PT  - JOURNAL ARTICLE
AU  - SHOICHI KIKUCHI
AU  - REIKI NISHIMURA
AU  - TOMOFUMI OSAKO
AU  - YASUHIRO OKUMURA
AU  - YASUYUKI NISHIYAMA
AU  - YASUO TOYOZUMI
AU  - NOBUYUKI ARIMA
TI  - Definition of p53 Overexpression and its Association with the Clinicopathological Features in Luminal/HER2-negative Breast Cancer
DP  - 2013 Sep 01
TA  - Anticancer Research
PG  - 3891--3897
VI  - 33
IP  - 9
4099  - http://ar.iiarjournals.org/content/33/9/3891.short
4100  - http://ar.iiarjournals.org/content/33/9/3891.full
SO  - Anticancer Res2013 Sep 01; 33
AB  - Aims: A suitable cut-off value for p53 overexpression and its usefulness as a prognostic factor in luminal/HER2-negative breast cancer were evaluated. Patients and Methods: A retrospective analysis of 1,987 patients with luminal/HER2-negative breast cancer who underwent surgery between 2001 and 2009 was performed. Results: p53 expression ≥50% was present in 9% of the patients. Moreover, these patients had significantly lower estrogen/progesterone receptor-positive rates, higher Ki-67 values, larger tumors, disease-positive nodes, higher nuclear grade, and shorter disease-free survival than patients with p53 expression <50% (p<0.0001). Therefore, status of p53-positive cells ≥50% was classified as p53 overexpression. These findings indicate that p53 overexpression is associated with unfavorable characteristics and prognosis. Conclusion: The suitable cut-off value for p53 overexpression was determined to be 50%, and p53 overexpression appears to be a significant prognostic factor in patients with luminal/HER2-negative breast cancer.