Postoperative radiation therapy and adjuvant chemoimmunotherapy in breast cancer. Aspects of timing and immune competence.

Abstract

The effects of radiation therapy and adjuvant chemoimmunotherapy on the immune competence of patients with breast cancer were investigated. The tests performed included intradermal tuberculin tests, T- and B-lymphocyte counts, and lymphocyte blast transformation tests; phytohemagglutinin (PHA), concanavalin A (ConA) and pokeweed mitogen (PWM) were used as mitogens. Enhancement in lymphocyte proliferative response to mitogenic stimulation by PHA and PWM was seen in patients after 3 courses of chemotherapy + levamisole, whereas irradiation given after chemotherapy caused long-lasting depression in response to PHA (p = 0.039) and PWM (not significant). T-lymphocyte counts were also lower after irradiation than after chemoimmunotherapy (p = 0.007). Clinically, the 16 patients treated with radiation therapy after chemotherapy exhibited a higher recurrence rate than the 24 patients treated first by irradiation. Enhanced reactivity to tuberculin tests occurred generally in patients receiving a planned treatment including irradiation, chemotherapy (5-fluorouracil, doxorubicin, cyclophosphamide) and levamisole. Enhancement of reactivity was seen more often in patients who had not relapsed.