL7, IL1 beta, tumor necrosis factor (TNF) alpha, granulocyte macrophage-colony stimulating factor (GM-CSF), soluble (s) IL2 receptor (R) and sIL6R were studied but only levels of IL4, sIL2R, IL8 and IL7 were found to be significant and would therefore be of use in defining diagnostic and prognostic indices for disease progression. In further detail, our results indicate that when serum levels of sIL2R < 522 U/ml, IL4 < 159 pg/ml and IL8 > 339 pg/ml there is a 95% probability that the disease is in stage I or II where there is no infiltration of lymph nodes; when serum levels of sIL2R > or = 522 Ug/ml, 159 pg/ml < or = IL4 < or = 319 pg/ml, and IL7 < 54 pg/ml, there is a 95% probability that the disease is in stage III and the tumor has invaded the lymph nodes; when the serum levels of IL4 > or = 431 pg/ml and IL7 > or = 54 pg/ml, there is a 95% probability that the disease is in stage IV and there is metastasis.