Increased p53 mutation frequency during tumor progression - Results from abreast cancer cohort

The mutational patterns of the p53 gene for exons 4-9 were analyzed in 30 r ecurring tumors compared with the p53 status of the corresponding 30 primar y breast cancers. The prevalence of p53 mutations was higher, although not statistically significant (P = 0.07), in the evaluable recurring tumors com pared with the corresponding primaries, 12 of 29 (41 %) versus 7 of 30 (23 %). Twenty-one of the patients had unchanged p53 mutation status in the rec urring compared with the primary tumors, whereas 8 had an altered mutationa l status or pattern in the sequential tumor. These findings indicate that p 53 mutations may be an important factor for tumor progression in human brea st cancer.