In a Bayesian approach, uncertainty explained by a prior distribution that contains information about an uncertain parameter. Determination of the prior distribution is important in because it impacts the posterior inference. The objective of this study is to use metaanalysis for proportion to obtain prior information about patients with breast cancer stage I who undergoing modified radical mastectomy treatment and applied Bayesian approach. R and WinBUGS programs are performed for meta-analysis and Bayesian approach respectively.