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Biomedical subjects

C Yiangou

Publications and source records attributed to C Yiangou.

At least 19 recordsLinked to original sources
PubMed2006

A double-blind randomised trial to evaluate the effect of anastrozole for the treatment of non-toxic multinodular goitre.

Multinodular goitre (MNG) is a common clinical finding, particularly in females and is usually asymptomatic. When symptoms occur because of local pressure-related effects the only treatment is surgical involving partial or total thyroidectomy. A number of epidemiological observations and experimental data have suggested that oestrogen aromatase activity may be involved in the pathogenesis of MNG. This study examines the effect of anastrozole, a non-steroidal aromatase inhibitor that inhibits the peripheral conversion of testosterone to oestradiol, in reducing the size of MNG. Thirty-two post-menopausal female patients, median age 63 years (range 42-84) were randomised in a double-blind fashion to receive either anastrozole 1 mg daily or placebo for 3 months. Ultrasonographic measurement of each thyroid lobe and isthmus together with complete biochemical and hormone profiles were performed at the start and end of treatment. There was no significant reduction in the goitre size for patients in the anastrozole group (p = 0.246) or the placebo group (p = 0.418). There were no significant changes in hormone profiles (including throglobulin concentration) within each group between the start and end of the study. We conclude that the use of anastrozole in the treatment of MNG does not appear to have any effect in reducing the size of MNG.

Adult↗
PubMed2006

Radiological review of specimen radiographs after breast localisation biopsy is not always necessary.

INTRODUCTION: The use of specimen radiographs to confirm the presence of the radiological abnormality in a breast specimen after localisation biopsy is standard practice. This study aims to show that a trained surgeon may assess breast specimen radiographs with similar efficacy as a radiologist. METHODS: This retrospective study assessed all patients who had localisation breast surgery using wire or ultrasound (US) techniques between January 2002 and March 2003. Histopathological records and mammographic details were recorded from the hospital notes. A consultant radiologist and surgeon reviewed the specimen radiographs, identifying mammographic abnormalities and assessing margins. RESULTS: Localisation surgery was performed on 101 patients with US used to localize 68. The median specimen weight was 64g. A malignant diagnosis was made in 86 patients. In 23, the histological resection margins were considered to be close or involved by tumour and re-excision was performed in eight patients. Sixty-one specimen radiographs were reviewed. The radiologist identified every mammographic abnormality, and the surgeon identified the lesion in 58. The positive predictive value of specimen radiographs to identify histologically involved margins was 75 and 74% by the radiologist and the surgeon, respectively. Where good radiograph margins were reported in 40 and 35 patients by the radiologist and surgeon, respectively, 11 and 7 had histologically involved margins. CONCLUSIONS: This study shows that a suitably trained or experienced surgeon can assess specimen radiographs effectively without the need for intraoperative radiological input although complete histological resection is not guaranteed despite specimen radiographs demonstrating clear margins.

Adult↗
PubMed2005

Galectin-3 is not useful in thyroid FNA.

INTRODUCTION: Previous studies have suggested that galectin-3 immunohistochemistry may be useful in the fine needle aspiration (FNA) diagnosis of thyroid carcinoma as it has been reported to selectively stain carcinomas and not adenomas or goitres. METHODS: Fifty-one patients were included in a prospective study of galectin-3 in thyroid FNA; 88.2% were female and 11.8% male, mean age 53 years, range 25-87 years. Cell blocks were prepared and stained for galectin-3 if any cells were present in needle washings from the respective FNAs. RESULTS: Twelve of 51 (23.5%) of cell blocks contained epithelial cells. One benign and one inadequate FNA were negative for galectin-3 staining. One of five non-diagnostic FNA cases, a papillary carcinoma on final histology showed positive staining. Four follicular neoplasm/suspicious of carcinoma cases showed negative staining. One malignant FNA case, a papillary carcinoma showed positive staining with galectin-3 but three further carcinomas, two papillary and one follicular were galectin-3 negative. CONCLUSION: Galectin-3 immunohistochemistry does not appear to be a useful adjunct to diagnosis in thyroid FNA as it does not reliably distinguish malignant and benign lesions. Many thyroid aspirates are of low cellularity and are not suitable for cell block immunohistochemistry.

Adult↗
PubMed2004

Sentinel lymph node biopsy in male breast cancer patients.

The concept of sentinel node biopsy has been validated for female breast cancer patients whereas, ALND remains the standard of care for male breast cancer patients with similar tumours. We evaluated the results of SLN biopsy in male breast cancer patients with clinically negative axillae. This study included all male breast cancer patients who underwent SLN biopsy between February 1998 and October 2003. All patients had negative axillae on clinical examination. All patients underwent pre-operative lymphoscintigraphy. SLN biopsy was performed using a combination of Patent blue V and 99mTc-radiolabelled colloidal albumin injected peritumourally. Nine patients, 26-79 years of age, were included in the study. Pre-operative lymphoscinitgraphy identified SLNs in all patients. Intraoperatively, SLNs were successfully localised in all patients. The mean number of SLNs encountered was 2.4. Five patients had a positive SLN, four a negative SLN. Five patients (one with a negative SLN, four with a positive SLN) had been elected pre-operatively to undergo ALND regardless of findings on SLN biopsy. ALND confirmed the SLN to be negative in one patient (false-negative rate: 0%) and three of the four patients with positive SLN(s) had additional positive nodes in the axilla. SLN biopsy accurately predicted axillary lymph node status in these five patients. These findings compare favourably with findings reported in the literature regarding SLN biopsy in female breast cancer patients. SLN biopsy accurately staged the axilla in male breast cancer patients and should be considered for axillary staging in male breast cancer patients with clinically negative axillae.

Adult↗
PubMed2003

The use of sentinel node biopsy in the treatment of cancer of an accessory breast.

A patient with an accessory breast on the anterior abdominal wall was found to have cancer of this tissue, because of its unusual position it was decided that lymphatic mapping was necessary to identify the lymphatic drainage of this tumour. A metastasis was found in a sentinel node deep to the 'true' ipsilateral breast; however, the sentinel node identified in the axilla of this patient was free of metastases. The use of the sentinel node technique up staged the cancer from I to II and the patient went on to have adjuvant treatment with chemotherapy. The use of lymphatic mapping and sentinel node biopsy in the case of cancer of an accessory breast allows more accurate determination of lymph node status.

Breast Neoplasms↗
PubMed1999

Primary tumour characteristics and axillary lymph node status in breast cancer.

This paper examines the correlation between axillary lymph node status and primary tumour characteristics in breast cancer and whether this can be used to select patients for axillary lymphadenectomy. The results are based on a retrospective analysis of 909 patients who underwent axillary dissection in our unit. Axillary lymph nodes containing metastases were found in 406 patients (44.7%), all with invasive carcinomas, but in none of the 37 carcinomas-in-situ. Nodal status was negative in all T1a tumours, but lymph node metastases were present in 16.3% and 35.7% of T1b and T1c tumours respectively. When histological grade was taken into account, positivity for grade I T1b and T1c tumours fell to 13.6% and 26.7% respectively. Lymph node metastases were found in 85% of patients with lymphovascular invasion in their tumours as compared to only 15.4% of those without and in 45.5% of oestrogen and progesterone receptor-positive tumours. When one or both hormone receptors were absent this figure was much higher. It appears that for T1a breast cancers axillary dissection is not necessary, whereas for T1b, T1c and grade I T2 tumours other histopathological parameters should be taken into consideration in deciding who should undergo axillary lymphadenectomy.

Breast Neoplasms↗
PubMed1997

A paracrine role for myoepithelial cell-derived FGF2 in the normal human breast.

We have studied separated normal human breast epithelial and myoepithelial cells for the presence of basic fibroblast growth factor (FGF2) and its receptors, both low (heparan sulfate proteoglycans) and high affinity (FGFR1), and for the effects of FGF2 on the proliferation of both cell types. Our results indicate that these cells differ markedly in their synthesis and response to FGF2. We found, using PCR of purified cell populations, mRNA for FGF2 only in the myoepithelial cells, whereas immunostaining and Western blotting results demonstrated the presence of FGF2 protein in both epithelial and myoepithelial cells. FGF2 had no effect on the proliferation of myoepithelial cells, but it did maintain the survival of the separated epithelial cells in low serum and stimulate their growth in 5% and 10% FCS. Immunostainable FGFR1 was present in epithelial cells and, to a lesser extent, in myoepithelial cells. Low-affinity binding sites for FGF2 were synthesized by epithelial and myoepithelial cells, but myoepithelial cells possessed a greater proportion of higher-affinity heparan sulfate proteoglycans. These results indicate that myoepithelial cell-derived FGF2 may be an important paracrine factor controlling epithelial cell survival and growth in the normal human breast.

Blotting, Southern↗
PubMed1997

Expression of keratinocyte growth factor and its receptor in human breast cancer.

The level of expression of keratinocyte growth factor (KGF) mRNA has been measured in human breast cell lines, purified populations of epithelial cells, myoepithelial cells and fibroblasts from reduction mammoplasty tissue and a panel of 42 breast cancers and 30 non-malignant human breast tissues using a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) procedure. We found similar levels of KGF mRNA in malignant and non-malignant breast tissues. The study of the amount of KGF mRNA in breast cell lines and purified populations of cells revealed that fibroblasts are the predominant source of KGF with malignant and non-malignant epithelial cells containing very low levels of KGF mRNA. We have examined the distribution of fibroblast growth factor receptor (FGFR)-2-IIIb, which is a high-affinity receptor for KGF and find that it is present on malignant and non-malignant epithelial cells. The level of FGFR-2-IIIb present on breast cancer cell lines was sufficient for KGF stimulation of breast cancer cell proliferation. Other members of the fibroblast growth factor family have been either not expressed in the human breast (FGF3, FGF4) or have been found at much reduced levels in breast cancer (FGF1, FGF2) and this is the first member of the family to potentially influence the progression of breast cancer through stimulation of cell division.

Breast↗
PubMed1997

The location of acidic fibroblast growth factor in the breast is dependent on the activity of proteases present in breast cancer tissue.

Acidic fibroblast growth factor (FGF1) and two of its receptors, FGFR1 and FGFR4, were localized in cryostat sections of normal, benign and malignant human breast tissue by immunohistochemistry. Without pretreatment, FGF1 staining was mainly seen in normal epithelial cells. However, polymerase chain reaction (PCR) analysis and immunoblotting of isolated normal epithelial and myoepithelial cells showed FGF1 mRNA and protein to be present in both cell types. Following incubation of frozen sections at 37 degrees C in phosphate-buffered saline, FGF1 staining was also revealed in myoepithelial cells and basement membrane adjacent to carcinoma cells. Treatment with protease inhibitors demonstrated that this effect was due to the activity of an endogenous protease. In contrast, FGF1 staining was found to be associated with the stroma adjacent to malignant cells only in the presence of protease inhibitors. FGFR1 and FGFR4 immunostaining was localized to both normal and malignant epithelial cells and to a lesser extent to myoepithelial cells. There was no difference in the staining intensity for the FGF receptors between normal and cancer samples. The change in location of FGF1 between normal and malignant tissues and the sensitivity of stored FGF1 to the action of endogenous proteases raises the possibility of both autocrine and paracrine roles for FGF1 in the normal and malignant human breast.

Animals↗
PubMed1997

Fibroblast growth factor 2 in breast cancer: occurrence and prognostic significance.

This paper examines the expression of fibroblast growth factor 2 (FGF-2) in the malignant human breast. Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the level of expression of FGF-2 in a series of 51 patients clinically followed up for a median of 84 months (Luqmani et al, 1992). Immunohistochemistry and Western blotting were used to show that the level of FGF-2 in breast tissues correlated with the amount of FGF-2 mRNA. FGF-2 was present in both malignant and non-malignant breast, although less was expressed in malignant tissues as determined by all three methods. Immunohistochemistry on frozen sections of breast tissue showed expression of FGF-2 in myoepithelial and epithelial cells in non-malignant samples and generally lower or undetectable levels of staining in malignant epithelial cells. The results obtained by immunohistochemistry correlated well with RT-PCR data showing similar levels of FGF-2 and FGF-2 mRNA expression in samples. No correlation was found between FGF-2 mRNA expression and T stage, nodal status or oestrogen receptor status. However, Kaplan-Meier survival plots show that higher levels of FGF-2 are associated with improved overall and disease-free survival. We suggest that FGF-2 expression may have value as a prognostic indicator in breast cancer.

Adult↗
PubMed1997

Down-regulation of a novel form of fibroblast growth factor receptor 1 in human breast cancer.

Monoclonal antibodies against two epitopes of FGFR-1 have been used to investigate FGFR-1 expression in the normal and neoplastic human breast. Different forms are detected in the different cell types constituting the normal breast. Moreover, breast cancer cells lack one form of FGFR-1. Western blot analysis showed 115-kDa and 106-kDa forms of FGFR-1 within the human breast. The 115-kDa band corresponds to the beta form of FGFR-1, whereas the 106-kDa band is truncated at the carboxyl terminus. The 106-kDa form of FGFR-1 is the major form present in breast fibroblasts and myoepithelial cells, whereas epithelial cells contain equal amounts of the 115-kDa and 106-kDa forms. Breast cancer cells, however, appear to contain only the 115-kDa form of FGFR-1. This expression pattern is reflected in malignant and non-malignant tissue samples. Using reverse transcription polymerase chain reaction (RT-PCR) analysis, we have shown that the 106-kDa FGFR-1 isoform is not the previously described alpha 2 receptor that arises from a 25-base pair insertion in the second kinase domain. It is probable that the 106-kDa FGFR-1 has different signalling properties to the full-length receptor, having lost at least one tyrosine at amino acid 766, which is required for phospholipase C activation. This form of FGFR-1 appears to be lost in all breast cancer cells analysed and its absence may have a bearing on malignancy.

Amino Acid Sequence↗
PubMed1996

Diagnostic role of cytology in screen-detected breast cancer.

Fine-needle aspiration cytology (FNAC) of the breast was performed in 491 patients over a 3-year period. Some 365 examinations (74.3 percent) were performed by palpation and the remaining 126 (25.7 percent) by stereotaxis. Ninety-six patients were excluded because of inadequate follow-up. Using a standard method of reporting the results 247 smears were classified as C1 and C2, but based on clinical and radiological criteria excision biopsy was recommended and performed in 122 patients with these lesions. Twenty-two per cent of C2 lesions were found to be malignant after histological examination. Forty-two patients with C3 or C4 cytology were advised to have excision biopsy and 41 had surgery. In all but one case the lesion was found to be malignant histologically. Definitive surgery was performed on 106 patients with C5 cytology and the diagnosis of malignancy was confirmed histologically in 105 of them. FNAC is a useful diagnostic tool in breast screening but in view of the number of false-negative results, cytology alone is unreliable and, therefore, full triple assessment is recommended.

Adenocarcinoma↗
PubMed1995

Expression of 2 variant forms of fibroblast growth factor receptor 1 in human breast.

The expression of variant mRNAs encoding isoforms of fibroblast growth factor receptor (FGFR)1 with either 2 or 3 Ig-like loops in the extracellular domain was investigated in human breast tissues and cell lines using a polymerase chain reaction amplification method. Almost all tissues contained both forms of FGFR1, but cancers (n = 137) had a significantly lower proportion of the transcript that encoded the full 3-loop form compared with non-malignant biopsies (n = 34). This was confirmed using microdissected populations of normal and cancerous cells from frozen tissue sections. A high ratio of the 2- to 3-loop form was found to be predictive of reduced relapse-free survival. In both groups, however, the predominant form of FGFR1 was that encoding the 2-loop receptor. Cell lines derived from a variety of tissues, including breast, also co-expressed both variants of FGFR1, suggesting their presence within the same cell type. Again, there was a similar preponderance of the shorter isoform. Our results were confirmed at the protein level, where out of 5 cancers analysed 4 expressed more of the 2-loop form than the 3-loop form. Our findings suggest that cells may normally simultaneously express several splice variants of FGFR1, and aberrant expression or a change in their relative amounts (i.e., in malignancy) could contribute to modified responses to either autocrine or paracrine factors.

Adult↗