Sentinel node staging for breast cancer: Intraoperative molecular pathology overcomes conventional histologic sampling errors

BACKGROUND: When sentinel node dissection reveals breast cancer metastasis, completion axillary lymph node dissection is ideally performed during the same operation. Intraoperative histologic techniques have low and variable sensitivity. A new intraoperative molecular assay (GeneSearch BLN Assay; Veridex, LLC, Warren, NJ) was evaluated to determine its efficiency in identifying significant sentinel lymph node metastases (\u3e.2 mm). METHODS: Positive or negative BLN Assay results generated from fresh 2-mm node slabs were compared with results from conventional histologic evaluation of adjacent fixed tissue slabs. RESULTS: In a prospective study of 416 patients at 11 clinical sites, the assay detected 98% of metastases \u3e2 mm and 88% of metastasis greater \u3e.2 mm, results superior to frozen section. Micrometastases were less frequently detected (57%) and assay positive results in nodes found negative by histology were rare (4%). CONCLUSIONS: The BLN Assay is properly calibrated for use as a stand alone intraoperative molecular test

Effect of Axillary Dissection vs No Axillary Dissection on 10-Year Overall Survival Among Women With Invasive Breast Cancer and Sentinel Node Metastasis: The ACOSOG Z0011 (Alliance) Randomized Clinical Trial

The results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial were first reported in 2005 with a median follow-up of 6.3 years. Longer follow-up was necessary because the majority of the patients had estrogen receptor–positive tumors that may recur later in the disease course (the ACOSOG is now part of the Alliance for Clinical Trials in Oncology)

The prospective MammaPrint MINT (Multi-Institutional Neo-adjuvant Therapy) study

TPS11122 Background: Patients with locally advanced breast cancer (LABC) are often treated with neo-adjuvant chemotherapy to reduce the size of the tumor before definitive surgery. Complete pathologic Response (pCR) predicts better long term outcome. Genomics assays that measure specific gene expression patterns in a patient's primary tumor have become important prognostic and predictive tools for early breast cancer. This study is designed to test the ability of molecular profiling, as well as traditional pathologic and clinical prognostic factors to predict responsiveness to neo-adjuvant chemotherapy in patients with LABC. Methods: Women ≥ 18 yrs with histologically-proven invasive breast cancer T2(≥3.5cm)-T4,N0M0 or T2-T4N1M0, with measurable disease, adequate bone marrow reserves and normal renal and hepatic function who signed informed consent are enrolled. Axillary lymph nodes will be staged according to protocol. MammaPrint risk profile, BluePrint molecular subtyping profile, TargetPrint ER, PR and HER2 single gene readout, and the 56-gene TheraPrint Research Gene Panel will be analysed using the whole genome expression array. Patients will receive neo-adjuvant chemotherapy treatment according to protocol. Response will be measured by centrally assessed Residual Cancer Burden (RCB). Objectives are: (1) To determine the predictive power of MammaPrint and BluePrint for sensitivity to neo-adjuvant chemotherapy as measured by pCR. (2) To identify and/or validate predictive gene expression profiles of clinical response or resistance to neo-adjuvant chemotherapy. (3) To compare TargetPrint ER, PR and HER2 with local and centralized IHC and/or CISH/FISH assessment. (4) To identify correlations between TheraPrint and response to neo-adjuvant chemotherapy. (5) To compare BluePrint molecular subtype with IHC-based subtype classification. To achieve a difference of 20% in chemotherapy sensitivity for patients stratified by MammaPrint, a total of 226 samples is needed (significance level 0.05 and power of 0.90). So far 45 patients have been enrolled from multiple institutions. Clinical trial information: NCT01501487

The prevalence of luminal B subtype is higher in older postmenopausal women with ER+/HER2- breast cancer and is associated with inferior outcomes.

OBJECTIVES: To establish whether clinicopathologic and genomic characteristics may explain the poor prognosis associated with advanced age in ER+/HER2- breast cancer. MATERIALS AND METHODS: The cohort included 271 consecutive post-menopausal patients with ER+/HER2- invasive breast cancer ages 55 years and older. Patients were categorized as younger (ages 55- \u3c 75) and older (ages ≥75). The Kaplan-Meier method was used to estimate locoregional recurrence (LRR), recurrence-free interval (RFi), and overall survival (OS). Gene expression of tumor samples was assessed with Affymetrix Rosetta/Merck Human RSTA microarray platform. Differential gene expression analysis of tumor samples was performed using R package Limma. RESULTS: 271 breast cancer patients were identified, including 186 younger and 85 older patients. Older patients had higher rates of Luminal B subtype (53% vs 34%) and lower rates of Luminal A subtype (42% vs 58%, p = 0.02). Older patients were less likely to receive chemotherapy (9% vs 40%, p \u3c 0.001) and hormone therapy (71% vs 89%, p \u3c 0.001). For cases of grade 1-2 disease, older patients had a higher proportion of the luminal B subtype (49% vs. 30%, p = 0.014). Age ≥ 75 predicted for inferior OS (HR = 3.06, p \u3c 0.001). The luminal B subtype predicted for inferior OS (HR = 2.12, p = 0.014), RFi (HR 5.02, p \u3c 0.001), and LRR (HR = 3.12, p = 0.045). There were no significant differences in individual gene expression between the two groups. CONCLUSION: Women with ER+/HER2- breast cancer ≥75 years old had higher rates of the more aggressive luminal B subtype and inferior outcomes. Genomic testing of these patients should be strongly considered, and treatment should be intensified when appropriate