IMMUNOSUPPRESSION FOLLOWING POSTOPERATIVE RADIOTHERAPY IN PATIENTS WITH HEAD AND NECK-CANCER

The effect of locoregional postoperative radiation therapy on cellular immunity was investigated in 11 patients with head and neck cancer. D uring the course of the radiation therapy, total lymphocyte counts, CD 8+ lymphocyte counts and especially CD4+ lymphocyte counts decreased s ignificantly. The mean CD4+ lymphocyte counts dropped from 739/mu l. t o 183/mu l (p<0.001) and the average CD4+/CD8+ ratio also decreased si gnificantly. In addition all patients showed impaired in vitro lymphoc yte stimulation responses to several mitogens, with reductions found t o be 10% to 50% of normal responses. Within 3-4 weeks after radiation therapy there was a slight increase of CD4+ lymphocyte counts and the in vitro lymphocyte stimulation responses showed a tendency to normali zation. These results indicate that locoregional postoperative radiati on therapy in patients with head and neck cancer can induce a severe i mpairment of cellular immunity.