FAMILIAL CANCER, EMOTIONAL DISTRESS, AND LOW NATURAL CYTOTOXIC ACTIVITY IN HEALTHY WOMEN

Background: We investigated the possibility that healthy individuals with a family history of cancer may have lower levels of natural cytotoxic activity and examined the possible contribution of distress-induced immune suppression. Materials and methods: Forty-three healthy women, recruited without regard to their family histories of cancer, came to the laboratory on two consecutive days. On each day, subjects completed questionnaires and provided blood samples for assessment of natural cytotoxic activity. Results: 1) Women with a history of cancer in one or more first degree relatives had lower levels of natural Cytotoxic activity than women without cancer in first degree relatives. 2) There were no differences in demographic, health, or behavioral variables, but we could not rule out differences in emotional distress. 3) Independent of family history, women with higher levels of distress had lower natural cytotoxic activity. 4) When the contribution of this distress-induced immune suppression was statistically removed, natural cytotoxic activity remained lower in women with cancer in first degree relatives. Conclusions: These findings raise the possibility that reductions in systemic natural cytotoxic activity, in conjunction with heritable defects in the preneoplastic cell, may contribute to increased cancer risk in individuals with a family history of cancer.