Lymphocyte transformation in patients with breast cancer and the effect of surgery.

Lymphocyte response to phytohemagglutinin (PHA) in vitro was subnormal in forty of fifty-one patients with breast cancer. After apparently successful surgery, lymphocyte response improved significantly in most of those in whom it had been previously impaired. It remained markedly subnormal in only five patients, two of whome subsequently died of metastases. This finding indicates that depressed cell mediated immunity in patients with breast cancer is the result of the malignant disease. Failure of the PHA response to revert to normal postoperatively may indicate a poor prognosis.