Leveraging metabolic modeling to identify functional metabolic alterations associated with COVID-19 disease severity

OBJECTIVE

Since the COVID-19 pandemic began in early 2020, SARS-CoV2 has claimed more than six million lives world-wide, with over 510 million cases to date. To reduce healthcare burden, we must investigate how to prevent non-acute disease from progressing to severe infection requiring hospitalization.

METHODS

To achieve this goal, we investigated metabolic signatures of both non-acute (out-patient) and severe (requiring hospitalization) COVID-19 samples by profiling the associated plasma metabolomes of 84 COVID-19 positive University of Virginia hospital patients. We utilized supervised and unsupervised machine learning and metabolic modeling approaches to identify key metabolic drivers that are predictive of COVID-19 disease severity. Using metabolic pathway enrichment analysis, we explored potential metabolic mechanisms that link these markers to disease progression.

RESULTS

Enriched metabolites associated with tryptophan in non-acute COVID-19 samples suggest mitigated innate immune system inflammatory response and immunopathology related lung damage prevention. Increased prevalence of histidine- and ketone-related metabolism in severe COVID-19 samples offers potential mechanistic insight to musculoskeletal degeneration-induced muscular weakness and host metabolism that has been hijacked by SARS-CoV2 infection to increase viral replication and invasion.

CONCLUSIONS

Our findings highlight the metabolic transition from an innate immune response coupled with inflammatory pathway inhibition in non-acute infection to rampant inflammation and associated metabolic systemic dysfunction in severe COVID-19.

Characterizations of handwashing sink activities in a single hospital medical intensive care unit

BACKGROUND

Handwashing sink drains are increasingly implicated as a potential reservoir of antibiotic-resistant bacteria in hospital outbreaks; however, usage patterns that may promote this source remain unknown.

AIM

To understand behaviours in the intensive care unit (ICU) that may facilitate establishment and nosocomial transmission of multidrug-resistant Gram negatives from a sink-trap reservoir to a patient.

METHODS

Motion-sensitive cameras captured anonymized activity paired with periodic in-person observations during a quality investigation from four ICU sinks (two patient rooms and two patient bathrooms) in a university hospital.

FINDINGS

We analysed 4810 sink videos from 60 days in patient rooms (3625) and adjoining bathrooms (1185). There was a false-positive rate of 38% (1837 out of 4810) in which the camera triggered but no sink interaction occurred. Of the 2973 videos with analysed behaviours there were 5614 observed behaviours which were assessed as: 37.4% medical care, 29.2% additional behaviours, 17.0% hand hygiene, 7.2% patient nutrition, 5.0% environmental care, 4.2% non-medical care. Handwashing was only 4% (224 out of 5614) of total behaviours. Sub-analysis of 2748 of the later videos further categorized 56 activities where a variety of nutrients, which could promote microbial growth, were disposed of in the sink.

CONCLUSION

Several non-hand hygiene activities took place regularly in ICU handwashing sinks; these may provide a mechanism for nosocomial transmission and promotion of bacterial growth in the drain. Redesigning hospital workflow and sink usage may be necessary as it becomes apparent that sink drains may be a reservoir for transmission of multidrug-resistant bacteria.

Characterization of the transient middle cerebral artery occlusion model of ischemic stroke in a HuR transgenic mouse line

This set of experiments characterizes a model of transient cerebral ischemic stroke in a transgenic (Tg) mouse line in which the glial fibrillary acidic protein (GFAP) promoter is utilized to drive expression of a human RNA-binding protein, HuR. Additionally, the effect of cerebral ischemia on the expression of endogenous Hu proteins is presented.

Phaeochromocytoma and Paraganglioma Excision Involving the Great Vessels

Objective/background

Phaeochromocytomas and paragangliomas are vascular neuroendocrine tumours distributed between the neck and the pelvis and may be associated with catecholamine secretion. The aim of the study was to describe the complex surgical management required to excise these tumours when in close proximity to the great vessels (aorta and vena cava).

Methods

This was a retrospective case series. Patients included those undergoing surgical excision of a phaeochromocytoma or paraganglioma involving the great vessels. Data on clinical presentation; genetic mutations; tumour location; catecholamine/metanephrine secretion; surgical strategy; pre-, intra-, and post-operative course were collated.

Results

Five patients (age range 16–60 years) were identified; three had thoracic paragangliomas located under the arch of the aorta, one had an abdominal paraganglioma invading the aorta, and one had a massive phaeochromocytoma invading the inferior vena cava via the adrenal vein. Three patients had predisposing germline mutations. All patients had adrenergic blockade prior to surgery. A diverse range of complex surgical techniques were employed to excise tumours, including cardiopulmonary bypass, aortic resection, grafting and venotomy of the vena cava. Early post-operative complications were limited.

Conclusions

Excision of phaeochromocytomas and paragangliomas involving the great vessels is high risk surgery optimally undertaken within a multidisciplinary setting in a tertiary referral centre. Comprehensive radiological and biochemical assessment, meticulous pre-operative preparation and close intra- and post-operative monitoring are essential. Radiological imaging may be unable to resolve the tumour extent and anatomy pre-operatively and direct visualisation of the tumour may be the only way to clarify the surgical strategy. Pre-operative knowledge of the genetic predisposition may influence surgical management.

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Highly vascular tumours which may be associated with catecholamine secretion.

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Comprehensive pre- and intra-operative preparation is essential.

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Final surgical strategy often requires direct tumour visualisation.

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The surgical strategy may alter for germline associated tumours.

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Management should be delivered by experienced multidisciplinary teams.

Clinical outcomes following unilateral adrenalectomy in patients with primary aldosteronism

BACKGROUND

In approximately half of cases of primary aldosteronism (PA), the cause is a surgically-resectable unilateral aldosterone-producing adrenal adenoma. However, long-term data on surgical outcomes are sparse.

AIM

We report on clinical outcomes post-adrenalectomy in a cohort of patients with PA who underwent surgery.

DESIGN

Retrospective review of patients treated for PA in a single UK tertiary centre.

METHODS

Of 120 consecutive patients investigated for PA, 52 (30 male, median age 54, range 30-74) underwent unilateral complete adrenalectomy. Blood pressure, number of antihypertensive medications, and serum potassium were recorded before adrenalectomy, and after a median follow-up period of 50 months (range 7-115). Recumbent renin and aldosterone were measured, in the absence of interfering antihypertensive medication, ≥3months after surgery, to determine if PA had been biochemically cured.

RESULTS

Overall, blood pressure improved from a median (range) 160/95 mmHg (120/80-250/150) pre-operatively to 130/80 mmHg (110/70-160/93), P < 0.0001. 24/52 patients (46.2%) had cured hypertension, with a normal blood pressure post-operatively on no medication. 26/52 (50%) had improved hypertension. 2/52 patients (3.8%) showed no improvement in blood pressure post-operatively. Median (range) serum potassium level increased from 3.2 (2.3-4.7) mmol/l pre-operatively to 4.4 mmol/l (3.3-5.3) post-operatively, P < 0.0001). Median (range) number of antihypertensive medications used fell from 3 (0-6) pre- to 1 post-operatively (range 0-4), P < 0.0001.

CONCLUSIONS

Unilateral adrenalectomy provides excellent long-term improvements in blood pressure control, polypharmacy and hypokalaemia in patients with lateralizing PA. These data may help inform discussions with patients contemplating surgery.

Pure aldosterone-secreting adrenocortical carcinoma in a patient with refractory primary hyperaldosteronism

We describe a young male patient with longstanding hypertension, who was diagnosed with primary hyperaldosteronism and treated by an attempted retroperitoneoscopic total unilateral adrenalectomy for a left-sided presumed aldosterone-secreting adenoma. Imaging had shown an unremarkable focal adrenal lesion with normal contralateral adrenal morphology, and histology of the resected specimen showed no adverse features. Post-operatively, his blood pressure and serum aldosterone levels fell to the normal range, but 9 months later, his hypertension recurred, primary aldosteronism was again confirmed and he was referred to our centre. Repeat imaging demonstrated an irregular left-sided adrenal lesion with normal contralateral gland appearances. Adrenal venous sampling was performed, which supported unilateral (left-sided) aldosterone hypersecretion. Redo surgery via a laparoscopically assisted transperitoneal approach was performed and multiple nodules were noted extending into the retroperitoneum. It was thought unlikely that complete resection had been achieved. His blood pressure returned to normal post-operatively, although hypokalaemia persisted. Histological examination, from this second operation, showed features of an adrenocortical carcinoma (ACC; including increased mitoses and invasion of fat) that was assessed as malignant using the scoring systems of Weiss and Aubert. Biochemical hyperaldosteronism persisted post-operatively, and detailed urine steroid profiling showed no evidence of adrenal steroid precursors or other mineralocorticoid production. He received flank radiotherapy to the left adrenal bed and continues to receive adjunctive mitotane therapy for a diagnosis of a pure aldosterone-secreting ACC.

Molecular subtyping of DCIS: heterogeneity of breast cancer reflected in pre-invasive disease

Background:

Molecular profiling has identified at least four subtypes of invasive breast carcinoma, which exhibit distinct clinical behaviour. There is good evidence now that DCIS represents the non-obligate precursor to invasive breast cancer and therefore it should be possible to identify similar molecular subtypes at this stage. In addition to a limited five-marker system to identify molecular subtypes in invasive breast cancer, it is evident that other biological molecules may identify distinct tumour subsets, though this has not been formally evaluated in DCIS.

Methods:

Tissue microarrays were constructed for 188 cases of DCIS. Immunohistochemistry was performed to examine the expression patterns of oestrogen receptor (ER), progesterone receptor (PR), Her2, EGFR, cytokeratin (CK) 5/6, CK14, CK17, CK18, β4-integrin, β6-integrin, p53, SMA, maspin, Bcl-2, topoisomerase IIα and P-cadherin. Hierarchical clustering analysis was undertaken to identify any natural groupings, and the findings were validated in an independent sample series.

Results:

Each of the intrinsic molecular subtypes described for invasive breast cancer can be identified in DCIS, though there are differences in the relative frequency of subgroups, in particular, the triple negative and basal-like phenotype is very uncommon in DCIS. Hierarchical cluster analysis identified three main subtypes of DCIS determined largely by ER, PR, Her2 and Bcl-2, and this classification is related to conventional prognostic indicators. These subtypes were confirmed in an analysis on independent series of DCIS cases.

Conclusion:

This study indicates that DCIS may be classified in a similar manner to invasive breast cancer, and determining the relative frequency of different subtypes in DCIS and invasive disease may shed light on factors determining disease progression. It also demonstrates a role for Bcl-2 in classifying DCIS, which has recently been identified in invasive breast cancer.

SDHD-related chromaffin tumours: disease localisation to genetic dysfunction

BACKGROUND/AIMS

To describe the management of a subject with multiple chromaffin tumours found to have a novel succinate dehydrogenase D (SDHD) mutation.

CASE

A 15-year-old boy with marked hypertension was found to have elevated urinary catecholamines and initial imaging thought to represent bilateral adrenal phaeochromocytomas. An adrenal venous catheter was required to clarify a right adrenal phaeochromocytoma and a left abdominal paraganglioma, distinct from the left adrenal gland. Excision of these tumours, with preservation of the left adrenal gland, provided a cure for this subject without the need for lifelong steroid replacement. Genetic analysis revealed a novel SDHD mutation (c. 169 + 1 G>A) which was shown to result in loss of the 5' splice site and exclusion of exon 2 during splicing. This suggests the likely pathogenicity of this mutation. Disease surveillance in this subject and genetic screening of first degree relatives is ongoing.

CONCLUSIONS

Genetic testing should be considered in all subjects presenting with a chromaffin tumour. In certain circumstances an adrenal venous sampling catheter for catecholamines may clarify diagnostic uncertainty. The complex management issues raised in the care of these subjects requires the involvement of a multidisciplinary team with the relevant expertise.

A Multi-Center Study To Determine the Optimum Duration of Neoadjuvant Letrozole on Tumour Regression To Permit Breast Conserving Surgery – An Interim Analysis

Background: Neoadjuvant letrozole is an attractive alternative to chemotherapy for post menopausal women with large, ER positive breast cancer, who are destined for mastectomy but would prefer breast conservation. Prospective studies have not investigated treatment duration beyond 6 months and retrospective studies suggest useful responses can occur after this period.Materials and Methods: This trial is a prospective, UK centrally quality assured, multi-centre, longitudinal study to assess the optimal duration of neoadjuvant letrozole treatment to allow breast conserving surgery for a period of up to12 months. Post menopausal women with large (≥T2), ER and/or PgR positive primary tumours, not considered eligible for breast conservation, were commenced on neoadjuvant letrozole and response was assessed every 2 months with clinical and ultrasound examination until sufficient shrinkage for breast conservation, progression or 12 months had been reached. Ultrasound and Mammography were undertaken at baseline and end-point. We present the initial analysis for time to response and breast conservation.Results: By January 2009, 103 women were available for analysis. 23 (22.3%) had undergone a mastectomy, 60 (58.3%) had achieved breast conservation and 20 (19.4%) remained under evaluation within the trial. The mean age of the group was 74.1 years (52-92). 25 (24.3%) had invasive lobular cancer and 13 (12.6%) had grade 3 tumours. 22 (21.4%) were node positive.Figure 1. Kaplan-Meier plot for time (days) to response sufficient for breast conservation.25% had breast conservation by 5.8 months, 50% by 8.2 months and 75% by 12 months. Median time to breast conservation was 8.2 months (95% CI 6.4-9.3)Figure 2. Median change in tumour volume from baselineAfter an initial rapid response in the first 4 months, the rate of response was slower and constant for a further 6 months. Tumour volume reduction to permit breast conservation varied between 65 and 80% .Discussion: This interim analysis indicates that the conventional treatment period of 4 to 6 months of neoadjuvant letrozole should be revised. For most women longer duration will increase the likelihood of achieving sufficient volume reduction to allow breast conserving surgery.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1082.

The expression and function of IGFBP-3 in normal and malignant breast tissue

The mitogenic and anti-apoptotic effects of insulin-like growth factor-I (IGF-I) are regulated by a family of insulin-like growth factor binding proteins (IGFBPs), particularly IGFBP-3. Little is known about the IGF-independent role of IGFBP-3 in breast cancer and the mechanisms regulating its production. The expression of IGFBP-3 in paired malignant and adjacent normal (n=53), and healthy normal (n=17) breast tissue samples was investigated using RT-PCR, immunohistochemistry and ELISA. We compared IGFBP-3 expression with other members of the IGF-I axis, other known tumorigenic genes and clinicopathological parameters. We also developed a novel tissue explant system using fresh normal and malignant breast tissue, with which we examined the in vitro effects of IGFBP-3 alone and in combination with known apoptotic agent, doxorubicin (n=6), on tissue viability and apoptosis. We demonstrated a high level of expression of IGFBP-3 mRNA in all samples. 96% of samples also expressed IGFBP-3 protein. No significant correlation was seen between IGFBP-3 expression and other clinicopathological parameters. The in vitro tissue explant system demonstrated that IGFBP-3 had little effect by itself on apoptosis. However, when used in combination with doxorubicin, increased apoptosis was seen in tumours. In contrast, less apoptosis was seen in normal tissue suggesting a protective effect. These divergent effects suggest a potential novel chemotherapeutic approach in the treatment of breast cancer. These findings suggest that IGFBP-3 may play a role in tumorigenesis, and that IGFBP-3 levels could be used in the future in cancer risk assessment/prevention or as markers of response to cancer treatments.

Follow-up for screen-detected ductal carcinoma in situ: results of a survey of UK centres participating in the Sloane project

AIMS

To investigate the variations in follow-up practice for screen-detected ductal carcinoma in situ (DCIS) in the UK.

METHODS

A questionnaire enquiring about follow-up practice and the perceived value of clinical follow-up after surgery for screen-detected DCIS was sent to the 74 UK screening centres participating in the Sloane Project.

RESULTS

Responses were received from 66 hospitals serving 54 screening centres. These demonstrate wide variations in practice. Clinical follow-up duration ranges from 1 year to indefinite, with the frequency of visits from three-monthly to annually. Formal mammographic follow-up duration ranges from none to indefinite. Mammographic frequency ranges from 1 to 2 years. Follow-up varies according to factors such as size and grade of disease and margin status in 23 units and according to whether adjuvant therapy is given in 23. Seven hospitals perform mammography of reconstructed breasts. Thirty-one centres consider clinical follow-up of DCIS to be of value or limited value whereas 28 consider it to be of little or no value.

CONCLUSIONS

There is no consensus with regard to the duration and frequency of follow-up for screen-detected DCIS, the contribution of predictive and treatment factors, the use of mammography of the reconstructed breast or the perceived value of clinical follow-up. Published guidelines show no consensus. Multidisciplinary teams involved in the care of women with screen-detected non-invasive cancer should contribute to audits such as the Sloane Project in order to determine the most effective and efficient ways to treat and follow up these patients.

Socio-economic deprivation independently predicts early recurrence in estrogen receptor positive breast cancer

Abstract #6081

Introduction: Socio-economic deprivation is associated with reduced survival in breast cancer, but little is known about how it affects the pattern of disease recurrence. We investigated the relationships between deprivation, other risk factors and recurrence in post-menopausal women with operable ER+ breast cancer.&#x2028; Methods: Patients who underwent potentially curative surgery for ER+ breast cancer between 1995 and 2005 at four UK centres were studied. Those patients whose area of residence was ranked in the highest quintile group according to the appropriate national Index of Multiple Deprivation were classed as deprived. The cumulative risk of recurrence was calculated using the Kaplan-Meier method, and hazard ratios were calculated using conventional and time-dependent Cox regression analysis stratified by centre.&#x2028; Results: 4110 patients were available for analysis, of whom 821 (20.0%) were classed as deprived. The median age at diagnosis was 62 years in both deprived and non-deprived groups. Tumour size and grade did not vary with deprivation status, but nodal involvement (38.0% vs 34.3%, p=0.05, Fisher's exact test) and lymphovascular invasion (28.1% vs 23.6%, p=0.01) were more prevalent in deprived patients. The latter were also more likely to undergo mastectomy (53.3% vs 47.2%, p=0.002) and less likely to receive adjuvant radiotherapy (50.4% vs 58.5%, P&lt;0.001) or chemotherapy (19.1% vs 22.8%, p=0.03).&#x2028; Median follow up was 5 years from diagnosis. Raw cumulative recurrence at 2.5 years was 8.4% (95% confidence interval 6.4-10.4) in deprived and 6.1% (5.3-6.9) in non-deprived patients. At 5 years the corresponding rates were 15.8% (13.1-18.5) and 13.3% (11.9-14.7). Only distant recurrence contributed to this difference, the local and contralateral recurrence rates being almost identical in deprived and non-deprived groups. Time-dependent Cox regression analysis showed that deprivation was a significantly stronger predictor of recurrence within 2.5 years of diagnosis than at later intervals, with or without adjustment for other prognostic variables (p&lt;0.05). For recurrence within 2.5 years, the unadjusted hazard ratio for deprivation was 1.64 (95% CI 1.22-2.22, p=0.001). After adjustment for age, mode of presentation, pathological variables and treatment, the hazard ratio was 1.51 (1.07-2.14, p=0.02).&#x2028; Conclusions: Post-menopausal women with ER+ breast cancer who are resident in areas of high deprivation are at increased risk of early recurrence, independently of known differences in tumour pathology and treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6081.

The role of radiotherapy in treating small early invasive breast cancer

AIM

The aim of the study was to identify if radiotherapy can be safely avoided in a selected subgroup of largely screening detected small invasive breast cancer.

METHODS

One hundred and eighty-eight patients with node negative invasive early breast cancer < or =1cm (< or =T1b) treated in our centre between 1990 and 2004 were retrospectively followed for local, regional and distant recurrences. Treatment involved adequate local excision by breast conserving surgery (BCS). Axillary staging was performed by a four node axillary sampling until 2000, following which sentinel lymph node sampling was employed. All sections were assessed histologically by haematoxylin and eosin stained sections. The inked margins were reported as being involved, close and clear. Radiotherapy (RT) was employed only if the resected margins were inadequate, and in those with involved axillary nodes who refused further completion axillary clearance.

RESULTS

Ninety-four patients (Group A) had BCS alone and 79 patients (Group B) had both BCS and RT. There was no ipsilateral breast tumour recurrence (IBTR) in 88 patients in Group A, corresponding to an actuarial freedom from IBTR of 96%, 91% and 88.1% at 5 years, 8 years and 9 years. In Group B, there was no IBTR in 75 patients corresponding to an actuarial freedom from IBTR of 97%, 94.9% and 90.6% at 5 years, 8 years and 10 years.

CONCLUSION

Our experience over 14 years has shown that it is possible to safely avoid radiotherapy in a selected subgroup of small invasive breast cancer.

Choosing early adjuvant therapy for postmenopausal women with hormone-sensitive breast cancer: aromatase inhibitors versus tamoxifen

AIMS

The aromatase inhibitors (AIs) anastrozole, exemestane, and letrozole have demonstrated superior disease-free survival (DFS) over tamoxifen in several trials. As the choice of adjuvant endocrine treatment for early breast cancer (EBC) is evolving from tamoxifen to the AIs, this review compares the AIs with tamoxifen to help surgeons choose a treatment plan that provides the greatest reduction of recurrence risk for their patients.

METHODS

MEDLINE was searched to identify relevant literature on the adjuvant use of tamoxifen and AIs in EBC.

RESULTS

Despite the use of adjuvant tamoxifen, recurrence is a persistent threat to women with hormone-sensitive EBC. Trials of the AIs versus tamoxifen have established that patients benefit from longer DFS, and in some cases distant DFS, after the use of an AI as initial adjuvant therapy, as switch therapy following 2-3 years of tamoxifen, or as extended adjuvant therapy following 5 years of tamoxifen. The AIs are well tolerated, with a different safety profile than that of tamoxifen in all these settings. Trials addressing the optimal regimen and treatment duration for AIs are also underway.

CONCLUSIONS

The advantage in DFS associated with AIs over tamoxifen use should prompt physicians and patients to consider the use of an AI as the initial adjuvant endocrine therapy or, alternatively, switching patients who currently take tamoxifen to an AI for the remainder of adjuvant endocrine therapy. Prolonging the period of adjuvant therapy with letrozole after 5 years of tamoxifen reduces recurrence and is associated with a survival advantage in node-positive patients.

The prevalence of seat belt use in Kingston, Jamaica: a follow-up observational study five years after the introduction of legislation

An observational cross-sectional study conducted in Kingston in 2004 showed that seat belts were used by 81.2% of private motor vehicle drivers and 74.0% offront seat passengers. This was significantly improved compared to 21.1% and 13.6% respectively in 1996 before the introduction of legislation in 1999 (p < 0.001). Females were significantly more likely than males to wear seat belts, both when driving (92.5% vs 77.3%; p < 0. 001) and as front seat passengers (79.9% vs 66.3%; p < 0.001). Of the 2289 motor vehicles examined, all except one were equipped with seat belts. Rear passenger utilization of seat belts was not examined. Drivers of new vehicles were more likely than other drivers to use seat belts (p < 0.001). Male drivers, drivers of older vehicles and all passengers may require specific targeting in an educational and enforcement campaign if the maximum benefits of seat belt use are to be realized

Methylene blue dye versus combined dye-radioactive tracer technique for sentinel lymph node localisation in early breast cancer

AIM

The study compared the accuracy and success rate of two techniques, methylene blue alone versus combined methylene blue and radioactive colloid in sentinel lymph node localisation in the management early breast cancer.

METHODS

Three hundred and twenty-nine patients with tumours less than 2 cm on ultrasound assessment were prospectively evaluated. One hundred and seventy-three patients (Group A) underwent sentinel lymph node localisation using 1 ml of 1% methylene blue. A combined technique of both methylene blue and radioactive colloid was used in 156 patients (Group B). Application of both was subdermal and subareolar. Sentinel lymph nodes were examined by standard microscopy. Patients underwent breast conservation surgery or mastectomy and sentinel node guided four node axillary sampling+/-clearance.

RESULTS

In Group A, the sentinel lymph node identification rate was 96.5%. The negative predictive value was 96.3%, with false negative of 3.7% and accuracy of 87.4%. In group B the identification rate for sentinel lymph node was 98.7%, with false negative of 4.1%, negative predictive value of 96%, and accuracy of 83.8%.

CONCLUSION

Sentinel lymph node localisation using methylene blue or combined dye and radioactive tracer technique predicts the axillary lymph node status in early breast cancer with comparable success rates, accuracy and false negative rates. The combined technique facilitates quicker identification of sentinel lymph node; however the dye technique alone can be used successfully in centres without nuclear medicine facilities.

Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork

The effect of grape seed extract (GSE) and bearberry (BB), on lipid oxidation (TBARS, mg malondialdehyde (MDA)/kg muscle), colour (CIE 'a' redness value), pH, microbial status (log(10)CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0-1000μg/g muscle) and BB (0-1000μg/g muscle) were added to raw pork (M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O(2):25% CO(2)) for up to 12 days at 4°C. Cooked pork patties were stored in MAP (70% N(2):30% CO(2)) for up to 4 days at 4°C. Mesophilic plate counts and pork pH were unaffected by GSE and BB. GSE and BB addition decreased (P<0.05) lipid oxidation (TBARS) in raw pork patties on days 9 and 12 of storage, relative to controls. Antioxidant activity of GSE and BB was observed in cooked pork patties demonstrating the thermal stability of GSE and BB. The 'a' redness values of raw and cooked pork patties marginally increased with increasing GSE concentration. The sensory properties of cooked pork patties were unaffected by GSE and BB addition. Results obtained demonstrate the potential for using health promoting nutraceuticals in meat and meat products.

Parathyroid carcinoma in multiple endocrine neoplasia type 1 (MEN1) syndrome: two case reports of an unrecognised entity

CONTEXT

Primary hyperparathyroidism occurs in almost all patients with the syndrome of multiple endocrine neoplasia type 1 (MEN1), but the association of MEN1 with parathyroid carcinoma has only been described previously in a single patient. In this report, we describe two further cases of parathyroid carcinoma presenting in MEN1 syndrome.

CASE REPORTS

The first patient was a 69-yr-old woman, who presented with severe primary hyperparathyroidism and tracheal compression by a large mediastinal mass, which was shown histologically to be a parathyroid carcinoma with a second similar lesion in the neck. She was treated with total parathyroidectomy followed by resection of the mediastinal mass with resolution of the hypercalemia. Remarkably, she also reported primary amenorrhea and was found to have an invasive pituitary lactotroph adenoma, which was treated with cabergoline and external beam radiotherapy. Magnetic resonance imaging (MRI) of the pancreas revealed a small lesion characteristic of an islet-cell tumor, which was clinically and biochemically non-functioning. The second patient was a 32-yr-old man who presented with symptomatic hypercalemia and markedly raised serum PTH concentration. Neck exploration revealed two parathyroid glands only. One of the parathyroid glands contained a tumor with fibrous banding, atypical mitoses, extra-capsular extension and moderate Ki 67 staining; features which are highly suggestive of carcinoma. He also had intractable dyspepsia associated with raised serum gastrin concentration. A lesion was localized to the neck of the pancreas by endocopic ultrasound, and a selective arterial calcium stimulation catheter suggested the presence of both a gastrinoma and an insulinoma, although he had no hypoglycemic symptoms. Pituitary MRI was normal. The patient's mother had primary hyperparathyroidism.

CONCLUSIONS

This case report describes two further patients in whom parathyroid carcinomas occurred in the context of MEN1, which gives a new insight to the possible presenting phenotype of this condition. Both patients had negative genetic screening for classic MEN1 gene mutation, which may suggest that one or more novel occult mutations may be responsible for this aggressive phenotype.

Selective parathyroid venous sampling in patients with complicated hyperparathyroidism

OBJECTIVE

The role of preoperative localisation of abnormal parathyroid glands remains controversial but is particularly relevant to the management of patients with recurrent or persistent hyperparathyroidism and familial syndromes. We report our experience of the use of selective parathyroid venous sampling (PVS) in the localisation of parathyroid disease in such patients.

DESIGN

We report a retrospective 10-year experience (n = 27) of the use of PVS in complicated primary hyperparathyroidism and contrast the use of PVS with neck ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) and sestamibi imaging modalities.

RESULTS

In 14 out of 25 patients who underwent surgery PVS results were completely concordant with surgical and histological findings and 88% of patients achieved post-operative cure. Out of 13 patients referred after previous failed surgery, 12 underwent further surgery which was curative in 9. In total PVS yielded useful positive (n = 13) and/or negative information (n = 6) in 19 out of 25 patients undergoing surgery. Using histology as the gold standard, 59% of PVS studies were entirely consistent with histology, as compared with 39% of ultrasound scans, 36% of sestamibi scans and 17% of MRI/CT scans.

CONCLUSIONS

PVS is a valuable adjunct to MRI/CT and sestamibi scanning in selected patients with complicated hyperparathyroidism when performed in an experienced unit.

Cyclo-oxygenase-2 (COX-2) mRNA expression and hormone receptor status in breast cancer

AIMS

The purpose of this study was to evaluate COX-2 mRNA expression with known clinical prognostic features of breast cancer, oestrogen/progesterone receptor status, tumour size and grade.

METHODS

Total RNA was extracted from 45 frozen breast tumour (invasive) and 22 normal breast tissue samples. COX-2 mRNA transcription was quantified using a real time RT-PCR assay and expressed as copy number/microg total RNA. All specimens were assessed for tumour grade, size, nodal status and presence of vascular invasion and oestrogen and progesterone receptor status.

RESULTS

COX-2 mRNA was detected in all samples with a median copy number of 1.15 x 10(7) for tumours and 6.5 x 10(6) for normal samples. Expression was significantly higher in oestrogen receptor negative tumours compared to the receptor positive group. There was no correlation between COX-2 mRNA levels and tumour size, grade, nodal status and presence of vascular invasion.

CONCLUSIONS

COX-2 mRNA expression is increased in oestrogen and progesterone receptor negative breast cancers.

Role of aromatase inhibitors in breast cancer

Primarily, the role of the aromatase inhibitors has been investigated in postmenopausal women with breast cancer, although it is also now being assessed in premenopausal patients following ovarian ablation/suppression. Aromatase inhibitors markedly suppress endogenous oestrogens without directly interacting with oestrogen receptors, and thus have a different mechanism of action to the antioestrogen, tamoxifen. The inhibitors may be divided into subgroups according to their structure (steroidal and nonsteroidal), and there appears to be a lack of cross-resistance between the classes of aromatase inhibitors enabling them to be used sequentially and potentially to prolong endocrine hormone therapy. In addition, with increased efficacy and favourable safety and tolerability profiles, the aromatase inhibitors are starting to challenge tamoxifen as first choice endocrine treatment in a number of settings. Potential differences in side-effect profiles may appear between the steroidal and nonsteroidal aromatase inhibitors when used in long-term settings. Thus, it has been suggested that the steroidal agents have favourable end organ effects; for example, the steroidal inhibitor, exemestane, has minimal negative effects on bone and lipid metabolism in animal and clinical studies. This paper provides an overview of the current and future roles of aromatase inhibitors for breast cancer treatment.

Surgery in the elderly: is age a risk factor?

This prospective, observational one-year study analyzed 623 patients who were 60 years and older, out of a cohort of 2375 patients who were admitted consecutively to the general surgery wards of the University Hospital of the West Indies (UHWI). Even though only 9.7% of the Jamaican population are 60 years and older, this age group accounted for 26.2% of total admissions. Comparison of elderly and non-elderly patients showed no differences in gender, but less elderly patients were emergency admissions (52% vs 64%, p < 0.001), more underwent surgery (68% vs 60%, p < 0.001), their mean hospital stay was longer (11.5 vs 8.0 days, p < 0.001) and their mortality rate was higher (8.8% vs 1.9%, p < 0.001). Emergency admissions (52%) exceeded elective admissions in the elderly. Forty-four (80%) of the 55 deaths in the elderly group were admitted as emergencies compared to elective admissions (p < 0.001). There were 11 deaths among the 296 elective admissions (3.7%) but 44 deaths among the 327 emergency admissions (13.5%), a significant difference in mortality rates (p < 0.001). Overall, the death rate for males was higher. Cancer was the commonest admission diagnosis (21%) and that amongst mortalities. Steps to improve the opportunities for earlier admission and optimization of care of elderly surgical patients would not only benefit them but would be an important step towards a more efficient use of already scarce resources.

Integrin expression and survival in human breast cancer

BACKGROUND

Integrin cell adhesion molecules are fundamental to numerous cellular functions including anchorage, differentiation and proliferation. Reduced expression of certain alpha and beta integrin subunits in primary breast cancer cells has been correlated with increased invasion and metastasis. Conversely, over-expression of the alpha6 subunit has been linked to poorer survival. The objective of this study was to measure the survival of a cohort with breast carcinoma in relation to integrin expression and to evaluate their potential as prognostic indicators.

METHOD

Integrin expression on samples from 99 consecutive patients with breast cancer was assayed using monoclonal antibodies to the subunits alpha(1,2,3,6,V) and beta(1,3,4,5). This cohort has now been followed prospectively for almost five years allowing for early assessment of survival in relation to integrin expression.

RESULTS

Whilst analysis of the data confirmed the relation of survival to proven predictors of tumour grade, tumour size and vascular invasion, statistical significance was not demonstrated with regard to both lymph node status and all integrin subunits studied.

CONCLUSION

Previous research correlating certain integrin subunits with survival has not been confirmed in this study. Despite proven molecular importance in tumour cell adhesion, invasion and metastasis, integrin expression would appear not to translate clinically as independent indicators of prognosis, at least in the short-term.

Cancer of the colon and rectum in a Jamaican population: diagnostic implications of the changing frequency and subsite distribution

The aim of this study was to examine the clinical and pathological characteristics of colorectal cancer in Jamaica, to determine whether there was a change in the anatomic distribution and clinical presentation and to discuss the options for diagnosis and management. A comprehensive retrospective review of patients newly diagnosed with colorectal carcinoma was conducted at The University Hospital of the West Indies by reviewing both patient records and pathological data. These data were compared with previous reports of patients with colorectal cancer seen in Jamaica. One hundred and forty-seven patients were studied There were 85 females and 62 males with a female to male ratio of 1.37:1. The median age was 65.5 years (range 19 to 94 years). The predominant symptoms were abdominal pain in 91 patients, change in bowel habit in 77 patients and rectal bleeding in 74 patients. Sixty patients presented with weight loss and 28 with a rectal mass. The most common tumours were right-sided colonic cancers in 42 patients (28.5%) followed by sigmoid colon in 30 (20.4%) rectum in 34 (23.1%) and left and transverse colon accounting for 16 and 10 cases respectively. Most of the tumours were well or moderately differentiated adenocarcinomas. Only eight patients presented with Dukes' A disease, 50 with Dukes'B, 53 with Dukes'C disease and 34 with advanced disease. The findings showed that sigmoid and rectal tumours accounted for 43.5% of cancers. The colon/rectum ratio in this series was 3.3:1 indicating a significant proximal shift of colorectal cancers in this population in keeping with recent reports. The results of the current study suggest that the sub-site location of colorectal cancers seen is similar to that reported in high incidence countries such as the United States of America and parts of Europe but differs from the African continent which has a high proportion of rectal tumours. This right-sided preponderance also differs from previous studies in Jamaica, which report a higher incidence of rectal lesions The detection of early colorectal carcinoma will require screening at a stage when the disease is asymptomatic in order to improve the chance for cure. The data presented here imply that screening programmes should allow evaluation of the entire colon rather than the distal 25 cm.

Phyllodes tumour of the breast: a retrospective analysis of 30 cases

Phyllodes tumour (PT) is a rare neoplasm of the female breast that resembles fibroadenoma but occurs in an older age group. We retrospectively reviewed the medical records of 30 women who were treated for phyllodes tumour in our centre. Histological examination was performed by an experienced breast pathologist in all cases and tumours were classified as benign, border line malignant or malignant according to standard histological criteria. The mean age at diagnosis was 49 years (range: 19-80 years). Twenty-one (70%) of 30 tumours were benign and 9 (30%) were malignant (n=7) or borderline malignant (n=2). The mean tumour size was 46 mm (range: 20-100 mm). The final microscopic margins contained tumour in 13 (43%) of 30 cases and were free of tumour in 17 (57%) of 30 patients. After a median follow-up period of 6 years (range: 6 months-20 years), the tumour recurred locally in 5 (17%) patients. One patient had six local recurrences over an 18-year period. Local recurrences were more frequently observed in patients with malignant tumours compared with those with benign lesions (33% versus 10%). However, this association failed to reach statistical significance. There was no association between local recurrence, patient age, tumour size or positive microscopic margins. There was one death (3%) associated with a completely excised malignant tumour. The present study suggests that histological type and margins do not accurately predict the clinical course of PT and that there is a need to identify novel biological markers that more accurately predict the behaviour of this rare neoplasm.

Hot-water bottle induced thermal injury of the skin overlying Becker's mammary prosthesis

We report a case of a full thickness burn to the breast following the application of a hot-water bottle to the insensate skin overlying a mammary prosthesis.

Abdominal ganglioneuromas in adults

Ganglioneuromas are rare tumours of the parasympathetic nervous system. Their definitive diagnosis is made on histological examination. When they arise from the adrenal medulla, their assessment and management are the same as those of other adrenal tumours. We here report 3 cases of ganglioneuromas highlighting important points regarding the radiological assessment, management, decision making and surgical approaches.

How significant is detection of ductal carcinoma in situ in a breast screening programme?

PURPOSE

To compare the histological grades of screen detected and non-screen detected ductal carcinoma in situ (DCIS) and to identify any differences that might support the contention that DCIS found by breast screening represents an over-diagnosis. The aim was also to establish whether any particular mammographic features of DCIS can be used to predict tumour grade reliably.

MATERIALS AND METHODS

Biopsy proven cases of DCIS (n=153) were reviewed with respect to grade and subdivided into high, intermediate and low grades using the Van Nuys classification. A more aggressive subset of DCIS (microinvasive and interval cancers) were similarly analysed. Mammograms were reviewed with regard to abnormal features and distribution, and the appearances correlated with grade.

RESULTS

Fifty-four percent (53/98) of screen detected and 62% (34/52) of non-screen detected DCIS were high grade. The rest were equally intermediate and low grade, with no statistical difference between the two groups. Eighty-four percent of the aggressive subset of tumours were high grade. Micro-calcification was present in 90% and in 10% there were soft tissue changes alone. Seventy-six percent of linear branching calcification was associated with high grade DCIS. Only 13% of high grade DCIS demonstrated punctate micro-calcification; however, 38% of cases of punctate micro-calfication were associated with high grade tumours and there was a great deal of overlap between the groups.

CONCLUSION

Most cases of DCIS in both screen and non-screen detected groups were high grade. Only one in five was low grade. Analysis of the aggressive subgroup underlines the significance of high grade DCIS. Mammographic patterns are not always reliable in the prediction of tumour grade. The detection of DCIS in screening programmes is important and should not be regarded as over-diagnosis.

Is radiotherapy needed after breast conservation for small invasive breast cancers?

AIMS

The purpose of this study was to determine the rate of local recurrence in patients with small invasive breast cancers (<1 cm) who had been treated with breast-conserving surgery either with (group 1) or without (group 2) adjuvant radiotherapy.

METHODS

This is a retrospective study of 110 patients with an invasive breast cancer less than 1 cm in size, treated in our centre by breast-conserving surgery. Parameters examined included age at and mode of presentation, histopathological features, adjuvant therapy, length of follow-up and outcome in terms of local recurrence rate and death.

RESULTS

In group 1 there were 59 women of median age 57 (38-80) years. The median tumour size was 9 (1-10) mm and median follow-up was 74 (15-110) months. There were no local recurrences. In group 2 the median age at presentation was 59 (48-81) years. The median tumour size was 7 (2-10) mm and median follow-up was 47 (14-93) months. There were three non-breast-cancer related deaths and three local recurrences (6%).

CONCLUSIONS

A local recurrence rate of 6% at almost 4 years median follow-up suggests that it may be possible to avoid adjuvant radiotherapy in a subgroup of largely screen-detected, node-negative patients with invasive tumours less than 1 cm, in whom adequate local excision is performed. Further follow-up is required to substantiate this.

Infiltrating fibromatosis of the breast: a potential pitfall

Mammary fibromatosis is a rare condition. It presents a big dilemma for the clinician, because it mimics breast cancer clinically, radiologically and sometimes cytologically. We report a case of fibromatosis of the breast and highlight the diagnostic difficulties and management.

Axillary node status in breast cancer patients prior to surgery by imaging with Tc-99m humanised anti-PEM monoclonal antibody, hHMFG1

In early breast cancer axillary nodes are usually impalpable and over 50% of such patients may have an axillary clearance when no nodes are involved. This work identifies axillary node status by imaging with a Tc-99m radiolabelled anti-Polymorphic Epithelial Mucin, humanised monoclonal antibody (human milk fat globule 1), prior to surgery in 30 patients. Change detection analysis of image data with probability mapping is undertaken. A specificity of 93% and positive predictive value of 92% (both 100% if a second cancer in the axilla with negative nodes is considered) were found. A strategy for combining negative imaging with the sentinel node procedure is presented.

Concomitant off-pump myocardial revascularization and pheochromocytoma resection

Surgical management of patients with coexisting ischemic heart disease and pheochromocytoma remains challenging. We present one such case in which hybrid myocardial revascularization (angioplasty with stenting and off-pump coronary artery bypass grafting) and resection of pheochromocytoma were undertaken. Unusual features included simultaneous coronary artery surgery and tumor resection and, in particular, coronary artery surgery being performed without cardiopulmonary bypass.

Improved rat model for cerebral vasospasm studies

While the rat has been used extensively in subarachnoid hemorrhage (SAH)-cerebral vasospasm studies, concerns exist whether this animal represents a usable model because its time course and pattern of cerebral vasospasm following SAH is not comparable to that observed in man. At present, our knowledge of the rat model is based almost exclusively on studies using a 'single hemorrhage' method. Since there is a positive correlation between severity of cerebral vasospasm, and volume of subarachnoid blood, an obvious question is whether the rat will show modifications in vascular responses when insulted by a second SAH. Here, an SAH was produced in rats using a 'double hemorrhage' method. Following SAH, cerebral arteries showed pathological alterations, significant decreases in luminal perimeter, and increases in arterial wall thickness, over a 7-day post-SAH period. The above vascular features are considered to be indicative of cerebral vasospasm and their presence over a 7-day post-SAH period represents a significant time extension when compared to a single hemorrhage. These modified vascular responses made the double hemorrhaged rat a much-improved animal model.