PubMed Health⌕ Search

Biomedical subjects

C M Quinn

Publications and source records attributed to C M Quinn.

At least 19 recordsLinked to original sources
PubMed2006

Impact of a national external quality assessment scheme for breast pathology in the UK.

BACKGROUND: This article presents the results and observed effects of the UK National Health Service Breast Screening Programme (NHSBSP) external quality assurance scheme in breast histopathology. AIMS/METHODS: The major objectives were to monitor and improve the consistency of diagnoses made by pathologists and the quality of prognostic information in pathology reports. The scheme is based on a twice yearly circulation of 12 cases to over 600 registered participants. The level of agreement was generally measured using kappa statistics. RESULTS: Four main situations were encountered with respect to diagnostic consistency, namely: (1) where consistency is naturally very high-this included diagnosing in situ and invasive carcinomas (and certain distinctive subtypes) and uncomplicated benign lesions; (2) where the level of consistency was low but could be improved by making guidelines more detailed and explicit-this included histological grading; (3) where consistency could be improved but only by changing the system of classification-this included classification of ductal carcinoma in situ; and (4) where no improvement in consistency could be achieved-this included diagnosing atypical hyperplasia and reporting vascular invasion. Size measurements were more consistent for invasive than in situ carcinomas. Even in cases where there is a high level of agreement on tumour size, a few widely outlying measurements were encountered, for which no explanation is readily forthcoming. CONCLUSIONS: These results broadly confirm the robustness of the systems of breast disease diagnosis and classification adopted by the NHSBSP, and also identify areas where improvement or new approaches are required.

Breast Neoplasms↗
PubMed2006

The NHS breast screening programme (pathology) EQA: experience in recent years relating to issues involved in individual performance appraisal.

BACKGROUND: The original role of the National Health Service breast screening programme (pathology) external quality assessment (EQA) scheme was educational; it aimed to raise standards, reinforce use of common terminology, and assess the consistency of pathology reporting of breast disease in the UK. AIMS/METHODS: To examine the performance (scores) of pathologists participating in the scheme in recent years. The scheme has evolved to help identify poor performers, reliant upon setting an acceptable cutpoint. Therefore, the effects of different cutpoint strategies were evaluated and implications discussed. RESULTS/CONCLUSIONS: Pathologists who joined the scheme improved over time, particularly those who did less well initially. There was no obvious association between performance and the number of breast cancer cases reported each year. This is not unexpected because the EQA does not measure expertise, but was established to demonstrate a common level of performance (conformity to consensus) for routine cases, rather than the ability to diagnose unusual/difficult cases. A new method of establishing cutpoints using interquartile ranges is proposed. The findings also suggest that EQA can alter a pathologist's practice: those who leave the scheme (for whatever reason) have, on average, marginally lower scores. Consequently, with the cutpoint methodology currently used (which is common to several EQA schemes) there is the potential for the cutpoint to drift upwards. In future, individuals previously deemed competent could subsequently be erroneously labelled as poor performers. Due consideration should be given to this issue with future development of schemes.

Breast Neoplasms↗
PubMed2006

Diagnostic accuracy of core biopsy for ductal carcinoma in situ and its implications for surgical practice.

BACKGROUND: Core biopsy is considered to be a highly accurate method of gaining a preoperative histological diagnosis of breast cancer. Ductal carcinoma in situ (DCIS) is often impalpable and is a more subtle form of breast cancer. AIM: To investigate the accuracy of core biopsy in the diagnosis of cancer in patients with DCIS. METHODS: All patients who had invasive cancer (n = 959) or DCIS (n = 92) that was confirmed by excision between 1999 and 2004 were identified. The diagnostic methods, histology of the core biopsy specimen and excision histology were reviewed in detail. RESULTS: Core biopsy was attempted in 88% (81/92) of patients with DCIS and in 91% (874/959) of those with invasive disease. Of those patients who underwent core biopsy, a diagnosis of carcinoma on the initial core was made in 65% (53/81) of patients with DCIS compared with 92% (800/874) of patients with invasive disease (p<0.0001). Smaller lesion size (p = 0.005) and lower grade (p = 0.03) were associated with increased risk for a negative or non-diagnostic core in patients with DCIS. The nature of the mammographic lesion or the method of biopsy did not affect the probability of an accurate core biopsy. Patients who had a preoperative diagnosis of DCIS by core biopsy had a reoperation rate of 36% compared with 65% of those that did not have a preoperative diagnosis (p = 0.007). CONCLUSION: Although core biopsies are highly accurate forms of obtaining a preoperative diagnosis in patients with invasive breast cancer, this is not the case in DCIS. As the number of surgical procedures can be reduced by core biopsy, it is still of considerable value in the management of DCIS.

Biopsy↗
PubMed2004

Intraoperative margin assessment and re-excision rate in breast conserving surgery.

AIM: The aim of this study was to assess the efficacy of intraoperative margin assessment in obtaining clear margins in conserving surgery for breast cancer. METHODS: Two hundred and twenty patients undergoing wide local excision (WLE) for core biopsy proven primary invasive breast cancer, during a 30 months period, were included in the study. Following surgical excision the breast specimen was orientated with sutures, inked using India ink and coloured pigments and incised to identify the tumour, maintaining orientation. The distance to the individual radial margins were estimated macroscopically by the pathologist and conveyed intraoperatively to the surgeon. A macroscopic tumour-margin distance of less than 10 mm was considered compromised and the margin(s) in question was then excised if feasible. RESULTS: Eighty-one patients (37%) were judged to have compromised margins following intraoperative macroscopic evaluation and had at least one margin re-excised. Sixteen of the 81 patients (20%) in this subgroup had compromised margins on microscopy and required a second operation. One hundred and thirty-nine patients (63%) were deemed to have clear margins intraoperatively, subsequently confirmed on microscopic examination in 135 patients (97%). Intraoperative macroscopic assessment of margin status was associated with 9.1% of patients requiring a second operation. In the absence of intraoperative assessment of margin status a further 47 patients (21.4%) would have required a second operation. CONCLUSION: Intraoperative macroscopic margin assessment is an effective technique in reducing the number of second operative procedures in patients undergoing conserving surgery for primary invasive breast cancer.

Breast Neoplasms↗
PubMed2004

Pathological axillary lymph nodes detected at mammographic screening.

AIM: To investigate the significance of abnormal axillary lymph nodes detected at mammographic screening in the absence of a concomitant breast lesion. METHODS: Twenty-three thousand, seven hundred and seven women were screened at the Merrion Unit as part of the Irish National Breast Screening Programme ("BreastCheck") in the period June 2000 to July 2002. Nine women (0.4 per 1000 women screened) were found to have an abnormal axillary lymph node(s) in the absence of a mammographic breast lesion and were recalled for assessment. The radiological criteria for recall included: size greater than or equal to 15 mm, round or irregular shape, increased node density and absence of hilar lucency. Each woman underwent further mammographic views, ultrasound examination of axilla and breast, clinical examination and lymph node biopsy either by 14G needle core biopsy (NCB) or open excision. RESULTS: The final pathological diagnoses in the nine patients were oestrogen receptor (OR) positive metastatic breast carcinoma (two patients), metastatic malignant melanoma (one patient), malignant lymphoma (two patients), caseating granulomatous lymphadenitis suggestive of tuberculosis (one patient), and other benign conditions (three patients). CONCLUSION: Abnormal axillary lymph nodes, in the absence of an accompanying breast lesion, are rarely identified on screening mammogram, but may harbour significant pathology and their presence on screening mammogram merits further investigation including biopsy.

Axilla↗
PubMed2004

Factors affecting metastases to non-sentinel lymph nodes in breast cancer.

AIMS: Because sentinel lymph node (SLN) biopsy for breast cancer has become well established, one of the challenges now is to determine which patients require a completion axillary dissection following a positive SLN biopsy. METHODS: A prospective database of patients who underwent SLN biopsy for invasive breast cancer from July 1999 to November 2002 (n = 180) was analysed. Fifty four patients (30%) had one or more positive SLN, and all underwent a completion axillary dissection. This subgroup was further analysed to delineate which factors predicted non-SLN metastasis. RESULTS: Twenty six of the 54 patients with a positive SLN had additional metastases in non-SLNs. Significant variables that predicted non-SLN metastasis included extranodal extension (odds ratio (OR), 17.399; 95% confidence interval (CI), 1.69 to 178.96) and macrometastasis within the SLN (OR, 6.985; 95% CI, 1.291 to 37.785). CONCLUSIONS: In patients with invasive breast cancer and a positive SLN, extranodal extension or macrometastasis within the SLN were both independent predictors of non-SLN involvement.

Adult↗
PubMed2004

Surgical intervention in screen-detected patients versus symptomatic patients with breast cancer.

OBJECTIVES: The impact of population-based screening for breast cancer on the rate of breast-conserving surgery has not been established. We sought to evaluate whether surgical intervention in patients with screen-detected breast cancer differed from those with clinically detected tumours. SETTINGS: St Vincent's University Hospital and the BreastCheck Merrion Unit, part of the Irish National Breast Screening Programme, were the setting for the study. METHODS: A total of 902 patients referred for surgery to St Vincent's University Hospital over a four-year period (2000-2003) were studied. Patients with breast cancers detected during the prevalent round of screening (n=325) were compared with patients presenting with symptomatic disease (n=577). The operative procedure, nature of axillary surgery and histopathological findings were recorded in each case. RESULTS: There was an increase in breast-conserving therapy in the screened population compared with symptomatic cases (68% screened versus 53% symptomatic; p<0.0001), with a corresponding reduction in axillary clearance rates (65% screened versus 81% symptomatic; p<0.0001). Nodal positivity was similar following correction for size in all tumours >1 cm, regardless of method of detection. Sentinel node biopsy was successfully undertaken in 39% of tumours <2 cm (T1 tumours) [corrected] in the screening population. CONCLUSIONS: The screened population was statistically more likely to have breast-conserving therapy than the symptomatic group. Sentinel node biopsy has evolved into an acceptable alternative to axillary clearance in T1 cancers, particularly in screen-detected cases.

Axilla↗
PubMed2002

Thrombospondin 1 protein expression relates to good prognostic indices in ductal carcinoma in situ of the breast.

AIM: Angiogenesis plays an important role in tumour growth and has been shown to occur around both in situ and invasive tumours. The degree of angiogenesis within tumours depends on the balance of pro-angiogenic and anti-angiogenic factors. One such anti-angiogenic factor is thrombospondin 1 (TSP-1). This study investigates the pattern of expression of TSP-1 in ductal carcinoma in situ (DCIS) of the breast and its relation to the surrounding microvessel pattern and density. MATERIALS/METHODS: The expression of TSP-1 was studied in formalin fixed, paraffin wax embedded sections from 58 cases of pure DCIS, using a monoclonal antibody against TSP-1 and the avidin-biotin-diaminobenzidine immunoperoxidase detection system. Vessels were stained with a monoclonal antibody to the endothelial cell marker CD31. Stromal microvessel density was assessed by counting "hot spots" within 500 micro m of the basement membrane of involved ducts using a 25 point Chalkey graticule. RESULTS: TSP-1 staining of the basement membrane around duct spaces with DCIS was seen in 69% of cases. In addition, staining of the stroma between involved duct spaces was seen in 31% of cases, with a fibrillary pattern identical to that seen in invasive breast carcinomas. In 12% of cases no staining for TSP-1 was seen. Two patterns of vascularity were identified. A cuff of vessels immediately adjacent to the basement membrane of ducts with DCIS was seen in 71% of cases. The presence of stromal TSP-1 was significantly associated with DCIS showing no/little necrosis (p = 0.01) and no/little periductal inflammation (p = 0.04). There was a trend between the presence of stromal TSP-1 and tumour cell negativity for p53 (p = 0.087). The stromal microvessel Chalkey point count ranged between 3.33 and 16. An increased stromal microvessel count was associated with high histological grade (p = 0.02), extensive necrosis (p = 0.047), and pronounced periductal inflammation (p = 0.049). There was no association between the presence of stromal TSP-1 and stromal microvessel density. CONCLUSIONS: TSP-1 is expressed in the stroma around DCIS and in the immediately adjacent basement membrane. Expression of stromal TSP-1 is lost in DCIS with more aggressive histological features. The absence of a relation with microvessel density suggests that other angiogenic factors may play an important role in DCIS.

Adult↗
PubMed2002

Angiogenesis, thrombospondin, and ductal carcinoma in situ of the breast.

Angiogenesis, the growth of new vessels from existing vasculature, plays an essential role in tumour development. The process involves interaction between a variety of cells, growth factors, and components of the extracellular matrix, regulated by pro-angiogenic and anti-angiogenic factors. This review profiles these factors, outlines the available methods for measuring new vessel formation, and discusses the importance of angiogenesis in breast cancer, with emphasis on ductal carcinoma in situ.

Angiogenesis Inducing Agents↗
PubMed2001

A human CD46 transgenic pig model system for the study of discordant xenotransplantation.

BACKGROUND: The chronic shortage in the supply of human organs available for allotransplantation has turned attention toward the use of animals as potential donors, with pigs as the most likely species under consideration. Hyperacute rejection, the initial and immediate barrier to a pig-to-primate xenograft, has been addressed by generation of transgenic pigs that express the human membrane-bound complement-regulatory proteins CD59 and/or CD55. Difficulty has been encountered in generation of transgenic animals that express a third membrane-bound complement-regulatory protein, CD46. METHODS: We have generated transgenic animals by using a large genomic construct that encompasses the entire human CD46 gene. RESULTS: We report the first description of transgenic mice and pigs that express high levels of human CD46 in a cell and tissue type-specific manner, resembling patterns of endogenous CD46 expression observed in human tissues. Furthermore, when human CD46 transgenic porcine hearts were transplanted into baboons, the grafts did not succumb to hyperacute rejection, and survival extended for up to 23 days. Under the same conditions, nontransgenic grafts underwent hyperacute rejection within 90 min. CONCLUSIONS: This is the first report to describe generation of transgenic pigs that express human CD46, and the first in vivo demonstration of the ability of human CD46 expressed on pig organs to regulate complement activation and overcome hyperacute rejection upon transplantation of a vascularized organ into nonhuman primates.

Animals↗
PubMed2001

Linked chromosome 16q13 chemokines, macrophage-derived chemokine, fractalkine, and thymus- and activation-regulated chemokine, are expressed in human atherosclerotic lesions.

Chemokines are important mediators of macrophage and T-cell recruitment in a number of inflammatory pathologies, and chemokines expressed in atherosclerotic lesions may play an important role in mononuclear cell recruitment and macrophage differentiation. We have analyzed the expression of the linked chromosome 16q13 genes that encode macrophage-derived chemokine (MDC/CCL22), thymus- and activation-regulated chemokine (TARC/CCL17), and the CX(3)C chemokine fractalkine (CX(3)CL1) in primary macrophages and human atherosclerotic lesions by reverse transcription-polymerase chain reaction and immunohistochemistry. We show that macrophage expression of the chemokines MDC, fractalkine, and TARC is upregulated by treatment with the Th2-type cytokines interleukin-4 and interleukin-13. High levels of MDC, TARC, and fractalkine mRNA expression are seen in some, but not all, human arteries with advanced atherosclerotic lesions. Immunohistochemistry shows that MDC, fractalkine, and TARC are expressed by a subset of macrophages within regions of plaques that contain plaque microvessels. We conclude that MDC, fractalkine, and TARC, which are chromosome 16q13 chemokines, could play a role in mononuclear cell recruitment into atherosclerotic lesions and influence the subsequent inflammatory response. Macrophage-expressed chemokines upregulated by interleukin-4 may be useful surrogate markers for the presence of Th2-type immune responses in human atherosclerotic lesions.

Adolescent↗
PubMed1999

The human eukaryotic initiation factor 4AI gene (EIF4A1) contains multiple regulatory elements that direct high-level reporter gene expression in mammalian cell lines.

The gene encoding human eukaryotic initiation factor 4A (EIF4A1) is located on chromosome 17p13, 667 bp upstream from the gene encoding the macrophage endosomal protein CD68. The EIF4AI gene contains 10 intervening sequences with the 1397-bp first intron containing a CpG-rich methylation-free island. Sequences capable of enhancing gene expression reside between positions -69 and -371 and positions -504 and -1100 of the EIF4AI 5' flanking sequence and within introns 1, 2, 3, 7, and 9. In macrophage cell lines, EIF4A1 expression vectors give sustained high-level reporter gene expression to levels 10 times higher than that obtained using the human cytomegalovirus immediate-early gene promoter/enhancer. Sequences of the human EIF4AI gene may find application in the development of new vectors for gene therapy and genetic vaccination.

5' Untranslated Regions↗
PubMed1998

Functional comparison of the murine macrosialin and human CD68 promoters in macrophage and nonmacrophage cell lines.

The glycoprotein macrosialin is expressed specifically in murine monocytes and macrophages. In the murine genome the macrosialin gene lies 877 bp 3' of the ubiquitously expressed elongation initiation factor 4A1 (eIF-4AI) gene on chromosome 11. The macrosialin gene promoter directs high-level expression in transiently transfected murine macrophage cell lines, but significant levels of expression are seen in nonmacrophage cell lines. The first intron of the gene encoding the human homologue of macrosialin, CD68, directs macrophage-specific expression when cloned downstream of the human CD68 gene promoter. Despite sharing extensive sequence homology with the human CD68 gene first intron, the murine macrosialin gene first intron does not act as a macrophage-specific enhancer when cloned downstream of the human CD68 or murine macrosialin promoters. We conclude that the genetic elements that are responsible for macrophage-specific gene expression are organized differently in the murine and human CD68 genes.

Animals↗
PubMed1998

Angiography after aneurysm surgery: indications for "selective" angiography.

BACKGROUND: The need for postoperative cerebral angiography to confirm clip placement is largely a matter of the individual surgeon's preference, but in an atmosphere of limited health care resources and rising costs this attitude may need to be changed. METHODS: A series of 312 intracerebral aneurysms harbored in 227 consecutive patients were clipped by a single surgeon (WF) and studied with postoperative selective angiography. Clues were sought to identify which (if any) aneurysms were prone to require postoperative recognition of incomplete or inaccurate clipping. We examined aneurysmal size, patient's sex, age, preoperative Hunt/Hess Grade, and Fisher CT grade, to determine their relationship to poor surgical clipping results (residual aneurysm or major vessel occlusion). RESULTS: There were 13 cases of residual aneurysm (4.2%) and one case of major vessel occlusion (0.3%). Deep midline aneurysms (posterior circulation, anterior communicating artery) and ophthalmic (paraophthalmic) artery regions formed a group of patients with an increased risk of imperfect clip placement (8.2%; 13/157) as compared to patients with aneurysms in other locations (0.6%; 1/155) (p < 0.05). In addition, incompletely obliterated aneurysms proved to have a high rehemorrhage rate in this series. CONCLUSIONS: A retrospective analysis revealed that deep midline aneurysms are more prone to inadequate clipping, and therefore, as a bare minimum represent aneurysms requiring confirmatory postoperative evaluation. This contemporary series can be used as a basis to compare the results from intraoperative angiography.

Adult↗
PubMed1998

Loss of bcl-2 expression in ductal carcinoma in situ of the breast relates to poor histological differentiation and to expression of p53 and c-erbB-2 proteins.

AIM: This study (1) investigates the incidence of bcl-2 protein expression in a series of 108 cases of ductal carcinoma in situ (DCIS), including 25 with early invasive carcinoma, and (2) evaluates the relationship of bcl-2 expression to the histological grade of DCIS and to the expression of oestrogen receptor (ER), c-erbB-2 and p53 proteins. METHODS AND RESULTS: The expression of bcl-2, oestrogen receptor (ER), c-erbB-2 and p53 proteins was determined immunohistochemically. Cases were regarded as positive for individual antibodies when at least 10% of the DCIS cells showed positive staining. DCIS was graded histologically as well (n = 9), intermediately (n = 24), or poorly differentiated (n = 75). bcl-2 expression was documented in 57 cases (53%) and was strongly associated with the histological grade of DCIS (P < 0.0001). All cases of well-differentiated DCIS were bcl-2 positive and loss of bcl-2 expression was almost exclusively confined to poorly differentiated DCIS lesions. bcl-2 expression was also closely associated with positive ER status (P < 0.0001). Forty-seven of 57 (82%) bcl-2 positive cases were ER positive while 49/51 (96%) bcl-2 negative cases were ER negative. There was a significant inverse correlation between bcl-2 expression and both p53 protein expression (P = 0.0004) and c-erbB-2 expression (P < 0.0001). Nineteen of 24 (79%) p53 positive cases and 38/45 (84%) c-erbB-2 positive cases showed loss of bcl-2. CONCLUSIONS: Loss of bcl-2 expression occurs in poorly differentiated DCIS and is related to negative ER status and to positive p53 and c-erbB-2 status. This pattern of bcl-2 expression and its association with other biological markers in DCIS is similar to that reported in invasive breast carcinoma.

Adult↗