Abdulmalik Alsheikh

Monopolar Electrosurgery through Single-Port Laparoscopy: A Potential Hidden Hazard for Bowel Burns

BACKGROUND Surveys indicate that up to 90% of general surgeons and gynecologists use monopolar radiofrequency during laparoscopy and 18% have experienced visceral burns. Monopolar electrosurgery compared with other energy sources is associated with unique characteristics and inherent risks and complications caused by inadvertent direct or capacitive coupling or insulation failure of instruments. These dangers become particularly important with the reemergence of single-port laparoscopy, which requires close proximity and crossing of multiple intraabdominal instruments outside the surgeons field of view. STUDY OBJECTIVES To determine the effects of monopolar electrosurgery on various tissues/organs during simulated single-port laparoscopic surgery in vitro and in vivo. DESIGN Simulation in a dry laboratory with fresh sheep liver, pig bowel and bowel in an anesthetized dog (Canadian Classification II-3). SETTING University-affiliated teaching hospital and animal facilities. MEASUREMENTS AND MAIN RESULTS We used Valleylab Force 2 and FX electrosurgical generators at clinically used power outputs of 40 to 60 watts, and both high- and low-voltage (coagulation and cut) waveforms and commercially-available single-port devices. The effect on tissue was recorded by pictures and video camera and graded visually and histologically with hematoxylin and eosin stains. During activation of any standard monopolar laparoscopic instrument (scissors, coagulating electrode, etc), capacitive coupled currents resulting in visible tissue burn (blanching) caused by other adjacent cold instrument (graspers, etc) including metallic suction-irrigation cannulas and the laparoscope itself were noted. Histopathologic study confirmed transmural thermal damage extending to the mucosa of small bowel, even in the presence of mild serosa blanching. With prolonged activation of the electrosurgical generator, the capacitive coupled corona discharge burned the insulation and caused rapid insulation breakdown of the electrode instrument resulting in direct coupling (sparking, arcing) to adjacent cold instruments and more severe burning to the contacted tissue/organ. CONCLUSIONS During single-port laparoscopy and use of monopolar radiofrequency, the proximity and crossing of multiple instruments generate capacitive or direct coupled currents, which may cause visceral burns.

Methylation of SFRPs and APC genes in ovarian cancer infected with high risk human papillomavirus.

BACKGROUND Secreted frizzled-related protein (SFRP) genes, new tumor suppressor genes, are negative regulators of the Wnt pathway whose alteration is associated with various tumors. In ovarian cancer, SFRPs genes promoter methylation can lead to gene inactivation. This study investigated mechanisms of SFRP and adenomatous polyposis coli (APC) genes silencing in ovarian cancer infected with high risk human papillomavirus. MATERIALS AND METHODS DNA was extracted from 200 formalin-fixed paraffin-embedded ovarian cancer and their normal adjacent tissues (NAT) and DNA methylation was detected by methylation specific PCR (MSP). High risk human papillomavirus (HPV) was detected by nested PCR with consensus primers to amplify a broad spectrum of HPV genotypes. RESULTS The percentages of SFRP and APC genes with methylation were significantly higher in ovarian cancer tissues infected with high risk HPV compared to NAT. The methylated studied genes were associated with suppression in their gene expression. CONCLUSION This finding highlights the possible role of the high risk HPV virus in ovarian carcinogenesis or in facilitating cancer progression by suppression of SFRP and APC genes via DNA methylation.

Human papillomavirus genotyping and integration in ovarian cancer Saudi patients

BackgroundHuman papillomavirus (HPV) is associated with different malignancies but its role in the pathogenesis of ovarian cancer is controversial. This study investigated the prevalence, genotyping and physical state of HPV in ovarian cancer Saudi patients.MethodsHundred formalin fixed paraffin embedded (FFPE) ovarian carcinoma tissues and their normal adjacent tissues (NAT) were included in the study. HPV was detected by nested polymerase chain reaction (PCR) using degenerated HPVL1 consensus primer pairs MY09/MY11 and GP5+/GP6 + to amplify a broad spectrum of HPV genotypes in a single reaction. The HPV positive samples were further genotyped using DNA sequencing. The physical state of the virus was identified using Amplification of Papillomavirus Oncogene Transcripts (APOT) assay in the samples positive for HPV16 and/or HPV18.ResultsHigh percentage of HPV (42%) was observed in ovarian carcinoma compared to 8% in the NAT. The high-risk HPV types 16, 18 and 45 were highly associated with the advanced stages of tumor, while low-risk types 6 and 11 were present in NAT. In malignant tissues, HPV-16 was the most predominant genotype followed by HPV-18 and -45. The percentage of viral integration into the host genome was significantly high (61.1%) compared to 38.9% episomal in HPV positive tumors tissues. In HPV18 genotype the percentage of viral integration was 54.5% compared to 45.5% episomal.ConclusionThe high risk HPV genotypes in ovarian cancer may indicate its role in ovarian carcinogenesis. The HPV vaccination is highly recommended to reduce this type of cancer.

Increased hypermethylation of glutathione S-transferase P1, DNA-binding protein inhibitor, death associated protein kinase and paired box protein-5 genes in triple-negative breast cancer Saudi females.

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-β (RARβ1) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin- fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.

Increased expression of biological markers as potential therapeutic targets in Saudi women with triple-negative breast cancer.

AIMS AND BACKGROUND Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks the expression of hormone receptors and human epidermal growth factor receptor 2 (HER2). Although TNBC represents only 15% of all types of breast cancer, it accounts for a large number of metastatic cases and deaths. Because of the high metastatic rate and both local and systemic recurrence associated with TNBC, extensive research efforts are actively looking for target therapies to effectively treat this aggressive disease. Accordingly, this study has been initiated to investigate the differential expression of biological markers in TNBC and non-TNBC Saudi women that might be utilized as potential targeted therapy and/or predict the sensitivity to currently available therapeutic regimens. METHODS AND STUDY DESIGN Two hundred formalin-fixed, paraffin-embedded (FFPE) breast cancer tissues were selected and divided into 3 groups: benign breast tissues (20), TNBC tissues (80) and non-TNBC tissues (100). Expression of mRNA in FFPE tissues was analyzed using real-time polymerase chain reaction (RT-PCR) for the following genes: poly (ADP-ribose) polymerase 1 (PARP-1), topoisomerase 2A (TOPO-2A), vascular endothelial growth factor (VEGF), C-MYC, basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMP-2 and MMP-9), human epidermal growth factor 1 (HER1) and multidrug resistance (MDR) genes. RESULTS In the TNBC group, expression of PARP-1, TOPO-2A, HER1, C-MYC, VEGF, bFGF and MMP-2 showed a highly significant increase compared to the non-TNBC group. CONCLUSIONS The results of this study suggest that (1) TNBC patients will benefit more from TOPO-2A inhibitors as well as antiangiogenic and antimetastatic therapies; (2) inhibition of these target genes is emerging as one of the most exciting and promising targeted therapeutic strategies to treat TNBC in which the intended targets are DNA repair, tumor angiogenesis and metastasis.

Screening for Lynch Syndrome in young colorectal cancer patients from Saudi Arabia using microsatellite instability as the initial test

BACKGROUND Lynch Syndrome (LS) is a familial cancer condition caused by germline mutations in DNA mismatch repair genes. Individuals with LS have a greatly increased risk of developing colorectal cancer (CRC) and it is therefore important to identify mutation carriers so they can undergo regular surveillance. Tumor DNA from LS patients characteristically shows microsatellite instability (MSI). Our aim here was to screen young CRC patients for MSI as a first step in the identification of unrecognized cases of LS in the Saudi population. MATERIALS AND METHODS Archival tumor tissue was obtained from 284 CRC patients treated at 4 institutes in Dammam and Riyadh between 2006 and 2015 and aged less than 60 years at diagnosis. MSI screening was performed using the BAT-26 microsatellite marker and positive cases confirmed using the pentaplex MSI analysis system. Positive cases were screened for BRAF mutations to exclude sporadic CRC and were evaluated for loss of expression of 4 DNA mismatch repair proteins using immunohistochemistry. RESULTS MSI was found in 33/284 (11.6%) cases, of which only one showed a BRAF mutation. Saudi MSI cases showed similar instability in the BAT-26 and BAT-25 markers to Australian MSI cases, but significantly lower frequencies of instability in 3 other microsatellite markers. CONCLUSIONS MSI screening of young Saudi CRC patients reveals that approximately 1 in 9 are candidates for LS. Patients with MSI are strongly recommended to undergo genetic counselling and germline mutation testing for LS. Other affected family members can then be identified and offered regular surveillance for early detection of LS-associated cancers.

Screening for Lynch syndrome in young Saudi colorectal cancer patients using microsatellite instability testing and next generation sequencing

Individuals with Lynch syndrome (LS) have germline variants in DNA mismatch repair (MMR) genes that confer a greatly increased risk of colorectal cancer (CRC), often at a young age. Identification of these individuals has been shown to increase their survival through improved surveillance. We previously identified 33 high risk cases for LS in the Saudi population by screening for microsatellite instability (MSI) in the tumor DNA of 284 young CRC patients. The aim of the present study was to identify MMR gene variants in this cohort of patients. Peripheral blood DNA was obtained from 13 individuals who were at high risk of LS due to positive MSI status and young age (<60 years at diagnosis). Next generation sequencing, Sanger sequencing and Multiplex Ligation-dependent Probe Amplification were used to screen for germline variants in the MLH1, MSH2, MSH6 and PMS2 MMR genes. These were cross-referenced against several variant databases, including the International Society for Gastrointestinal Hereditary Tumors Incorporated database. Variants with pathogenic or likely pathogenic significance were identified in 8 of the 13 high risk cases (62%), comprising 4 in MLH1 and 4 in MSH2. All carriers had a positive family history for CRC or endometrial cancer. Next generation sequencing is an effective strategy for identifying young CRC patients who are at high risk of LS because of positive MSI status. We estimate that 7% of CRC patients aged <60 years in Saudi Arabia are due to LS, potentially involving around 50 new cases per year.