Lymphocyte subpopulations in colo-rectal cancer. Preoperative evaluation.

The percentage and absolute numbers of T, T active and B cells determined by rosette and immunofluorescence procedures, together with the lymphocyte response to PHA stimulation, were studied in 50 patients with colo-rectal adenocarcinoma before surgery. In addition, a group of these patients were tested for the presence of circulating CEA. Sixty percent of the patients studied presented a decrease in absolute numbers of T cells. The percentage and absolute number of Ea rosettes were significantly reduced (p less than 0.01), showing a selective loss of the active T cell subpopulations. In 62% of the cases there was a notable decrease in the lymphocyte response to PHA stimulation. There were no significant variations in the B lymphocyte populations. CEA values showed a close correlation with the clinical tumour staging according to the Dukes classification. Pre-operative immunological testing may have prognostic value in tumours of the large intestine and its results can subsequently be used to evaluate the results of surgery and to indicate avenues which may improve and complete the treatment.