Clinical and ultrasound features correlated with a heavy axillary nodal tumor burden in colon cancer

Aim: This study aimed to investigate the correlation between the pathologic and ultrasound (US) characteristics of colon cancer and the heavy axillary nodal burden. Methods: In total, 631 patients diagnosed with invasive colon cancer were recruited with ethical ratification. Results: The unitary pathologic features correlated with heavy axillary lymph nodal burden included the age of patient (p = 0.035), tumor size (p = 0.001), lymph node metastasis (p = 0.001), lymphovascular invasion (p = 0.020) and pathology type (p = 0.012). The independent US characteristics correlated with heavy axillary nodal burden included posterior acoustic enhancement (p = 0.006). Heavy axillary nodal burden was correlated with tumor size, lymph node metastasis, lymphovascular invasion and pathology type. Conclusion: Tumor size, lymph node metastasis and posterior acoustic can be used to predict the axillary lymph node tumor burden.

O30: EVALUATION OF AXILLARY LYMPH NODE METASTATIC BURDEN BY PREOPERATIVE ULTRASOUND

Introduction Sentinel lymph node biopsy (SLNB) is the gold standard for determining axillary nodal status. There is growing interest in using preoperative axillary ultrasound (AUS) as a non-invasive means of assessing the axilla. However, AUS has limited sensitivity and is subject to operator dependency. This study aimed to quantify axillary nodal burden in preoperative AUS. Method This retrospective study used an institutional database of all primary invasive breast carcinomas from 2006–2019. Those with pathologically proven axillary metastatic disease were included. Patients were considered in two groups, low nodal burden/LNB(1-2LN) and high nodal burden/HNB(≥3LN) based on total positive lymph node count(SLNB+ALND). Preoperative AUS reports were assessed to determine those suspicious for axillary metastasis. Result Of the 347 patients (n=349 axillae), 77.9% had LNB and 22.1% had HNB. In patients with LNB, 228(83.8%) had a normal AUS versus 44(16.2%) suspicious AUS. In those with HNB 60(77.9%) had normal AUS findings versus 17(22.1%) suspicious findings. On multivariate analysis Nottingham Grade-3 was associated with suspicious AUS findings (p=0.02). However, receptor status, SLN macro-metastasis and extra-nodal extension were not associated with abnormal AUS. Conclusion As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. In this cohort, AUS did not reliably identify patients with axillary metastasis. These results highlight the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging. Take-home message As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. This study highlights the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

Prognostic Value of Extranodal Extension in Axillary Lymph Node-positive Breast Cancer

Background Several studies have demonstrated that extranodal extension (ENE) is associated with prognosis in breast cancer. Whether this association should be described in pathological reports warrants further investigation.Objective In this research, we evaluated the predictive value of ENE in axillary lymph nodes (ALNs) in invasive breast cancer and explored the feasibility of employing ENE to predict clinicopathological features, nodal burden, disease recurrence-free survival (DRFS) and overall survival (OS) in clinical practice. In addition, the cutoff values of perpendicular diameter (PD-ENE) and circumferential diameter (CD-ENE) of ENE were investigated.Methods A total of 402 cases of primary invasive breast cancer were extracted from Fudan University Shanghai Cancer Center; these patients underwent axillary lymph node dissection (ALND) between 2010 and 2015. ENE in the axillary lymph node (ALN) was defined as the tumor cells breaking through the lymph node capsule into peripheral adipose tissue and causing connective tissue reactions. Relationships between ENE and clinicopathological features, nodal burden, disease recurrence-free survival (DRFS) and overall survival (OS) were analyzed. PD-ENE was defined by measuring from the point where tumor tissue broke the node capsule to the highest point of the tumor cells in the perinodal adipose tissue. The average PD-ENE was 1.8 mm; therefore, we divided ENE-positive patients into two groups: PD-ENE no greater than 2 mm and PD-ENE greater than 2 mm. CD-ENE was defined as measuring along the nodal capsule as the distance between peripheral edges of the ENE area. According to the average circumferential diameter (CD-ENE), we classified ENE-positive patients into two groups: CD-ENE no greater than 3 mm and CD-ENE greater than 3 mm. Correlations between ENE cutoffs and prognosis were analyzed.Results In this cohort of patients, 158 (39.3%) cases were positive for ENE in ALN.98 (24.4%) cases had PD-ENE no larger than 2 mm, and 60 (14.9%) cases had PD-ENE larger than 2 mm. Also, 112 (27.9%) cases had CD-ENE no larger than 3 mm, and 46 (11.4%) cases had CD-ENE larger than 3 mm. Statistical analysis indicated that histological grade, N stage, and HER2 overexpression subtype were associated with ENE. The presence of ENE had significant statistical correlations with nodal burden, including N stage, median metastatic tumor diameter and peri-lymph node vascular invasion (p < 0.001, p < 0.001, p = 0.001, respectively). Cox regression analysis demonstrated that patients with ENE exhibited significantly reduced DRFS in both univariate analysis (HR 2.126, 95% CI 1.453 - 3.112, p < 0.001) and multivariate analysis (HR 1.745, 95% CI 1.152 - 2.642, p = 0.009) compared with patients without ENE. For overall survival (OS), patients with ENE were associated with OS in univariate analysis (HR 2.505, 95% CI 1.337 - 4.693, p = 0.004) but not in multivariate analysis (HR 1.639, 95% CI 0.824 - 3.260, p = 0.159). Kaplan–Meier curves and log-rank test showed that patients with ENE in ALN had lower DRFS and OS (for DRFS: p < 0.0001; and for OS: p = 0.002, respectively). However, neither the PD-ENE group (divided by 2 mm) nor the CD-ENE group (divided by 3 mm) exhibited significant differences regarding nodal burden and prognosis.Conclusions Our study indicated that ENE in the ALN was a predictor of prognosis in breast cancer. ENE was an independent prognostic factor for DRFS and was associated with OS. ENE in the ALN was associated with a higher nodal burden. The size of ENE, which was classified by a 3-mm (CD-ENE) or 2-mm (PD-ENE) cutoff value, had no significant prognostic value in this study. Based on our findings, the presence of ENE should be included in routine pathological reports of breast cancers. However, the cutoff values of ENE warrant further investigation.