The present invention relates to compounds and methods useful for the detection and treatment of disorders associated with frameshift mutations in coding microsatellite regions. The compounds and methods are applicable in cancers, especially of DNA mismatch repair deficient (MMR) sporadic tumors and HNPCC associated tumors. The compounds disclosed in the invention are useful for detection of disorders and in therapy such as e.g. immuno-therapy. The diagnostic methods relate to diagnosis and prognostic assessment of disorders associated with frameshift polypeptides originating from frameshift mutations in coding microsatellite regions of genes based on the detection of immunological entities directed against said frameshift polypeptides in body fluids. With respect to the treatment of cancer, especially of DNA mismatch repair deficient (MMR) sporadic tumors and HNPCC associated tumors, the invention pertains to methods which use immuno therapy with combinatorial mixtures of tumor specific frameshift peptides to elicit a cytotoxic T-cell response specifically directed against tumor cells for use in prevention as well as in curative treatment of cancers and precancers.