Local responses in primary and secondary human lung cancers. II. Clinical correlations.

Local infiltrates of eosinophilic leucocytes and macrophages and the deposition of acid mucopolysaccharides (AMPS) in 72 operable primary lung cancers and 17 isolated pulmonary metastases of known origin were correlated to tumour stage (radically or non-radically operable) and clinical course, by following the patients for 2-3 1/2 years. Half of the primary lung cancers showed strong local eosinophilia which, in combination with either strong macrophage infiltration or absence of AMPS reaction, characterized a very good prognosis in radically operable patients. No eosinophils, together with a strong AMPS reaction, indicated a very poor prognosis, irrespective of tumour stage. 16/17 metastases (7 different histologies) had either no local eosinophilia (13), strong AMPS deposition (12) or both (9). This suggests that malignant clones with great metastatic potential in general are characterized by absence of local eosinophilia and/or a strong AMPS reaction. These observations taken together indicate that local eosinophilia expresses an immune reaction which is, houl metastatic clones. It if does, metastatic success may be due to an escape mechanism based on the elaboration of AMPS.