We present a query-driven algorithm for the distributed indexing of large document collections within structured P2P networks. To cope with bandwidth consumption that has been identified as the major problem for the standard P2P approach with single term indexing, we leverage a distributed index that stores up to top-k document references only for carefully chosen indexing term combinations. In addition, since the number of possible term combinations extracted from a document collection can be very large, we propose to use query statistics to index only such combinations that are indeed frequently requested by the users. Thus, by avoiding the maintenance of superfluous indexing information, we achieve a substantial reduction in bandwidth and storage. A specific activation mechanism is applied to continuously update the indexing information according to changes in the query distribution, resulting in an efficient, constantly evolving query-driven indexing structure. We show that the...