TY - JOUR

T1 - Robust and validated models to predict high risk of non-sentinel node metastases in breast cancer patients with micrometastases or isolated tumor cells in the sentinel node

AU - Tvedskov, Tove F

AU - Jensen, Maj-Britt

AU - Balslev, Eva

AU - Kroman, Niels

PY - 2014/2

Y1 - 2014/2

N2 - BACKGROUND: Benefit from axillary lymph node dissection in sentinel node positive breast cancer patients is under debate. Based on data from 1820 Danish breast cancer patients operated in 2002-2008, we have developed two models to predict high risk of non-sentinel node metastases when micrometastases or isolated tumor cells are found in sentinel node. The aim of this study was to validate these models in an independent Danish dataset.MATERIAL AND METHODS: We included 720 breast cancer patients with micrometastases and 180 with isolated tumor cells in sentinel node operated in 2009-2010 from the Danish Breast Cancer Cooperative Group database. Accuracy of the models was tested in this cohort by calculating area under the receiver operating characteristic curve (AUC) as well as sensitivity and specificity.RESULTS: AUC for the model for patients with micrometastases was comparable to AUC in the original cohort: 0.63 and 0.64, respectively. The sensitivity and specificity for predicting risk of non-sentinel node metastases over 30% was 0.36 and 0.81, respectively, in the validation cohort. AUC for the model for patients with isolated tumor cells decreased from 0.73 in the original cohort to 0.60 in the validation cohort. When dividing patients with isolated tumor cells into high and low risk of non-sentinel node metastases according to number of risk factors present, 37% in the high-risk group had non-sentinel node metastases. Specificity and sensitivity was 0.48 and 0.88, respectively, in the validation cohort when using this cut-point.CONCLUSION: In this independent dataset, the model for patients with micrometastases was robust with accuracy similar to the original cohort, while the model for patients with isolated tumor cells was less accurate. The models may be used to identify patients where axillary lymph node dissection should still be considered.

AB - BACKGROUND: Benefit from axillary lymph node dissection in sentinel node positive breast cancer patients is under debate. Based on data from 1820 Danish breast cancer patients operated in 2002-2008, we have developed two models to predict high risk of non-sentinel node metastases when micrometastases or isolated tumor cells are found in sentinel node. The aim of this study was to validate these models in an independent Danish dataset.MATERIAL AND METHODS: We included 720 breast cancer patients with micrometastases and 180 with isolated tumor cells in sentinel node operated in 2009-2010 from the Danish Breast Cancer Cooperative Group database. Accuracy of the models was tested in this cohort by calculating area under the receiver operating characteristic curve (AUC) as well as sensitivity and specificity.RESULTS: AUC for the model for patients with micrometastases was comparable to AUC in the original cohort: 0.63 and 0.64, respectively. The sensitivity and specificity for predicting risk of non-sentinel node metastases over 30% was 0.36 and 0.81, respectively, in the validation cohort. AUC for the model for patients with isolated tumor cells decreased from 0.73 in the original cohort to 0.60 in the validation cohort. When dividing patients with isolated tumor cells into high and low risk of non-sentinel node metastases according to number of risk factors present, 37% in the high-risk group had non-sentinel node metastases. Specificity and sensitivity was 0.48 and 0.88, respectively, in the validation cohort when using this cut-point.CONCLUSION: In this independent dataset, the model for patients with micrometastases was robust with accuracy similar to the original cohort, while the model for patients with isolated tumor cells was less accurate. The models may be used to identify patients where axillary lymph node dissection should still be considered.

KW - Area Under Curve

KW - Breast Neoplasms

KW - Cohort Studies

KW - Denmark

KW - Female

KW - Humans

KW - Lymphatic Metastasis

KW - Models, Biological

KW - Neoplasm Micrometastasis

KW - ROC Curve

KW - Risk Factors

KW - Sentinel Lymph Node Biopsy

U2 - 10.3109/0284186X.2013.806993

DO - 10.3109/0284186X.2013.806993

M3 - Journal article

C2 - 23772767

VL - 53

SP - 209

EP - 215

JO - Acta Oncologica

JF - Acta Oncologica

SN - 1100-1704

IS - 2

ER -