Immunological overshoot phenomenon following cancer chemotherapy: significance in prognosis evaluation of solid tumors.

Immunological function was studied in 48 patients before, during and after cancer treatment, using cutaneous tests, spontaneous rosettes test and the PHA and PWM lymphocyte stimulation tests. Chemotherapeutic drugs were used individually or in combination for 5 days a month and were preceeded by a cellular synchronization using Vincristine (1 mg/m2/day). When treatment was discontinued, we observed in 30 patients increased rates of spontaneous rosettes and of thymidine uptake. We noticed in several cases that the cutaneous tests became positive even if they were negative before and during treatment. The I.O.P. appeared 5 days after chemotherapy was discontinued and lasted 8 to 12 days. The topography of the neoplasm had no influence on the I.O.P. Failure to manifest I.O.P. is not indicative of a negative response of the tumor to chemotherapy (9 positive responses to chemotherapy out of 18 patients without I.O.P.) But the I.O.P. was a fairly constant feature in patients with positive response to chemotherapy and with favorable prognosis (28/30).