The prognostic significance of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 proteins expression in gastric cancer: a clinicopathological and immunohistochemical study of 121 Arab patients

BACKGROUND

The variability of prognosis within a pathological stage of gastric cancer (GC) at presentation, underscores the need for specific biological markers to identify subgroups of patients with aggressive course for intensive treatment. To our knowledge, this is the first study from an Arab population reporting on the relationship of p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67 expression, and clinicopathological features and their prognostic significance.

METHODS

Formalin-fixed paraffin-embedded tumors were studied by immunohistochemistry, using monoclonal antibodies to p53, p27 kip1, p21 waf1, HER-2/neu, and Ki67. The results were correlated with clinicopathological features and survival.

RESULTS

M:F = 80:41; median age = 60 years; stage III and IV = 71%; and median follow-up = 34.4 months. Positive expression rates of p53, p27 kip1, p21 waf1, Ki67, and HER-2/neu were 54%, 40%, 8.3%, 70%, and 12% respectively. p53 expression correlated with age <60 years (P = 0.03), tumor size >5 cm (P = 0.01), p27 kip1 and Ki67 expression (P = 0.0001), and HER-2/neu (P = 0.04). p21 waf1 correlated inversely with T-stage (P = 0.008) and Her-2/neu expression correlated with histological grade (P = 0.04) and T-stage (P = 0.008). Univariate analysis showed that p53 overexpression (P = 0.01), fungating and infiltrative macroscopic appearance (P = 0.02), size >5 cm (P = 0.0001), lymph node metastasis (P = 0.0001), p T3 and T4 disease (P = 0.01), and overall stage III and IV (P = 0.0001) disease were adverse prognostic factors. Patients with tumor profiles p53 (-)/p27 (+) had better survival than those with p53 (+)/p27 kip1 (-)(P = 0.02). On multivariate analysis by Cox regression model, the expression of p53 (P = 0.03) and lymph node involvement (P = 0.01) were significant adverse prognostic factors for overall survival.

CONCLUSIONS

The expression of p53 in Arab patients with GC correlates with aggressive tumor characteristics and is an independent prognostic factor. The combined analysis of p53 and p27 kip1 is of added prognostic value.

Differences in vascular response between primary and transplanted tumours

The vast majority of studies on tumour vasculature are performed on transplanted tumours in rodents. However, it is known that there may be differences between primary and transplanted lesions. The purpose of this study is to test whether a specific vascular response is similar in primary tumours and in transplanted tumours derived from them. The technique used was to give an intraperitoneal injection of 5 mg kg-1 hydralazine, which is known to result in hypoxia in transplanted tumours. Changes in perfusion were indicated by changes in metabolism, monitored using 31P Magnetic Resonance Spectroscopy. The primary tumours were induced by local irradiation many months previously and only 4/11 (36%) of these responded to hydralazine. One of the non responders was subsequently transplanted into isogeneic mice to produce a tumour line which was histologically very similar to the primary. Of these 16/17 (94%) responded. The difference is statistically significant (P = 0.001). The reasons for this difference are not known. A number of possibilities are discussed and in the authors' opinion, the most likely cause is that it results from an artefact of transplantation.

Measurement of circulating levels of VEGF-A, -C, and -D and their receptors, VEGFR-1 and -2 in gastric adenocarcinoma

AIM: To analyze the serum levels and prognostic significance of vascular endothelial growth factor (VEGF) -A, -C, and -D, and their receptors, VEGFR-1 and -2 in gastric adenocarcinomas.

METHODS: The serum levels of VEGF family members were measured in 76 control subjects and 76 patients with gastric adenocarcinoma using an enzyme-linked immunosorbent assay (ELISA). These measurements were correlated with clinco-pathological features and survival rates.

RESULTS: The serum levels of VEGF-A and its receptor, VEGFR-1, were significantly higher in patients with gastric cancer than in healthy donors (t = 2.3, P = 0.02 and t = 4.2, P < 0.0001, respectively). In contrast, the serum levels of VEGF-D were significantly higher in control subjects than in patients (t = 2.9, P = 0.004). There was no significant difference in serum levels of VEGF-C and VEGFR-2 between patients and controls. VEGF-C was associated with advanced tumor stage and presence of metastasis. VEGFR-1 was associated with metastasis, advanced overall stage, tumor differentiation and survival. VEGFR-2 levels were associated with poor tumor differentiation. There was no significant prognostic value for any of the VEGF family members or their receptors except for VEGFR-1 where high levels were associated with a poor overall survival.

CONCLUSION: Serum VEGF levels vary significantly in the same cohort of patients with variable clinico-pathological features and prognostic values. The simultaneous measurement of VEGF receptors levels in sera may overcome the limitations of a single biomarker assay.

Acute tumor lysis syndrome after transcatheter chemoembolization of hepatocellular carcinoma

Two cases of acute tumor lysis syndrome occurring in patients with hepatocellular carcinoma are reported. Both patients were treated with transcatheter chemoembolization. Tumor lysis syndrome was not anticipated in the first case and was diagnosed late. However, the second patient's syndrome was detected early and treated appropriately. Subtle changes in electrolytes may be missed because of aggressive hydration that many of these patients receive because of cisplatin therapy. I propose that all patients with large hepatoma, particularly those with a short history, be monitored closely for acute tumor lysis syndrome.

Association of E-cadherin (CDH1) gene polymorphisms and gastric cancer risk

AIM: To investigate the associations between CDH1 gene polymorphisms and gastric cancer (GC) risk predisposition.

METHODS: We analyzed four CDH1 polymorphisms (+54 T>C, -160 C>A, -616 G>C, -3159 T>C) in an Omani population, by extraction of genomic DNA from the peripheral blood of 192 patients with GC and 170 control participants and performed CDH1 genotyping using DNA sequencing.

RESULTS: CDH1 -160 -AA genotype was associated with an increased risk of GC (OR = 3.6, 95% CI: 1.1-11.8) (P = 0.03). There was no significant association between the other polymorphisms and GC risk. The haplotype analysis of +54 T>C, -160 C>A, -616 G>C, -3159 T>C genotypes revealed that the OR of CCGC and CAGC haplotypes was 1.5 (95% CI: 0.7-3.5) and 1.5 (95% CI: 0.2-3.0), but did not reach statistical significance.

CONCLUSION: The current study suggests that the -160 AA genotype was associated with an increased risk of GC in Oman.

Interleukin-1beta gene (IL-1B) and interleukin 1 receptor antagonist gene (IL-1RN) polymorphisms and gastric cancer risk in an Omani Arab population

BACKGROUND

Gastric cancer (GC) is the most common malignancy in Oman. Interleukin-1beta gene (IL-1B) and interleukin-1 receptor antagonist gene (IL-1RN) polymorphisms have been associated with increased GC risk. No previous studies have examined their role in an Arab population. We tested the associations between polymorphisms of IL1B at positions -31, -511, and +3954 and the IL-1RN polymorphism [variable number of tandem repeats (VNTR) and TC polymorphism at the -2018 position] and GC in Omani Arab patients.

METHODS

Genomic DNA was extracted from peripheral blood of 245 control subjects and 118 gastric cancer patients. The DNA samples were analyzed using the TaqMan allelic discrimination test for IL-1B -31, -511, and +3954 polymorphisms and IL-1RN -2018 polymorphism. The VNTR of IL-1RN was genotyped using the polymerase chain reaction followed by agarose gel electrophoresis.

RESULTS

There was an association between the presence of IL-1RN*2 allele and gastric cancer [odds ratio (OR) = 2.2, 95% confidence interval (CI) = 1.0-3.3, P = 0.04). The GC risk further increased to OR = 3.5 (95% CI = 1.0-11.9) in Helicobacter pylori-positive patients. No association was found between any of the other polymorphisms studied and GC.

CONCLUSION

IL-1RN polymorphism increased the risk of GC in an Omani Arab population, consistent with previous reports. In contrast, the IL-1B -31 polymorphism was not associated with an increased GC risk. These findings underscore the role of cytokine gene polymorphisms in the development of GC and further support the ethnic differences in the effect of IL-1B polymorphism on GC carcinogenesis.

Colorectal Cancer Patient Characteristics, Treatment and Survival in Oman--a Single Center Study

BACKGROUND

Colorectal cancer is the most common gastrointestinal cancer in Oman with an increasing incidence. We here report the presenting features, treatment outcomes and survival in a University hospital in Oman and compare our data with regional and international studies.

MATERIALS AND METHODS

Medical records of patients with colorectal cancer were reviewed retrospectively between June 2000 and December 2013 and were followed until June 2014.

RESULTS

A total of 162 patients were diagnosed with colorectal cancer. The majority were males (58.6%), with a median age of 56 years. Rectum was involved in 29.6% of patients, followed by ascending and sigmoid colon. The majority of patients had stage III (42.6%) and stage IV (32.7%) disease at presentation. K-Ras status was checked for 79 patients, and 41 (51.9%) featured the wild type. Median relapse free survival was 22 months. Median overall survival for all patients was 43 months. Observed 5 year overall survival (OS) for stages I, II and III was 100%, 60% and 60% respectively. On Log rank univariate analysis, age, BMI, diabetes, hypertension, metformin use, stage, clinical nodal status for rectal cancer, pathological T and nodal status, site of metastasis, surgical intervention, chemotherapy, radiotherapy, chemotherapy regimen, no of cycles of chemotherapy, response, RFS, site of recurrence and administration of 2nd line chemotherapy were significant factors affecting OS. On Cox regression multivariate analysis none of the factors independently affected the OS.

CONCLUSIONS

The majority of patients present with advanced disease and at young age. The survival rates are comparable to the published regional and international literature.

Gastric cancer risk predisposition and prognostic significance of vascular endothelial growth factor (VEGF) gene polymorphisms--a case-control study in an Omani population

Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis, tumor growth, and metastasis. We investigated the associations between VEGF gene polymorphisms and gastric cancer (GC) risk predisposition and prognostic characteristics in an Omani population, an ethnic group which has not been studied previously. We analyzed three VEGF polymorphisms (+405 G/C, -460 T/C, and +936 C/T) by the extraction of genomic DNA from peripheral blood of 130 GC patients and 130 control subjects followed by VEGF genotyping using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. There were no significant associations between the VEGF polymorphisms and GC risk. There were significant correlations between the +405 C/C genotype and both poor tumor differentiation (P = 0.007) and lymph node metastasis (P = 0.03) and between the -460 T/T genotype and poor tumor differentiation (P = 0.03) with a statistical trend toward lymph node involvement (P = 0.05). VEGF gene polymorphisms had no significant effects on survival, but the VEGF +405 G/G genotype had a statistical trend toward lower survival rate with a hazard ratio of 1.6 [95% CI, 0.9-2.9] compared with the VEGF +405 CC/GC combined genotype (P = 0.049). Multivariate analysis showed that disease stage at diagnosis and the +405 G/G genotype were independent variables of adverse prognostic significance. There were no associations between the six common haplotypes identified and both GC risk predisposition and survival. The current study suggests that VEGF polymorphisms have no role in GC risk predisposition, but may have prognostic significance in GC patients.

Interprofessional collaboration as a mediator in the relationship between nurse work environment, patient safety outcomes and job satisfaction among nurses

BACKGROUND

As an important organisational feature, the nurse work environment has been associated with increased work effectiveness, reduced patient safety issues and improved care quality. However, the mechanism underlying this association remains unexplored.

AIM

This study aims to assess the mediating role of interprofessional collaboration in the relationships between nurse work environment, select patient safety outcomes and job satisfaction.

METHODS

This cross-sectional, descriptive study used five standardized scales and included 881 clinical nurses employed in select teaching hospitals in Oman.

RESULTS

Nurses who worked in teaching hospitals in Oman perceived their work environment as highly favourable. Nurse work environment was directly and indirectly associated with nurse-assessed quality of care, adverse patient events and job satisfaction, through interprofessional collaborations.

CONCLUSION

Findings of the study suggest that enhancing nurse work environments can be a potential strategy to foster interprofessional collaboration and improve job satisfaction and patient safety outcomes.

IMPLICATIONS FOR NURSING MANAGEMENT

Organisational strategies to improve patient safety outcomes and job satisfaction in nurses can be facilitated by improving nurses' work conditions and enhancing interprofessional collaboration through supportive leadership, theory-driven approaches, obtaining hospital accreditation/certification and relevant workplace policies.

Authentic leadership, nurse-assessed adverse patient events and quality of care: The mediating role of nurses' safety actions

BACKGROUND

Authentic leadership has been consistently cited as a strong precursor of sustained job performance and work effectiveness in nurses; however, studies linking authentic leadership with nurses' safety actions, nurse-assessed adverse patient events and nursing care quality are scarce.

AIM

To examine whether nurses' safety actions mediate the relationship between authentic leadership, nurse-assessed adverse events and nursing care quality.

METHODS

A multi-centre, cross-sectional study involving 1,608 nurses employed in acute care facilities in Oman. Multi-stage regression analysis was conducted in testing for the mediation model.

FINDINGS

Nurse managers in Oman were perceived to be highly authentic by their staff nurses. Authentic leadership significantly predicted nurses' safety actions (β = 0.168, p < .001), decrease in nurse-assessed adverse events (β = -0.017, p = .024) and increase in care quality (β = 0.121, p < .001). Further, the association between authentic leadership and nurse-assessed adverse events (β = -0.063, p = .057) and care quality (β = 0.038, p = .002) was mediated by nurses' safety actions.

CONCLUSION

Results suggest the importance of developing nurse managers' authentic leadership to foster nurses' safety actions and reduce adverse patient outcomes and promote nursing care quality.

IMPLICATIONS FOR NURSING MANAGEMENT

Organizational efforts to address patient safety issues should be directed towards developing authentic leadership in nurse managers through leadership programmes, periodic evaluation of leadership competencies (e.g., 360-degree or a bottom-up performance evaluation), and a creation of a safe culture in which nurses can openly report safety concerns for corrective action.

FAT4 silencing promotes epithelial-to-mesenchymal transition and invasion via regulation of YAP and β-catenin activity in ovarian cancer

Background

The adhesion molecule, FAT4, has a tumor suppressor function with a critical role in the epithelial-to-mesenchymal-transition (EMT) and anti-malignant growth in several cancers. No study has investigated yet its role in epithelial ovarian cancer (EOC) progression. In the present study, we examined the role of FAT4 in proliferation and metastasis, and its mechanisms of interaction in these processes.

Methods

We have performed cell viability, colony formation, and invasion assays in ovarian cancer cells treated with siRNA to knockdown FAT4 gene expression. The regulatory effects of FAT4 on proteins involved in apoptotic, Wnt, Hippo, and retinoblastoma signaling pathways were evaluated by Western blotting following FAT4 repression. Also, 426 ovarian tumor samples and 88 non-tumor samples from the Gene Expression Profiling Interactive Analysis (GEPIA) database were analyzed for the expression of FAT4. Pearson’s correlation was performed to determine the correlation between FAT4 and the E2F5, cyclin D1, cdk4, and caspase 9 expressions.

Results

Lower expression of FAT4 was observed in ovarian cancer cell lines and human samples as compared to non-malignant tissues. This down-regulation seems to enhance cell viability, invasion, and colony formation. Silencing FAT4 resulted in the upregulation of E2F5, vimentin, YAP, β-catenin, cyclin D1, cdk4, and Bcl2, and in the downregulation of GSK-3-β, and caspase 9 when compared to control. Furthermore, regulatory effects of FAT4 on the EMT and aggressive phenotype seem to occur through Hippo, Wnt, and cell cycle pathways.

Conclusion

FAT4 downregulation promotes increased growth and invasion through the activation of Hippo and Wnt-β-catenin pathways.

Survival data and prognostic factors seen in Pakistani patients with esophageal cancer

BACKGROUND

Esophageal cancer is common in Pakistan. An attempt has been made for the first time to look at the survival data and prognostic factors associated with esophageal cancer in this region.

PATIENTS AND METHODS

We did a retrospective review of 263 cases seen at the Aga Khan University Hospital in Karachi. Data analysis was done using the Kaplan-Meier method and the Cox proportional hazard model.

RESULTS

Squamous cell carcinoma was noted in 81% of the cases, whereas adenocarcinoma was the second most common. At the time of diagnosis, early-stage disease was found in 25%, locally advanced in 41% and metastatic in 34% of all cases. Mean age at diagnosis was 56 years, with 59% males and 41% females. Survival data were available in 89 cases. Median survival was 7 months. On univariate analysis, the following factors were of prognostic significance: obstruction, histology, albumin level at diagnosis, age and platelet count. On multivariate analysis, three factors were found prognostic: presence or absence of obstruction, squamous cell carcinoma versus adenocarcinoma and platelet count.

CONCLUSIONS

We found that patients with squamous cell carcinoma and absence of thrombocytopenia and obstruction had a better overall survival. However, this is a limited retrospective analysis; we therefore recommend that these prognostic factors be evaluated in larger studies.

Significance of p53, Bcl-2, and HER-2/neu protein expression in Omani Arab females with breast cancer

Racial disparity in the presentation of breast cancer and the outcome of its treatment is well established. However, the causes remain unexplained. The scarcity of reports about the prognostic significance of p53, bcl-2, and HER-2/neu in Arab females with breast cancer has been the impetus to this study. We evaluated the prognostic significance of altered expression of p53, bcl-2, HER-2/neu in Omani Arab females with non-metastatic breast cancer with correlation to other established prognostic factors. We have retrospectively analyzed the immunohistochemical expression of p53, HER-2/neu and bcl-2 in paraffin embedded blocks of 72 females diagnosed with invasive breast cancer between 1992 and 2002. The expression of the above proteins was correlated with other prognostic factors and univariate and multivariate analysis was carried out for all prognostic factors. Overexpression of p53 significantly correlated with younger age (<40), pre-menopausal status, poor differentiation with inverse correlation with bcl-2 expression. Expression of bcl-2 immunopostivity significantly correlated to low histological grade and positive estrogen and progesterone receptor status. On univariate and multivariate p53 overexpression and lack of bcl-2 immunostaining resulted in worse survival outcome, but not Her-2/neu overexpression. Expression patterns of p53 and bcl-2 are independent predictors of survival in Omani Arab population which may help to stratify these patients into different risk groups.

Relationship between interprofessional teamwork and nurses' intent to leave work: The mediating role of job satisfaction and burnout

BACKGROUND

Reducing nurse turnover is a top priority for nursing management globally. While evidence has demonstrated that working in a favorable environment with greater interprofessional teamwork is essential in increasing nurse retention, few studies have explored the mechanism underlying this relationship.

AIM

To examine the direct and indirect effects of interprofessional teamwork on nurses' intentions to leave their jobs via the intermediary roles of job satisfaction and burnout.

METHODS

A cross-sectional study was conducted to collect data from 2113 nurses working in 21 hospitals in Oman. Data were collected using a survey questionnaire measuring teamwork, job satisfaction, burnout, and intention to leave. Logistic regression was used to investigate the direct effect of teamwork on intent to leave. A sequential mediation model was conducted to examine the mediating role of job satisfaction and burnout.

RESULTS

Interprofessional teamwork was directly associated with nurses' intentions to leave. The influence of teamwork on intention to leave was indirectly mediated by both job satisfaction and job burnout.

CONCLUSION

Findings illustrate the potential benefits of enhancing interprofessional teamwork in reducing nurses' intentions to leave. Interventions intended to foster teamwork could create satisfying workplaces, reduce perceived burnout, and ultimately contribute to organizational strategy for reducing nursing shortages.

Use of port-a-cath in cancer patients: a single-center experience

INTRODUCTION

Central venous catheters play an important role in the management of cancer patients. Different types of devices are associated with different patterns of complications. We report on the pattern of use and rate of complications of port-a-caths in patients diagnosed with malignant cancer at a single institution.

METHODOLOGY

The data were collected retrospectively from patients who received the treatment for solid tumors or lymphoma through a port-a-cath at the Sultan Qaboos University Hospital (SQUH) between January 2007 and February 2013.

RESULTS

A total of 117 port-a-caths were inserted in 106 patients. The majority (86; 73.5%) were implanted by an interventional radiologist, and the right internal jugular vein was accessed in 79 (67.5%) patients. Mean catheter indwelling time was 354 (range 3-1,876) days for all patients, 252 (3-1,876) and 389 days (13-1,139) for patients with and without complications, respectively. Thirty (25.6%) port-a-caths were removed prematurely, mainly due to infectious complications, while 17 (14.5%) were removed after completion of treatment. Staphylococcus aureus was the most frequently isolated organism, found in 8 (6.8%) patients. Underlying diagnosis (p < 0.001), chemotherapy regimen (p < 0.001), sensitivity to antibiotics (p = 0.01), and any complication (p < 0.001) were significant factors affecting the duration of port-a-cath use. None of these factors were significant on multivariate cox regression analysis.

CONCLUSIONS

The mean duration of port-a-cath use was almost one year. Infection was the most common complication leading to premature removal, followed by port thrombosis.

Complications and Management of Totally Implantable Central Venous Access Ports in Cancer Patients at a University Hospital in Oman

Objectives

Totally implantable central venous access ports (port-a-caths) are increasingly used for the safe administration of chemotherapy; however, their use is associated with complications. This study reviews patterns of complications, reasons for premature removal and the duration of the use of port-a-caths in patients receiving cancer treatment at Sultan Qaboos University Hospital (SQUH) and compares the infection rate with the literature and the researchers’ experiences.

Methods

This retrospective follow-up study included patients who had received cancer treatment through a port-a-cath and were admitted to SQUH between January 2007 and April 2019. Demographic features, underlying diagnosis, clinical stage, treatment, duration of use and the cause of premature removal of the port-a-cath were recorded.

Results

A total of 516 port-a-caths were inserted in 482 cancer patients. The majority of devices were implanted by interventional radiologists (n = 459; 89.0%) and the right internal jugular vein was most frequently accessed (n = 396; 76.7%). The mean indwelling time of a port-a-cath was 288 days (range: 3–1,872 days) for patients with complications and 550 days (range: 7–3,123 days) for patients without complications. Port-a-cath-related infection was the main complication (n = 63; 12.2%). Patient age, gender, treatment intent, underlying diagnosis, clinical stage, chemotherapy regimen, number of treatment courses, operator implanting the port, the type of micro-organism isolated from the port-a-cath and body mass index were significant factors affecting catheter indwelling time (P <0.05). On multivariate analysis, however, none of the factors was found to be significant.

Conclusion

Infection was the most common complication necessitating port-a-cath removal. The infection rate was much lower than the researchers’ previous experience and compares favorably with several published reports.

Screening for Anti-Cancer Compounds in Marine Organisms in Oman

OBJECTIVES

Marine organisms are a rich source of bioactive molecules with potential applications in medicine, biotechnology and industry; however, few bioactive compounds have been isolated from organisms inhabiting the Arabian Gulf and the Gulf of Oman. This study aimed to isolate and screen the anti-cancer activity of compounds and extracts from 40 natural products of marine organisms collected from the Gulf of Oman.

METHODS

This study was carried out between January 2012 and December 2014 at the Sultan Qaboos University, Muscat, Oman. Fungi, bacteria, sponges, algae, soft corals, tunicates, bryozoans, mangrove tree samples and sea cucumbers were collected from seawater at Marina Bandar Al-Rowdha and Bandar Al-Khayran in Oman. Bacteria and fungi were isolated using a marine broth and organisms were extracted with methanol and ethyl acetate. Compounds were identified from spectroscopic data. The anti-cancer activity of the compounds and extracts was tested in a Michigan Cancer Foundation (MCF)-7 cell line breast adenocarcinoma model.

RESULTS

Eight pure compounds and 32 extracts were investigated. Of these, 22.5% showed strong or medium anti-cancer activity, with malformin A, kuanoniamine D, hymenialdisine and gallic acid showing the greatest activity, as well as the soft coral Sarcophyton sp. extract. Treatment of MCF-7 cells at different concentrations of Sarcophyton sp. extracts indicated the induction of concentration-dependent cell death. Ultrastructural analysis highlighted the presence of nuclear fragmentation, membrane protrusion, blebbing and chromatic segregation at the nuclear membrane, which are typical characteristics of cell death by apoptosis induction.

CONCLUSION

Some Omani marine organisms showed high anti-cancer potential. The efficacy, specificity and molecular mechanisms of anti-cancer compounds from Omani marine organisms on various cancer models should be investigated in future in vitro and in vivo studies.

The potential for prazosin and calcitonin gene-related peptide (CGRP) in causing hypoxia in tumours

Using 31P NMR spectroscopy, changes in tumour metabolic status were studied in a transplanted rat fibrosarcoma following the administration of vasodilators. Mean Arterial Blood Pressure (MABP) was monitored simultaneously. Two vasodilators were studied, prazosin and CGRP, which altered the NMR parameters Pi/sigma P, beta NTP,Pi, PCr/Pi and PME/Pi in a dose dependent manner. There was a good correlation between the various NMR parameters; for analysis, Pi/sigma P was used for convenience. With increasing doses of vasodilator, Pi/sigma P increased and the MABP decreased. Reduction in pHNMR showed a correlation with decreasing MABP following the administration of prazosin but not after CGRP. Both prazosin and CGRP produced changes in 31P NMR spectra consistent with a reduction in tumour blood flow. The results for prazosin and CGRP were comparable and showed a 15-20% increase in Pi/sigma P for a 20% reduction in MABP. These results were compared with those from hydralazine. With hydralazine an acceptable reduction in blood pressure (up to approximately 25%) has little effect and may even alter NMR parameters consistent with an increase in blood flow, a reduction of approximately 40% is required for a significant decrease in flow. Both prazosin and CGRP are shown to be far more effective than hydralazine in causing tumour hypoxia at a clinically acceptable reduction in blood pressure. CGRP may be the more suitable for clinical use because of its short half life, its capability to achieve controlled hypotension and the relatively few side effects associated with its use.

Molecular genetics complexity impeding research progress in breast and ovarian cancers

Breast and ovarian cancer are heterogeneous diseases. While breast cancer accounts for 25% of cancers worldwide, ovarian cancer accounts for 3.5% of all cancers and it is considered to be the most lethal type of cancer among women. In Oman, breast cancer accounts for 25% and ovarian cancer for 4.5% of all cancer cases. Various risk factors, including variable biological and clinical traits, are involved in the onset of breast and ovarian cancer. Although highly developed diagnostic and therapeutic methods have paved the way for better management, targeted therapy against specific biomarkers has not yet shown any significant improvement, particularly in triple-negative breast cancer and epithelial ovarian cancer, which are associated with high mortality rates. Thus, elucidating the mechanisms underlying the pathology of these diseases is expected to improve their prevention, prognosis and management. The aim of the present study was to provide a comprehensive review and updated information on genomics and proteomics alterations associated with cancer pathogenesis, as reported by several research groups worldwide. Furthermore, molecular research in our laboratory, aimed at identifying new pathways involved in the pathogenesis of breast and ovarian cancer using microarray and chromatin immunoprecipitation (ChIP), is discussed. Relevant candidate genes were found to be either up- or downregulated in a cohort of breast cancer cases. Similarly, ChIP analysis revealed that relevant candidate genes were regulated by the E2F5 transcription factor in ovarian cancer tissue. An ongoing study aims to validate these genes with a putative role as biological markers that may contribute to the development of targeted therapies for breast and ovarian cancer.

NAT2 polymorphism in Omani gastric cancer patients-risk predisposition and clinicopathological associations

AIM: To study whether N-acetyltransferase 2 (NAT2) genotypes and phenotypes are associated with increased risk factor for gastric cancer in Omani patients and to study the clinico-pathological correlations and the prognostic significance of NAT2.

METHODS: Genomic DNA was extracted from peripheral blood of 100 gastric cancer patients and 100 control subjects. NAT2 genotyping was performed using DNA sequencing. The prognostic significance of NAT2 and other clinicopathological features was assessed by univariate and multivariate analyses.

RESULTS: We observed no significant association between NAT2 genotypes and phenotypes and gastric cancer risk. The NAT2 phenotype polymorphisms and gastric cancer risk predisposition were not modified by concomitant H pylori infection and smoking. There was no significant association between NAT2 and clinicopathological features, and NAT2 had no independent prognostic significance.

CONCLUSION: In the current study, NAT2 genotypes and phenotypes are not associated with gastric cancer risk predisposition. Moreover NAT2 phenotypes had no clinicopathological associations or prognostic significance.

Improving Outcomes in Advanced Lung Cancer: Maintenance therapy in non-small-cell lung carcinoma

Systemic chemotherapy has remained the traditional treatment for metastatic non-small-cell lung carcinoma (NSCLC), enhancing survival rate at 1 year to 29%. The median survival had plateaued at around 10 months until early 2008, and in an attempt to enhance survival in advanced disease, maintenance chemotherapy trials were initiated which had recently demonstrated prolongation of survival by an additional 2-3 months in patients who had performance status (PS) 0-1 and well-preserved organ functions. Suitable patients with any degree of clinical benefit are treated with 4-6 cycles, and then one of the active agents is continued until best response, or toxicity (continued maintenance), or changed to a cross non-resistant single agent (switch maintenance). The article briefly reviews the evolution of systemic therapy and describes key randomised trials of maintenance therapy instituting chemotherapy and targeted agents in an attempt to improve outcomes in advanced metastatic NSCLC, based on certain clinical features, histology, and genetics.

Cytokeratin-positive primitive neuroectodermal tumor of the prostate: case report and review of literature

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) of the prostate is extremely rare. Here, we report a case of ES/PNET of prostate in a 24-year-old man presenting with dysuria and pelvic discomfort. Computed tomography scan revealed a heterogeneous mass involving the prostate without evidence of distant metastases. Histologically, the tumor was composed of small round blue cells strongly and diffusely positive for CD99 and epithelial markers. Fluorescence in situ hybridization confirmed rearrangement of the Ewing's sarcoma region on chromosome 22.