Abstract. In the present study, clinical tumor response following neoadjuvant chemotherapy (NAC) was diagnosed by magnetic resonance imaging (MRI) and clinicopathological factors, including molecular subtypes at baseline, were analyzed for correlations with pathological tumor responses. In addition, clinicopathological factors were analyzed for a correlation with the MRI capacity to predict pathological complete response (pCR). Clinical tumor response evaluated by MRI following NAC was determined as a clinical CR (cCR) or a residual tumor. cCR was confirmed if no gadolinium enhancement or an enhancement equal to or less than that of glandular tissue was observed in any phase of the MRI. Pathological tumor responses following NAC were classified into grades 0 (no change) to 3 (no residual invasive cancer) according to criteria of the Japanese Breast Cancer Society. pCR was defined as grade 3 in the present study. Of 264 cases of invasive breast cancer in 260 patients (4 synchronous bilateral breast cancer cases), 59 (22%) were diagnosed by MRI following NAC as cCR and 98 (37%) were pathologically diagnosed as pCR. In terms of predicting pCR by MRI, the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 44, 90, 73, 73 and 73%, respectively. Tumor size, hormone receptor status, human epidermal growth factor receptor 2 (HER2) status, molecular subtype and histological type were significantly correlated with pathological tumor responses. pCR rates increased in the following order: luminal/HER2-negative (14%), luminal/HER2-positive (32%), triple-negative (46%) and non-luminal/HER2-positive (73%) tumors. Sensitivity and specificity were the highest (60 and 100%, respectively) in triple-negative tumors. PPV decreased in the following order: triple-negative (100%), non-luminal/HER2-positive (92%), luminal/HER2-positive (46%) and luminal/HER2-negative (33%) tumors. In conclusion, MRI evaluation is useful for predicting pCR following NAC, particularly for triple-negative tumors.

Ipsilateral breast tumor relapse (IBTR) after breast-conserving treatment (BCT) may represent two distinct types of lesion, including a true recurrence (TR) or a new primary tumor (NPT). The aim of this study was to ascertain the difference between TRs and NPTs and to show the clinical significance of classifying IBTR into these two types of recurrence. Patients (n = 2,075) with unilateral invasive breast cancer who underwent BCT between 1987 and 2005 at Saitama Cancer Center were analyzed. IBTR was classified into TR and NPT, which was based on all clinical and pathological features of both a primary tumor and IBTR that can be evaluated. IBTR-free survival and the risk factors were analyzed in order to compare the findings for TR and NPT. In addition, the salvage surgical methods for IBTR and overall survival after IBTR were analyzed. Sixty patients with IBTR were classified into 52 with TR and eight with NPT. IBTR-free survival was significantly shorter in the patients with TR than those with NPT. Young age, tumor size, a positive surgical margin, and omission of radiation therapy (RT) were significant risk factors for TR. Omission of RT was the only significant risk factor for NPT. In 27 patients who underwent a repeat lumpectomy for TR, four had a second IBTR. The overall survival after IBTR was worse in patients with TR than NPT. TR and NPT show quite different clinical features. Classifying IBTR into TR or NPT can therefore help to select the most appropriate treatment for IBTR.

ALND can be avoided in most patients with breast cancer with intraoperative, false-negative SLNB.

Abstract. although triple-negative breast cancer (tnBc) is associated with a poor prognosis, recent reports have indicated that a higher proportion of tnBc patients shows a pathological complete response (pcr) to neoadjuvant chemotherapy (nac) than is the case for non-tnBc patients. the aim of this study was to identify markers that predict pcr to nac in tnBc patients, and to clarify prognostic factors that affect the outcome of tnBc patients with residual disease (rd) after nac. among 44 tnBc patients who received anthracycline-and taxane-based combination nac, we analyzed the relationship between pathological response and clinicopathological characteristics, including immunohistochemical parameters (cytokeratin 5/6, epidermal growth factor receptor, Ki-67, p53, breast cancer susceptibility protein 1 and topoisomerase iiα). We also assessed the prognostic impact on patients with rd by analyzing the correlation between disease-free survival (dFS) and clinicopathological parameters. Sixteen patients (36%) achieved a pcr and logrank test showed that these patients had a significantly more favorable outcome than patients with rd (dFS, p=0.00184; overall survival, p=0.0080). among the clinicopathological parameters examined, none was correlated with pathological response, with the exception of p53. patients with immunohistochemical overexpression of p53 more frequently achieved a pcr than those without p53 overexpression (p=0.0484). in the patients with rd, the cox proportional hazards model showed that the presence of lymphovascular invasion was significantly associated with shorter dFS (hazard ratio, 13.333; 95% ci 1.587-111.111; p=0.0171). p53 overexpression may be a key predictor of a favorable response to nac. Since patients with rd, particularly those positive for lymphovascular invasion, had an extremely poor outcome, novel therapeutic approaches for these patients are warranted.

Aromatase inhibitors (AIs) were more effective than tamoxifen as a neoadjuvant endocrine therapy (NAE) for postmenopausal women with estrogen receptor (ER)-positive breast cancer. Neoadjuvant AIs were shown to reduce tumor volume and to allow the performance of breast-conserving surgery (BCS) in cases that would normally require mastectomy. Predictive markers of neoadjuvant AIs may be ER-rich, progesterone receptor (PgR)-rich and human epidermal growth factor receptor 2 (HER2)-negative tumors. However, the ability of HER2 expression to predict a response to neoadjuvant AIs is controversial. Pathological tumor size, nodal status, Ki67 level, and ER score are predictive for the survival of postmenopausal women with breast cancer who have been treated with NAE. These factors could be useful in order to select patients who do not require chemotherapy. Indeed, neoadjuvant AIs are a potential treatment option for postmenopausal women with ER-rich breast cancer who prefer BCS despite having large tumors suitable for mastectomy.