Clinical Significance of Galectin-3 Expression in Squamous Cell Carcinoma of Lung

Squamous cell carcinoma of lung is an aggressive disease with a poor a prognosis. While majority of these patients do not survive longer than five years, a minor proportion of patients go on to live longer without disease progression. Identification of biomarkers using easily available immunohistochemical assays could improve risk-stratification in lung cancer patients. Galectin-3, a lectin binding protein, expression has been linked to cancer progression and metastasis. We examined the prognostic impact of tumoral galectin-3 expression in 236 patients with completely resected squamous cell carcinoma of the lung and matching normal tissue using tissue microarray samples. In normal lung, galectin-3 staining is present in alveolar macrophages. Galectin-3 expression is detected in 87% of lung squamous cell carcinoma with a mean galectin-3 score of 2 (range 0-3). There was a significant association between galectin-3 expression and pathological stage (p=0.012) and nodal metastasis (p= 0.013). Galectin-3 expression level, however, was not associated with survival outcome. In conclusion, galectin-3 is expression is seen in alveolar macrophages and close to 90% of lung squamous cell carcinoma. Galectin-3 expression is not associated with survival outcome in North American cohort.