RECOMMENDATIONS In addition to estrogen and progesterone receptors and human epidermal growth factor receptor 2 , the panel found sufficient evidence of clinical utility for the biomarker assays Oncotype DX , EndoPredict , PAM50 , Breast Cancer Index , and urokinase plasminogen activator and plasminogen activator inhibitor type 1 in specific subgroups of breast cancer .
No biomarker except for estrogen receptor , progesterone receptor , and human epidermal growth factor receptor 2 was found to guide choices of specific treatment regimens .
PURPOSE To provide recommendations on appropriate use of breast tumor biomarker assay results to guide decisions on adjuvant systemic therapy for women with early-stage invasive breast cancer .
p27Kip1 is a predictive factor for tamoxifen treatment response but not a prognostic marker in premenopausal breast cancer patients.
The cell-cycle regulating protein p27(Kip1 ) ( p27 ) has dual roles by acting as both a cdk inhibitor and as an assembly factor for different cdk complexes . Loss of p27 has been linked to malignant features in tumours ; however , the exact role of p27 deregulation in breast cancer regarding prognostic and treatment predictive information has not been fully clarified . We have evaluated p27 expression in 328 primary , Stage II breast cancers from premenopausal patients who had been r and omised to either tamoxifen treatment or no adjuvant treatment after surgery .  p27 was associated with the oestrogen receptor and cyclin D1 , and p27 downregulation was associated with high proliferation . There was no association between recurrence-free survival ( RFS ) and p27 ( HR = 0.800 , 95 % CI 0.523 - 1.222 , p = 0.300 ) , indicating that p27 is not a prognostic marker . The predictive value of p27 was analysed by comparing RFS in tamoxifen-treated and untreated patients in subgroups of low and high p27 expression ( HR = 0.747 , 95 % CI 0.335 - 1.664 , p = 0.474 and HR = 0.401 , 95 % CI 0.240 - 0.670 , p < 0.001 , respectively ) . Only patients with p27-high tumours benefited from tamoxifen ( multivariate interaction analysis p = 0.034 ) . Our study suggests that p27 downregulation is associated with tamoxifen resistance in premenopausal breast cancer but is not linked to impaired prognosis
RECOMMENDATIONS In addition to estrogen and progesterone receptors and human epidermal growth factor receptor 2 , the panel found sufficient evidence of clinical utility for the biomarker assays Oncotype DX , EndoPredict , PAM50 , Breast Cancer Index , and urokinase plasminogen activator and plasminogen activator inhibitor type 1 in specific subgroups of breast cancer .
No biomarker except for estrogen receptor , progesterone receptor , and human epidermal growth factor receptor 2 was found to guide choices of specific treatment regimens .
PURPOSE To provide recommendations on appropriate use of breast tumor biomarker assay results to guide decisions on adjuvant systemic therapy for women with early-stage invasive breast cancer .