SIALOMUCIN EXPRESSION IS ASSOCIATED WITH ERBB-2 ONCOPROTEIN OVEREXPRESSION, EARLY RECURRENCE, AND CANCER DEATH IN NON-SMALL-CELL LUNG-CANCER

Mucin production, when heavily sialylated, can promote cancer cell inv asion and metastasis, and modulate the immune recognition system of th e host. To explore the prognostic implication of sialomucin expression in lung cancer, we studied 116 patients with non-small-cell lung canc er (NSCLC). Tumor specimens were stained immunohistochemically with mo noclonal antibodies (mAbs) against mucin glycoprotein (17Q2, HMFG2, SM 3), and histochemically with periodic acid-Schiff/alcian blue to diffe rentiate neutral mucin from acid mucin, and with high-iron diamine/alc ian blue to differentiate sialomucin from sulfomucin. The expression s tatus of two established molecular prognostic factors, the p53 and erb B-2 oncoproteins, were evaluated immunohistochemically. The staining w as performed on two separately archived, paraffin-embedded tumor block s for each patient, with normal lung as a control. Correlations were s ubsequently made among stains and various clinicopathologic factors. A ll analyses were blinded, and included Kaplan-Meier survival estimates with Cox proportional hazards regression modeling. Associations were established among adenocarcinoma histotype and erbB-2 overexpression, sialomucin expression, and 17Q2 and HMFG2 immunohistochemical positivi ty (p < 0.05). Sialomucin expression was closely linked to erbB-2 over expression (p = 0.01). Significant univariate predictors (p < 0.05) of recurrence and cancer death were surgical stage, p53 expression, erbB -2 overexpression, and sialomucin expression. These four factors remai ned as independent predictors of early recurrence (p < 0.05) after mul tivariate analysis. For cancer death prediction, p53 and sialomucin ex pression had a marginal effect. We concluded that sialomucin expressio n is also a poor indicator of prognosis, which is associated with erbB -2 oncoprotein overexpression, early postoperative recurrence, and can cer death in NSCLC.