Galectin-3 expression in prostate cancer and benign prostate tissues: correlation with biochemical recurrence

Galactin-3 is a cell adhesion molecule involved in tumor progression. Our aim was to examine Gal-3 expression in tumor, benign tissue adjacent to the tumor (adjacent-benign) and benign prostate specimens and correlated it with biochemical recurrence.

Tissue microarrays were prepared from 83 tumor, 78 adjacent-benign and 75 benign tissues obtained from 83 patients undergoing prostatectomy for clinically localized prostate cancer. Tissues were stained using a Gal-3 antibody and immunohistochemistry. The staining was graded between 0 and 300 depending upon staining intensity and the area of staining. In 37 patients on whom there was follow-up (Mean: 57.8 months; Median: 68 months), staining intensity was correlated with biochemical recurrence.

Gal-3 showed both nuclear and cytoplasmic localization in benign, adjacent-benign and tumor tissues. Median Gal-3 staining scores significantly decreased from benign (192.5) to adjacent-benign (148.8 p = 0.007) and to tumor (108.8; p < 0.0001) tissues. In univariate analysis, age (p = 0.028), Gleason sum (p = 0.007), T stage (p = 0.011), seminal vesicle invasion (p = 0.009), pre-operative prostate-specific antigen (p = 0.045) and Gal-3 staining in tumor tissues (0.018) significantly correlated with biochemical recurrence. In multivariate analysis, Gal-3 expression in tumor (p = 0.04), adjacent-benign (p = 0.037) and benign (p = 0.005) tissues significantly correlated with biochemical recurrence. Gal-3 staining in tumor tissues had 91.7 % sensitivity, 64 % specificity and 73 % accuracy in predicting biochemical recurrence.

This is the first study that showed a decreasing gradient of Gal-3 expression in benign, adjacent-benign and tumor tissues. Gal-3 expression may be useful in predicting biochemical recurrence.