To Dissect or Not to Dissect? The Surgeon's Perspective on the Prediction of Greater Than or Equal to 4 Axillary Lymph Node Metastasis in Early-Stage Breast Cancer: A Comparative Analysis of the Per-Protocol Population of the SINODAR-ONE Clinical Trial

Utilizing multiclassifier radiomics analysis of ultrasound to predict high axillary lymph node tumour burden in node-positive breast cancer patients: a multicentre study

BACKGROUND

The tumor burden within the axillary lymph nodes (ALNs) constitutes a pivotal factor in breast cancer, serving as the primary determinant for treatment decisions and exhibiting a close correlation with prognosis.

OBJECTIVE

This study aimed to investigate the potential of ultrasound-based radiomics and clinical characteristics in non-invasively distinguishing between low tumor burden (1-2 positive nodes) and high tumor burden (more than 2 positive nodes) in patients with node-positive breast cancer.

METHODS

A total of 215 patients with node-positive breast cancer, who underwent preoperative ultrasound examinations, were enrolled in this study. Among these patients, 144 cases were allocated to the training set, 37 cases to the validation set, and 34 cases to the testing set. Postoperative histopathology was used to determine the status of ALN tumor burden. The region of interest for breast cancer was delineated on the ultrasound image. Nine models were developed to predict high ALN tumor burden, employing a combination of three feature screening methods and three machine learning classifiers. Ultimately, the optimal model was selected and tested on both the validation and testing sets. In addition, clinical characteristics were screened to develop a clinical model. Furthermore, Shapley additive explanations (SHAP) values were utilized to provide explanations for the machine learning model.

RESULTS

During the validation and testing sets, the models demonstrated area under the curve (AUC) values ranging from 0.577 to 0.733 and 0.583 to 0.719, and accuracies ranging from 64.9% to 75.7% and 64.7% to 70.6%, respectively. Ultimately, the Boruta_XGB model, comprising five radiomics features, was selected as the final model. The AUC values of this model for distinguishing low from high tumor burden were 0.828, 0.715, and 0.719 in the training, validation, and testing sets, respectively, demonstrating its superiority over the clinical model.

CONCLUSIONS

The developed radiomics models exhibited a significant level of predictive performance. The Boruta_XGB radiomics model outperformed other radiomics models in this study.

Sentinel lymph node biopsy versus axillary lymph node dissection in breast cancer patients undergoing mastectomy

Axillary lymph node dissection (ALND) has been a cornerstone of breast cancer (BC) treatment, traditionally ensuring loco-regional control but associated with significant morbidity. Recent advancements suggest sentinel lymph node biopsy (SLNB) as a less invasive alternative. This review examines the outcomes of omitting ALND in BC patients with positive sentinel lymph nodes (SLNs) undergoing mastectomy. We conducted a comprehensive review of historical comparative studies and pivotal randomized clinical trials. Key sources included the ACOSOG Z0011 and SINODAR-ONE trials, alongside retrospective studies and ongoing trials like SENOMAC and POSNOC. Historical studies predominantly focused on patients undergoing breast-conserving surgery, revealing low recurrence rates and comparable survival outcomes between SLNB alone and ALND. Retrospective analyses of mastectomy patients indicated that omitting ALND did not significantly impact recurrence-free survival (RFS) or overall survival (OS). The SINODAR-ONE trial sub-analysis, involving 218 mastectomy patients, found no significant differences in 5-year OS and RFS between ALND and SLNB groups. The SENOMAC trial similarly showed non-inferior outcomes for mastectomy patients treated without ALND. The ongoing POSNOC trial aims to provide further insights, particularly focusing on the subgroup of mastectomy patients. Emerging evidence supports the feasibility of omitting ALND in BC patients with positive SLNs undergoing mastectomy, potentially reducing surgical morbidity without compromising oncological outcomes. However, further randomized clinical trials are essential to confirm these findings and refine treatment guidelines, ensuring optimal patient care.

The role of multiparametric MRI in predicting lymphovascular invasion in breast cancer patients

Background: This study aims to investigate the efficacy of multifactorial MRI in diagnosing breast cancer, specifically in the context of predicting lymphovascular invasion (LVI).Materials & methods: The patients were stratified into two groups: the primary group (100 patients) and the validation group (100 patients), based on essential characteristics. Multifactorial MRI, encompassing tumor size evaluation, diffusion coefficient assessment and dynamic contrast enhancement, was employed for patient examination.Results: Statistically significant differences were observed in tumor size, diffusion coefficient and dynamic contrast enhancement between groups with LVI (LVI+) and those without (LVI-). Key parameters were identified for predicting the degree of invasion.Conclusion: The results affirm the effectiveness of multifactorial MRI in forecasting LVI.

Abemaciclib Therapy Using the MonarchE Criteria Results in Large Numbers of Excess Axillary Node Clearances-Time to Pause and Reflect?

The monarchE study added the CDK4/6 inhibitor abemaciclib to the care of women with oestrogen-positive (ER+) breast cancers. Eligibility required meeting monarchE criteria-either >3 positive axillary nodes, or 1-3 positive sentinel nodes (SNB+) with tumour size >50 mm or grade 3 cancers. Women were advised to proceed to completion axillary node clearance (cANC) if size/grade criteria were not fulfilled for >3 positive nodes to be identified. However, cANC is associated with significant morbidity, conflicting with the potential benefits of abemaciclib. We analysed data of 229 consecutive women (2016-2022) with ER+ breast cancer and SNB+ who proceeded to cANC, keeping with contemporary treatment guidelines. We used this cohort to assess numbers that, under national guidance in place currently, would be advised to undergo cANC solely to check eligibility for abemaciclib treatment. Using monarchE criteria, 90 women (39%) would have accessed abemaciclib based on SNB+ and size/grade, without cANC. In total, 139 women would have been advised to proceed to cANC to check eligibility, with only 15/139 (11%) having >3 positive nodes after sentinel node biopsy and cANC. The remaining 124 (89%) would have undergone cANC but remained ineligible for abemaciclib. Size, age, grade, and Ki67 did not predict >3 nodes at cANC. Following cANC, a large majority of women with ER+, <50 mm, and grade 1-2 tumours remain ineligible for abemaciclib yet are subject to significant morbidity including lifelong lymphoedema risk. The monarchE authors state that 15 women need abemaciclib therapy for 1 to clinically benefit. Thus, in our cohort, 139 women undergoing cANC would lead to one woman benefitting.

Omission of axillary surgery in cN0, postmenopausal ER-positive/HER2-negative breast cancer patients undergoing breast-conserving treatment

Background

Previous clinical trials have diminished the significance of lymph node (LN) metastasis and axillary surgery in breast cancer, particularly in cN0, postmenopausal estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative patients undergoing breast-conserving treatment (BCT). We assessed the replacement of axillary surgery with preoperative imaging modalities by analyzing the proportion of high nodal burden (HNB) patients with ≥3 LN metastases in these patients.

Methods

We retrospectively identified 333 cN0, postmenopausal ER-positive/HER2-negative breast cancer patients who underwent BCT in two hospitals between January 2003 and December 2017. The proportion of LN metastasis patients and the number of metastatic LN were investigated. Risk factors of LN metastasis were analyzed and recurrence-free survival (RFS) was compared.

Results

Axillary surgery confirmed LN metastasis in 81 (24.3%) of the cN0 patients. The clinical tumor size (cT) and age were factors associated with LN metastasis [cT: odds ratio (OR), 2.92, 95% confidence interval (CI): 1.69-5.05, P<0.001; age: OR, 0.33, 95% CI: 0.11-0.99, P=0.048]. However, HNB patients with ≥3 LN metastases were 15 (4.5%) of all the patients. There was statistically significant difference in the incidence of HNB between patients with cT1 tumors (3.6%) and those with cT2 tumors (7.4%) (P<0.001).

Conclusions

In cN0, postmenopausal ER-positive/HER2-negative patients who underwent BCT, patients with cT1 tumors had lower rate of LN metastasis, and there were fewer instances of HNB. Therefore, in these patients, omission of axillary surgery including SLNB can be carefully considered.

New Insight for Axillary De-Escalation in Breast Cancer Surgery: "SoFT Study" Retrospective Analysis

Background: The SOUND study demonstrated that an axillary de-escalation may be sufficient in locoregional and distant disease control in selected early breast cancer (EBC) patients. To establish any preoperative variables that may drive sentinel lymph node biopsy (SLNB) omission, a study named sentinel omission risk factor (SOFT) 1.23 was planned. Methods: A single-center retrospective study from a prospectively maintained database was designed, aiming at underlying preoperative prognostic factors involved in sentinel lymph node (SLN) metastasis (lymph node involvement (LN+) vs. negative lymph node (LN-) group). Secondary outcomes included surgical room occupancy analysis for SLNB in patients fulfilling the SOUND study inclusion criteria. The institutional ethical committee Area Territoriale Lazio 2 approved the study (n° 122/23). Results: Between 1 January 2022 and 30 June 2023, 160 patients were included in the study and 26 (%) were included in the LN+ group. Multifocality, higher cT stage, and larger tumor diameter were reported in the LN+ group (p = 0.020, p = 0.014, and 0.016, respectively). Tumor biology, including estrogen and progesterone receptors, and molecular subtypes showed association with the LN+ group (p < 0.001; p = 0.001; and p = 0.001, respectively). A total of 117 (73.6%) patients were eligible for the SOUND study and the potential operating room time saved was 2696.81 min. Conclusions: De-escalating strategies may rationalize healthcare activities. Multifactorial risk stratification may further refine the selection of patients who could benefit from SLNB omission.

Early Stage Breast Cancer: Does Histologic Subtype (Ductal vs. Lobular) Impact 5 Year Overall Survival?

Histology is an important predictor of the behavior of breast cancer. We aim to study the impact of histology on the overall survival (OS) of breast cancer patients. We studied 11,085 breast cancer patients diagnosed with T1-T2 tumors, clinically node-negative and non-metastatic, from 2004 to 2019 included in the National Cancer Database. Kaplan-Meier curves, log-rank tests and Cox regression models were used to study the impact of histology and other variables on OS. In our patient population, 8678 (78.28%) had ductal cancer (IDC), while 2407 (21.71%) had lobular cancer (ILC). ILC patients were significantly more likely to be older, Caucasian, have a lower grade at diagnosis and be hormone receptor-positive compared to IDC patients. There was no statistically significant difference in the 5-year OS of early stage ductal (16.8%) and lobular cancer patients (16.7%) (p = 0.200). Patients of Hispanic and African American origin had worse OS rates compared to non-Hispanic and Caucasian patients, respectively. For node-positive disease, HER2+ tumors and triple-negative tumors, chemotherapy had a positive influence on OS (HR 0.85, 95% CI 0.77-0.93, p = 0.0012). Histology did not have a significant impact on the 5-year OS of early stage breast cancer patients.