Rin Nagaoka

Tamoxifen activates CYP3A4 and MDR1 genes through steroid and xenobiotic receptor in breast cancer cells

Cytochrome P450 monooxygenase 3A4 (CYP3A4) and P-glycoprotein, encoded by multidrug resistance 1 (MDR1) gene, are responsible for the metabolism of endogenous steroids, prescribed drugs, and xenobiotics. Both genes are regulated by steroid and xenobiotic receptor (SXR), a member of nuclear hormone receptors. Various endogenous steroids and drugs function as ligands of SXR. Although CYP3A4, MDR1, and SXR are expressed mainly in the liver and the small intestine, these gene products are also expressed in breast cancer cells. Because tamoxifen (TAM) is known to be metabolized by CYP3A4 and P-glycoprotein, weinvestigated the effect of TAM on these SXR-targeted genes in breast cancer cells. Transient transfection-based reporter gene assays showed 4-hydroxy TAM activated the SXR-mediated transcription through CYP3A4 and MDR1 promoters in a ligand- and receptor concentration-dependent manner. We confirmed the binding of 4-hydroxy TAM to SXR by ligand binding assay. Moreover, semiquantitative RT-PCR studies revealed that 4-hydroxy TAM activated the expression of CYP3A4 and MDR1 mRNA in MCF-7 cells. These results suggest that TAM induces CYP3A4 and MDR1 gene expression through SXR, which may affect TAM metabolic pathway in breast cancer cells.

Circulating Tumor Cells in Breast Cancer Patients Treated by Neoadjuvant Chemotherapy: A Meta-analysis.

Background We conducted a meta-analysis in nonmetastatic breast cancer patients treated by neoadjuvant chemotherapy (NCT) to assess the clinical validity of circulating tumor cell (CTC) detection as a prognostic marker. Methods We collected individual patient data from 21 studies in which CTC detection by CellSearch was performed in early breast cancer patients treated with NCT. The primary end point was overall survival, analyzed according to CTC detection, using Cox regression models stratified by study. Secondary end points included distant disease-free survival, locoregional relapse-free interval, and pathological complete response. All statistical tests were two-sided. Results Data from patients were collected before NCT (n = 1574) and before surgery (n = 1200). CTC detection revealed one or more CTCs in 25.2% of patients before NCT; this was associated with tumor size (P < .001). The number of CTCs detected had a detrimental and decremental impact on overall survival (P < .001), distant disease-free survival (P < .001), and locoregional relapse-free interval (P < .001), but not on pathological complete response. Patients with one, two, three to four, and five or more CTCs before NCT displayed hazard ratios of death of 1.09 (95% confidence interval [CI] = 0.65 to 1.69), 2.63 (95% CI = 1.42 to 4.54), 3.83 (95% CI = 2.08 to 6.66), and 6.25 (95% CI = 4.34 to 9.09), respectively. In 861 patients with full data available, adding CTC detection before NCT increased the prognostic ability of multivariable prognostic models for overall survival (P < .001), distant disease-free survival (P < .001), and locoregional relapse-free interval (P = .008). Conclusions CTC count is an independent and quantitative prognostic factor in early breast cancer patients treated by NCT. It complements current prognostic models based on tumor characteristics and response to therapy.

Abstract S3-01: IMENEO: International MEta-analysis of circulating tumor cell detection in early breast cancer patients treated by NEOadjuvant chemotherapy

Background We performed an international meta-analysis of individual patient data to assess the clinical validity of circulating tumor cell (CTC) count in non-metastatic breast cancer (BC) patients (pts) treated by neoadjuvant chemotherapy (NCT). Methods A protocol pre-specified the study objectives. We performed a literature & abstracts search up to Dec 2014, then contacted all centers deemed to have eligible data (published or not): early BC pts treated with NCT with CTC count by CellSearch®. The primary endpoint was overall survival (OS); secondary endpoints included distant disease-free survival (DDFS), locoregional relapse-free interval (LRFI) and pathological complete response (pCR). Non-overlapping CTC time points were: baseline (5-0 weeks before NCT), 1-8 weeks after NCT start, 5-0 weeks before surgery and 1-52 weeks after surgery. We used Cox regression models, stratified by study, and the landmark method to establish the prognostic value of CTC count/changes during treatment and survival. Results We collected 2,156 individual pt data from 21 studies and 16 centers worldwide. With ≥1/≥2/≥5 CTC/7.5ml as thresholds, CTC positivity rate was 25/13/6% at baseline, 17/6/3% after NCT start, 15/5/1% before surgery and 11/4/1% after surgery (decrease, p 301, 418 and 157 events were reported for OS, DDFS and LRFI, respectively. In univariate analyses, ≥1 CTC at baseline was a prognostic factor for OS (HR=2.6 [1.9-3.4], p Finally, in multivariate analyses, baseline CTC detection (whatever the CTC threshold used : ≥1/≥2/≥5 CTC) was an independent prognostic factor for OS, DDFS and LRFI, together with pCR, cT, cN and tumor subtype, (e.g. for OS: CTC≥2 HR=4.2 [3.0-5.9] p Conclusions Our study demonstrates with the highest level of evidence that CTCs are a prognostic biomarker in early BC treated by NCT. This impact was independent to that of pCR and was observed on OS, DDFS and also -for the first time- on LRFI. CTC count can usefully complement standard prognostic factors and pCR to improve the prognostication of early BC pts. Citation Format: Bidard F-C, Michiels S, Mueller V, Riethdorf S, Esserman LJ, Lucci A, Naume B, Horiguchi J, Gisbert-Criado R, Sleijfer S, Toi M, Garcia-Saenz JA, Hartkopf A, Generali D, Rothe F, Smerage J, Muinelo L, Stebbing J, Viens P, Magbanua M, Hall CS, Engebratenm O, Takata D, Vidal-Martinez J, Onstenk W, Fujisawa N, Diaz-Rubio E, Taran F-A, Cappelletti MR, Ignatiadis M, Name N, Proudhon C, Wolf D, Bowman Bauldry J, Borgen E, Nagaoka R, Caranana V, Kraan J, Maestro M, Brucker SY, Weber K, Reyal F, Amara D, Gopalkrishna Karhade M, Ruud Mathiesen R, Tokiniwa H, Llombart-Cussac A, D9Hollander K, Cottu P, Park JW, Loibl S, Pierga J-Y, Pantel K. IMENEO: International MEta-analysis of circulating tumor cell detection in early breast cancer patients treated by NEOadjuvant chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S3-01.

Characteristics of Japanese aldosterone-producing adenomas with KCNJ5 mutations

Somatic mutations in KCNJ5 gene have been identified in patients with adrenal aldosterone-producing adenomas (APAs). We previously reported that Japanese patients with APAs had distinct characteristics from patients in Western countries; i.e. they had a high frequency of KCNJ5 mutations and exhibited a frequent association with cortisol co-secretion. Therefore, APAs among Japanese patients may have different features from those in Western countries. We added recent cases, examined 47 cases (43% male) of APAs, including clinicopathological features, KCNJ5 mutations, and the mRNA levels of several steroidogenic enzymes, and compared the results obtained to those reported in other countries. While the prevalence of KCNJ5 mutations is approximately 40% in Western countries, 37 APA cases (78.7%) showed mutations: 26 with p.G151R and 11 with p.L168R. Although a significant gender difference has been reported in the frequency of KCNJ5 mutations in Europe, we did not find any gender difference. However, the phenotypes of Japanese patients with mutations were similar to those of patients in Western countries; patients were younger and had higher plasma aldosterone levels, lower potassium levels, and higher diastolic blood pressure. Reflecting these phenotypes, APAs with mutations had higher CYP11B2 mRNA levels. However, in contrast to APAs in Western countries, Japanese APAs with mutations showed lower CYP11B1, CYP17A1, and CYP11A1 mRNA levels. These findings demonstrated that Japanese APA patients may have distinct features including a higher prevalence of KCNJ5 mutations, no gender difference in the frequency of these mutations, and characteristics similar to the zona glomerulosa.

Abstract P3-06-29: Change of circulating tumor cells before and after neoadjuvant chemotherapy in patients with primary breast cancer

Background: Circulating tumor cells (CTCs) in peripheral blood may represent the possible presence of early tumor dissemination. However, relatively few studies were designed to investigate the change of CTC status by adjuvant chemotherapy in operable breast cancer patients. Patients and methods: Peripheral blood (7.5ml) was collected from 95 patients with stage II/III breast cancer before neoadjuvant chemotherapy (NAC). NAC consisted of anthracycline and paclitaxel chemotherapy and additional trastuzumab treatment for patients with HER2-positive tumors. Results: The average age of patients was 52.6 year old (median 52.0). One or more CTCs were detected in 18 (18.9%) of 95 patients. CTCs were detected in 6 (12.0%) of 50 patients with clinical stage II disease and 12 (26.7%) of 45 patients with clinical stage III disease. According to tumor subtypes, CTCs were detected in 5 (17.9%) of 28 patients with hormone receptor (HR)-positive and HER2-negative tumors (L subtype), 3 (12.5%) of 24 patients with HR-positive and HER2-positive tumors (L-H subtype), 4 (22.2%) of 18 patients with HR-negative and HER2-positive tumors (H subtype), and 6 (24.0%) of 25 patients with HR-negative and HER2-negative tumors (TN subtype). After NAC, 17 (94.4%) of 18 patients who were CTC-positive before chemotherapy changed into negative status. 30 (31.6%) of 95 patients had a pathologic complete response (pCR) after NAC. There was no correlation between CTC status before NAC and pathological response. At the median follow up of 27 months, distant metastasis was observed in 9 patients (9.5%). Patients with clinical stage III, TN subtype, or non-pCR had a significantly worse disease-free survival (DFS). However, CTC status before NAC was not a significant prognostic factor. Conclusion: NAC has a significant impact on CTC status irrespective of tumor subtypes. CTC status before NAC was not a significant prognostic factor in this study. The reason of which may be that most of patients showing positive for CTCs before NAC have changed into negative after NAC. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-29.

Huge myoid hamartoma of the breast treated with reduction mammaplasty: report of a case.

Breast hamartoma is an uncommon benign tumor characterized by the variety of component tissues. Adipose tissue, mammary glands, and fibrous tissue in various proportions are the main components and form a well-circumscribed mass. Myoid (muscular) hamartoma is an extremely rare subtype of breast hamartoma, which contains an additional smooth muscle component. Inadequate breast contour and nipple-areola complex malposition and expansion can occur after resection of a large myoid hamartoma. Immediate mammaplasty for the affected breast, using the dermoglandular flap technique, is required to provide symmetry of the bilateral breasts. We report a case of myoid hamartoma that was larger than ever documented before. An acceptable aesthetic result was achieved by resection and application of reduction mammaplasty in a single-stage operation.

Abstract P2-05-07: Comparison of hormone receptor and HER-2 expression in primary breast cancers and sentinel lymph node metastases

Background: Recently, it is a hot topic that the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor type 2 (HER2) may differ between the primary tumors and the paired recurrent metastatic tumors. On the other hand, the concordance of the ER, PR, and HER2 status between the primary tumor and ipsilateral axillary lymph node metastases is reported to be high in previous study. However, in these reports, the majority of lymph nodes metastases examined are macrometastases obtained from axillary lymph node dissection. The aim of the present study is to compare the ER, PR, and HER2 status of the primary breast tumors with that of sentinel lymph node micrometastases and macrometastases. Methods: A total of 770 breast cancer patients underwent sentinel lymph node biopsy between 2006 and 2010 at our hospital. Among them, 87 patients who had only one node positive were eligible for our study. ER, PR, and HER2 status were determined by immunohistochemistry (IHC) and/or FISH. Result: We analyzed 76 patients with 50(66%) patients with macrometastasesn and 26 (34%) micrometastases, except 11 cases those were indeterminate for IHC. ER status of primary tumor and the paired metastatic lymph node were almost full concordance except one case, in which ER was negative in primary tumor but ER was positive in lymph node. Discordance for PR was 15.8% (n = 12). Among these, six patients had PR-positive on primary and PR-negative in lymph node while six patients had PR-negative in primary and PR-positive in lymph node. Discordance for HER2 between primary tumor and metastatic lymph node was 5.3% (n = 4). Among these, three had negative in primaries and positive in lymph nodes while one had positive in primary and negative in lymph node. A discordance between primary and lymph node in HER2, ER, or PR status was observed in 14 of 67 (18.4%) cases. Conclusions: The concordance in HER2, ER, and PR was high between the primary tumor and sentinel lymph nodes. However some cases had discordance of receptor status and these result may cause of discordance for distant metastases or poor prognosis. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-07.

Isolated retromammary lymph node metastasis of breast cancer without axillary lymph node involvement: a case report with a false-negative sentinel lymph node biopsy

A 54-year-old woman visited our hospital with a palpable tumor in her left breast, which was diagnosed as invasive ductal carcinoma. Breast-conserving surgery was performed, in association with a sentinel lymph node (SLN) biopsy and back-up dissection of the axillary lymph nodes. One dyed axillary lymph node with high radioactivity was defined as an SLN, and intraoperative frozen-section analysis of the SLN was negative for metastasis. The final pathological diagnosis of the tumor was invasive ductal carcinoma, and one small lymph node, located in the retromammary space, just under the tumor, was positive for metastasis. The backup axillary lymph nodes were not metastatic. This patient was diagnosed false-negative by SLN biopsy, despite being positive for retroMLN metastasis. It should be recognized that retroMLNs are difficult to detect preoperatively, or intra-operatively, using dye or radiocolloid, if they are located in the post-tumoral retro-mammary space. RetroMLNs may be a pitfall in SLN biopsies.