Background/Aim: Sentinel lymph node biopsy (SLNB) has become the standard procedure for axillary staging in clinically node-negative breast cancer. Traditionally, axillary lymph node dissection (ALND) has been performed when intraoperative pathological assessment revealed sentinel lymph node (SLN) metastasis. However, growing evidence suggests that postoperative radiotherapy and systemic therapy may safely replace ALND in selected patients, challenging the clinical necessity of intraoperative SLNB assessment. Patients and Methods: We retrospectively reviewed 540 patients with stage I-III primary breast cancer who underwent curative surgery and SLNB without intraoperative pathological evaluation between January 2018 and December 2021. Clinicopathological characteristics, adjuvant treatment strategies, and survival outcomes were analyzed, with a focus on patients with SLN metastases. Results: SLN metastases were identified in 87 patients. Postoperative management consisted of ALND (n=19), axillary radiotherapy (n=39), systemic therapy alone (n=28), or no further treatment (n=1). Patients undergoing ALND showed a significantly higher recurrence rate compared with other treatment groups (p=0.028, log-rank), though ALND was more commonly performed in those with ≥3 positive SLNs or after mastectomy (p<0.001). In a high-risk subgroup of 31 patients not fulfilling ALND omission criteria, recurrence-free survival did not significantly differ between ALND and non-ALND groups (p=0.209, log-rank). Multivariate analysis confirmed that omission of ALND was not an independent prognostic factor for recurrence (hazard ratio=0.29; 95% confidence interval=0.03-2.39; p=0.248). Conclusion: In the era of effective adjuvant radiotherapy and systemic therapy, the indications for omitting ALND may be further extended even to higher-risk patients. These results highlight the diminishing role of intraoperative pathological assessment of SLNB in contemporary breast cancer management.

Background/Aim: Residual disease after neoadjuvant systemic therapy (NST) is strongly associated with prognosis in breast cancer. However, currently available indices such as the Residual Cancer Burden (RCB) and Neo-Bioscore are complex and not readily applicable in daily clinical practice. This study aimed to evaluate the prognostic significance of residual tumor morphology using only pathological T and N factors as a simple and clinically implementable index. Patients and Methods: Among 327 patients who received NST at our institution, 174 non-pathological complete response (non-pCR) cases who underwent axillary lymph node dissection were analyzed. Patients were classified according to the presence or absence of residual T and/or N factors (ypT+/ypN+, ypT+/ypN−, ypT−/ypN+). Disease-free survival (DFS) and cancer-specific survival (CSS) were assessed using Kaplan–Meier and Cox regression analyses. Results: Patients who achieved pCR had significantly better DFS and CSS (p<0.001 and p=0.010, log-rank) than those with residual disease. Among the non-pCR cohort, the ypT+/ypN+ group showed markedly worse DFS and CSS (p= 0.010 and p<0.001, log-rank) than patients without simultaneous residual T and N positivity. Multivariate analysis confirmed that concurrent ypT and ypN positivity was an independent predictor of poor DFS (hazard ratio=0.33; 95% confidence interval=0.17-0.62; p<0.001), along with high Ki67 expression. Conclusion: Residual T and N positivity after NST represents a simple yet powerful prognostic indicator in breast cancer. This two-factor classification, easily derived from routine pathology, may serve as a practical reference for post-NST risk stratification and inform decisions regarding additional adjuvant treatment.

Background/Aim: The Oncotype DX Recurrence Score (RS) is widely implemented to guide adjuvant chemotherapy in early hormone receptor-positive (HR+)/HER2− breast cancer. However, discordance between RS and conventional clinicopathological risk assessment (clinical risk, CR) remains a significant clinical challenge, particularly in real-world practice. Patients and Methods: We retrospectively analyzed 216 consecutive patients with early HR+/HER2− breast cancer who underwent Oncotype DX testing at Osaka Metropolitan University Hospital. CR was defined according to the St. Gallen criteria, and patients were categorized into four groups: RS-low/CR-low, RS-high/CR-high, RS-low/CR-high, and RS-high/CR-low. The concordance/discordance between RS and CR, their associations with clinicopathological features, and the impact on adjuvant chemotherapy decisions were evaluated. Results: Concordance was observed in 122 patients (56.5%), consisting of 93 (43.1%) with RS-low/CR-low and 29 (13.4%) with RS-high/CR-high. Discordance was found in 94 patients (43.5%), including 90 (41.7%) with RS-low/CR-high and 4 (1.8%) with RS-high/CR-low. Compared with RS-low, RS-high patients more often had tumors >2 cm (57.1% vs. 30.4%, p=0.002), nodal metastasis (34.3% vs. 21.5%, p20% (60.0% vs. 15.5%, p2 was more frequent but not significant (34.3% vs. 5.0%, p=0.104). Regarding therapy, 73.2% received endocrine therapy alone, 19.4% combination endocrine therapy, and 7.4% intravenous chemotherapy. Chemotherapy was strongly associated with concordance: 93.7% of treated cases were concordant, versus 6.3% discordant (p<0.001). Conclusion: Clinical–genomic discordance was common. RS reflected tumor biology rather than nodal status, and chemotherapy use depended more on genomic–clinical concordance than CR alone. Integration of clinical and genomic risk is essential for optimizing adjuvant strategies in early HR+/HER2− breast cancer.

Background: Axillary lymph node dissection (ALND) remains necessary for selected patients with breast cancer but is associated with lymphatic morbidity, including seroma formation and breast cancer-related lymphedema (BCRL). The Total Sealing Technique (TST) is a technique-centered operative concept that emphasizes systematic sealing of lymphatic and vascular structures during ALND. Methods: This review integrates mechanistic rationale and clinical evidence derived from comparative cohort studies evaluating TST (using advanced bipolar vessel-sealing systems) versus conventional electrocautery (CONV). Key perioperative and long-term outcomes are summarized quantitatively. Results: In a comparative cohort of total mastectomy with ALND, TST significantly reduced total drainage volume (360.5 ± 187.9 vs. 820.6 ± 661.6 mL; p < 0.001) and shortened time to drain removal (4.8 ± 1.3 vs. 6.8 ± 2.1 days; p < 0.001). Postoperative hospital stay was reduced by 3.7 days on average (5.9 ± 1.3 vs. 9.6 ± 3.4 days; p < 0.001). The incidence of seroma decreased from 65.9% to 28.6% (p = 0.001), with fewer aspiration procedures (1.8 vs. 4.6 per patient; p = 0.022). Importantly, long-term follow-up demonstrated a statistically significant reduction in BCRL incidence (2.9% vs. 22.2%; p = 0.028). Operative time and blood loss were not increased. Conclusions: Current single-center data indicate that TST is associated with substantial reductions in postoperative lymphatic morbidity and a statistically significant decrease in BCRL incidence. While independent multicenter validation is warranted, TST represents a reproducible technique-centered approach with meaningful clinical impact in ALND.

Background/Aim: The introduction of the HER2-low concept has redefined the biological spectrum of breast cancer. However, the clinicopathological and prognostic significance of HER2 expression in ductal carcinoma in situ (DCIS) remains unclear. This study aimed to reassess HER2 expression in DCIS using the HER2-low classification. Patients and Methods: A total of 221 patients who underwent surgery and were pathologically diagnosed with DCIS at Osaka Metropolitan University hospital between June 2007 and December 2023 were retrospectively analyzed. HER2 expression was assessed using immunohistochemistry (IHC) and classified as HER2-0, HER2-low (IHC 1-2+), or HER2-high (IHC 3+). Clinicopathological features were compared among groups, and disease-free survival (DFS) and recurrence-free interval (RFI) were evaluated using Kaplan–Meier and Cox regression analyses. Results: HER2-0, HER2-low, and HER2-high were observed in 96 (43.4%), 80 (36.2%), and 45 (20.4%) patients, respectively. HER2 expression correlated significantly with estrogen receptor (p=0.011), progesterone receptor (p<0.001), comedonecrosis (p=0.030), calcification (p=0.019), and nuclear grade (p=0.006). Although no significant differences were found among the three groups, the HER2-0 subgroup tended to show longer RFI compared with HER2-positive cases (p=0.051). Multivariate analysis identified tumor size as an independent prognostic factor for DFS (hazard ratio=34.47, p=0.004). Conclusion: HER2 expression redefined by the HER2-low concept reflects the biological diversity of DCIS. Evaluation of HER2 status as a continuous spectrum may aid in risk stratification and contribute to understanding early HER2-driven tumor evolution.

Background/Aim: Peripheral blood neutrophil-lymphocyte ratio (NLR) has been reported to predict the effects of surgery and chemotherapy in breast cancer patients. However, the majority of the studies performed only one-time evaluation before commencement of treatment, while few evaluated the ratio over a period of time. In this study, we calculated NLR before surgery and postoperative adjuvant chemotherapy for patients with resectable breast cancer who underwent surgery as the initial treatment, and examined its correlation with clinicopathological factors and prognosis. Patients and Methods: A total of 1,095 patients with primary resectable breast cancer underwent curative resection as the first line of treatment between December 2007 and October 2018. Of these 1,095 patients, 178 were included in this study. Peripheral blood was collected before, and after the surgery. Preoperative NLR was evaluated during the first hospital visit before biopsy. Postoperative NLR was evaluated using peripheral blood collected immediately prior to postoperative adjuvant chemotherapy. The cut-off value of NLR was set to 3, which has been reported to be the most commonly used value. Results: Examination of postoperative NLR and prognosis in 24 breast cancer patients with higher pre-NLR revealed no significant difference [disease-free survival (DFS), p=0.320; overall survival (OS), p=0.409, log-rank test]. However, when post-NLR and prognosis were examined in 154 breast cancer patients with lower pre-NLR, the lower post-NLR group showed significant prolongation in DFS (p<0.001, log-rank test). Furthermore, OS tended to be prolonged in the lower post-NLR group (p=0.056, log-rank test). Multivariate analysis of DFS in 154 breast cancer patients with lower pre-NLR showed that large tumors [hazard ratio (HR)=4.132, p=0.009], nuclear grade 3 (HR=2.746, p=0.043), and higher post-NLR (HR=4.639, p=0.003) were independent factors. Conclusion: Prognosis of breast cancer patients can be predicted by evaluating the NLR over time.