Association between immunity and prognostic factors in early stage breast cancer patients before adjuvant treatment

Objective: The association of known prognostic factors with immune cell cou nts and beta(2)-microglobulin and soluble IL-2 receptor (sIL-2r) serum leve ls as markers of activation of the immune system was investigated in breast cancer. Methods: Two hundred thirty five operated stage I and II breast cancer pati ents to receive adjuvant treatment in IBSCG trials were assessed in a cross -sectional study immediately before the first treatment. Leukocytes, lympho cytes and lymphocyte subset counts, beta(2)-microglobulin and sIL-2r serum levels were assessed as immunological parameters. Prognostic factors were t umor load, receptor status, patient characteristics, and contextual factors of the immune assessment (such as time of the day, time since surgery, typ e of surgery, concomitant medication, co-morbidity). Results: In an operated early stage breast cancer patient population, tumor load was not associated with immune cell counts, beta(2)-microglobulin, or sIL-2r before adjuvant treatment. There was a pattern of association of pr ognostically favorable factors such as estrogen receptor (ER) positive tumo r and older age with higher NK cell counts or with beta(2)-microglobulin or sIL-2r. In addition, immune cell counts and the markers of activation of t he immune system were affected by several contextual factors, such as diurn al variability, time since surgery, type of surgery, and the intake of conc omitant medication. Conclusions: The association of NK cell counts and beta(2)-microglobulin or sIL-2r serum levels with prognostically favorable factors such as ER posit ive tumor and older age supports the assumption that the immune system play s a role in the course of early breast cancer. The exact nature of this rol e requires further study.