Decreased absolute counts of T lymphocyte subsets and their relation to disease in squamous cell carcinoma of the head and neck.

PURPOSE Apoptosis of circulating CD8+ T cells seen in patients with squamous cell carcinoma of the head and neck [SCCHN (Hoffmann T, et al. Clin Cancer Res 2002;8:2553-62)] suggested a possibility of lymphocyte imbalance. Therefore, absolute numbers and percentages of lymphocyte subsets were examined in the peripheral blood of SCCHN patients and controls. EXPERIMENTAL DESIGN Venous blood was obtained from 146 patients with SCCHN and 54 normal volunteers. Absolute numbers of CD3+, CD4+, and CD8+ T lymphocytes were determined using fluorobeads in a flow cytometry-based technique. Percentages of T lymphocyte subsets were also evaluated by flow cytometry. The patients were grouped at the time of blood draw [active versus no evidence of disease (NED), type of therapy administered, and the length of follow-up]. RESULTS Patients with SCCHN had significantly lower absolute numbers of CD3+ CD4+, and CD8+ T cells than normal controls. However, no differences in the percentages of T-cell subsets between patients and normal controls were observed. Patients with active disease had significantly lower CD3+ and CD4+ T-cell counts than those with NED. Patients who had NED after surgery and radiotherapy had the lowest T-cell counts among the NED cohort. Patients who had NED for >2 years did not recover their T-cell counts, and the T-cell imbalance was evident many years after curative surgery. The tumor-node-metastasis (TNM) stage or site of the disease was not related to the absolute T-cell count. Patients with recurrent disease at the time of blood draw tended to have the lowest CD4+ T-cell counts. CONCLUSIONS Patients with SCCHN have altered lymphocyte homeostasis, which persists for months or years after curative therapies.