IMMUNOSUPPRESSION BY BREAST-CANCER ASSOCIATED P43-EFFECT OF IMMUNOMODULATORS

It has been previously shown that p43 - a breast cancer associated ant igen - has immunosuppressive properties. The present study was carried out in order to elucidate the pathomechanisms of immunosuppression in breast cancer patients influenced by the expression of p43. Lymphocyt es were cultured from blood of 29 women with benign lesions in the bre ast as well as from 41 female patients with breast cancer. Lymphocyte stimulation was performed by addition of Concanavalin (Con A) in cultu res with lymphocytes alone (CONLYM) or in lymphocytes incubated with p 43 (CONAg). In other series immunomodulation was tried by addition of indomethacin (INDLYM, INDAg), levamisole (LEVLYM, LEVAg), or interleuk in-2 (ILLYM, ILAG). In breast cancer patients, addition of p43 signifi cantly inhibited the activation of lymphocyte proliferation by Con A c ompared to women with benign tumors. The addition of indomethacin or l evamisole did not influence this inhibitory effect of p43 in breast ca ncer patients. Contrary to these observations, addition of IL-2 result ed in increased proliferation of lymphocytes from patients with benign as well as malignant tumors, which was inhibited after addition of p4 3. Analysis of the correlation of the immunosuppressive properties of p43 in correlation with prognostic factors for breast cancer showed ev idence for a stronger activity of p43 in early stage tumors (i.e. smal ler than 2 cm, lymph node negative, histologic grading GI), confirming previous observations of a higher expression of p43 in early stages o f breast cancer.