Tumour specificity of the SCM test for cancer diagnosis

Phytohaemagglutinin (PHA), a well-known mitogen, and encephalitogenic factor (EF) are recognized by lymphocytes of patients with different malignant diseases as non-specific antigens. Utilizing these two antigens, the SCM (structuredness of the cytoplasmatic matrix) test offers a means of discrimination between malignant and non-malignant diseases. The SCM test can also be used as a specificity test since lymphocytes from donors with a given malignant disease react exclusively with the tumour-associated antigen (TAA) of that disease. Results from 73 donors (15 healthy patients, 38 patients with different types of malignant disorders and 20 patients with autoimmune diseases) indicate the predictive value of the test. First, the non-specific test was applied in order to establish whether the patients suffered from an active malignant disease. The lymphocytes of those patients which were found to suffer from an active malignant disorder were then exposed to different types of tumour tissues. Twenty-five out of the 38 patients with malignant disorders were found by the SCM test to have an active disease. The lymphocytes of 24 out of these 25 patients showed a positive reaction when exposed to tumour tissue of the same type of cancer of which they were found to suffer by other clinical tests, and displayed no reaction with any other tumour tissues for which they were tested. One patient, with an inconclusive value of the SCM test, showed no reaction with any type of tumour to which he was exposed. The remaining 13 patients, who were diagnosed by the test as non-cancerous, did not show any clinical evidence of malignancy at the time of the test, after their tumours had been excised. Eighteen out of 20 patients with autoimmune diseases showed negative results when tested by the general test and by the various specificity tests.