Eriko Abe

Loss of p16 expression is associated with the stem cell characteristics of surface markers and therapeutic resistance in estrogen receptor-negative breast cancer

Triple‐negative breast cancer [TNBC, which is negative for the estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor 2] is a high‐risk form of the disease without a specific therapy. DNA microarray and immunohistochemical analyses have shown that most TNBCs fall within the basal‐like histological subset of breast cancers, which frequently exhibit inactivation of the retinoblastoma tumor suppressor (Rb) and upregulation of the cyclin‐dependent kinase inhibitor p16INK4a (p16). However, downregulation of p16 expression has been observed in some basal‐like breast cancer cell lines, suggesting that such cells can be divided into two groups according to Rb and p16 status. We now show that cells that are CD44+ and CD24−, a phenotype associated with stem‐like breast cancer cells, are more abundant in ER−/p16− breast cancer cell lines than in ER−/p16+ lines. It was also found that p16 expression was downregulated in mammospheres from an ER‐negative breast cancer cell line. Depletion of p16 by RNA interference in ER‐negative breast cancer cells increased the percentage of CD44+/CD24− cells and increased the expression of mRNA of the ES‐like genes Nanog, Oct4, and Sox2 through an Rb‐independent pathway. Furthermore, such depletion of p16 reduced chemosensitivity. The loss of p16 expression may thus reduce the response of ER‐negative breast cancer cells to chemotherapy by conferring cancer stem cell‐like properties. Consistent with this conclusion, immunohistochemical analysis of the clinical samples suggests that low p16 expression in TNBC is associated with resistance to preoperative chemotherapy.

An induction of microRNA, miR-7 through estrogen treatment in breast carcinoma

BackgroundEstrogen plays an important role in the development of estrogen-dependent breast carcinoma. Recently, several studies demonstrated a possible involvement of several micro RNAs (miRNAs) in the development of resistance to endocrine therapy in breast cancer patients, but the correlation between estrogen actions and miRNA expression in breast carcinoma still remains largely unknown. Therefore, in this study, we examined the in vitro effects of estrogen upon miRNA expression profiles in breast carcinoma.MethodsWe first screened the miRNA expression profiles induced by 17β-Estradiol (E2) using RT2 miRNA PCR Array in the ER-positive breast carcinoma cell line MCF-7. We identified miR-7 as the important miRNA associated with estrogen actions in these cells and further examined the changes of estrogen-dependent EGFR expression by miR-7 in ER-positive or -negative breast carcinoma cell lines including MCF-7. We also evaluated the correlation between miR-7 and EGFR expression in breast carcinoma cells derived from 21 patients using laser capture microdissection combined with quantitative reverse transcriptase-PCR.ResultsSeventeen miRNAs were significantly induced by E2 treatment in the MCF-7 cell line. Among 17 miRNAs induced by estradiol treatment, only miR-7 expression was significantly decreased by subsequent ICI treatment. The expression of miR-7 was up-regulated 2.94-fold by E2 treatment. miR-7 was reported to suppress epidermal growth factor receptor (EGFR) expression in several human malignancies. Transfection of miR-7 significantly suppressed EGFR mRNA levels in MCF-7 cells. Depletion of E2 from cell culture media also increased the expression level of EGFR mRNA in MCF-7 and T-47D cells but not in ER-negative, MDA-MB-231 and SK-BR-3 cells. We also evaluated the status of miR-7 in breast carcinoma tissues, but the correlation between the status of miR-7 and EGFR in carcinoma cells isolated by laser capture microscopy was not detected.ConclusionsThese results suggest that miR-7 may play a role in the development of resistance to endocrine therapy in breast cancer patients through regulating EGFR expression of carcinoma cells.

The significance of combined CK5/6 and p63 immunohistochemistry in predicting the risks of subsequent carcinoma development in intraductal papilloma of the breast.

Prediction of subsequent risks of breast carcinoma (BC) development in intraductal papilloma (IDP) has remained controversial with the exception of atypical papilloma (AP). The potential value of immunohistochemistry (IHC) of cytokeratin 5/6 [CK5/6] and p63 have been proposed but its standardization has also remained controversial. We studied 17 patients initially diagnosed as IDP or AP who subsequently developed BC with 34 age‐matched controls. We compared histological features, results of IHC (estrogen receptor [ER], progesterone receptor [PR], human epidermal growth factor receptor 2 [HER2], p63, CK5/6, Ki67), and ultrasound findings. Univariate conditional logistic regression analysis revealed that the status of both CK5/6 and p63/CK5/6 were significantly associated with subsequent BC development (P < 0.05). BC development in CK5/6 positive patients was 17.9% and p63/CK5/6 double positive patients 8.6%, respectively. Ultrasound evaluation was not significantly associated with any of the parameters examined and subsequent carcinoma development. Despite CK5/6 positivity, the subsequent incidence of BC development was nearly 20%. However p63/CK5/6 double positive status could predict a significantly lower subsequent carcinoma incidence, indicating a more accurate prognostic utility. Combining p63/CK5/6 with histological findings could be easily applied and could predict the subsequent BC development of the patients diagnosed as IDP at biopsy.

Clinicopathological significance of 'atypical ductal proliferation' in core needle biopsy of the breast.

Atypical ductal proliferation or ADP has been used in histopathological diagnosis of core needle biopsy (CNB) but its details have not been well studied. Therefore, we examined the clinicopathological characteristics of the initial CNB cases diagnosed as ‘ADP ’ who subsequently turned out to be malignant, and compared the findings to those that did not. Among 101 cases initially diagnosed as ADP in CNB, the second biopsy revealed no carcinoma (38), ductal carcinoma in situ (DCIS) (45) and invasive carcinoma (18). Significant differences were detected between those which turned out to be carcinoma and those that did not, in the status of myoepithelial cells identified by p63 immunohistochemistry (P = 0.026) and ultrasound (US) categories (P < 0.001). We further compared the histopathological characteristics of those initially diagnosed as ADP and subsequently as DCIS or invasive ductal carcinoma (IDC) with those initially diagnosed as such. DCIS or IDC cases initially diagnosed as ADP had significantly lower Ki67 labeling index (P < 0.01, P < 0.01) and histological grade using Van nuys prognostic index (P < 0.01) or Nottingham histological grades (P < 0.01) respectively than those initially as DCIS or IDC. An assessment of myoepithelial components with US findings might contribute to determine the subsequent clinical algorithm of the patients diagnosed as ADP at initial CNB.

Mucin‑poor and aggressive mucinous tubular and spindle cell carcinoma of the kidney: Two case reports

Mucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare renal epithelial neoplasm. Although MTSCC is considered to be a low-grade and indolent neoplasm, aggressive cases have been recently reported. The present study discussed two additional cases of high-grade MTSCC causing multiple distant metastases with a fatal course. In case 1, a 71-year-old patient presented with hematuria and pyuria. Computed tomography (CT) scan of the right kidney revealed a mass lesion, for which partial nephrectomy was performed. However, a follow-up CT imaging revealed distant metastases in the liver, the paraaortic lymph nodes and the bone. Despite molecular targeted therapy and irradiation, the patient succumbed due to tumor progression. In case 2, a 64-year-old patient presented with an incidentally identified mass lesion in the right kidney. A laparoscopic nephrectomy was performed, and a follow-up CT imaging revealed metastases in the skin and lungs. The cytology of pleural effusion revealed pleuritis carcinomatosa. Histologically, both cases were diagnosed as mucin-poor MTSCC with high-grade transformation, which comprised uniform tumor cells primarily forming slender tubules. The tumors contained low- and high-grade regions. In addition, venous invasion and necrosis were observed. The tumor cells also demonstrated increased Ki-67 labeling indices and cellular tumor antigen p53 (p53) nuclear accumulation. High-grade transformation, large tumor size, necrosis, venous invasion, high Ki-67 labeling index and p53 nuclear accumulation are generally predictive findings for aggressive behavior of malignant tumors. In the current report, it was emphasized that MTSCC possesses a wide spectrum of clinicopathological features. Thus, careful postoperative investigation is required for MTSCC with high-grade elements due to its aggressive nature.

Abstract P2-01-32: Comparison between positive and false-negative sentinel lymph nodes in breast cancer patients

Background: Intra-operative sentinel node biopsy (SNB) is performed for clinically node negative invasive carcinoma (IC). Despite a negative result for metastasis from rapid frozen section (FS) diagnosis of intra-operative SNB, some cases may be diagnosed positive when permanent sections (PS) are analyzed (i.e., false negative). In order to reduce the false-negative rate, it is necessary to determine why macrometastases measuring greater than 2 mm cannot be accurately diagnosed using frozen specimens. The aim of this study was to compare the pathological characteristics of false-negative and positive cases of macrometastasis using FSs. We also reviewed whether there were differences in postoperative prognoses between positive and false-negative cases. Methods: We retrospectively reviewed 1632 intra-operative SNBs collected from 2008 to 2011 at St. Luke’s International Hospital, Tokyo, JAPAN. Of these, 980 patients had undergone surgery for the treatment of IC without neoadjuvant chemotherapy. Lymph nodes were sectioned every 2 mm and examined. For FSs, we performed hematoxylin and eosin (HE) staining, and for PSs, we used HE and cytokeratin (AE1/AE3) staining. Image J (NIH Image, Bethesda, MD, USA) was used for assessment of the metastatic area of lymph nodes. Micro- and macrometastases were defined as metastatic lesions measuring between 0.2 and 2 mm or measuring 2 mm or more, according to TMN classification. Results: Using FSs, we identified 104 patients (10.6%) who were positive for macrometastasis, 16 patients (1.6%) who were positive for micrometastasis, and 860 patients (87.8%) who were negative for metastasis. Of the negative cases, the result was changed to micrometastasis in 37 cases (4.3%) and to macrometastasis (false-negative cases) in 14 cases (1.6%). Ten of the 14 patients did not have additional axillary lymph nodes dissection. The mean age of the patients was 55.1 ± 3.1 years for false-negative cases and 52.3 ± 1.2 years for positive cases. In terms of histological features, there were statistically significant differences between false-negative and positive cases for invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), and IDC plus ILC (p Conclusions: Although it is necessary to reduce false-negative cases, no difference in prognosis was detected in our study. False-negative cases had lower metastasis area ratios than positive cases diagnosed using rapid diagnosis of intra-operative SNBs, and ILC is known to be high in histological features. Therefore, using AE1/AE3 stain together with rapid diagnosis of intra-operative SNBs may lower the false-negative rate when a diagnosis includes ILC in pre-operation analysis. Citation Format: Eriko Abe, Naoki Hayashi, Toshinao Onoda, Yang Yang, Mieko Uno, Hideko Yamauchi, Sachiko Ohde, Koyu Suzuki. Comparison between positive and false-negative sentinel lymph nodes in breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-32.

Response to neoadjuvant chemotherapy in patients with triple negative breast cancer.

CTRC-AACR San Antonio Breast Cancer Symposium: 2008 Abstracts Abstract #6069 Background: Triple negative breast cancer (TNBC) is defined by the lack of estrogen receptor(ER), progesterone receptor (PR), and human epidermal growth factor receptor2 (HER-2) expression. TNBC has poor outcome due to no specific therapeutic agents. But TNBC includes two major phenotypes, basal-like and non basal-like phenotypes. Basal-like phenotype has poor prognosis and is associated with positive expression of basal markers. We compared response to neoadjuvant chemotherapy between patients with TNBC and non-TNBC, in addition, basal-like and non basal-like phenotype. Material and Methods: We retrospectively reviewed a total of 1948 operated patients with a diagnosis of primary breast cancer from November 2002 to December 2006 at St. Lukes International Hospital. 369 (18.9%) patients received neoadjuvant chemotherapy. Clinical and pathological response rates, survival measurements and relapse rates were compared between patients with TNBC and non-TNBC. Clinical response was determined by MRI or CT which was performed before and after neoadjuvant chemotherapy. Histopathological parameter(ER, PGR, HER-2, nuclear grade, mitosis) were confirmed from the specimens of needle biopsy performed before treatment. The specimens were also stained with basal markers (cytokeratin 5/6 and EGFR) to identify basal-like phenotype in TNBC. Basal-like phenotype was defined by the expression of CK5/6 and/or EGFR in >10% of tumor cells. Results: Fifty-four of 369 patients (14.6%) had TNBC. Progressive disease (PD) rate was significantly higher in patients with TNBC than those patients with non-TNBC (20.7% v 2.3%).And pathologic complete response rate (pCR) was also higher in patients with TNBC than those patients with non-TNBC (17% v 9.6%).14of 48 patients (29.1%) was diagnosed as Basal-like phenotype in TNBC. Clinical response rate for basal-like phenotype was worse than non basal-like phenotype (42.9% v 67.6%). Furthermore, both disease free survival and overall survival for basal-like subtype were significantly worse than non basal-like phenotype (p<0.05).Other parameters including age, histological grade, and tumor size were not significant for response to neoadjuvant chemotherapy. Conclusions: Patients with TNBC have higher PD rate but also pCR rate to treatment compared with non TNBC. Furthermore, basal-like phenotype could predict poor prognosis. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6069.