Prognostic significance of heat shock protein 105 in lung adenocarcinoma

Heat shock protein 105 (HSP105) is overexpressed in various tumors and is known to protect cells from cytotoxic stimuli. The prognostic significance of HSP105 expression in cancer has not been fully evaluated. Here, HSP105 expression in lung adenocarcinoma was immunohistochemically examined in 116 patients: 68 males and 48 females with ages ranging from 38-81 (median 63) years. Tumor stage was I in 64, II in 16 and III in 36 patients. In non-cancerous tissues, HSP105 was expressed in the ciliated cells of bronchi. Tumor cells were constantly positive for HSP105, with varying intensities. The HSP105 score in each case was determined based on the staining intensity of the tumor cells occupying the widest area of cancerous tissue as follows: cases with tumor cells showing an intensity weaker than, comparable to and stronger than the bronchial epithelium were assigned a score of 1, 2 and 3, and numbered 84, 19 and 13 cases, respectively. HSP105 score was significantly correlated with the rate of recurrence and the stage of the disease. Univariate analysis showed that lymph node metastasis, disease stage and HSP105 score were unfavorable prognostic factors. Multivariate analysis revealed that lymph node metastasis and HSP105 score were independent prognostic factors for overall and disease-free survival. HSP105 expression is useful for the prediction of prognosis in patients with lung adenocarcinoma.