Objective: To study the association between HAb18G expression, tumor parameters, metastatic potential and prognosis in non-small cell lung carcinoma (NSCLC).
Methods: Immunohistochemical study for HAb18G protein using SP methods was carried out in 144 cases of NSCLC. Nineteen cases of benign lung lesions and 41 cases of normal lung tissue were used as controls. The intensity (positive unit/PU) of HAb18G expression was assessed quantitatively by image analysis software. The results were correlated with tumor parameters, metastatic potential and follow-up data.
Results: The intensity of HAb18G protein expression was significantly higher in NSCLC than that in controls (P = 0.000). In squamous cell carcinomas and adenocarcinomas, the expression of HAb18G protein in well-differentiated tumors was lower than that in moderately to poorly differentiated tumors (P = 0.001). Tumors of TNM stage IV had stronger expression than tumors of lower stages (P = 0.000). HAb18G PU was greater in tumors with lymph node metastasis than those without nodal metastasis (P = 0.045). The PU value of tumors with maximal diameter greater than 5 cm was higher than that of the smaller tumors (P = 0.000). It was also higher in male than in female patients (P = 0.046). There was no association between HAb18G protein expression and age of patients, history of smoking, tumor types and gross morphology (P > 0.05). The five-year survival rate in cases with low HAb18G protein expression was higher than that in cases with high expression (P = 0.006). Univariate analysis indicated that patients with high HAb18G protein expression carried a poor prognosis (P = 0.007). Multivariate analysis showed that expression of HAb18G protein was an independent prognostic factor in patients with NSCLC (P = 0.032, relative risk 3.962).
Conclusions: HAb18G protein expression is associated with tumor progression and prognosis. It may represent a useful biomarker for prognostic evaluation.