Immunological directives for biotherapy improvement in the treatment of colorectal cancer.

A major cause of failure in biotherapy in cancer may be the non-existence of predictive indices to individualize the substances which might be helpful to switch the patients' immune response to tumour from an non-productive to a productive one. The defect in the patients' immune system needs to be identified and so the evaluation of their responses to biotherapeutic agents, in correlation to the disease progression is essential. We have addressed this problem in colorectal cancer at systemic level by examining the proliferative response of peripheral blood mononuclear cells (PBMC) to interleukins (IL) IL-2, IL-4, antiCD3 monoclonal antibody (antiCD3), IL- 2+CD3, IL-2+IL-4, IL-4+CD3, IL-2+CD3+IL-4; the PBMC expression of phenotypic antigens CD3, CD4, CD8, CD25, DR, CD16, CD56, CD57 and CD19 in the patients and healthy subjects as control group. Analysing our data, it seems that as the disease progresses in these patients the peripheral blood cells change their ability to respond to activation agents which appears to be due to a phenotypic modification of their subsets. Our overall results might give a possible explanation of the variable responses to biotherapy in colorectal cancer patients.