Histology of bronchial carcinoma and regional lymph nodes as putative immune response of the host to the tumor.

Two hundred forty-two patients who had bronchial carcinoma and who underwent radical surgery were studied in order to determine putative host resistance to the tumor at histologic level, i.e., lymphocytic infiltration in the center and around the tumor, together with sinus histiocytosis and follicular hyperplasia in the regional lymph nodes. These features were evaluated in a semiquantitative way, giving rise to three groups of patients: D- (reaction absent or poor), D+ (reaction present), and D++ (strong reaction present). Five-year survival rates and the incidence of metastases in regional nodes were significantly related to the putative host resistance against the tumor, but no clear-cut correlation between grade of malignancy of the tumor and histologic type was evidenced. The significance of these reactive changes is fully discussed.