Clinical Implications of p57KIP2 Expression in Breast Cancer


Objective: To study the relationship between expression of p57KIP2 and prognosis and other clinicopathologicalparameters in invasive breast cancers.
Methods: We assessed the expression of p57KIP2 in 89 cases of invasivebreast cancer and 20 cases of normal breast tissue by immunohistochemical methods and analyzed the resultswith SPSS software (ver. 16.0).
Result: The positive expression rates of p57KIP2 protein in the invasive breastcancers and surrounding normal tissue were 30.3% (27/89) and 65% (13/20), respectively. Cases with nop57KIP2 expression exhibited a significantly higher post-operative distant metastasis rate than those with p57KIP2expression (37.9% vs. 14.8%; P = 0.01). DFS analysis showed that p57KIP2-/C-erbB-2+ tumors also exhibited asignificantly higher post-operative distant metastasis rate than the other groups (66.7% vs. 29.2%; P = 0.007),as did p57KIP2-/p53+ tumors (64.3% vs. 22.7%; P = 0.001). Survival analysis revealed that p57KIP2 was associatedwith breast cancer-specific survival overall (P = 0.045, log-rank test). Subgroup analysis demonstrated thatindividuals with p57KIP2-/C-erbB-2+tumors experienced significantly worse post-operative survival than thosewith p57KIP2- /C-erbB-2- or other tumors (P = 0.006, log-rank test). p57KIP2-/p53+ tumors were associated withsignificantly worse post-operative survival than p57KIP2-/p53- or other tumors (P = 0.001, log-rank test). Coxregression analysis showed that p57KIP2 was a non-independent prognostic factor for breast cancer (P = 0.303).
Conclusions: p57KIP2 is expressed at low levels in invasive breast cancer and is associated with better overallsurvival rate and disease-free survival in breast cancer patients, but it was a non-independent prognostic factorfor breast cancer. Thus, the connection between p57KIP2/p53 and p57KIP2/C-erbB-2 may provide biomarkers forbreast cancer.