A prospective feasibility study applying the ACOSOG Z0011 criteria to Japanese patients with early breast cancer undergoing breast-conserving surgery.

BACKGROUND: In patients undergoing breast-conserving surgery and having positive sentinel lymph nodes (SLNs), the ACOSOG Z0011 trial showed equivalent loco-regional outcomes for patients receiving SLN dissection (SLND) alone and those receiving axillary lymph node dissection (ALND). We conducted a prospective single-arm study to confirm the applicability of the Z0011 criteria to Japanese patients with breast cancer. METHODS: Patients meeting the Z0011 inclusion criteria and providing consent to receive no additional ALND were prospectively enrolled at the Osaka International Cancer Institute from April 2012 to December 2016. Cumulative incidence of loco-regional recurrence was estimated and compared to that of the Z0011 study. RESULTS: Among a total of 881 patients who underwent breast-conserving surgery, 189 fulfilling the Z0011 criteria were enrolled and eligible for the subsequent analysis. Adjuvant chemotherapy was given to 113 (59.8%) patients, adjuvant hormone therapy to 170 (89.9%), and whole breast irradiation to 183 (96.8%). The frequency of tumors with positive lymphovascular invasion (p < 0.0001) and macrometastases in SLNs (p < 0.0001) were significantly higher in our study than in the Z0011 study. At the median follow-up of 36 months (range 10-64 months), only 2 of 189 patients (1.1%) experienced loco-regional recurrence. The 5-year cumulative rate of loco-regional recurrences was 1.3% (95% CI 0-3.1%), and the 3-year distant DFS rate was 96.8% (95% CI 94.0-99.6%). CONCLUSIONS: Our prospective study showed that it is feasible to apply the Z0011 strategy to Japanese patients with clinically node-negative breast cancer undergoing breast-conserving surgery with planned whole breast irradiation.

Regional lymphatic recurrence after salvage surgery for ipsilateral breast tumor recurrence of breast cancer without local treatment for regional lymphatic basin.

BACKGROUND: There is limited information regarding rates of and risk factors for regional lymphatic recurrence (RLR) after salvage surgery for ipsilateral breast tumor recurrence (IBTR) without local treatment for the regional lymphatic basin. METHODS: One hundred two patients, who underwent salvage breast surgery without local treatment for the regional lymphatic basin (surgery or radiotherapy) for IBTR that relapsed after breast-conserving surgery for primary breast cancer, were reviewed retrospectively to examine the rate of and risk factors for RLR. RESULTS: Of the 102 patients, 9 patients (8.8%) had RLR with a median follow-up period of 3.7 years after salvage breast surgery for IBTR. The estrogen receptor (ER) status and lymphovascular invasion of the recurrent breast tumor were both independent predictive factors of RLR (P = 0.04 and 0.02, respectively). CONCLUSIONS: The rate of RLR was not low in patients with IBTR who received salvage breast surgery only without any treatment for the regional lymphatic basin. The ER status and lymphovascular invasion of the recurrent breast tumor were predictive factors of RLR.

Sentinel nodes identified by computed tomography-lymphography accurately stage the axilla in patients with breast cancer.

BACKGROUND: Sentinel node biopsy often results in the identification and removal of multiple nodes as sentinel nodes, although most of these nodes could be non-sentinel nodes. This study investigated whether computed tomography-lymphography (CT-LG) can distinguish sentinel nodes from non-sentinel nodes and whether sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. METHODS: This study included 184 patients with breast cancer and clinically negative nodes. Contrast agent was injected interstitially. The location of sentinel nodes was marked on the skin surface using a CT laser light navigator system. Lymph nodes located just under the marks were first removed as sentinel nodes. Then, all dyed nodes or all hot nodes were removed. RESULTS: The mean number of sentinel nodes identified by CT-LG was significantly lower than that of dyed and/or hot nodes removed (1.1 vs 1.8, p <0.0001). Twenty-three (12.5%) patients had ≥2 sentinel nodes identified by CT-LG removed, whereas 94 (51.1%) of patients had ≥2 dyed and/or hot nodes removed (p <0.0001). Pathological evaluation demonstrated that 47 (25.5%) of 184 patients had metastasis to at least one node. All 47 patients demonstrated metastases to at least one of the sentinel nodes identified by CT-LG. CONCLUSIONS: CT-LG can distinguish sentinel nodes from non-sentinel nodes, and sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Successful identification of sentinel nodes using CT-LG may facilitate image-based diagnosis of metastasis, possibly leading to the omission of sentinel node biopsy.

Correlation between the area of high-signal intensity on SPIO-enhanced MR imaging and the pathologic size of sentinel node metastases in breast cancer patients with positive sentinel nodes.

BACKGROUND: We previously demonstrated that superparamagnetic iron oxide (SPIO)-enhanced MR imaging is promising for the detection of metastases in sentinel nodes localized by CT-lymphography in patients with breast cancer. The purpose of this study was to determine the predictive criteria of the size of nodal metastases with SPIO-enhanced MR imaging in breast cancer, with histopathologic findings as reference standard. METHODS: This study included 150 patients with breast cancer. The patterns of SPIO uptake for positive sentinel nodes were classified into three; uniform high-signal intensity, partial high-signal intensity involving ≥50% of the node, and partial high-signal intensity involving <50% of the node. Imaging results were correlated with histopathologic findings. RESULTS: Thirty-three pathologically positive sentinel nodes from 30 patients were evaluated. High-signal intensity patterns that were uniform or involved ≥50% of the node were observed in 23 nodes that contained macro-metastases and no node that contained micro-metastases, while high-signal intensity patterns involving <50% of the node were observed in 2 nodes that contained macro-metastases and 8 nodes that contained micro-metastases. When the area of high-signal intensity was compared with the pathological size of the metastases, a pathologic >2 mm sentinel node metastases correlated with the area of high-signal intensity, however, a pathologic ≤2 mm sentinel node metastases did not. CONCLUSIONS: High-signal intensity patterns that are uniform or involve ≥50% of the node are features of nodes with macro-metastases. The area of high-signal intensity correlated with the pathological size of metastases for nodes with metastases >2 mm in this series.

SPIO-enhanced magnetic resonance imaging for the detection of metastases in sentinel nodes localized by computed tomography lymphography in patients with breast cancer.

BACKGROUND: Superparamagnetic nanoparticle-enhanced magnetic resonance (MR) imaging has been reported to be a promising improvement for diagnostic imaging of lymph node metastases from various tumors. Moreover, sentinel nodes have been reported to be well identified using computed tomography (CT) lymphography (CT-LG) in patients with breast cancer. The aim of this study was to evaluate MR imaging with superparamagnetic iron oxide (SPIO) enhancement for the detection of metastases in sentinel nodes localized by CT-LG in patients with breast cancer. METHODS: This study included 102 patients with breast cancer and clinically negative nodes. Sentinel nodes were identified by CT-LG, and SPIO-enhanced MR imaging of the axilla was performed to detect metastases in the sentinel nodes. A node was considered nonmetastatic if it showed a homogenous low signal intensity and metastatic if the entire node or a focal area did not show low signal intensity on MR imaging. Sentinel node biopsy was performed, and imaging results were correlated with histopathologic findings. RESULTS: The mean number of sentinel nodes identified by CT-LG was 1.1 (range, 1-3). The sensitivity, specificity, and accuracy of MR imaging for the diagnosis of sentinel node metastases were 84.0%, 90.9%, and 89.2%, respectively. In 4 of 10 patients with micrometastases, metastases were not detected, but all 15 patients with macrometastases were successfully identified. CONCLUSIONS: SPIO-enhanced MR imaging is a useful method of detecting metastases in sentinel nodes localized by CT-LG in patients with breast cancer and may avoid sentinel node biopsy when the sentinel node is diagnosed as disease-free.

Repeat lumpectomy for ipsilateral breast tumor recurrence after breast-conserving treatment.

OBJECTIVES: There are limited data on the outcomes of patients treated with repeat lumpectomy at the time of ipsilateral breast tumor recurrence (IBTR). METHODS: We retrospectively analyzed 78 patients who underwent repeat lumpectomy after IBTR. The risk factors for second IBTR were assessed. RESULTS: The median follow-up period was 40 months. The 5-year second IBTR-free survival rate was 78.8%. Patients with estrogen receptor (ER)-positive or unknown tumors at IBTR had a significantly better second IBTR-free survival rate than those with ER-negative tumors at IBTR (88.3 vs. 55.4%, respectively; p = 0.0022). Multivariate analysis revealed that the ER status of IBTR was a significantly independent predictive factor for second IBTR-free survival (p = 0.0177). The low-risk group for second IBTR was detected using the ER status, disease-free interval, margin status of IBTR, and age at diagnosis (5-year cumulative incidence, 7.0%). CONCLUSION: The ER status of IBTR was a significantly independent predictive factor for second IBTR-free survival. Some patients could safely undergo repeat lumpectomy for IBTR.

Aesthetic utility of addition of nipple-areola recentralization to rotation flap according to nipple tumor distance for patients with lower-outer or upper-inner located breast cancers.

We aimed to validate the cosmetic utility of addition of nipple-areola recentralization (NAR) to rotation flap according to nipple tumor distance (NTD) as a volume displacement technique after breast conserving surgery (BCS) for lower-outer and upper-inner breast cancers. Twenty breast cancer patients who had been treated with rotation flap with (Group 1; n = 6) or without (Group 2; n = 14) NAR after BCS for lower-outer or upper-inner located tumors, and those who had undergone BCS without oncoplastic surgical technique for tumors in the same area (Control group; n = 43), were retrospectively investigated. Cosmetic outcome was evaluated using Harvard scale and/or BCCT.core. As a result, the ratio of patients categorized as excellent/good was 83% in Group 1 and 93% in Group 2, respectively, and there was no significant difference between them (P = 0.521). In addition, Group 1 + 2 showed a significantly higher ratio of patients classified as excellent/good than the control group (90% vs. 56%; P = 0.009). After adjustment of clinical background parameters using propensity score matching analysis between Group 1 + 2 and the control group, 12 pairs with similar background factors were matched. Among them, Group 1 + 2 showed a higher ratio of patients categorized as excellent/good than the control group (92% vs. 42%; P = 0.034). In conclusion, addition of NAR to rotation technique according to NTD may enable us to perform a volume displacement after BCS for lower-outer or upper-inner located tumors irrespective of NTD without sacrificing postoperative breast appearance.

Prognostic significance of neutropenia on day one of anthracycline-based neoadjuvant chemotherapy in operable breast cancer.

OBJECTIVES: It is currently unknown whether neutropenia during neoadjuvant chemotherapy for early breast cancer is associated with prognosis. METHODS: We retrospectively analyzed 103 breast cancer patients who were treated with neoadjuvant chemotherapy including epirubicin-based chemotherapy followed by docetaxel. The association between neutropenia due to epirubicin-based chemotherapy and distant disease-free survival (DDFS) was assessed. RESULTS: Thirty-one patients (30%) demonstrated neutropenia during the epirubicin-based regimen. Patients without neutropenia showed a significantly (p = 0.004) lower 5-year DDFS rate (64%) than those with neutropenia (97%). In addition, multivariate analysis showed that neutropenia is an independent prognostic factor for DDFS (p = 0.02). CONCLUSION: Neutropenia occurring in early breast cancer patients during the initial neoadjuvant treatment is strongly associated with a better prognosis.

Expression of estrogen receptor beta and phosphorylation of estrogen receptor alpha serine 167 correlate with progression-free survival in patients with metastatic breast cancer treated with aromatase inhibitors.

Aromatase inhibitor (AI) is widely used as an endocrine treatment in postmenopausal patients with hormone receptor-positive breast cancer. To identify useful prognostic factors for patients with metastatic breast cancer treated with AI therapy, we investigated the association between several hormone receptor-related factors and prognosis. The expressions of estrogen receptor-α (ERα), ERß, progesterone receptor, the phosphorylation of ERα serine 118 (Ser118) and ERα Ser167 were examined using immunohistochemical techniques for the primary tumors of 41 patients with metastatic breast cancer who received first-line AI therapy after relapse. To assess the associations of protein expression and phosphorylation levels with progression-free survival (PFS), the levels of each factor were categorized into low and high values at optimal cutoff points. In univariate analysis, high ERα expression and high ERα Ser167 phosphorylation correlated with longer PFS (p = 0.016 and 0.013, respectively). In multivariate analysis, low ERß expression and high ERα Ser167 phosphorylation correlated with longer PFS (p = 0.031 and 0.004, respectively). Patients with both low ERß expression and high ERα Ser167 phosphorylation had longer PFS than the others (p = 0.0107). These data suggest that the expression of ERß and phosphorylation of ERα Ser167 may be useful prognostic factors in patients with metastatic breast cancer who received first-line AI therapy.

Phase II trial in Japan of sequential administration of weekly paclitaxel followed by FEC as neoadjuvant chemotherapy for locally advanced breast cancer [KBCSG0206 trial: Kinki Breast Cancer Study Group (KBCSG)].

OBJECTIVE: We conducted a phase II trial in Japan to evaluate the efficacy and tolerability of weekly paclitaxel followed by fluorouracil, epirubicin, and cyclophosphamide (FEC) as neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC). METHODS: Patients with clinical stage IIIA-IIIB breast cancer received NAC consisting of 12 once-a-week cycles of paclitaxel followed by 4 once-every-third-week cycles of FEC. RESULTS: Fifty patients with LABC were enrolled, 47 of whom were administered paclitaxel followed by FEC as NAC. The clinical response rate for all chemotherapies was 85.1%, and the pathological complete response rate was 27.7%. Regarding toxicity, grade 3-4 neutropenia was observed in 10% of patients. No serious toxicities requiring the discontinuation of treatment were encountered. The rate of breast conservation surgery was 31.9%, median survival had not been reached at the time of conclusion of this study, and the 3-year survival rate was 85.1%. Median disease-free survival was 40.2 months, and the 3-year disease-free survival rate was 62.1%. CONCLUSIONS: Weekly paclitaxel followed by FEC demonstrated efficacy and tolerable toxicity in a neoadjuvant setting for LABC.

Clinical utility of the 70-gene MammaPrint profile in a Japanese population.

OBJECTIVE: van't Veer and colleagues developed a 70-gene prognosis profile known as MammaPrint to identify breast cancer patients who were at low risk of developing metastases. We evaluated the prognostic value of the 70-gene MammaPrint profile in Japanese women with node-negative breast cancer. METHODS: Frozen tumour samples from 102 eligible node-negative breast cancer patients aged 70 or younger were characterized with the MammaPrint array. The patients were treated with breast-conserving therapy or mastectomy with axillary lymph node dissection between December 1998 and August 2001. About 73 percent received adjuvant hormonal therapy and 28 percent received adjuvant chemotherapy. The gene expression profiles obtained by MammaPrint classified the patients as high- or low-genomic risk. The median follow-up was 7.1 years. RESULTS: Among the 102 patients, 20 (20%) were classified as low-genomic risk and 82 (80%) were classified as high-genomic risk. The probability of distant metastasis-free survival at five years was 100% for the low-risk group and 94% for the high-risk group. CONCLUSIONS: The 70-gene MammaPrint prognosis profile accurately identified Japanese breast cancer patients at low risk of developing recurrences. In fact, 100% of the individuals in the low-risk category remained metastasis-free for the duration of the observation period.

Early response to neo-adjuvant chemotherapy in carcinoma of the breast predicts both successful breast-conserving surgery and decreased risk of ipsilateral breast tumor recurrence.

Neo-adjuvant chemotherapy enables us to increase the possibility of breast-conserving surgery for large, bulky tumors. However, several studies have reported that ipsilateral breast tumor recurrences (IBTRs) occur more frequently after neo-adjuvant chemotherapy than originally envisaged. Recently, it was demonstrated that clinical early response after neo-adjuvant chemotherapy predicts pathological complete response. In this study, we assessed the association of clinical early response after neo-adjuvant chemotherapy with successful breast-conserving surgery and IBTR risk. Between 1995 and 2002, 114 patients with T 3.1-6 cm, N 0 or 1, M 0 breast cancer who were candidates for mastectomy but desired breast-conserving surgery were treated with neo-adjuvant chemotherapy. After two cycles of anthracycline-based neo-adjuvant chemotherapy and before surgery, breast tumors were measured by palpation or ultrasound. Clinical response after two cycles of chemotherapy was defined as positive when the largest tumor dimension was reduced by 30% or greater. Median follow-up time was 72 months. After two cycles of neo-adjuvant chemotherapy, 54 (47.4%) of 114 patients achieved an early response. Patients with the early response underwent breast-conserving surgery significantly more frequently than those without the early response (78% versus 58%, p = 0.03). In addition, the early response was significantly correlated with selection of breast-conserving surgery (odds ratio 3.8, p = 0.01) after adjustments for various clinicopathological factors. Patients without the early response showed significantly lower 6-year IBTR-free survival than patients with the early response (75% versus 97%, p = 0.02). In addition, patients with the early response showed significantly higher 6-year disease-free survival rates than those with the early response (p = 0.02). Multivariate analysis showed that the early response was a predictive factor of IBTR-free survival, being independent of other clinicopathological factors. In conclusion, the early response to neo-adjuvant chemotherapy may be a useful predictor of both selection of surgical method and IBTR risk.

Accuracy of imprint cytology for intraoperative diagnosis of sentinel node metastases in breast cancer.

OBJECTIVE: The aim of this study was to determine the accuracy of imprint cytology for the intraoperative diagnosis of sentinel node metastases in patients with breast cancer. SUMMARY BACKGROUND DATA: Accurate intraoperative diagnosis of sentinel node metastases enables the selection of patients who need axillary lymph node dissection during the same operation. METHODS: This study included 631 patients with clinical T1 breast cancer with clinically negative nodes. Sentinel nodes were serially sectioned at 2-mm intervals. Imprint cytologic samples were made from all cut surfaces and stained with Papanicolaou staining. Patients with positive sentinel nodes underwent immediate axillary lymph node dissection. Those with negative sentinel nodes diagnosed by intraoperative imprint cytology, but positive by final pathologic results, underwent subsequent axillary lymph node dissection. The results of imprint cytology were compared with the final pathologic results using hematoxylin and eosin staining and immunohistochemistry. RESULTS: In 110 of 130 patients with positive sentinel nodes diagnosed by final pathology, imprint cytology of at least one sentinel node was positive. In 17 of 501 patients with tumor-negative sentinel nodes diagnosed by final pathology, imprint cytology of at least one sentinel node was positive. The sensitivity, specificity, and overall accuracy of imprint cytology for the diagnosis of sentinel node metastases were 84.6%, 96.6%, and 94.1%, respectively. Only 20 (3.2%) patients required a second axillary operation in the present study. CONCLUSION: Intraoperative imprint cytology is a useful method for evaluating sentinel node metastasis in patients with breast cancer.

[A long-term survival case of metastatic breast cancer treated with trastuzumab and paclitaxel].

We report a long-term survival case of metastatic breast cancer treated with trastuzumab and paclitaxel. The patient was a 50-year-old female. She underwent left mastectomy with axillary lymphadenectomy for advanced breast cancer with liver metastases. Histological examination showed papillotublar carcinoma, f, T3, ly3, v2, N2 (24/34), histological grade III, ER (-), PgR (-), HER2 (3+). Trastuzumab and paclitaxel was performed. One year after the operation, any lesions of liver were not detected by CT and she was diagnosed as a complete response. No evidence of viable lesions has been found for 7 years. Breast cancer with liver metastases often could be a life threatening, and therefore an optimal chemotherapy should be applied as soon as possible. Trastuzumab and paclitaxel would be one of the optimal chemotherapies for HER2 positive breast cancer.

Sentinel node biopsy for breast cancer: technical aspects and controversies.

Sentinel node biopsy has rapidly emerged as a minimally invasive, highly accurate method of axillary staging, and has replaced routine axillary lymph node dissection as the new standard of care in breast cancer. However, many practical problems remain and details of the technique have not been standardized yet. Guideline recommendations help us to perform appropriate sentinel node biopsy and pathological examination. We should perform sentinel node biopsy without deviation from such consensus guidelines. The technical controversies of sentinel node biopsy are discussed in this article and the results of our studies about sentinel node biopsy in breast cancer are reviewed.

Identification of sentinel lymph nodes by contrast-enhanced ultrasonography with Sonazoid in patients with breast cancer: a feasibility study in three hospitals.

The aim of this prospective study was to evaluate the feasibility of periareolar injection of the contrast agent Sonazoid (SNZ) followed by ultrasonography (US) for the identification of sentinel lymph node (SLN) in breast cancer patients with clinically negative node. Patients (n = 100) with T1-2N0M0 breast cancer received a periareolar injection of SNZ followed by US to identify contrast-enhanced SLN. Each contrast-enhanced SLN underwent fine needle aspiration cytology (FNAC) followed by SLN biopsy with a conventional method using blue dye and/or radiocolloid (B/R). In almost all cases, contrast-enhanced lymphatic vessels were clearly visualized by US soon after the periareolar injection of SNZ and the SLNs were easily identified with an identification rate of 98% (98/100) for SNZ and 100% (100/100) for B/R. The number of SLNs identified by SNZ (SNZ-SLN) (mean per patient, 1.52) was significantly lower than that identified by B/R (B/R-SLN) (2.19) (P < 0.0001). Twenty-five patients with positive SLNs had at least one positive SNZ-SLN. On a node-by-node basis, sensitivity, specificity, and accuracy of FNAC for SNZ-SLNs (n = 149) were 33.3%, 99.2%, and 85.9%, respectively. Identification of SLN by periareolar injection of SNZ is a technically simple method with an identification rate as high as 98%. SNZ-SLN thus seems to be a good target for FNAC, but sensitivity of FNAC for SNZ-SLNs needs to be improved.

A pilot study of wider use of accelerated partial breast irradiation: intraoperative margin-directed re-excision combined with sole high-dose-rate interstitial brachytherapy.

BACKGROUND: Accelerated partial breast irradiation (APBI) is generally limited to patients at extremely low risk of local recurrence. The significance of the risk factors, however, depends on the extent of surgery, radiation, and systemic therapy. In Japan, wide excision is generally supplemented by intraoperative margin-directed re-excision if the frozen section examination yields positive results. This approach combined with conventional radiotherapy achieved an excellent 10-year local control rate of 93%, and young age and ductal carcinoma in situ were not risk factors for local recurrence. To reduce the treatment duration, high-dose-rate interstitial brachytherapy (HDRIB) was employed. The first APBI phase I / II trial in Japan was conducted to determine if wider indications for early breast cancer patients were appropriate. METHODS: The subjects comprised 20 patients including those with extensive intraductal component (n=7), ductal carcinoma in situ (n=2), positive final margins (n=3), and of younger age (< or = 45 years; n=5). Breast-conserving surgery using an intraoperative re-excision approach was followed by intraoperative implantation of applicators. Sole HDRIB of a 36-42 Gy in 6-7 fractions was delivered postoperatively over 3-4 days. Tumors were staged as follows: cT1 (n=12), cT2 (n=8), cN0 (n=20). Systemic therapy was used in 16 patients (80%). The median follow-up period was 52 months (range, 26-86 months). RESULTS: Te five-year crude local, distant control, and Kaplan-Meier cause-specific survival rates were 95%, 95%, and 89%, respectively. Fat necrosis developed in 1 patient. CONCLUSIONS: Sole HDRIB with intraoperative margin-directed re-excision was feasible under wider indications compared to other contemporary APBI series, and achieved acceptable and similar results to these series in terms of the local control rate and complications.

[Sentinel node biopsy in breast cancer].

Sentinel node biopsy is a new promising technique in the treatment of breast cancer. This technique may be a less invasive, highly accurate alternative to axillary lymph node dissection. An increasing number of studies demonstrated the feasibility and accuracy of sentinel node biopsy. However, many problems remain to be answered and must be addressed before sentinel node biopsy becomes the standard of care for patients with breast cancer. We reviewed and discussed here the proof of the sentinel node concept and several problems of sentinel node biopsy; identification technique, preoperative, intraoperative and postoperative examination of sentinel node.

Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Patients With an Initial Diagnosis of Cytology-Proven Lymph Node-Positive Breast Cancer.

BACKGROUND: Sentinel lymph node biopsy (SNB) is the standard treatment of node-negative breast cancer; however, whether SNB should be performed for patients with node-positive disease before neoadjuvant chemotherapy (NAC) is controversial. We evaluated the accuracy of SNB after NAC in patients with breast cancer with nodal metastasis before chemotherapy to determine the false-negative rate (FNR) and detection rate for SNB. PATIENTS AND METHODS: In the present multicenter prospective study performed from September 2011 to April 2013, 143 patients with breast cancer and positive axillary nodes, proved by fine needle aspiration cytology at the initial diagnosis (stage T1-T3N1M0), were enrolled. All patients underwent breast surgery with SNB and complete axillary lymph node dissection. RESULTS: After NAC, the pathologic complete nodal response rate was 52.4%. The sentinel lymph node could be identified in 130 cases (90.9%); the FNR was 16.0% (13 of 81). The FNR of each clinical subtype was 42.1% (8 of 19) for the estrogen receptor-positive and human epithelial growth factor 2 (HER2)-negative (luminal type), 16.7% (2 of 12) for ER-positive and HER2-positive (luminal-HER2 type), 3.2% (1 of 31) for HER2-positive (HER2-enriched type), and 10.5% (2 of 19) for ER-negative and HER2-negative (triple-negative breast cancer; P = .003). The FNR was significantly greater in the luminal than in the nonluminal type (odds ratio, 9.91; 95% confidence interval, 6.77-14.52). CONCLUSION: SNB after NAC in patients with initially node-positive breast cancer was technically feasible but should not be recommended for the luminal subtype. However, the tumor subtype can guide patient selection, and axillary lymph node dissection could be omitted for the luminal-HER2, HER2-enriched, and triple-negative breast cancer subtypes.