[Peripheral lymphocyte populations in patients treated with pelvic and mediastinal radiotherapy]

Solid tumor bearing patients often show a large variety of immunologic alterations: increase in immune complexes number, reduced NK activity, decreased IL-2 production, T4/T8 reverse and s.o. Most literature data generally concern chemotherapy and/or radiotherapy pretreated patients, so it is difficult to relate the immunological alterations with either antineoplastic treatments or the disease itself. We tried to evaluate any possible alteration of immunological parameters in patients with solid neoplasms who underwent radiotherapy on mediastinum or pelvis. The aim was to detect any variation in peripheral lymphoid sub-populations (even per site of irradiation) and a possible activation of an immune therapy. The evaluable patients were 38 (12 treated with surgery). The minimum dose delivered was 5000 cGys through conventional fractionation. The immunological parameters (T, B, N, T4, T8, H/S) were evaluated before the treatment, at the end and every 2 months during follow-up. Cases were analyzed also per single irradiation volume. No statistically significant variation in immunological parameters was found, although suppressor activity was confirmed as prevailing in immune responsiveness of cancer patients. Thus any significant correlation between immunological state and disease evolution or response to treatment has still to be verified.