A Prospective, Multicenter Registry Study to Evaluate the Clinical Feasibility of Targeted Axillary Dissection (TAD) in Node-positive Breast Cancer Patients.

OBJECTIVE: This study aimed to investigate the feasibility and accuracy of non-radioactive TLN biopsy and TAD in routine clinical practice. BACKGROUND DATA: TAD involves TLN biopsy (TLNB) and sentinel lymph node biopsy and was recently introduced as a new standard for less invasive axillary staging in BC patients undergoing neoadjuvant systemic therapy (NST); however, clinical evidence is limited. METHODS: The SenTa study is a prospective registry study conducted at 50 centers. Patients with invasive BC who nderwent clip insertion into the most suspicious axillary lymph node were eligible. Axillary surgery was performed with or without sentinel lymph node biopsy, TLNB, and/or axillary lymph node dissection (ALND). Main endpoints were the detection rate and FNR of TLNB and TAD after NST. RESULTS: Between 2017 and 2018, 548 consecutive BC patients underwent clip placement into biopsy-confirmed positive lymph nodes. After NST (n = 473), the clipped TLN was intraoperatively resected in 329 of 423 patients [77.8%, 95% confidence interval (CI): 74.0-82.0]. TAD was successful in 199 of 229 patients (detection rate: 86.9%, 95% CI: 81.8-91.0), the SLN and TLN were identical in 129 patient (64.8%). FNRs were 7.2% (8 of 111, 95% CI: 3.1-13.6) for TLNB followed by ALND (n = 203) and 4.3% (2 of 46, 95% CI: 0.5-14.8) for TAD followed by ALND (n = 77). CONCLUSIONS: The SenTa study demonstrates the feasibility of TAD in a real-world cohort of BC patients. Our findings are of great importance for de-escalation of surgical strategies.

Safety of Targeted Axillary Dissection After Neoadjuvant Therapy in Patients With Node-Positive Breast Cancer.

Importance: The increasing use of neoadjuvant systemic therapy (NST) has led to substantial pathological complete response rates in patients with initially node-positive, early breast cancer, thereby questioning the need for axillary lymph node dissection (ALND). Targeted axillary dissection (TAD) is feasible for axillary staging; however, data on oncological safety are scarce. Objective: To assess 3-year clinical outcomes in patients with node-positive breast cancer who underwent TAD alone or TAD with ALND. Design, Setting, and Participants: The SenTa study is a prospective registry study and was conducted between January 2017 and October 2018. The registry includes 50 study centers in Germany. Patients with clinically node-positive breast cancer underwent clipping of the most suspicious lymph node (LN) before NST. After NST, the marked LNs and sentinel LNs were excised (TAD) followed by ALND according to the clinician's choice. Patients who did not undergo TAD were excluded. Data analysis was performed in April 2022 after 43 months of follow-up. Exposure: TAD alone vs TAD with ALND. Main Outcomes and Measures: Three-year clinical outcomes were evaluated. Results: Of 199 female patients, the median (IQR) age was 52 (45-60) years. A total of 182 patients (91.5%) had 1 to 3 suspicious LNs; 119 received TAD alone and 80 received TAD with ALND. Unadjusted invasive disease-free survival was 82.4% (95% CI, 71.5-89.4) in the TAD with ALND group and 91.2% (95% CI, 84.2-95.1) in the TAD alone group (P = .04); axillary recurrence rates were 1.4% (95% CI, 0-54.8) and 1.8% (95% CI, 0-36.4), respectively (P = .56). Adjusted multivariate Cox regression indicated that TAD alone was not associated with an increased risk of recurrence (hazard ratio [HR], 0.83; 95% CI, 0.34-2.05; P = .69) or death (HR, 1.07; 95% CI, 0.31-3.70; P = .91). Similar results were obtained for 152 patients with clinically node-negative breast cancer after NST (invasive disease-free survival: HR, 1.26; 95% CI, 0.27-5.87; P = .77; overall survival: HR, 0.81; 95% CI, 0.15-3.83; P = .74). Conclusions and Relevance: These results suggest that TAD alone in patients with mostly good clinical response to NST and at least 3 TAD LNs may confer survival outcomes and recurrence rates similar to TAD with ALND.

Two progressed malignant phyllodes tumors of the breast harbor alterations in genes frequently involved in other advanced cancers.

BACKGROUND: The genomic landscape of phyllodes tumors (PTs) of the breast is not well defined, especially in patients with advanced disease. To shed light on this topic, paired primary and progressed tumor samples from two patients with malignant PTs were subjected to next-generation sequencing (NGS) followed by functional analysis of genetic alterations using two prediction tools. METHODS: The DNA of both the primary tumor and distant metastases of Patient 1 and the primary and recurrent tumor of Patient 2 were subjected to molecular profiling. NGS with the FoundationOne® assay was performed in a commercial molecular pathology laboratory. Two in silico prediction tools were used to estimate the pathogenicity of indicated genetic alterations. RESULTS: In total, 38 genomic alterations were detected, of which 11 were predicted to be probably benign. In Patient 1, 14 aberrations were identified in the primary tumor and 17 in pulmonary metastases, 12 of which were identical. In the primary and recurrent tumor of Patient 2, 17 and 15 sequence variants, respectively, were found, with 13 overlapping findings. Affected genes included seven (TP53, TERT, APC, ARID1A, EGFR, KMT2D, and RB1) of the top 10 most frequently altered genes in other advanced cancer entities, as well as four actionable therapeutic targets (EGFR, KIT, PDGFRA, and BRIP1). Of note, seven genes coding for receptor tyrosine kinases were affected: three in Patient 1 and four in Patient 2. Several genes (e.g. EPHA3, EPHA7, and EPHB1) were shown to be altered for the first time in PTs. CONCLUSIONS: The two progressed malignant PTs investigated here share some of the major genetic events occurring in other advanced cancers.