Radiotherapy has an important role in the treatment of prostate cancer both as curative treatment and postoperative or salvage ones. Several studies demonstrated a significant reduction of lymphocytes during RT but there are only a few studies monitoring these cells in the treatment of prostate cancer. This study will enroll 50 patients with hystologically proven prostate cancer who will undergo to radiotherapy according to Institutional protocols.

This study aims to evaluate the effect of RT on immuno-regulatory B, NK, T, B and T lymphocyte subpopulations (Breg and Treg) and plasma cells, quantitative / qualitative changes,their correlations with the clinical course of the disease and acute and late toxicity. In parallel, using multicolor panels (12 colors) we will evaluate the expression of inhibitory checkpoints and TGFβ signaling.

The final objective is to identify new therapeutic targets to be combined with RT.

Inclusion Criteria:

• Histologically documented prostatic cancer
• Indication to perform radiotherapy treatment
• Age over 18 years
• Informed consent

Exclusion Criteria:

• Hematological diseases
• Autoimmune diseases
• Previous neoplasias
• Prior chemotherapy or other therapies that may have violated the hematopoietic organs
• Patient's refusal to undergo periodic blood samples