The relation between tissue galectin-3 level and platinum resistance in neoadjuvant bladder cancer treatment.

Purpose This study aimed to reveal the relationship between the level of galectin-3 expression and the depth of response to neoadjuvant therapy in bladder tumor tissue with muscle invasion revealed by transurethral biopsy. Methods The percentage of galectin-3 staining in transurethral biopsy tissue with muscle invasion was determined by immunohistochemistry. The patients were divided into two groups: the down-staging (+) group consisting of patients with pathological complete response or non-invasive bladder cancer, and the down-staging (-) group consisting of patients with stage 2 and above. Results There were 11 patients in the down-staging (+) group and 12 patients in the down-staging (-) group. There was no significant difference between the two groups in terms of median age, gender, smoking, clinical stage at the time of diagnosis, distribution of carboplatin or cisplatin used as a platinum agent. Galectin-3 was positive in 2 patients (18.2%) in the group where down-staging was achieved with neoadjuvant therapy, while it was positive in 9 patients (75%) in the other group (p = 0.01). The median follow-up period of the patients was 31.6 months (95% CI 25.1-39.3). Overall survival was 43.4 months in the down-staging (+) group (95% CI 25.1-61.6) and 31.6 months in the down-staging (-) group (95% CI 12.7-50.6). Although there was a numerical difference, it did not reach statistical significance (p=0.37). Conclusion The rate of down-staging after platinum-based neoadjuvant chemotherapy is significantly higher in patients with low galectin-3 staining in transurethral bladder biopsy tissue.