Mitochondrial DNA aberrations as clonal markers for the determination of the relationship between multiple tumors within one patient

B7 The treatment of patients with multiple primary tumors is different from the treatment of metastatic disease. Therefore it is important to determine the relationship between multiple tumors within one patient. Recently, a high frequency of somatic mt DNA aberrations in a mononucleotide repeat (D310) has been described in several tumor types. In previous studies we determined the relationship between multiple tumors within single patients in 40 cases using LOH and p53 mutation analyses. These 40 cases were now investigated for D310 aberrations. The 40 cases comprised 93 tumors and in 37 tumors of 16 cases D310 mutations were found. In all these 16 cases the results of the D310 analyses indicated the same relationships as were found by LOH and p53 analyses. Our results indicate that mt DNA aberrations can be used as tumor-specific clonal markers to determine the relationship between multiple tumors in one patient.