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

Background: We investigated the possibility that healthy individuals w ith a family history of cancer may have lower levels of natural cytoto xic activity and examined the possible contribution of distress-induce d immune suppression. Materials and methods: Forty-three healthy women , recruited without regard to their family histories of cancer, came t o the laboratory on two consecutive days. On each day, subjects comple ted questionnaires and provided blood samples for assessment of natura l cytotoxic activity. Results: 1) Women with a history of cancer in on e or more first degree relatives had lower levels of natural Cytotoxic activity than women without cancer in first degree relatives. 2) Ther e were no differences in demographic, health, or behavioral variables, but we could not rule out differences in emotional distress. 3) Indep endent of family history, women with higher levels of distress had low er natural cytotoxic activity. 4) When the contribution of this distre ss-induced immune suppression was statistically removed, natural cytot oxic activity remained lower in women with cancer in first degree rela tives. Conclusions: These findings raise the possibility that reductio ns in systemic natural cytotoxic activity, in conjunction with heritab le defects in the preneoplastic cell, may contribute to increased canc er risk in individuals with a family history of cancer.