Co-expression of HER3 and MUC1 is associated with a favourable prognosis in patients with bladder cancer.

Objectives To investigate the functional impact of the interaction of MUC1 with the epidermal growth factor receptors HER3 and HER4 in patients with bladder cancer. Patients and Methods Using reverse transcription quantitative polymerase chain reaction, we examined MUC1 expression in 82 bladder cancer biopsies previously examined for the expression of HER3. Results Patients expressing high MUC1 had a favourable survival when the expression of HER3 was also high compared with when the expression of HER3 was low (P = 0.004). When MUC1 expression was low, HER3 co-expression did not influence the prognostic value of MUC1 (P = 0.488). MUC1 expression had no correlation with survival, tumour stage or grade, or to the prognostic value of HER4. Conclusions A high MUC1 expression was associated with a favourable prognosis in patients with bladder cancer when the expression of HER3 was also high. This suggests an involvement of HER3 in MUC1 function in bladder cancer.