Effects of concurrent cisplatinum administration during radiotherapy vs. radiotherapy alone on the immune function of patients with cancer of the uterine cervix

Purpose: To compare the effects of concurrent administration of cisplatinum (40 mg/m2/weekly) with radiation therapy (C-RT) to those induced by radiation therapy alone (RT) on the immune function of patients with locally advanced cervical cancer.Methods and Materials: In 8 prospectively randomized patients (i.e., 4 receiving RT vs. 4 receiving C-RT), lymphocyte populations including CD3+, CD4+ and CD8+ T-cell subsets, B cells (CD19+) and natural killer cells (CD56+, CD16+, CD3-) were studied before, during, and after therapy. Expression of the activation marker CD25 on CD3+ T cells, intracellular levels of perforin in CD8+ and CD56+ cells, and interferon-γ (IFN-γ) and IL-2 in CD4+ and CD8+ T cells was also measured. Finally, lymphoblast transformation and natural killer (NK) cytotoxic activity were assessed. Results: Both RT and C-RT significantly decreased the mean absolute number of all lymphocyte subsets compared to pretreatment levels (p > 0.001). However, no differences were detected in the characteristics or the magnitude of the lymphopenia induced by the two treatments. Both RT and C-RT increased similarly the percentages of CD25-positive lymphocytes (p > 0.001), and significantly decreased PHA-induced T-cell lymphoblast transformation (p > 0.001) and NK cytotoxic activity against K562 cells (p > 0.001). The percentage of perforin-positive and CD8+ T cells was not altered during either treatment, whereas the percentage of perforin-positive and CD56+ cells was significantly reduced during both treatments, and correlated with reduced cytotoxicity against K562 cells. The percentages of CD8+ IFN-γ+ and CD4+ IFN-γ+ T cells as well as that of CD8+ IL-2+ and CD4+ IL2+ T cells were not significantly altered by C-RT compared to RT alone. Finally, with both regimens, NK cells and B-cell numbers showed a more rapid recovery than T-cell numbers. Conclusion: Administration of concurrent cisplatinum to radiation may synergistically increase cytotoxic effects of radiation on tumor cells but does not alter the magnitude and the characteristics of radiation-induced immunosuppression. Copyright (C) 2000 Elsevier Science Inc.