[Phytohemagglutinin (PHA) skin tests: its relevance in carcinology (author's transl)].

The skin response to 1 microgram Phytohemagglutinin (PHA) was studied in 359 subject including 235 cancer patients and 124 without cancer. Responses to PHA, tuberculin, candidin were compared. A positive skin response to PHA was observed in 88% of patients without malignancy. This percentage remained almost equal in older patients (more than 70 years). Among patients with advanced malignancies, there was a fall down to 64.5% of the percentage of positive responses. A negative response to both PHA and tuberculin was observed in 6% of patients without malignancy and 28% of cancer patients. 38 +/- 5 days was the average survival of this last group. The arguments favouring the fact that PHA induces cutaneous basophilic hypersensitivity are reviewed. An advantage of this test is that no presensitization is required.