Loss of Single-Stranded DNA Binding Protein 2 Expression Is Associated with Aggressiveness and Poor Overall Survival in Patients with Invasive Breast Carcinoma.

BACKGROUND

Single-stranded DNA binding protein 2 () is involved in the DNA damage response and the maintenance of genome stability. Previous studies have suggested that has a tumor suppressor function or oncogenic function. Loss of expression has been reported in various tumors. However, the role of expression in invasive breast carcinoma has not been reported.

METHODS

Immunohistochemical staining for was performed on tissue microarrays consisting of 491 invasive breast carcinoma cases. The result of nuclear staining was stratified as either negative or positive. Then, we investigated the correlations between expression and various clinicopathological parameters and patient outcomes.

RESULTS

Loss of nuclear expression was observed in 61 cases (12.4%) of 491 invasive breast carcinomas. Loss of nuclear expression was significantly correlated with larger tumor size ( < 0.001, chi-squared test), higher histological grade ( = 0.016, Cochran-Armitage trend test), higher pathological T stage ( < 0.001, Cochran-Armitage trend test), estrogen receptor status ( < 0.001, chi-squared test), and molecular subtype ( < 0.001, chi-squared test). Kaplan-Meier survival analysis revealed that patients with loss of nuclear expression had worse overall survival ( = 0.013, log-rank test). However, loss of nuclear expression was not correlated with recurrence-free survival ( = 0.175, log-rank test).

CONCLUSIONS

Loss of nuclear expression was associated with adverse clinicopathological characteristics and poor patient outcomes. acts as a tumor suppressor in invasive breast carcinoma and may be used as a prognostic biomarker.