Association Between Diabetes and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis of Observational Studies by Ana Paula Pagano, Bruna Ramos da Silva, Flávio Teixeira Vieira, Luiz Fernando Meira Filho, Sarah A. Purcell, John D. Lewis, Michelle L. Mackenzie, Paula J. Robson, Jennifer E. Vena, Flávia Moraes Silva, Carla M. Prado