Are Breast Cancer Nomograms Still Valid to Predict the Need for Axillary Dissection?

BACKGROUND: Nomograms can help in estimating the nodal status among clinically node-negative patients. Yet their validity in external cohorts over time is unknown. If the nodal stage can be estimated preoperatively, the need for axillary dissection can be decided. OBJECTIVES: The aim of this study was to validate three existing nomograms predicting 4 or more axillary lymph node metastases. METHOD: The risk for ≥4 lymph node metastases was calculated for n = 529 eligible breast cancer patients using the nomograms of Chagpar et al. [Ann Surg Oncol. 2007;14:670-7], Katz et al. [J Clin Oncol. 2008;26(13):2093-8], and Meretoja et al. [Breast Cancer Res Treat. 2013;138(3):817-27]. Discrimination and calibration were calculated for each nomogram to determine their validity. RESULTS: In this cohort, the AUC values for the Chagpar, Katz, and Meretoja models were 0.79 (95% CI 0.74-0.83), 0.87 (95% CI 0.83-0.91), and 0.82 (95% CI 0.76-0.86), respectively, showing good discrimination between patients with and without high nodal burdens. CONCLUSION: This study presents support for the use of older breast cancer nomograms and confirms their current validity in an external population.

The Sentinel Node with Isolated Breast Tumor Cells or Micrometastases. Benefits and Risks of Axillary Dissection.

BACKGROUND/AIM: Sentinel lymph node (SLN) biopsy has become the standard procedure to identify metastases in axillary nodes in breast cancer. Even after careful SLN examination additional micrometastases and isolated tumor cells (ITCs) are sometimes found, resulting in a need for delayed axillary lymph node dissection (ALND). This study was undertaken to assess prognostic factors identifying additional axillary lymph node (ALN) metastases at delayed ALND. PATIENTS AND METHODS: To define the impact of late ALND regarding their outcome, 162 breast cancer patients with 169 operated breasts treated between 2010 and 2012 were evaluated, with follow-up through 2016. Data were collected on the patients, histology and biologic profile of the cancer, lymph node involvement, recurrence of breast cancer and adverse effects of ALND. RESULTS: With thorough examination and immunohistochemical stainings twenty-nine of 168 SLN biopsies (28 patients, 17% of the patients) showed micrometastases or ITC, and a full ALND was performed at a later time. During these ALNDs 13 to 31 lymph nodes were removed. Additional ALN metastases were found in three (10%) patients. Two (7%) of the 28 patients with triple-negative cancer deceased of metastatic breast cancer. Three patients (11%) reported adverse effects of ALND requiring physiotherapy due to pain, stiffness, swelling or arm oedema. Tumor factors such as molecular subtype (p=0.002), tumor size (p=0.004), and proliferation index (Ki-67) (p=0.003) correlated with higher numbers of ALN metastases. CONCLUSION: Since most patients with micrometastases found in the primary operation showed no additional positive lymph nodes, completion ALND may not be required in patients with micrometastases or ITCs in the SLN. In our study, the predictive factors for additional ALN metastases were tumur size, molecular subtype and proliferation index. It is conceivable that the features of the primary tumor, rather than the amount of cancer cells in the SLN, might serve to identify patients in whom ALDN can be avoided.