Phytohaemagglutinin (PHA) skin test in predicting prognosis in cancer patients.

The response to intradermal injection of 1 mug of purified PHA was found to correlate with survival of patients with advanced solid tumours treated by chemotherapy, with responders surviving longer than non-responders. In patients with prolonged survival, the reaction was enhanced. Negative intradermal response to PHA was found to be less common in cancer patients than negative responses to tuberculin or streptokinase, and was more easily reversed by successful chemotherapy.