Absence of Immunohistochemical Metallothionein Staining in Bladder Tumor Specimens Predicts Response to Neoadjuvant Cisplatin, Methotrexate and Vinblastine Chemotherapy

Pre-chemotherapy bladder tumor tissue was retrospectively analyzed in 21 patients treated with neoadjuvant cisplatin, methrotrexate and vinblastine. Immunohistochemical staining for 2 proposed mediators of drug resistance, p-glycoprotein and metallothionein, was performed and compared to chemotherapeutic response and survival. There was no significant relationship between staining for p-glycoprotein and the response to chemotherapy or survival. Patients with no detectable staining for metallothionein were statistically more likely to sustain a complete pathological response (p = 0.029) after chemotherapy than those with any detectable staining. No relationship between metallothionein immunostaining and survival was apparent. This study offers further evidence linking metallothionein in tumor resistance to cisplatin containing chemotherapy regimens.