Mobile Peer-to-Peer (MP2P) networks consist of mobile devices that communicate with each other via short-range wireless transmissions to facilitate sharing of information among them. Such networks present a constrained communication environment due to fundamental limitations of battery power and wireless bandwidth, and users' frequent mobility. These characteristics of MP2P networks make scalable data retrieval a challenging problem. In this paper we propose a novel scheme, called Proximity Regions for Caching in Cooperative MP2P Networks(PReCinCt), to efficiently support scalable data retrieval in large-scale MP2P networks. In the PReCinCt scheme, the network topology is divided into geographical regions where each region is responsible for a set of keys representing the data. Each key is then mapped to a region location based on a geographical hash function. A geographic-aided routing protocol is used to route traffic of each data retrieval. In order to further save bandwidth for each data retrieval, PReCinCt incorporates a cooperative caching scheme that caches relevant data among a set of peers in a region. Simulation results show that the proposed scheme achieves significant improvements in average latency and energy consumption.