Background. The concentration of cysteine proteinase cathepsin B has b
een shown to be elevated in association with malignancy or metastatic
potential of human and rodent tumors, but its prognostic value for hum
an lung cancer remains undetermined. Methods. Using a polyclonal antib
ody, immunohistochemical analyses of cathepsin B were performed on par
affin embedded sections of tumors obtained surgically from 108 patient
s with non-small cell lung cancer (49 squamous cell carcinomas, 59 ade
nocarcinomas). The immunohistochemical expressions of cathepsin B in t
he tumors were compared with patient survival. Results. Higher grade e
xpression of cathepsin B was associated significantly with shorter sur
vival in nonsmall cell lung cancer (P < 0.01), in squamous cell carcin
oma (P < 0.05), and in adenocarcinoma (P < 0.01). A similar result als
o was seen in Stage I non-small cell lung cancer (P < 0.05). Conclusio
ns. The authors concluded that the immunohistochemical staining patter
n of cathepsin B may be a useful predictor of survival for human lung
cancer.