Natural killer cell response to regional lymph node metastases.

A determination of natural killer cell activity was performed in 67 individuals with advanced head and neck cancer. The mean activity of 28 patients clinically staged T3 NO or T4 NO was 81 +/- 11 lytic units (LU), significantly higher than 39 patients with palpable lymph node metastases (54 +/- 5 LU). Assessing patients by extent of nodal disease revealed that activity actually increased, though not significantly, with progressive N-staging. A major determinate of increased natural killer cell cytotoxicity in patients with lymph node metastases was extranodal cancer within the neck. The mean activity of nine patients whose tumor was fixed to underlying structures or adherent to skin was 87 +/- 15 LU, significantly higher than the 45 +/- 4 LU mean value of the remaining patients with clinically determined regional nodal disease. The potential clinical implications of these findings are discussed.