Clinical Behavior in Metastatic Brain Disease Is Not Influenced by the Immunological Defense Mediated by CD57...

Objectives. The purpose of the present study is to verify if the degree of immunological response against metastatic tumors, measured by the number of CD57(+) NK-cells in the tissue of a brain metastasis, influences the later development of new brain metastases or tumor recurrence. Patients and Methods. CD57(+) NK-cells were immunohistochemically identified in the resected tumor, in a series of twenty patients operated on by a single brain metastasis secondary to lung adenocarcinoma. In each case, the degree of CD57(+) NK-cells infiltration within the tumor tissue and the period free of new intracranial disease after brain surgery were recorded. Results. All the studied tumors showed variable number of CD57(+) NK-cells (mean ± standard deviation: 8.4 ± 4.8 per microscopical field, at 200x). The period free of intracranial disease ranged between 10 and 52 weeks (mean ± standard deviation: 22.7 ± 11.9). Statistical analysis showed that there was no correlation between the degree of NK-cells infiltration within the resected tumor and the period free of intracranial disease after surgery (P > 0.05). Conclusion. This finding supports that clinical behavior in metastatic brain disease is not influenced by the immunological response mediated by CD57(+) NK-cells.