Effects of combined immunotherapy with levamisole and Bacillus Calmette-Guérin on immunocompetence of patients with squamous cell carcinoma of the cervix, head and neck, and lung undergoing radiation therapy.

Patients with squamous cell carcinoma of the head and neck, squamous cell carcinoma of the cervix, and lung carcinoma were treated with radiation therapy (RT) prior to being randomly assigned either to a group receiving no further treatment or to a group treated with combined adjuvant immunotherapy (bacillus Calmette-Guérin and levamisole). A battery of in vitro immunologic evaluations in addition to skin tests was used to evaluate these patients prior to RT, immediately following RT, and at regular intervals thereafter. Mean percentages and levels of circulating T lymphocytes were significantly lower in all three types of patients prior to RT than in normal healthy controls. B-lymphocyte percentages and levels, however, were not significantly different from controls except for lower B-cell levels in the lung group. Following completion of RT, circulating levels of both T and B lymphocytes were significantly lower than pretreatment values although the percentages were not significantly changed. Mitogenic responses of patient lymphocytes to both phytohemagglutinin and pokeweed mitogen were significantly lower prior to RT than were healthy control responses. A further depression of blastogenesis following RT was statistically significant. Preliminary data at intervals following RT indicate a gradual recovery of depressed immune parameters (T- and B-lymphocyte levels and mitogenic responses) both in patients treated with adjuvant immunotherapy and in those receiving no further treatment. Although not statistically significant in preliminary data, there is a suggestion that recovery of these immune parameters is slower in the group receiving immunotherapy. Plasma sialic acid levels were elevated in patients when compared to healthy controls and remained elevated throughout the study with little fluctuation. Lymphocyte cytotoxic activity against tumor target cells was variably affected by RT, but was generally increased at 8 weeks following RT when compared to previous values.