Long-Term Outcomes of Breast Cancer Patients with Local Recurrence After Mastectomy Undergoing Immediate Breast Reconstruction: A Retrospective Multi-institutional Study of 4153 Cases.

BACKGROUND: The number of breast cancer patients in Japan undergoing immediate breast reconstruction (IBR) has increased and the postoperative follow-up period has been extended. This study was conducted to clarify the clinical aspects of, and factors associated with, local recurrence (LR) after IBR. METHODS: This was a multicenter study which included 4153 early breast cancer patients who underwent IBR. Clinicopathological characteristics were examined and factors potentially contributing to LR were analyzed. Risk factors for LR were examined separately for non-invasive and invasive breast cancers. RESULTS: The median follow-up period was 75 months. The 7-year LR rates were 2.1% and 4.3% for non-invasive and invasive cancers, respectively (p < 0.001). The proportions of LR detected by palpation, subjective symptoms, and ultrasonography were 40.0%, 27.3%, and 25.9%, respectively. Overall, 75.7% of LR were solitary, and 92.7% of these cases had no further recurrences during the observational period. Multivariate analysis of LR for invasive cancer showed that skin-sparing mastectomy (SSM) or nipple-sparing mastectomy (NSM), the presence of lymphovascular invasion, cancer at the surgical margin, and not receiving radiation therapy were factors related to LR. The 7-year overall survival rates of the patients with LR and non-LR of invasive cancers were 92.5% and 97.3%, respectively, (p = 0.002). CONCLUSIONS: The rate of LR after IBR was acceptably low and IBR can thus be performed safely for early breast cancer patients. Invasive cancer, SSM/NSM, lymphovascular invasion, and/or cancer at the surgical margin should prompt awareness of the possibility of LR.

Classification of Local Recurrence After Nipple-Sparing Mastectomy Based on Location: The Features of Nipple-Areolar Recurrence Differ from Those of Other Local Recurrences.

BACKGROUND: Little information is available about the clinical and pathologic characteristics of local recurrence (LR) after nipple-sparing mastectomy according to the locations of LR. METHODS: This study classified 99 patients into the following two groups according to the location of LR after nipple-sparing mastectomy: nipple-areolar recurrence (NAR) group and other locations of LR (oLR) group. The study evaluated whether the location of LR was associated with disease-free survival (DFS) after LR resection. RESULTS: For about half of the patients (44.4 %) with NAR, the primary cancer was estrogen receptor (ER)-negative and human epidermal growth factor receptor 2 (HER2)-positive. Conversely, in most of the patients with oLR (79.2 %), the primary cancer was ER-positive and HER2-negative. Among the LR tumors, the frequency of noninvasive carcinoma in the NAR tumors was significantly higher than in the oLR tumors (51.9 % vs 4.2 %, respectively). During a median follow-up period of 46 months, the location of LR was not associated with DFS after LR. In the NAR group, the presence or absence of LR tumor invasiveness was the only factor associated with DFS. In the oLR group, age at primary surgery was the only factor associated with DFS. CONCLUSION: This multi-institutional retrospective study demonstrated that the features of NAR, such as the characteristics of the primary and recurrent tumors and the prognostic factors after LR resection, were quite different from those of oLR.

Childbirth after perioperative systemic therapy in patients with breast cancer: a retrospective single institutional study in Japan.

BACKGROUND: The number of breast cancer patients of childbearing age has been increasing. Therefore, we investigated the characteristics and the childbearing status of the patients who received systemic therapy for breast cancer during their childbearing age to better understand the clinical impact of childbirth. METHODS: Female patients with breast cancer younger than 40 years old who underwent surgery and received perioperative systemic therapy from 2007 to 2014 were included in this study. We compared the characteristics of patients with and without childbirth after treatment. RESULT: Of 590 patients, 26 delivered a child, and 355 did not bear a child during the median observation period of 8.1 years, whilst 209 had unknown childbirth data. The childbirth group had a lower mean age at surgery (32.2 vs. 35.1, P < 0.001). The proportion of patients who desired childbirth and used assisted reproductive technology was significantly higher in the childbirth group (65.4 vs. 23.9% and 45.2 vs. 5.1%, respectively, P < 0.001). The patients in the childbirth group had significantly less advanced disease (P = 0.002). In the childbirth group, the age at childbirth was significantly older in patients who received combined endocrine therapy and chemotherapy (40.8 years) than in patients who received either alone (endocrine therapy: 36.9 years, chemotherapy: 36.7 years, P = 0.04). However, survival was not different between those with and without childbirth. CONCLUSION: It is critical to recognize the desire for childbirth in patients with breast cancer who are receiving systemic therapy and to provide them with necessary fertility information before treatment to support their decision-making.

Prognostic impact and possible pathogenesis of lymph node metastasis in ductal carcinoma in situ of the breast.

PURPOSE: Ductal carcinoma in situ (DCIS)-preinvasive breast cancer-with lymph node metastasis can clinically be treated as different stages: occult invasive cancer with true metastasis (T1N1) or pure DCIS with iatrogenic dissemination (TisN0). In this retrospective cohort study, we aimed to elucidate the prognostic impact and possible pathogenesis of nodal metastasis in DCIS to improve clinical management. METHODS: Subjects were comprised of 427 patients with routine postoperative diagnosis of DCIS who underwent sentinel node (SN) biopsy using molecular whole-lymph-node analysis. Clinicopathological characteristics and prognosis were compared between SN-positive and -negative patients. Primary tumour tissues of SN-positive patients were exhaustively step-sectioned to detect occult invasions, and predictive factors for occult invasion were investigated. Median follow-up time was 73.6 months. RESULTS: Of the 427 patients, 19 (4.4%) were SN-positive and 408 (95.6%) were SN-negative. More SN-positive patients received adjuvant systemic therapy than SN-negative patients (84.2% vs. 5.4%). Seven-year distant disease-free survivals were favourable for both cohorts (SN-positive, 100%; SN-negative, 99.7%). By examining 1421 slides, occult invasion was identified in 9 (47.4%) of the 19 SN-positive patients. Tumour burdens in SN and incidence of non-SN metastasis were similar between patients with and without occult invasion, and no predictive factor for occult invasion was found. CONCLUSIONS: Node-positive DCIS has favourable prognosis with adjuvant systemic therapy. Half of the cases may be occult invasive cancer with true metastasis. In practical settings, clinicians may have to treat these tumours as node-positive small invasive cancers because it is difficult to predict the pathogenesis without exhaustive primary tumour sectioning.

Intraoperative Nomograms, Based on One-Step Nucleic Acid Amplification, for Prediction of Non-sentinel Node Metastasis and Four or More Axillary Node Metastases in Breast Cancer Patients with Sentinel Node Metastasis.

BACKGROUND: One-step nucleic acid amplification (OSNA) for cytokeratin 19 messenger RNA is an intraoperative diagnostic procedure for the detection of lymph node metastasis. OBJECTIVE: This study aimed to construct intraoperative nomograms using OSNA for the prediction of non-sentinel lymph node (NSLN) metastasis and four or more axillary lymph node (ALN) metastases. METHODS: Of the 4736 breast cancer patients (T1-3, N0) who underwent sentinel lymph node (SLN) biopsy and had SLNs examined intraoperatively with OSNA, 623 with SLN metastasis treated with completion ALN dissection (cALND) were retrospectively analyzed, and were randomly divided into training (n = 312) and validation (n = 311) sets. RESULTS: Of the clinicopathological parameters available preoperatively and intraoperatively, the multivariate analysis of the training set revealed that clinical tumor size and total tumor load (TTL) determined by OSNA were significantly associated with NSLN metastasis, and that clinical tumor size, number of macrometastatic SLNs, and TTL were significantly associated with four or more ALN metastases. Nomograms for NSLN metastasis and four or more ALN metastases were constructed using these parameters, and their area under the receiver operating characteristic curve (AUC) of the validation set were both 0.70, with a diagnostic accuracy similar to that of previously reported postoperative nomograms. CONCLUSIONS: We constructed intraoperative nomograms using OSNA for the prediction of NSLN metastasis and four or more ALN metastases. These nomograms are as accurate as the conventional postoperative nomograms and might be helpful for decision making regarding the indication for cALND or the choice of adjuvant chemotherapeutic regimens and radiation field.

Differences in expression of the cancer stem cell marker aldehyde dehydrogenase 1 among estrogen receptor-positive/human epidermal growth factor receptor type 2-negative breast cancer cases with early, late, and no recurrence.

BACKGROUND: The significance of the expression of aldehyde dehydrogenase 1 (ALDH1), a cancer stem cell marker, for predicting the recurrence of estrogen receptor (ER)-positive/human epidermal growth factor receptor type 2 (HER2)-negative breast cancer is still poorly understood. The value of ALDH1 in predicting the time of recurrence remains unknown. METHODS: In total, 184 patients with early distant recurrence, 134 patients with late distant recurrence, and 321 control patients without recurrence for more than 10 years after starting initial treatment for ER-positive/HER2-negative breast cancer, registered in 9 institutions, were analyzed. We assessed relationships between ALDH1 and other clinicopathological features, and ALDH1 expression was compared among the three groups. The relationship between ALDH1 expression and overall survival after recurrence was also evaluated in each group. RESULTS: The rates of ALDH1 expression positivity (more than 1 %) in the early, late, and no recurrence groups were 18.4 %, 13.4 %, and 8.4 %, respectively. ALDH1 expression correlated significantly with lymph node metastases (p = 0.048) and the Ki-67 labeling index (p < 0.001) in the early recurrence group. Multivariate analysis revealed ALDH1 expression to be significantly higher in the early recurrence group than in the no recurrence group (adjusted OR 2.140, 95 % CI 1.144-4.003, p = 0.016). Moreover, there was a significant difference in ALDH1 expression between the early and no recurrence groups receiving adjuvant endocrine therapy and chemotherapy (adjusted OR 4.625, 95 % CI 1.881-12.474, p < 0.001). However, there was no difference in ALDH1 expression between the late and no recurrence groups in univariate analysis (OR 1.507, 95 % CI 0.738-2.998, p = 0.253). In multivariate analysis, ALDH1 was not a factor independently predicting overall survival after the detection of recurrence (adjusted OR 1.451, 95 % CI 0.985-2.085, p = 0.059). CONCLUSIONS: Among patients with ER-positive/HER2-negative breast cancer, ALDH1 expression was more common in those with early recurrence, and this expression was found to be associated with a more aggressive breast cancer phenotype than that in the patients without recurrence. Further study is needed to clarify the prognostic significance of the heterogeneity of cancer stem cells and to confirm their role in resistance to chemotherapy.

Four types of ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery: classification of IBTR based on precise pathological examination.

We classified ipsilateral breast tumor recurrences (IBTRs) based on strict pathological rules. Ninety-six women who were surgically treated for IBTR were included. IBTRs were classified according to their origins and were distinguished based on strict pathological rules: relationship between the IBTR and the primary lumpectomy scar, surgical margin status of the primary cancer, and the presence of in situ lesions of IBTR. The prognosis of these subgroups were compared to that of new primary tumors (NP) in the narrow sense (NPn) that occurred far from the scar. Distant-disease free survival of IBTR that occurred close to the scar with in situ lesions and a negative surgical margin of the primary cancer (NP occurred close to the scar, NPcs) was similar to that of NPn. In contrast, IBTR that occurred close to the scar without in situ lesions (true recurrence (TR) that arose from residual invasive carcinoma foci, TRinv) had significantly poorer prognosis than NPn. IBTR that occurred close to the scar with in situ lesions and a positive surgical margin of the primary cancer (TR arising from a residual in situ lesion, TRis) had more late recurrences than NPcs. Precise pathological examinations indicated four distinct IBTR subtypes with different characteristics.

Extensive analysis of signaling pathway molecules in breast cancer: association with clinicopathological characteristics.

BACKGROUND: The aim of this study was to extensively analyze the signaling pathway molecules in breast cancer and to explore candidate biomarkers for clinicopathological relevance. METHODS: We assessed the expression of key factors in cell signaling, namely p-AKT, cyclin D1, P27, p-p70S6 K, p-4EBP1, and p-MAPK/ERK, within 338 invasive breast cancer patients. These factors were immunohistochemically examined in tumor tissues and assessed by staining score. Staining scores were analyzed by a clustering method to devise a new classification based on pathway activity. We investigated the relationships among staining scores, the clustering classification, and patient characteristics. RESULTS: The proportion of patients displaying high expression levels were as follows: p-AKT, 75%; cyclin D1, 12%; P27, 53%; p-p70S6 K, 37%; p-4EBP1, 19%; and p-MAPK/ERK, 3%. Patients were classified into two groups on the basis of staining scores. Group 1 (39%) included more positive cases for p-4EBP1, p-MAPK/ERK, and p-p70S6 K and fewer positive cases for P27 and cyclin D1 than Group 2 (61%). The clustering classification was significantly related to subgrouping by hormone receptor and HER2 (P < 0.001), nuclear grade (P < 0.001) and histological subtype (P = 0.034). A strong positive correlation was identified between p-AKT and P27, cyclin D1 and P27, p-p70S6 K and p-4EBP1, p-p70S6 K and p-MAPK/ERK, and between p-4EBP1 and p-MAPK/ERK. Levels of p-p70S6 K were significantly related to recurrence in both univariate (RR = 0.75, P < 0.001) and multivariate (RR = 0.71, P = 0.049) analyses. CONCLUSIONS: The present study helps us to understand the characteristics of signaling pathway status in breast cancers. Moreover, p-p70S6 K expression may be of use in predicting clinical outcome.

Time trend of breast cancer-related lymphedema according to body mass index.

PURPOSE: To clarify how body mass index (BMI) affects the development and temporal trend of breast cancer-related lymphedema (BCRL). METHODS: This is a prospective study in which patients with operable breast cancer were registered in a single institute between November 2009 and July 2010. The incidence of lymphedema at 1, 3, and 5 years after surgery was assessed according to BMI, and the trend of newly developed BCRL was examined. Obesity was defined as BMI ≥25 in accordance with the Japan Society for the Study of Obesity. RESULTS: A total of 368 patients were included in this study. The multivariate analysis of the whole population showed that high BMI, axillary dissection, and radiotherapy remained as risk factors for BCRL. Patients with high BMI showed a significantly higher incidence of new lymphedema than those with low BMI at 1 year (p < 00.001) regardless of axillary procedures (39.1 % vs 16.3 % for axillary dissection; 15.6 % vs 1.5 % for sentinel lymph node biopsy) but not at 3 and 5 years. Once BCRL developed, patients with high BMI showed slow recovery and 50.0 % of the patients retained edema at 5 years while patients with low BMI showed rapid recovery and 26.7 % retained after 3 years (p = 0.04). CONCLUSION: The preoperative BMI affected the incidence and temporal trend of BCRL regardless of axillary procedures or radiotherapy. Patients with high BMI should be given appropriate information about BCRL before surgery with careful follow-up for BCRL after treatment.

Impact of neoadjuvant chemotherapy on the safety and long-term outcomes of patients undergoing immediate breast reconstruction after mastectomy.

BACKGROUND: In breast cancer patients receiving neoadjuvant chemotherapy (NAC), immediate breast reconstruction (IBR) as a breast cancer treatment option remains controversial. We assessed the impact of NAC on surgical and oncological outcomes of patients undergoing IBR. METHODS: This was a retrospective multicenter study of 4726 breast cancer cases undergoing IBR. The rate of postoperative complications and survival data were compared between IBR patients who received NAC and those who did not receive NAC. Propensity score matching analysis was performed to mitigate selection bias for survival. RESULTS: Of the total 4726 cases, 473 (10.0%) received NAC. Out of the cases with NAC, 96 (20.3%) experienced postoperative complications, while 744 cases (17.5%) without NAC had postoperative complications. NAC did not significant increase the risk of complications after IBR (Odds ratio, 0.96; 95%CI 0.74-1.25). At the median follow-up time of 76.5 months, 36 patients in the NAC group and 147 patients in the control group developed local recurrences. The 5-year local recurrence-free survival rate was 93.1% in the NAC group and 97.1% in the control group. (P < 0.001). After matching, there was no significant difference between the two groups. CONCLUSION: IBR after NAC is a safe procedure with an acceptable postoperative complication profile.

Impact of radiation therapy for breast cancer with involved surgical margin after immediate breast reconstruction: A multi-institutional observational study.

INTRODUCTION: Involved surgical margins are risk factors for local recurrence and re-excision is often difficult, particularly in patients with breast cancer undergoing immediate breast reconstruction (IBR). However, the magnitude of the effect of radiation therapy on preventing local recurrence for breast cancers with involved margins has not been sufficiently assessed. MATERIALS AND METHODS: We retrospectively assessed sites of involved surgical margins and local recurrence after mastectomy with IBR in patients with early breast cancer between 2008 and 2016. The effect of postoperative radiation therapy was evaluated in patients with involved margins, adjusted for nuclear grade, lymphatic invasion, surgical procedures, and primary systemic therapy. RESULTS: A total of 274 (5.8 %) out of 4726 patients who underwent mastectomy with IBR had involved surgical margins: 133, 68, 88, and 26 had involvement of the skin, deep margin, lateral margins, and nipple, respectively (including duplicates). Radiation therapy was administered to 54 patients with involved margins. In patients with involved margins, 7-year cumulative incidences of local recurrence were 1.9 % and 12.6 % with and without radiation therapy, respectively (adjusted hazard ratio, 0.17; 95 % CI, 0.04-0.80). Local recurrence occurred in 28 patients, and the sites were skin, subcutaneous tissue, muscle, and nipple-areola complex in 7, 17, 1, and 3 patients, respectively. Among them, 23 (82.1 %) were associated with involved margin sites. CONCLUSIONS: Radiation therapy meaningfully reduced the incidence of local recurrence in patients with breast cancer with margin involvement after mastectomy with IBR. Most local recurrences occurred at involved margin-related sites.

Nipple-areolar complex malposition in breast reconstruction after nipple-sparing mastectomy: a multi-institutional retrospective observational study in Japan.

BACKGROUND: Position of the nipple-areolar complex (NAC) is an important factor in the esthetic impression of the breast, and NAC malposition is often an issue in breast reconstruction after nipple-sparing mastectomy (NSM). The purpose of this study was to evaluate the degree of NAC malposition depending on several factors using data quantified with the Mamma Balance application (Medic Engineering K.K., Kyoto, Japan). METHODS: Patients who underwent unilateral breast reconstruction after NSM at eight hospitals in Japan between 2007 and 2020 were retrospectively investigated. Using Mamma Balance, NAC malposition was quantified separately in horizontal and vertical directions using patient photographs from pre-operatively and 6-24 months post-operatively. The degree of malpositioning was then statistically compared using various factors. RESULTS: The NAC deviated more cranially and medially with implants than that with flaps. Cases with latissimus dorsi flap showed lateral malposition more often than cases with deep inferior epigastric artery perforator flap. With flaps, lateral incisions showed more lateral malposition, and peri-areolar incisions tended to show more medial NAC malposition. In cases with severe post-operative infection of the implant, the NAC tended to deviate cranially. In radiation cases, the NAC deviated cranially. No significant difference was observed according to the degree of breast ptosis or use of the pull-down operation. Only a very weak correlation was observed between a larger amount of mastectomy and more cranial NAC malposition with both flaps and implants. CONCLUSIONS: This study provides insights into the tendencies and characteristics of NAC malposition.

Prognosis of isolated locoregional recurrence after early breast cancer with immediate breast reconstruction surgery: a retrospective multi­institutional study.

BACKGROUND: The prognosis in patients with breast cancer with isolated locoregional recurrence (ILRR) without simultaneous distant metastases after immediate breast reconstruction (IBR) remains unknown. We aimed to investigate the prognosis in this patient population. METHODS: This multi-institutional retrospective observational study evaluated 3295 patients with primary breast cancer who underwent IBR at 12 Japanese medical facilities between January 1, 2008 and December 31, 2016. The outcome measures were the prognostic factors for ILRR after IBR, 5-year distant metastasis-free interval (DMFI), and 5-year overall survival (OS). RESULTS: Mastectomy or skin-sparing mastectomy was performed in 3295 patients. ILRR occurred in 70 patients, and the median observation period from ILRR diagnosis was 39.3 months. Of the 70 patients, 9 (12.9%) had axillary lymph node recurrence (ALNR) at the time of ILRR diagnosis. The 5-year DMFI and OS rates after ILRR were 92.4% and 91.2%, respectively. Pathological lymph node metastasis at primary surgery (P = 0.041) and ALNR (P = 0.022) at ILRR were significantly associated with DMFI in the univariate analysis. ALNR was the only independent prognostic factor in the multivariate analysis (P = 0.041). Post-mastectomy radiation therapy (PMRT; P = 0.022) and ALNR (P = 0.043) were significantly associated with OS in the univariate analysis, and both PMRT (P = 0.010) and ALNR (P = 0.028) were independent prognostic factors in the multivariate analysis for OS. CONCLUSIONS: Although patients with breast cancer who had ILRR after IBR have favorable prognosis, ALNR may lead to poor prognosis. To the best of our knowledge, this study is the first to report the prognosis of these patients.

Physicians' perception about the impact of breast reconstruction on patient prognosis: a survey in Japan.

BACKGROUND: One barrier to the widespread use of breast reconstruction (BR) is physicians' perception that BR adversely affects breast cancer prognosis. However, there is limited information regarding physicians' understanding of the impact of BR on patient prognosis and which physicians have misunderstandings about BR. METHODS: We conducted an e-mail survey regarding the impact of BR on the prognosis of patients with breast cancer among members of the Japanese Breast Cancer Society. RESULTS: Of 369 respondents, 99 (27%) said that they believe BR affects patient prognosis. Female respondents and those who treat fewer new breast cancer patients per year were more likely to state that they believe BR affects patient prognosis (P = 0.006 and 0.007). Respondents who believed that BR affects patient prognosis underestimated 5-year overall survival rates in patients who receive BR and subsequently have local or regional recurrence in different sites. CONCLUSION: Our survey demonstrated that a quarter of respondents believe that BR affects patient prognosis and underestimate survival rates in patients who receive BR and have subsequent local or regional recurrence. Because of the lack of evidence regarding the impact of BR on patient prognosis, educating physicians by providing accurate knowledge regarding BR and patient prognosis is highly recommended.

Characteristics, treatment trends, and long-term outcomes of Japanese patients with pregnancy-associated breast cancer (PABC).

PURPOSE: To clarify the characteristics, treatment trends, and long-term outcomes of patients with pregnancy-associated breast cancer (PABC). METHODS: PABC includes breast cancer diagnosed during pregnancy (PBC) and breast cancer diagnosed within 1 year after childbirth or during lactation (LBC). We compared clinical characteristics of 126 patients with LBC and 49 patients with PBC who underwent surgery at our hospital from 1946 to 2018. Survival was compared between patients with LBC and those with PBC in terms of breast cancer-specific disease-free survival (BC-DFS) and overall survival (OS). RESULTS: Patients with LBC were more likely to have family history, lymph node metastasis, lymphatic invasion, and to receive chemotherapy than patients with PBC. Patients with LBC showed poorer BS-DFS and OS than patients with PBC. Among patients with LBC, those treated after 2005 were older at surgery, had a smaller tumor size, received more systemic therapy, and had a more favorable prognosis than patients treated before 2004. Family history, breast cancer within 1 year after childbirth, and surgery before 2004 as well as cStage, lymph node metastasis, and lymphatic invasion were significantly associated with poor prognosis in patients with LBC. In the multivariate analysis for BC-DFS and OS among patients with PABC, LBC vs PBC did not remain as an independent prognostic factor while cStage remained. CONCLUSION: Patients with LBC had a poorer prognosis than those with PBC, most likely due to disease progression rather than biological characteristics. Early detection and optimization of systemic treatments are critical for improving the outcomes of patients with LBC.

Assessment of axillary node status by ultrasound after neoadjuvant chemotherapy in patients with clinically node-positive breast cancer according to breast cancer subtype.

The use of sentinel node biopsy (SNB) following neoadjuvant chemotherapy (NAC) for patients with cN1 breast cancer is controversial. Improvements of negative predictive value (NPV) by axillary ultrasound (AUS), which corresponds to the accurate prediction rate of node-negative status after NAC, would lead to decreased FNR of SNB following NAC. In this study, we retrospectively investigated the accurate prediction rate of NPV by AUS after NAC in patients with cytologically node-positive breast cancer treated between January 2012 and December 2016. Of 279 eligible patients, the NPV was 49.2% in all patients, but varied significantly by tumor subtype (p < 0.001) and tumor response determined by magnetic resonance imaging (MRI) (p = 0.0003). Of the 23 patients with clinically node negative (ycN0) by AUS and clinical complete response in primary lesion by MRI, the NPV was 100% in patients with HR±/HER2+ or HR-/HER2- breast cancer. In conclusion, regarding FNR reduction post-NAC, it will be of clinical value to take tumor subtype and primary tumor response using MRI into account to identify patients for SNB after NAC.

Ductal carcinoma in situ and sentinel lymph node metastasis in breast cancer.

BACKGROUND: The impact of sentinel lymph node biopsy on breast cancer mimicking ductal carcinoma in situ (DCIS) is a matter of debate. METHODS: We studied the rate of occurrence of sentinel lymph node metastasis in 255 breast cancer patients with pure DCIS showing no invasive components on routine pathological examination. We compared this to the rate of occurrence in 177 patients with predominant intraductal-component (IDC) breast cancers containing invasive foci equal to or less than 0.5 cm in size. RESULTS: Most of the clinical and pathological baseline characteristics were the same between the two groups. However, peritumoral lymphatic permeation occurred less often in the pure DCIS group than in the IDC-predominant invasive-lesion group (1.2% vs. 6.8%, p = 0.002). One patient (0.39%) with pure DCIS had two sentinel lymph nodes positive for metastasis. This rate was significantly lower than that in patients with IDC-predominant invasive lesions (6.2%; p < 0.001). CONCLUSIONS: Because the rate of sentinel lymph node metastasis in pure DCIS is very low, sentinel lymph node biopsy can safely be omitted.

Histogenesis of metaplastic breast carcinoma and axillary nodal metastases.

A 40-year-old breast-feeding woman presented with left breast swelling. On physical examination a 7 cm mass was found in the breast. Because biopsy demonstrated malignant tissue, mastectomy with axillary nodal dissection was performed. Pathological findings were consistent with metaplastic breast carcinoma with nodal metastases. The primary tumor consisted of three types of invasion: ductal, squamous, and sarcomatous. Furthermore, three morphological transitions were observed: ductal-squamous, ductal-sarcomatous, and squamous-sarcomatous. Ductal-squamous (12/18 microscopy slides) and squamous-sarcomatous transitions (10/18) were more commonly observed than ductal-sarcomatous transition (3/18). Furthermore, immunohistochemistry showed loss of epithelial marker (cytokeratin) and acquisition of mesenchymal markers (vimentin and alpha-smooth muscle actin) in the sarcomatous component. These findings suggested that epithelial-mesenchymal transition had occurred in the tumor and that two pathways, ductal-squamous-sarcomatous and ductal-sarcomatous transition, were involved in progression of metaplastic breast carcinoma. The main pathway appeared to be ductal-squamous-sarcomatous transition. Regarding the nodal metastases, of 13 positive nodes, ductal, squamous, and sarcomatous components were observed in 13, seven, and two nodes, respectively. Moreover, as in the primary tumor, ductal-squamous and squamous-sarcomatous transitions were observed. This suggested that the ductal component metastasized to the nodes and that epithelial-mesenchymal transition subsequently occurred within the nodes.