Omission of Axillary Dissection Following Nodal Downstaging With Neoadjuvant Chemotherapy.

Importance: Data on oncological outcomes after omission of axillary lymph node dissection (ALND) in patients with breast cancer that downstages from node positive to negative with neoadjuvant chemotherapy are sparse. Additionally, the best axillary surgical staging technique in this scenario is unknown. Objective: To investigate oncological outcomes after sentinel lymph node biopsy (SLNB) with dual-tracer mapping or targeted axillary dissection (TAD), which combines SLNB with localization and retrieval of the clipped lymph node. Design, Setting, and Participants: In this multicenter retrospective cohort study that was conducted at 25 centers in 11 countries, 1144 patients with consecutive stage II to III biopsy-proven node-positive breast cancer were included between April 2013 and December 2020. The cumulative incidence rates of axillary, locoregional, and any invasive (locoregional or distant) recurrence were determined by competing risk analysis. Exposure: Omission of ALND after SLNB or TAD. Main Outcomes and Measures: The primary end points were the 3-year and 5-year rates of any axillary recurrence. Secondary end points included locoregional recurrence, any invasive (locoregional and distant) recurrence, and the number of lymph nodes removed. Results: A total of 1144 patients (median [IQR] age, 50 [41-59] years; 78 [6.8%] Asian, 105 [9.2%] Black, 102 [8.9%] Hispanic, and 816 [71.0%] White individuals; 666 SLNB [58.2%] and 478 TAD [41.8%]) were included. A total of 1060 patients (93%) had N1 disease, 619 (54%) had ERBB2 (formerly HER2)-positive illness, and 758 (66%) had a breast pathologic complete response. TAD patients were more likely to receive nodal radiation therapy (85% vs 78%; P = .01). The clipped node was successfully retrieved in 97% of TAD cases and 86% of SLNB cases (without localization). The mean (SD) number of sentinel lymph nodes retrieved was 3 (2) vs 4 (2) (P < .001), and the mean (SD) number of total lymph nodes removed was 3.95 (1.97) vs 4.44 (2.04) (P < .001) in the TAD and SLNB groups, respectively. The 5-year rates of any axillary, locoregional, and any invasive recurrence in the entire cohort were 1.0% (95% CI, 0.49%-2.0%), 2.7% (95% CI, 1.6%-4.1%), and 10% (95% CI, 8.3%-13%), respectively. The 3-year cumulative incidence of axillary recurrence did not differ between TAD and SLNB (0.5% vs 0.8%; P = .55). Conclusions and Relevance: The results of this cohort study showed that axillary recurrence was rare in this setting and was not significantly lower after TAD vs SLNB. These results support omission of ALND in this population.

Safety and effectiveness of sacituzumab govitecan in patients with metastatic triple-negative breast cancer in real-world settings: first observations from an interdisciplinary breast cancer centre in Germany.

Background: Sacituzumab govitecan has been recently approved by the USFDA and EMA for the treatment of patients with metastatic triple-negative breast cancer (mTNBC). We report real-world safety and effectiveness in patients with mTNBC receiving sacituzumab govitecan treatment at a breast cancer centre in Germany. Methods: Data from patients who had received sacituzumab govitecan as treatment for mTNBC, in both de novo and relapsed disease, at the Kliniken Essen-Mitte, Essen, Germany, were collected through institutional records. Data were analysed for safety parameters and survival outcomes and reported using descriptive statistics. Results: Patients (N = 43) received a median (range) of 5 (1-28) cycles of sacituzumab govitecan and were followed up for a median of 12.9 months. The most reported adverse events (AEs) of any grade were alopecia (n = 39; 90.7%), diarrhoea (n = 16; 37.2%), fatigue (n = 15, 34.9%), anaemia (n = 15, 34.9%) and neutropenia (n = 14, 32.6%). AEs ⩾ Grade 3 with the highest incidence were neutropenia (n = 12; 27.9%) and diarrhoea (n = 8; 18.6%). In eight (18.6%) patients, dose of sacituzumab govitecan dose was reduced due to patients' clinical condition prior to commencing treatment; in further 17 (39.5%) patients, sacituzumab govitecan dose had to be reduced or treatment interrupted on account of AEs associated with the drug after treatment had commenced. Median progression-free survival and median overall survival were calculated to be 5.0and 13.1 months, respectively. Conclusion: The real-world safety and effectiveness profile of sacituzumab govitecan in patients with mTNBC are in line with clinical trial data. Further studies are required to guide optimal use of sacituzumab govitecan against mTNBC, especially in context of management of accompanying AEs.

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.

Prognostic and predictive impact of gene expression in node-positive early breast cancer patients receiving dose-dense versus standard-dose adjuvant chemotherapy.

The utility of multigene expression assays in advanced (≥ 4 positive lymph nodes) early breast cancer (EBC) is limited. We conducted exploratory transcriptomic analysis of 758 genes (Breast Cancer 360 panel, nCounter® platform; NanoString) in primary tumor samples collected during a phase 3 trial comparing adjuvant taxane-containing dose-dense chemotherapy (ddCTX) versus standard-dosed chemotherapy (stCTX) in resected EBC with ≥ 4 positive lymph nodes. Prognostic and predictive associations with disease-free survival (DFS) and overall survival (OS) were evaluated by Cox regression with false discovery rate (FDR) adjustment. Data were available from tumor samples of 141/226 patients (median follow-up: 14 years). Several genes/signatures, including immune markers, showed prognostic relevance in unadjusted analyses. Of these, two remained significant after multiplicity adjustment: a positive effect on DFS of programmed cell death 1 ligand-2 (PD-L2) in the ddCTX arm (univariate HR: 0.53, FDR-adjusted P = 0.036) and a negative effect on OS of HER2-enriched (HER2-E) signature in the stCTX arm (univariate HR: 5.40, FDR-adjusted P = 0.036). Predictive analyses showed greater DFS benefit of ddCTX in tumors with high antigen processing machinery (APM) expression (multivariate interaction P = 0.024). Multigene expression assays have a prognostic and predictive potential in advanced EBC, and further investigation is warranted in order to identify candidates for de-escalated treatment. In addition, intrinsic subtype and immune gene expression have predictive potential.

Gene signatures in patients with early breast cancer and relapse despite pathologic complete response.

A substantial minority of early breast cancer (EBC) patients relapse despite their tumors achieving pathologic complete response (pCR) after neoadjuvant therapy. We compared gene expression (BC360; nCounter® platform; NanoString) between primary tumors of patients with post-pCR relapse (N = 14) with: (i) matched recurrent tumors from same patient (intraindividual analysis); and (ii) primary tumors from matched controls with pCR and no relapse (N = 41; interindividual analysis). Intraindividual analysis showed lower estrogen receptor signaling signature expression in recurrent tumors versus primaries (logFC = -0.595; P = 0.022). Recurrent tumors in patients with distant metastases also exhibited reduced expression of immune-related expression parameters. In interindividual analyses, primary tumor major histocompatibility complex class II expression was lower versus controls in patients with any relapse (logFC = -0.819; P = 0.030) or distant relapse (logFC = -1.151; P = 0.013). Primaries with later distant relapse also had greater homologous recombination deficiency than controls (logFC = 0.649; P = 0.026). Although no associations remained statistically significant following adjustment for false discovery rate, our results show that transcriptomic analyses have potential for prognostic value and may help in selecting optimal treatment regimens for EBC at risk of relapse and warrant further investigation.

Next-Generation Sequencing-Directed Therapy in Patients with Metastatic Breast Cancer in Routine Clinical Practice.

Next-generation sequencing (NGS) followed by matched therapy has opened up new therapeutic options to patients with metastatic breast cancer (mBC). Here we report our experience with this approach in everyday clinical practice. This retrospective study included 95 patients with mBC who were genotyped with the FoundationOne® (CDx) assay in a commercial molecular pathology laboratory. Genetic alterations were identified in all tumor specimens, and 83 patients (87.4%) had a median of 2 (range, 1-6) potentially actionable alterations. A multidisciplinary tumor board recommended genomically guided therapy to 63 patients, 30 of whom received such treatment. Everolimus (n = 15) and anti-human epidermal growth factor receptor 2 (HER2) therapy (n = 6) were most frequently administered. The ratio of progression-free survival (PFS) under NGS-based therapy to PFS under the last line of standard therapy prior to NGS was >1.3 in 13 (43.3%) patients, indicative of a clinical benefit to NGS-directed therapy. One-year overall survival rates were 22.7% (95% CI, 6.5-44.4) in 65 patients allocated to the standard therapy versus 62.9% (95% CI, 41.6-78.2) in 30 patients receiving the matched therapy. In conclusion, NGS-matched treatment improved the clinical outcomes in a subgroup of mBC patients.

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.