Outcomes of sentinel node biopsy according to MRI response in an association with the subtypes in cN1-3 breast cancer after neoadjuvant systemic therapy, multicenter cohort study.

BACKGROUND: This study investigated the feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant systemic therapy (NAST) in patients with initially high nodal burden. METHODS: In the multicenter retrospective cohort, 388 individuals with cN1-3 breast cancer who underwent NAST and had SLNB followed by completion axillary lymph node dissection were included. In an external validation cohort, 267 patients with HER2+ or triple-negative breast cancer (TNBC) meeting similar inclusion criteria were included. Primary outcome was the false-negative rates (FNRs) of SLNB according to the MRI response and subtypes. We defined complete MRI responders as patients who experienced disappearance of suspicious features in the breast and axilla after NAST. RESULTS: In the multicenter retrospective cohort, 130 (33.5%) of 388 patients were of cN2-3, and 55 (14.2%) of 388 patients showed complete MRI responses. In hormone receptor-positive HER2- (n = 207), complete and non-complete responders had a high FNRs (31.3% [95% CI 8.6-54.0] and 20.9% [95% CI 14.1-27.6], respectively). However, in HER2+ or TNBC (n = 181), the FNR of complete MRI responders was 0% (95% CI 0-0), whereas that of non-complete responders was 33.3% (95% CI 20.8-45.9). When we validated our findings in the external cohort with HER2+ or TNBC (n = 267), of which 34.2% were cN2-3, the FNRs of complete were 7.1% (95% CI 0-16.7). CONCLUSIONS: Our findings suggest that SLNB can be a reliable option for nodal status evaluation in selected patients who have responded well to NAST, especially in HER2+ and TNBC patients who show a complete MRI response.

Oncological Safety of Skipping Axillary Lymph Node Dissection in Patients with Clinical N0, Sentinel Node-Positive Breast Cancer Undergoing Total Mastectomy.

OBJECTIVE: This study aimed to determine whether sentinel lymph node biopsy (SLNB) alone could afford oncological outcomes comparable with axillary lymph node dissection (ALND) in patients with early breast cancer without palpable lymphadenopathy who underwent total mastectomy (TM) and were SLN-positive. METHODS: This study analyzed clinical data of 6747 patients with breast cancer who underwent TM between 2014 and 2018 in two tertiary hospitals in Korea. Overall, 643 clinical stage T1-3 N0 patients who did not receive neoadjuvant therapy and had one to two metastatic SLNs at the time of surgery were included. Propensity score matching was performed between the SLNB alone and ALND groups, adjusting for clinical T stage and number of metastatic SLNs. In total, 237 patients were allocated to each group. RESULTS: Mean number of metastatic SLNs was 1.2 for the SLNB group and 1.6 for the ALND group. With a median follow-up of 65.0 months, 5 year disease-free survival was 90.8% for the SLNB group and 93.9% for the ALND group (hazard ratio [HR] 1.35, 95% confidence interval [CI] 0.70-2.58; p = 0.36). 5 year ipsilateral locoregional recurrence-free survival (LRRFS) was not significantly different between the two groups (95.1% and 98.3% for the SLNB and ALND groups, respectively) [HR 1.86, 95% CI 0.69-5.04; p = 0.21]. In the SLNB group, patients who received radiation therapy (RT) showed superior 5 year LRRFS than patients who did not receive RT (100% vs. 92.9%; p = 0.02). CONCLUSION: Collectively, our findings suggest that SLNB could afford comparable outcomes to ALND in patients with early breast cancer and one to two metastatic SLNs who underwent TM. Importantly, RT could decrease locoregional recurrence in patients who underwent SLNB alone.

A Comparison of the Prognostic Effects of Fine Needle Aspiration and Core Needle Biopsy in Patients with Breast Cancer: A Nationwide Multicenter Prospective Registry.

(1) Background: Breast core needle biopsy (CNB) is preferred over fine needle aspiration (FNA) as it has higher sensitivity and specificity and enables immunohistochemical evaluation. However, breast FNA remains widely used because of its low cost, minimally invasive nature, and quick results. Studies analyzing the effects of each test on the prognoses of patients with breast cancer are scarce and controversial, and the criteria for test selection remain unknown. (2) Methods: This study included adult female patients who underwent breast cancer surgery at 102 general hospitals. The trend of breast biopsies over time was analyzed, and the prognoses of patients with breast cancer who underwent CNB and FNA were compared. (3) Results: This study included 73,644 patients who underwent FNA (n = 8027) and CNB (n = 65,617). A multivariate Cox regression analysis showed that patients diagnosed using FNA had significantly worse overall survival (OS) and breast-cancer-specific survival (BCSS) than those diagnosed using CNB. In the subgroup analysis, patients with breast imaging reporting and data system (BI-RADS) 5 lesions, palpable tumors, or centrally located tumors had significantly worse OS and BCSS with FNA than with CNB. (4) Conclusions: CNB should be performed preferentially instead of FNA in patients with BI-RADS 5 lesions and nonpalpable or centrally located tumors.

Non-sentinel node metastasis prediction during surgery in breast cancer patients with one to three positive sentinel node(s) following neoadjuvant chemotherapy.

Our aim was to develop a tool to accurately predict the possibility of non-sentinel lymph node metastasis (NSLNM) during surgery so that a surgeon might decide the extent of further axillary lymph node dissection intraoperatively for patients with 1-3 positive sentinel lymph node(s) (SLN) after neoadjuvant chemotherapy. After retrospective analysis of Asan Medical Center (AMC) database, we included 558 patients' records who were treated between 2005 and 2019. 13 factors were assessed for their utility to predict NSLNM with chi-square and logistic regression with a bootstrapped, backward elimination method. Based on the result of the univariate analysis for statistical significance, number of positive SLN(s), number of frozen nodes, Progesterone Receptor (PR) positivity, clinical N stage were selected for the multivariate analysis and were utilized to generate a nomogram for prediction of residual nodal disease. The resulting nomogram was tested for validation by using a patient group of more recent, different time window at AMC. We designed a nomogram to be predictive of the NSLNM which consisted of 4 components: number of SLN(s), number of frozen nodes, PR positivity, and clinical N stage before neoadjuvant chemotherapy. The Area under the receiver operating characteristics curve (AUC) value of this formula was 0.709 (95% CI, 0.658-0.761) for development set and 0.715 (95% CI, 0.634-0.796) for validation set, respectively. This newly created AMC nomogram may provide a useful information to a surgeon for intraoperative guidance to decide the extent of further axillary surgery.

Surgical margin status and survival outcomes of breast cancer patients treated with breast-conserving surgery and whole-breast irradiation after neoadjuvant chemotherapy.

PURPOSE: The definition of "no tumor on ink" is generally applied for clear resection margin (RM) after breast-conserving surgery (BCS). However, few studies reported the effect of RM in the setting of neoadjuvant chemotherapy (NAC). We investigated the association between RM status and survival outcomes for those who underwent BCS after NAC for breast cancer. METHODS: We retrospectively reviewed the data of 2,803 patients who underwent BCS and whole-breast irradiation after NAC between January 2008 and December 2016 from three institutions in South Korea. RESULTS: The 786 patients in the pathologic complete response group (RpCR) had significantly longer local recurrence-free survival (LRFS) than the 1,949 patients in clear or close RM and non-pCR group (R0) and the 68 patients in involved RM and non-pCR group (R1) (vs. R0, p = 0.001; vs. R1, p = 0.049). Patients in R0 showed no benefit in LRFS compared to R1 on both log-rank test (HR = 1.20; 95% C.I., 0.49-2.93; p = 0.692) and Cox regression analysis (HR = 2.05; 95% C.I., 0.64-6.58; p = 0.227). Subgroup analysis according to tumor subtypes revealed that there was no significant difference in LRFS, distant metastasis-free survival, and recurrence-free survival between the R0 and R1 group. Additionally, among 286 patients with pCR with residual ductal carcinoma in situ (DCIS) alone, RM status was not significantly associated with LRFS. CONCLUSION: Clear RM of specimen does not have benefit on LRFS after NAC. Additionally, for the patients showing pCR with residual DCIS in the breast, margin involvement also did not affect the risk of local recurrence.

Comparison of survival outcomes for axillary surgery extent based on intraoperative sentinel lymph node biopsy result after neoadjuvant chemotherapy for breast cancer.

PURPOSE: To investigate the survival difference between limited axillary surgery and full axillary lymph node dissection (ALND) in patients with 1-3 positive sentinel lymph node biopsies (SLNBs) after neoadjuvant chemotherapy (NAC). METHOD: We retrospectively analyzed data from 676 patients who underwent surgery between 2007 and 2017 with cT1-4, cN0-3, cM0 breast cancer at the time of diagnosis and 1-3 positive SLNBs after NAC. The patients received either SLNB only or completed level I or II ALND based on SLNB results. After propensity score matching, 483 patients who had undergone SLNB only (n = 188) and ALND (n = 295) were included. We examined overall survival, axillary recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival and compared them between the subgroups. RESULT: At a median follow-up of 59.4 months, no significant statistical difference was observed in overall survival, axillary recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival between SLNB only and ALND. No significant differences were observed in the 5-year axillary recurrence-free survival (93.1% vs. 94.0%, hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.43-2.05, p = 0.876) and 5-year overall survival (97.7% vs. 97.3%, HR = 1.65, 95% CI = 0.58-4.65, p = 0.347) between the two groups. CONCLUSION: Our analysis suggests that SLNB alone may be a possible option for patients with 1-3 sentinel node-positive breast cancer following NAC without significant compromise of recurrence or overall survival.

Sentinel node biopsy alone for breast cancer patients with residual nodal disease after neoadjuvant chemotherapy.

For residual N1 nodal disease following neoadjuvant chemotherapy (NAC) for patients with breast cancer, the optimal local therapy for axilla is an evolving area. We analyzed the long-term results of these patients according to axillary surgical methods using propensity score matching (PSM) to clarify whether omission of axillary lymph node dissection (ALND) is oncologically safe. This was a single institution retrospective study of patients with ypN1 from Asan Medical Center (AMC). We included 324 patients who had undergone axillary surgery with either sentinel lymph node biopsy (SLNB) only or ALND. The patients received NAC at AMC between 2008 and 2013. General indications for ALND included prominent nodes detected clinically before NAC, evident macrometastasis on multiple nodes during SLNB. Patients who had either micrometastasis or macrometastasis in 1 or 2 node(s) were included. SLNB was performed for patients with good responders to NAC with limited nodal burden. Patients were matched for baseline characteristics. After matching, we included 98 patients in each SLNB only group and ALND group respectively. We compared axillary recurrence-free survival (ARFS), distant metastasis-free survival (DMFS), overall survival (OS), and breast cancer-free survival (BCSS) according to the surgical method. The median follow-up period was 71 months. Univariate and multivariate analyses revealed no statistically significant differences between the two groups for ARFS, DMFS, OS, and BCSS. After the propensity score matching, no significant statistical differences were observed in 5-year ARFS, DMFS, OS, and BCSS between the SLNB only group and ALND group. SLNB might be a possible option for ALND in patients with breast cancer who have limited axillary node metastasis after NAC without compromising survival outcomes.

Usefulness of 3-Dimensional-Printed Breast Surgical Guides for Undetectable Ductal Carcinoma In Situ on Ultrasonography: A Report of 2 Cases.

Tumor localization is challenging in the context of ductal carcinoma in situ (DCIS) treated with breast-conserving surgery. Conventional localization methods are generally performed under the guidance of ultrasonography or mammography and are rarely performed with magnetic resonance imaging (MRI), which is more sensitive than the aforementioned modalities in detecting DCIS. Here, we report the application of MRI-based individualized 3-dimensional (3D)-printed breast surgical guides (BSGs) for patients with breast cancer. We successfully resected indeterminate and suspicious lesions that were only detected using preoperative MRI, and the final histopathologic results confirmed DCIS with clear resection margins. MRI guidance combined with 3D-printed BSGs can be used for DCIS localization, especially for lesions easily detectable using MRI only.