Published in:
01-11-2011 | Epidemiology
Association of the germline TP53 R72P and MDM2 SNP309 variants with breast cancer survival in specific breast tumor subgroups
Authors:
Alexandra J. van den Broek, Annegien Broeks, Hugo M. Horlings, Sander V. M. Canisius, Linde M. Braaf, Anita Langerød, Laura J. Van’t Veer, Marjanka K. Schmidt
Published in:
Breast Cancer Research and Treatment
|
Issue 2/2011
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Abstract
The tumor suppressor gene TP53 and its regulator MDM2 are both important players in the DNA-damage repair “TP53 response pathway”. Common germline polymorphisms in these genes may affect outcome in patients with tumors characterized by additional somatic changes in the same or a related pathway. To evaluate this hypothesis, we determined the effect of the common germline TP53 R72P and MDM2 SNP309 polymorphisms on breast cancer survival in a consecutive cohort of breast cancer patients (age at diagnosis <53 years, n = 295) with gene expression data available. Patients were classified in subgroups according to their tumor TP53 mutation status and three gene expression profiles; a TP53 mutation status expression signature, a PTEN/PI3K pathway signature and the 70-gene prognosis profile. Survival analyses were performed using Cox regression models adjusting for clinico-pathological characteristics and treatment. An increase in breast cancer-specific mortality was observed for carriers of the germline MDM2 SNP309 rare GG-genotype (range hazard ratios: 2–3) or TP53 R72P heterozygous GC-genotype (range hazard ratios: 1–2) compared to those having the common genotypes within subgroups of tumors displaying a “more aggressive phenotype” gene expression profile. There was no evidence of such an effect on survival within the TP53-mutated tumor group for TP53 R72P carriers but a suggestion of an effect for MDM2 SNP309 carriers (GG vs. TT-genotype HR 2.99, P = 0.06). These results indicate that common polymorphisms in specific pathways may add to the worse prognosis of patients with tumors in which these pathways are affected by somatic alterations.