Myopodin methylation is associated with clinical outcome in patients with T1G3 bladder cancer.

PURPOSE

Bacillus Calmette-Guerin is standard treatment to decrease tumor recurrence and delay progression of high risk, nonmuscle invasive bladder tumors. However, it is not yet clear which T1G3 cases are more prone to more aggressive clinical behavior or susceptible to respond to bacillus Calmette-Guerin. We evaluated the role of myopodin methylation as a clinical outcome prognosticator and predictive biomarker for the bacillus Calmette-Guerin response in patients with T1G3 bladder tumors.

MATERIALS AND METHODS

We analyzed the methylation status of myopodin in tumor specimens from 170 patients with T1G3 bladder cancer, including a subset of 108 who underwent bacillus Calmette-Guerin treatment. Myopodin methylation was assessed by methylation specific polymerase chain reactions. Recurrence, progression to muscle invasive tumors and disease specific overall survival were analyzed using competing risks regression analysis.

RESULTS

Of the 170 cases analyzed 72 recurred (42.4%) and 36 progressed (21.2%). A total of 24 patients (14.1%) died of the disease. Univariate and multivariate survival analysis revealed that myopodin methylation was significantly associated with an increased recurrence rate (p = 0.004), progression (p = 0.002) and shorter disease specific overall survival (p = 0.020). In a subset treated with bacillus Calmette-Guerin myopodin methylation was also related to an increased recurrence rate (p = 0.011), progression (p = 0.030) and shorter disease specific overall survival (p = 0.028).

CONCLUSIONS

Epigenetic analysis revealed that myopodin methylation was associated with tumor aggressiveness and clinical outcome in patients with T1G3 disease. Myopodin methylation distinguished patients responding to bacillus Calmette-Guerin from those who may require a more aggressive therapeutic approach.