Prognostic significance of mutations in the p53 gene, particularly in the zinc-binding domains, in lymph node- and steroid receptor positive breast cancer patients. Austrian Breast Cancer Study Group.

The aim of our study was to evaluate if p53 mutations, especially those in the L2/L3 domains of the p53 gene, add prognostic information for node-positive and steroid receptor positive breast cancer patients. Two hundred and five tumour samples from a randomised clinical trial of 596 lymph node- and steroid receptor positive breast cancer patients were included. All patients had been randomly allocated to receive 20 mg of adjuvant tamoxifen (TAM) daily for 2 years or TAM plus one cycle of low-dose, short-term chemotherapy. For detection of p53 mutations we used in vitro amplification by polymerase chain reaction and consecutively performed temperature gradient gel electrophoresis (PCR-TGGE) and direct sequencing. We found p53 mutations in 42/205 (20%) cases: 16/42 (38%) p53 mutations occurred within the L2/L3 domains of the p53 gene, and 26/42 (62%) outside the L2/L3 domains. p53 mutation served as a statistically significant parameter in predicting disease-free survival in univariate (P = 0.02) and multivariate (P = 0.009) analysis. For overall survival, no significant differences were observed. Patients with tumours that had p53 mutations within the L2/L3 domains of the gene showed no significant difference to those with mutations outside the L2/L3 domains for disease-free survival. For overall survival, mutations in the L2/L3 domains showed a marginally significant difference (P = 0.05) in multivariate analysis, but not in univariate analysis (P = 0.13). We conclude that mutation in the L2/L3 domains of the p53 gene is not an independent prognostic indicator of disease outcome for patients suffering from breast cancer with lymph node metastases and positive steroid receptors.

RCT Entities:   Population Interventions Outcomes