Systemic and regional natural cytotoxicity in patients with head and neck cancer

Summary Forty patients with squamous carcinoma of the oral cavity (head and neck cancer) were investigated for natural killer cell (NK) activity in peripheral blood (PB) and tumour-draining lymph nodes (LNs). For measuring NK activity a 4 hrs 51 Cr release assay and K 562 target cells were used. Mononuclear cells of PB (PBMNC) and LNs (LNMNC) were separated by Ficoll Hypaque gradient centrifugation. NK activity was determined before tumour surgery. LNs were obtained either at the time of surgery of the primary tumour (en bloc neck dissection) — “immediately dissected LNs (ID-LNs)” or some time after removal of the primary tumour, especially for prophylactic purposes, — “delayed dissected LNs (DD-LNs)”. Preoperatively, NK activity was clearly stage-dependent, patients with stages T 1−2 displaying mean values similar to those of a control group without malignant disease, whereas values were significantly lower in patients with stages T 3−4 . Spontaneous cytotoxicity was significantly lower in LNMNC than in PBMNC of identical donors. NK activity was significantly lower in ID-LNs than in DD-LNs. These results suggest some negative influence of the primary tumour in the spontaneous cytotoxicity in both PB and tumour-draining LNs. In vitro incubation at +37° together with addition of lymphoblastoid interferon (IFN-α) achieved a significant stimulation of NK activity in both PBMNC and LNMNC.