Δ133p53 is an independent prognostic marker in p53 mutant advanced serous ovarian cancer

BACKGROUND: We aimed to evaluate the clinical relevance of p53 and p73 isoforms that modulate the function of p53. METHODS: This prospective multicentre study included 154 patients with stage III and IV serous ovarian cancer. A functional yeast-based assay and subsequent sequencing were performed to analyse the p53 mutational status. Expression of p53 and p73 isoforms was determined using RT-qPCR. RESULTS: Delta 133p53 expression constituted an independent prognostic marker for recurrence-free (hazard ratio = 0.571, P = 0.016, 95% CI: 0.362-0.899) and overall survival (hazard ratio = 0.365, P = 0.004, 95% CI: 0.182-0.731) in patients with p53 mutant ovarian cancer (n = 121). High Delta 40p53 expression was associated with favourable tumour grading (P = 0.037) and improved recurrence-free survival (33.4 vs 19.6 months, P = 0.029), but not overall survival (43.1 vs 33.6 months, P = 0.139), in patients with p53 wild-type cancer (n = 33). Neither the p53 mutational status nor p73 isoform expression possessed prognostic significance in the examined ovarian cancer cases. CONCLUSION: Delta 133p53 expression was associated with prognosis in the vast majority of ovarian cancer cases, that is, patients with p53 mutant advanced serous carcinomas. Thus, our findings underline the importance of considering the complex p53 regulatory network. British Journal of Cancer (2011) 105, 1593-1599. doi:10.1038/bjc.2011.433 www.bjcancer.com Published online 18 October 2011 (C) 2011 Cancer Research UK