Thymus‐dependent lymphocyte levels in bronchogenic carcinoma: Correlations with histology, clinical stage, and clinical course after surgical treatment

The in vitro spontaneous lymphocyte rosette (T cell) assay was used to determine cellular immunologic competence in 112 patients with bronchogenic carcinoma. Among preoperative patients with localized tumors, T cell levels were significantly lower than in 237 normal controls. With advanced stages of disease, T cell levels declined progressively among patients with squamous cell carcinoma, oat cell carcinoma, and undifferentiated carcinoma, but not among patients with adenocarcinoma. Squamous carcinoma patients considered cured had persisting low T cell levels, but cured adenocarcinoma patients had normal levels. Serial determinations that showed a fall in T cell levels preceded the development of clinically evident metastases by an average of 2.5 months. Postoperative patients with rising T cell levels have remained clinically free of disease. The data indicate that T cell levels correlate with extent of tumor and clinical course of patients with bronchogenic carcinoma. The assay may, therefore, provide a rational basis for the selection of patients who are at high risk for the development of recurrence after surgical resection and who may benefit from the early institution of adjunctive therapy.