Effects of the conventional antitumor therapies surgery, chemotherapy, radiotherapy and immunotherapy on regulatory T lymphocytes in cancer patients.

BACKGROUND: Several clinical studies have clearly demonstrated that the immune status is one a major prognostic factor for the survival time in cancer patients. However the main clinical problem is to identify the most prognostically important index within the great number of immune parameters. Recently the evaluation of regulatory T (T-reg) (CD4CD25) lymphocyte count and function with respect to the T helper (TH) (CD4) number has been shown to represent the main immune parameters capable of representing the functional status of the anticancer immunity in cancer patients. This study evaluated the influence of the four main conventional anticancer therapies (surgery, chemotherapy, radiotherapy, immunotherapy) on the CD4/CD4CD25 ratio. PATIENTS AND METHODS: The study included 70 patients. The oncological treatments consisted of surgery in 14, chemotherapy in 36, radiotherapy in 12 and immunotherapy (subcutaneous low-dose, S.C.-low, interleukin, IL-2) in 8 patients. The normal value of the CD4/CD4CD25 ratio was greater then 4.0.
RESULTS: Surgery induced a significant decline in the CD4/CD4CD25 mean ratio. Radiotherapy also induced also a dramatic significant decrease in the CD4/CD4CD25 ratio, whereas the effect of both chemotherapy and immunotherapy reflected the clinical response to the treatments. The CD4/CD4CD25 mean ratio was significantly enhanced in the patients who obtained control of the neoplastic growth, whereas it diminished in progressing patients.
CONCLUSION: The commonly used anticancer therapies profoundly modify the levels of amounts of T-reg lymphocytes. Because of the fundamental role of T-reg cells in suppressing the anticancer immunity, thus diminishing survival, the monitoring of the CD4/CD4CD25 ratio could constitute an important clinical index during conventional anticancer therapies to predict the prognosis of cancer patients.