Oncoplastic breast surgery to prevent "Bird's beak" deformity in the breast: a comparative retrospective study.

PURPOSES: Breast deformity occurring in the lower pole after breast conserving surgery (BCS) is known as bird's beak (BB) deformity. This retrospective study evaluated the outcomes in breasts reconstructed with a conventional closing procedure (CCP) and a downward-moving procedure (DMP), respectively, after BCS. METHODS: In CCP, the inferomedial and inferolateral portions of breast tissues were reapproximated toward the midline after wide excision to repair the breast defect. In DMP, the retro-areolar breast tissue was detached from the nipple-areolar complex after wide excision, and the upper pole breast tissue was moved downward to refill the breast defect. RESULTS: CCP was performed in 20 patients (Group A), and DMP was performed in 28 patients (Group B). Although retraction of the lower part of the breast was postoperatively observed in 13 (72%) of 18 patients from Group A, it was observed in 7 (28%) of 25 patients in Group B (p < 0.05). The downward pointing of the nipple was observed in 8 (44%) of 18 patients from Group A and in 4 (16%) of 25 patients in Group B (p < 0.05). CONCLUSIONS: DMP is more useful for preventing BB deformity than CCP.

Case-based survey: The impact of breast-cancer treatment on fertility in Japan.

AIM: To assess the impact of breast-cancer treatment on fertility. METHODS: We conducted a retrospective, case-based survey of treatments administered for infertility and pregnancy outcomes after patients underwent treatment for breast cancer. Surveys were distributed to breast oncology facilities and reproductive endocrinology and infertility (REI) facilities. RESULTS: As high as 60% of the pregnancies in women under the age of 35 years occurred spontaneously. Additionally, the fertility rates decreased as age increased (under 35 years of age: 40%, 35-39 years of age: 21%, 40-44 years of age: 10%, respectively). In women who became pregnant after treatment for breast cancer, conception was achieved within 1 to 3 years after beginning to try for pregnancy. CONCLUSIONS: After treatment for breast cancer, women can expect spontaneous pregnancy, especially if they are under 35 years of age. It is important for patients 35 years of age and older to commence assisted reproductive technology in a timely manner when pursuing fertility after treatment for breast cancer.

Neural EGFL like 2 expressed in myoepithelial cells and suppressed breast cancer cell migration.

Breast tissue has a branching structure that contains double-layered cells, consisting primarily of luminal epithelial cells inside and myoepithelial cells outside. Ductal carcinoma in situ (DCIS) still has myoepithelial cells surrounding the cancer cells. However, myoepithelial cells disappear in invasive ductal carcinoma. In this study, we detected expression of neural EGFL like (NELL) 2 and one of its receptors, roundabout guidance receptor (ROBO) 3, in myoepithelial and luminal epithelial cells (respectively) in normal breast tissue. NELL2 also was expressed in myoepithelial cells surrounding the non-cancerous intraductal proliferative lesions and DCIS. However, the expression level and proportion of NELL2-positive cells in DCIS were lower than those in normal and non-cancerous intraductal proliferative lesions. ROBO3 expression was decreased in invasive ductal carcinoma compared to that in normal and non-cancerous intraductal proliferative lesions. An evaluation of NELL2's function in breast cancer cell lines demonstrated that full-length NELL2 suppressed cell adhesion and migration in vitro. In contrast, the N-terminal domain of NELL2 increased cell adhesion in the early phase and migration in vitro in some breast cancer cells. These results suggested that full-length NELL2 protein, when expressed in myoepithelial cells, might serve as an inhibitor of breast cancer cell migration.

The role of axillary reverse mapping in intraoperative nodal palpation during sentinel lymph node biopsy.

Intraoperative nodal palpation in the axilla is a mandatory part of sentinel lymph node biopsy. However, there is no consensus regarding the definition of suspicious palpable node. The sampling rate and involvement rate of suspicious palpable nodes are inconsistent. We hypothesized that axillary reverse mapping is helpful to select suspicious palpable sentinel lymph nodes more accurately. Patients with clinically negative nodes underwent sentinel lymph node biopsy with intraoperative nodal palpation and axillary reverse mapping. Blue and hot nodes were removed as sentinel lymph nodes. Suspicious palpable nodes that were neither blue nor hot were removed as palpable sentinel lymph nodes. Nodes around blue and hot sentinel lymph node were incidentally removed as para-sentinel lymph nodes. Fluorescent nodes were considered axillary reverse mapping nodes. Patients with positive sentinel lymph node underwent axillary lymph node dissection. Palpable sentinel lymph nodes and para-sentinel lymph nodes were removed in 130 (15%) of 850 patients with clinically negative nodes. Although palpable sentinel lymph nodes and para-sentinel lymph nodes were involved in 19 (15%) of 130 patients, fluorescent palpable sentinel lymph nodes were involved only in 2 patients and fluorescent para-sentinel lymph nodes were not involved. When excluding fluorescent palpable sentinel lymph nodes and para-sentinel lymph nodes, the sampling rate of suspicious palpable nodes significantly decreased (15% vs. 5%, p < 0.01) and the involvement rate of palpable sentinel lymph nodes significantly increased (15% vs. 31%, p < 0.05). Axillary reverse mapping is helpful to avoid an unnecessary removal of palpable nodes without metastases.

Ovarian hyperstimulation closely associated with resumption of follicular growth after chemotherapy during tamoxifen treatment in premenopausal women with breast cancer: a multicenter retrospective cohort study.

BACKGROUND: We previously reported that tamoxifen (TAM)-induced ovarian hyperstimulation (OHS) is associated with high serum concentrations of estradiol in premenopausal women with breast cancer. To investigate risk factors for TAM-induced OHS, we performed a retrospective multicenter study. METHODS: Premenopausal patients who received surgical therapy for endocrine-dependent breast cancer (n = 235) were recruited in this study and classified into 4 groups: group A, treated with TAM alone; group B, TAM treatment after 2-year-combined therapy with a gonadotropin-releasing hormone (Gn-RH) agonist; group C, TAM treatment after chemotherapy; group D, 5-year-combined therapy with TAM and a Gn-RH agonist. A serum estradiol value of more than 300 pg/mL or mean follicular diameter of more than 30 mm was defined as OHS. RESULTS: The incidence of OHS in group A (n = 13/26, 50.0%) was significantly higher than those in group B (n = 17/63, 27.0%), group C (n = 20/110, 18.2%), and group D (n = 0/36, 0%). The incidence of OHS was significantly correlated with aging, and the median serum concentration of estradiol in the presence of OHS was 823.0 pg/mL. The incidence of OHS (less than 47 years old) was 62.5% in group A, 48.6% in group B, and 28.2% in group C, respectively. Notably, the incidence rate of OHS following amenorrhea in group C (n = 13/20, 65.0%) was significantly higher than that in group B (n = 1/17, 5.9%). CONCLUSIONS: These findings indicate that the onset of OHS following amenorrhea was common in the post-chemotherapeutic group, while its ratio was low in the group after Gn-RH analog treatment, suggesting that combined treatment-based management involving TAM therapy is necessary for premenopausal patients with breast cancer.

The relation between anti-TGBFR1 immunohistochemical reaction and low Ki67, small tumor size and high estrogen receptor expression in invasive breast cancer.

Most breast cancers are derived from the luminal epithelium, which composes the inside of the breast ductal structure. Ductal carcinoma in situ (DCIS) leads to invasive ductal carcinoma, but noncancerous intraductal proliferative lesions are also a risk factor for ductal carcinoma. The transforming growth factor beta (TGFB) signaling pathway behaves as a tumor suppressor in the early stage of cancer, and conversely as a tumor growth factor in invasive stages in several cancers. In this study, we performed immunohistochemistry with an antibody that detects the cytoplasmic region of TGFB receptor 1 (TGFBR1) and elucidated TGFBR1 protein expression in luminal epithelial cells of noncancerous breast ducts and in several cases of DCIS and invasive carcinoma. TGFBR1 expression was higher in noncancerous breast tissue than in cancerous tissue, and a difference in expression was also seen among histological subtypes. Comparing the expression level of TGFBR1 in cancer cells and clinico-pathological parameters, cases expressing low TGFBR1 tended to show low estrogen receptor expression, large tumor size (≥10 mm), and a high Ki67 labeling index. These data suggested that TGFBR1 protein expression may be related to the suppression of breast cancer cell growth.

Nationwide survey of Japanese breast oncology and reproductive endocrinology departments about the impact of breast cancer treatment on fertility.

The purpose of this study is to assess the impact of breast cancer treatment on the reproductive potential. We conducted a nationwide survey of breast oncology and reproductive endocrinology and infertility (REI) departments using a questionnaire designed to assess the impact of breast cancer treatment on fertility. We received responses from 312 breast oncology departments (response rate, 31.9%) and 541 REI departments (response rate, 50.9%). The most common method of achieving pregnancy reported by breast oncology departments was natural insemination (69.6%), followed by assisted reproductive technology ( 15.6%) and intrauterine insemination (IUI; 14.8%). The most common method of achieving pregnancy reported by REI departments was conventional in vitro fertilization and/or intracytoplasmic sperm injection (51.0%), followed by natural insemination with or without ovulation induction (40.0%) and IUI (8.0%). The overall pregnancy rate for patients who underwent treatment for infertility at REI departments after breast cancer treatment was 39.0%. Vast patients who experienced breast cancer treatments conceived mainly by natural insemination based on the data from breast oncology departments. On the other hand, 61.0% of the patients who visited REI departments presumably due to infertility by natural insemination did not conceive even by infertility treatments with exclusive knowledge in REI departments.

[A Case of Thrombotic Microangiopathy Arising from Breast Cancer Treated with Chemotherapy].

The present study reports the case of a 49-year-old woman who was diagnosed with cancer of the left breast at the age of 43 years.Following chemotherapy, the patient had undergone partial mastectomy and axillary lymphadenectomy.Postoperatively, she underwent radiotherapy and hormone therapy.Five years and 4 months after the operation, the patient developed pain in the cervical vertebrae and was diagnosed with spinal metastasis.During the period, she began experiencing fatigue and hematological investigations indicated anemia, as well as thrombocytopenia, jaundice, and schistocytes.The patient was referred to our facility for further examination and treatment.On investigation, she was diagnosed with cancer-related thrombotic microangiopathy(TMA).The patient was advised to undergo chemotherapy due to which symptoms of TMA were relieved.She continued to receive chemotherapy for the following 3 years and 2 months until her death.

[A Case of Histiocytoid Breast Carcinoma Accompanied by Multiple Axillary Lymph Node Metastases].

According to previous reports in our country, histiocytoid breast carcinoma is a very rare case of its tissue type, accounting for only 0.3% of all breast cancer cases. We have neither established a diagnostic standard nor a general idea for these tumors. Previously, its inherited pathology was assumed to be a sub-form of invasive lobular carcinoma. However, some researchers indicate the presence of components that are assumed to originate from milk ducts or differentiation in the apocrine gland. In this way, origins of pathologies for these tumors seem to be complex. Previous reports suggest cases of relatively long survival times without spreading to distant sites. Recently, we encountered one case of histiocytoid breast carcinoma accompanied by multiple axillary lymph node metastases.

[A Case of Spontaneous Esophageal Rupture That Required Operation during Adjuvant Chemotherapy for Transverse Colon Cancer].

A 75-year-old male underwent adjuvant chemotherapy with tegafur uracil(UFT)plus Leucovorin(LV)after surgery for transverse colon cancer(pT3pN0M0, ly1, v2, pStageⅡ). Although he had diarrhea(Grade 3)and vomiting(Grade 2)from day 15, he continued to take the medicine at his own discretion. He visited a hospital because of acute renal failure from severe dehydration. He went into shock after evacuation, and the computed tomography(CT)finding suggested a diagnosis of spontaneous esophageal rupture at the lower esophagus. We made a diagnosis of intrathoracic perforation of the esophagus by using thoracic drainage. Then, we performed an operation for mediastinal drainage via a transabdominal approach and the lesser omentum. He started ingestion from POD36 and transferred to another hospital on POD85. He had no disease recurrence in our outpatient care. We think that the spontaneous esophageal rupture occurred because of the frequent vomiting caused by the continued chemotherapy despite the severe side effects. Treatments must be selected by considering patients' life background and medical compliance, and common guidance in taking medications must be provided to elderly patients at the start of chemotherapy.

[A Case of Esophagogastric Junction Adenocarcinoma with Neuroendocrine Differentiation].

Gastric cancer rarely contains neuroendocrine component. This mixed tumor is defined as neuroendocrine carcinoma (NEC), mixed adenoneuroendocrine carcinoma(MANEC)and so on according to the WHO classification. We report a patient with esophagogastric junction cancer with neuroendocrine differentiation(NED). The patient was 54-year-old man who diagnosed of esophagogastric junction cancer at the medical examination. Upper gastrointestinal endoscopy revealed a type 3 tumor at esophagogastric junction, and the pathological findings were poorly differentiated adenocarcinoma with focal positivity of chromogranin A. CT and FDG/PET revealed a metastatic regional lymph node. He had undergone proximal gastrectomy and lower esophagectomy, with dissection of D1+and double-tract reconstruction. Pathological findings revealed moderate to poorly differentiated adenocarcinoma containing chromogranin A-positive tumor cells. Neuroendocrine components were lower than 30%, and we diagnosed adenocarcinoma with NED. Standard treatment for gastric cancer with NED has not been established and more reports and reviews are required.

[A Case of Pneumocystis Pneumonia Developed during Chemotherapy for Sigmoid Colon Cancer].

A 69-year-old man with multiple liver metastases from sigmoid colon cancer received mFOLFOX6 plus cetuximab(Cmab) chemotherapy. A partial response was observed; hence, we performed an extended left hepatectomy, 3 partial liver resections, and a sigmoidectomy. After 4 courses of CapeOX, a recurrent lesion occurred between S8 and S7 of the liver, and we changed the regimen to FOLFIRI plus bevacizumab(BV). Three months later, he had Grade 3 febrile neutropenia and CT scan findings showed ground glass opacity in the superior lobes of both lungs. We diagnosed pneumocystis pneumonia(PCP)and administered steroids and trimethoprim/sulfamethoxazole. The signs of PCP thus improved. PCP during chemotherapy for gastrointestinal cancer is rarely reported, but recently it has increased.

[Early Enteral Nutrition for Gastric Cancer Patients with Extended Surgery].

The effectiveness of multi-modal therapy for advanced gastric cancer were reported recently.These therapies are highly invasive, therefore the peri-operative management for regulation of general condition is important.We introduced early enteral nutrition for these cases aiming for improvement of post-operative course.We examined 18 cases with early enteral nutrition in 76 gastrectomised patient after pre-operative chemotherapy.In 15 of 18 patients, maximum dose of enteral nutrition was 960 kcal/day or more.Side effects of enteral nutrition, such as diarrhea or vomiting, abdominal pain, were observed in 11 cases.These symptoms ware controllable except 1 case with severe diarrhea.The weight loss during hospitalization was suppressed with early enteral nutrition.Early enteral nutrition was safe and essential peri-operative management for advanced gastric cancer patients received highly invasive multi-modal therapy.

Clonal profiling of mixed lobular and ductal carcinoma revealed by multiplex ligation-dependent probe amplification and fluorescence in situ hybridization.

A needle biopsy of a mass in the right breast of a 36-year-old woman revealed invasive ductal carcinoma (IDC), and approximately 20% of cancer cells showed unequivocal membranous staining with the HercepTest. After systemic therapy with trastuzumab and paclitaxel followed by FEC (fluorouracil + epirubicin + cyclophosphamide), a right mastectomy was performed. By histological and immunohistochemical examinations, the resected tumor consisted mainly of E-cadherin-negative invasive lobular carcinoma (ILC), and the rest was ERBB2-positive IDC; thus, the diagnosis was mixed ductal and lobular carcinoma. Multiplex ligation-dependent probe amplification and fluorescence in situ hybridization (FISH) analyses revealed that ILC and IDC shared high-level amplification of CCND1 in homogeneously staining regions (HSR) and that IDC had an additional HSR-type amplicon of ERBB2. These findings strongly indicate that IDC and ILC had a common precursor cell with CCND1 amplification. Review of the biopsy specimen with FISH showed IDC with gene amplifications of CCND1 and ERBB2 as a minor component, IDC without amplification of CCND1 or ERBB2 as a major component, and a minute portion of ILC with CCND1 amplification. We speculate that chemotherapy and trastuzumab caused a marked reduction in IDC; however, ILC with CCND1 amplification was resistant to chemotherapy and grew.

[Report of a gastric adenocarcinoma patient who developed multiple skin metastasis after gastrectomy].

A 59-year-old man with gastric cancer underwent a total gastrectomy with splenectomy and D2 lymph node dissection. Pathological findings after the first operation were as follows: ML, AntLess, type 3, por, pT3, ly1, v0, and M, Post, 0-II c, tub1, pT1b2, ly0, v0, pN2M0P0H0, pStage IIIA. At 3 years and 6 months after the operation, multiple small nodules were noted on the skin of his face, neck, body, and arms. Biopsy of a skin lesion indicated that it was a metastatic skin cancer resulting from an adenocarcinoma. Thus, we diagnosed the lesions as skin metastases originating from an adenocarcinoma of the stomach. We also detected the presence of multiple metastases to the bone and lymph nodes, and we have treated the patient with chemotherapy. Metastases to the umbilicus from gastric cancer are termed as Sister Mary Joseph's nodules (SMJN). Although cases of SMJN are often reported, cases of multiple metastases from gastric cancer, without invasion to the umbilicus, are rare.

[A case of advanced gastric cancer in which the serum HER2-ECD level could be used as a biomarker].

An 83-year-old woman was diagnosed as having advanced gastric cancer with multiple lymph node and hepatic metastases. Histopathological examination revealed that the tissue was human epidermal growth factor receptor 2(HER2)positive. The patient underwent gastrojejunostomy to improve stomach obstruction. Thereafter, S-1 and trastuzumab combination chemotherapy was administered as first-line treatment; irinotecan(CPT-11), cisplatin, and trastuzumab combination chemotherapy, as second-line treatment; and docetaxel plus trastuzumab combination chemotherapy, as third-line treatment. Although both primary and metastatic lesions decreased in size temporarily, their size increased again, and the patient died 1 year and 7 months later. The level of serum HER2-extracellular domain(ECD)was a valuable indicator of response to chemotherapy. Thus, serum HER2-ECD could be a useful biomarker for HER2-positive gastric cancer.

Giant Borderline Phyllodes Tumor Fungating Through the Skin as Fleshy Polypoid Outgrowths.

We present the case of a 52-year-old female with a giant phyllodes tumor (GPT), which was fungating through the skin that showed fleshy polypoid outgrowths. Histological analysis revealed stromal atypia, mitotic activity, and stromal overgrowth; however, the tumor border was well-defined, and malignant heterologous elements were not observed. Therefore, as some but not all malignant histological characteristics were present, we diagnosed the patient with borderline GPT. In cases of phyllodes tumor (PT) with the unique gross findings of fungation through the skin as fleshy polypoid outgrowths, caution is required for the subsequent course because even if the PT is graded as benign histologically, a malignant process can occur. Pathologists should note that the sampling of the collection site and the ambiguity of the histological grading of PT may affect the final diagnosis of GPT. It is also important to perform surgery with adequate preservation of the resected margins to control recurrence for patients with GPT.

Periarterial or perivenous invasion is an independent indicator of lymph node metastasis in invasive breast carcinoma of no special type.

Pathological diagnosis of breast cancer often includes cases of lymph node metastases without lymphatic or lymphovascular invasion by the primary tumor. In this study, to resolve this discrepancy, we designed a sensitive method to detect lymphatic invasion and correlate it with lymph node metastasis. Elastica van Gieson (EVG) staining and D2-40 immunohistochemistry revealed the abundant distribution of lymphatic vessels around blood vessels in the mammary tissue in close proximity to the elastic fibers around the arteries and veins. Based on the histological location of the blood and lymphatic vessels, we hypothesized that, in breast cancer, perivascular invasion is similar to lymphatic invasion and correlates with the presence of lymph node metastasis. Using EVG staining, perivascular invasion was histologically classified into periarterial invasion (periA), perivenous invasion (periV), and periarterial or perivenous invasion (periA/V). We tested our method and compared it to other methods commonly used for identifying lymphatic invasion in 105 patients with invasive breast carcinoma of no special type (IBC-NST) who received minimal preoperative therapy. The correlation between perivascular invasion and lymph node metastasis in these patients was statistically analyzed, including findings related to lymphatic invasion, such as retractile artifacts and perineural invasion. PeriA, periV, and periA/V showed significant correlations with lymph node metastasis. PeriA/V had high sensitivity and negative predictive value. The odds ratio (OR) for periV was significantly high in the univariate analysis, while the ORs for periA/V, retraction artifacts, and perineural invasion were significantly high in both the univariate and multivariate analyses. In particular, periA/V revealed a strong correlation with lymph node metastasis (OR: 61.8). These findings indicate that the IBC-NST periA/V ratio is a sensitive pointer of lymphatic invasion and could be an independent and reliable indicator of lymph node metastasis.

A Unique Surgical Case of Mixed Metaplastic Breast Carcinoma With Heterologous Mesenchymal Differentiation and Conventional Adenocarcinomatous Elements.

Metaplastic breast carcinoma (MBC) is very rare among all invasive breast carcinomas, accounting for less than 1.0% of them. MBCs are classified into five subtypes, including mixed MBC - where the mix might be multiple metaplastic elements or a mixture of epithelial and mesenchymal elements. Overall survival for mixed MBC tends to correlate with a significantly worse outcome. Therefore, an early accurate diagnosis and surgical treatment for mixed MBCs must allow for an improved quality of life and better prognosis. However, there have not been many recently published papers describing the detailed cytological features of mixed MBCs on fine-needle aspiration (FNA) specimens. A 60-year-old female presented with a history of a hard breast mass on the left lateral side, showing an ill-defined and marginally enhanced tumor nodule on magnetic resonance imaging. The cytologic specimens of FNA contained a large number of three-dimensional, cohesive and sheet-like clusters, or non-cohesive single cells, of highly atypical spindled sarcomatoid to oval epithelioid cells having hyperchromatic pleomorphic nuclei and mitotic figures, in a necrotic and hemorrhagic background. A small amount of osteoid matrix-like substance was rarely seen, associated with a very small number of osteoclast-like giant cells. We first interpreted it as an invasive breast carcinoma of high grade. A mastectomy was performed, and a gross examination of the neoplasm revealed a hemorrhagic solid tumor lesion with a gray-whitish cut surface, measuring approximately 35 × 24 × 21 mm in diameter. On a microscopic examination, the tumor was predominantly composed of the proliferation of highly atypical oval to spindled cells predominantly in a sarcomatous growth fashion with focal production of chondroid and osteoid matrix, peripherally coexisted with a smaller volume of conventional invasive breast carcinoma. Immunohistochemistry showed that the sarcomatous tumor cells were specifically positive for vimentin, α-smooth muscle actin, or epithelial membrane antigen. Therefore, we finally made a diagnosis of invasive mixed MBC with heterologous mesenchymal differentiation and conventional adenocarcinomatous elements. To the best of our knowledge, this would most recently be the first case report of mixed MBC with heterologous mesenchymal differentiation and conventional adenocarcinomatous elements, with a focus on its FNA cytomorphologic findings. We should be aware that owing to its characteristic cytological features, cytopathologists might be able to make a correct diagnosis of MBC, based on multiple and adequate samplings.

Gene amplification of ESR1 in breast cancers--fact or fiction? A fluorescence in situ hybridization and multiplex ligation-dependent probe amplification study.

Oestrogen receptor-alpha (ERα), encoded by the ESR1 gene located on 6q25, is a nuclear transcription factor. Since it was reported in 2007 that more than 20% of breast cancers show ESR1 gene amplification, there has been considerable controversy about its frequency and clinical significance. We set out to assess the frequency and levels of ESR1 amplification in breast cancers. In a total of 106 breast needle biopsy specimens examined by immunohistochemistry, 78 tumours contained more than 10% ERα-positive cancer cells. In fluorescence in situ hybridization (FISH) analysis with an ESR1-specific probe, variously extended ESR1 signals were found in ERα-expressing cells. Some of these were indistinguishable from large clustered signals generally accepted to mean high-level gene amplification in homogeneously staining regions (HSRs), and could be considered to represent gene amplification. However, with RNase treatment, the 'HSR-like' signals changed to small compact signals, and are thus thought to represent concentrated RNA. FISH using two differently labelled probes corresponding to the non-overlapping 5'- and 3'-end portions of the ESR1 gene on touch smears showed a preserved spatial relationship of the 3' to 5' sequence of ESR1, therefore strongly suggesting that the RNA consisted of primary transcripts. Using touch smears obtained from 51 fresh tumours, precise enumeration of ESR1 signals with a correction by the number of centromere 6 on FISH after RNase A treatment revealed that three tumours (5.9%) had tumour cells with one to three additional copies of ESR1 as predominant subpopulations. This infrequent and low level of gene amplification of ESR1 was also detected as a 'gain' of the gene by analysis with multiplex ligation-dependent probe amplification (MLPA). The consistent results from immunohistochemistry, FISH, and MLPA in the present study settle the long-standing debate concerning gene amplification of ESR1 in breast carcinoma.