Ligation of the Intersphincteric Fistula Tract as an Emergency Treatment for Cryptoglandular Anal Fistula.

Introduction: Ligation of the intersphincteric fistula tract (LIFT) is a sphincter-preserving procedure for treating anal fistula of cryptoglandular origin. Our prospective study aimed to determine the postoperative outcomes of patients undergoing LIFT in emergency and elective settings. Methods: This was a single-centre prospective observational study of the LIFT procedure for the treatment of anal fistulas. The differences in the 6-month postoperative outcomes between the emergency and elective procedures were analysed, including the healing rate, healing time, recurrence rate, recurrence time, postoperative complications and length of hospital stay. Results: Twenty-two patients were recruited for this study: 11 patients underwent LIFT as an emergency procedure (EM-LIFT), while the others underwent LIFT as an elective procedure (EL-LIFT). The healing rate for the EM-LIFT group was 90.9% (n = 10), with a median healing time of 2 months (range 0.5-4). For the EL-LIFT group, the healing rate was 100% (n = 11), with the same median healing time of 2 months (range 0.5-4). Two of the patients in the EM-LIFT group developed recurrence, with a median recurrence time of 5 months (range 4-6) and three developed recurrence in the EL-LIFT group, with the same median recurrence time of 5 months (range 4-6). There were minor postoperative complications of pain and subcutaneous infection, with no faecal incontinence. There was no statistically significant difference in postoperative outcomes between the groups. Conclusion: EM-LIFT is a feasible and safe primary procedure for active cryptoglandular-type anal fistulas.

Randomised controlled trial to assess and compare the performance and safety of two-piece ostomy appliances.

BACKGROUND: Choice of ostomy appliances is based on multiple factors including economic considerations, individual patient requirements and lifestyle. A recently launched two-piece ostomy collection device with an extended tape border is expected to provide a long wear time and increase patients' sense of security. AIMS AND METHODS: A randomised controlled, non-blinded, cross-over study involving 38 patients (with colostomies and ileostomies) compared the test device to a similar device from the same manufacturer but without the tape border. The main objective was to assess wear time for non-inferiority as a measure of efficacy. Secondary efficacy assessment included peristomal skin condition using the DET (discolouration, erosion and tissue growth) score and patient acceptability, which was assessed through questionnaires using Likert-scale options. Safety was assessed according to the incidence and intensity of device-related adverse events, and the condition of the peristomal skin. RESULTS AND CONCLUSION: Analysis of results in the per-protocol population showed an average wear time of 4.5 days for both devices and demonstrated non-inferiority. DET scores were similar in both groups, and both had low rates of device-related adverse events, all of which related to peristomal skin. Patients said the devices were user friendly. While the two devices are similar, some patients may find one with an adhesive tape more suited to their needs.

TCGA-My: A Systematic Repository for Systems Biology of Malaysian Colorectal Cancer.

Colorectal cancer (CRC) ranks second among the most commonly occurring cancers in Malaysia, and unfortunately, its pathobiology remains unknown. CRC pathobiology can be understood in detail with the implementation of omics technology that is able to generate vast amounts of molecular data. The generation of omics data has introduced a new challenge for data organization. Therefore, a knowledge-based repository, namely TCGA-My, was developed to systematically store and organize CRC omics data for Malaysian patients. TCGA-My stores the genome and metabolome of Malaysian CRC patients. The genome and metabolome datasets were organized using a Python module, pandas. The variants and metabolites were first annotated with their biological information using gene ontologies (GOs) vocabulary. The TCGA-My relational database was then built using HeidiSQL PorTable 9.4.0.512, and Laravel was used to design the web interface. Currently, TCGA-My stores 1,517,841 variants, 23,695 genes, and 167,451 metabolites from the samples of 50 CRC patients. Data entries can be accessed via search and browse menus. TCGA-My aims to offer effective and systematic omics data management, allowing it to become the main resource for Malaysian CRC research, particularly in the context of biomarker identification for precision medicine.

The Value of Cutting Seton for High Transsphincteric Anal Fistula in the Era of Its Misery.

Objectives: We studied the outcome of cutting seton in the treatment of a high transsphincteric anal fistula in Sudan. Methods: This was a prospective study of high transsphincteric anal fistulas at Kassala Police Hospital, Sudan, over the course of 24 months (2016-2017). The main outcomes measured were recurrence, incontinence and primary healing rates. Results: The cases of 72 patients treated with cutting seton for high transsphincteric fistula were analysed, with 50 (70%) of the patients being male and 22 (30%) being female. Forty-eight (66.7%) patients required two sessions of seton tightening with a duration of seton treatment of 30 days and 24 (33.3%) patients required three sessions with a duration of seton treatment of 45 days. Only one patient (1.4%) had flatus incontinence. Three (4.2%) patients had minimal bleeding from the seton site and two (2.8%) patients experienced fistula recurrence. Twenty-six (36%) patients achieved complete healing within 30 days, while 36 (54.3%) patients healed within 60 days. The remaining seven (9.7%) patients healed after 60 days. Chronic pain was reported by two (2.8%) patients after complete healing. Conclusion: In Sudan, cutting seton remains relevant, as it produces minimal incontinence with a low recurrence rate in high transsphincteric fistula treatment.

Cancer testis antigen PASD1 expression and immunogenicity in human colorectal cancer and polyps.

Colorectal cancer (CRC) is a malignant tumor arising from a human inner colon lining that may spread to other organs such as the liver and lungs. Per ARNT Sim domain containing 1 (PASD1) is a cancer-testis antigen expressed in cancers including CRC but not in normal tissues except for normal testes. This study aims to study PASD1 protein as a potential target for CRC immunotherapy. A total of 90 CRC and polyps tissue samples were investigated for PASD1 RNA and protein expression using a real-time polymerase chain reaction and immunohistochemical staining, respectively. Matched patients' peripheral blood mononuclear cells were pulsed with PASD1 peptides and measured for immunogenicity, cell cytotoxicity, and cytokine assays. The clinical data were collected and analyzed accordingly. Our results show that PASD1_v2 mRNA expression was highly expressed in CRC (46.0%) and polyps samples (33.3%). Both PASD1-1 and PASD1-2 proteins were expressed in 31.7% of CRC and 29.4% of polyps samples. Protein expression was weak to moderate positive in the cytoplasm and/or nucleus of the tissues. Immune responses towards CD4-specific PASD1 peptides were detected in 21.7% of CRC and 23.5% of polyps patients. The most immunogenic peptide was PASD1 (1) in CRC while PASD1 (3) in polyps. Cytotoxicity effects were detected up to 57.20% observed in CRC samples while IL-17A and IL-6 cytokines were highly expressed. The demographic data suggest that Chinese female patients more than 60 years old, diagnosed with late-stage rectosigmoid tumors may benefit from the PASD1 peptide immunotherapy approach. This is the first report describing CD4-positive T-helper response to the PASD1 positive CRC patients and its cytotoxicity.

Whole genome sequencing of Malaysian colorectal cancer patients reveals specific druggable somatic mutations.

The incidences of colorectal cancer (CRC) are continuously increasing in some areas of the world, including Malaysia. In this study, we aimed to characterize the landscape of somatic mutations using the whole-genome sequencing approach and identify druggable somatic mutations specific to Malaysian patients. Whole-genome sequencing was performed on the genomic DNA obtained from 50 Malaysian CRC patients' tissues. We discovered the top significantly mutated genes were APC, TP53, KRAS, TCF7L2 and ACVR2A. Four novel, non-synonymous variants were identified in three genes, which were KDM4E, MUC16 and POTED. At least one druggable somatic alteration was identified in 88% of our patients. Among them were two frameshift mutations in RNF43 (G156fs and P192fs) predicted to have responsive effects against the Wnt pathway inhibitor. We found that the exogenous expression of this RNF43 mutation in CRC cells resulted in increased cell proliferation and sensitivity against LGK974 drug treatment and G1 cell cycle arrest. In conclusion, this study uncovered our local CRC patients' genomic landscape and druggable alterations. It also highlighted the role of specific RNF43 frameshift mutations, which unveil the potential of an alternative treatment targeting the Wnt/ß-Catenin signalling pathway and could be beneficial, especially to Malaysian CRC patients.

Incidence and clinicopathological features of colorectal cancer among multi-ethnic patients in Kuala Lumpur, Malaysia: a hospital-based retrospective analysis over two decades.

BACKGROUND: The incidence rate of colorectal cancer (CRC) in Asian countries is increasing. Furthermore, recent studies have shown a concerning rise in the incidence of CRC among younger patients aged less than 50 years. This study aimed to analyze the incidence trends and clinicopathological features in patients with early-onset CRC (EOCRC) and later-onset CRC (at age ≥ 50 years). METHODS: A retrospective analysis was performed on 946 patients with CRC diagnosed from 1997 to 2017 at Universiti Kebangsaan Malaysia Medical Centre. The time trend was assessed by dividing the two decades into four 5-year periods. The mean age-standardized and age-specific incidence rates were calculated by using the 5-year cumulative population of Kuala Lumpur and World Health Organization standard population. The mean incidence was expressed per 100,000 person-years. RESULTS: After a stable (all age groups) CRC incidence rate during the first decade (3.00 per 100,000 and 3.85 per 100,000), it sharply increased to 6.12 per 100,000 in the 2008-2012 period before decreasing to 4.54 per 100,000 in the 2013-2017 period. The CRC incidence trend in later-onset CRC showed a decrease in the 2013-2017 period. Contrariwise, for age groups of 40-44 and 45-49 years, the trends showed an increase in the latter 15 years of the study period (40-44 years: 1.44 to 1.92 to 2.3 per 100,000; 45-49 years: 2.87 to 2.94 to 4.01 per 100,000). Malays' EOCRC incidence rate increased from 2008-2012 to 2013-2017 for both the age groups 40-44 years (1.46 to 2.89 per 100,000) and 45-49 years (2.73 to 6.51 per 100,000). Nearly one-fifth of EOCRC cases were diagnosed at an advanced stage (Dukes D: 19.9%), and the majority of them had rectal cancer (72.8%). CONCLUSION: The incidence of EOCRC increased over the period 1997-2017; the patients were predominantly Malays, diagnosed at a later stage, and with cancer commonly localized in the rectal region. All the relevant stakeholders need to work on the management and prevention of CRC in Malaysia.

Role of imaging in managing lateral trocar site incisional hernia after abdominoperineal resection.

Trocar site incisional hernia (TSIH) is an unpleasant complication of laparoscopic surgery. A 70-year-old male with low rectal carcinoma underwent a laparoscopic abdominoperineal resection after completion of neoadjuvant radiotherapy. The postoperative recovery was smooth; however, he developed abdominal distension and pain over the previous drain site after removal on day 3. In view of diagnostic ambiguity, an imaging tool was requested as an adjunct to further management. Computed tomography of the abdomen showed small bowel obstruction secondary to herniated ileal loops passing through the right iliac fossa anterior abdominal wall defect at the previous drainage site. An exploration was made and the rectus defect was closed using a non-absorbable suture.

Global metabolomics profiling of colorectal cancer in Malaysian patients.

Introduction: The serum metabolomics approach has been used to identify metabolite biomarkers that can diagnose colorectal cancer (CRC) accurately and specifically. However, the biomarkers identified differ between studies suggesting that more studies need to be performed to understand the influence of genetic and environmental factors. Therefore, this study aimed to identify biomarkers and affected metabolic pathways in Malaysian CRC patients. Methods: Serum from 50 healthy controls and 50 CRC patients were collected at UKM Medical Centre. The samples were deproteinized with acetonitrile and untargeted metabolomics profile determined using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOFMS, Agilent USA). The data were analysed using Mass Profiler Professional (Agilent, USA) software. The panel of biomarkers determined were then used to identify CRC from a new set of 20 matched samples. Results: Eleven differential metabolites were identified whose levels were significantly different between CRC patients compared to normal controls. Based on the analysis of the area under the curve, 7 of these metabolites showed high sensitivity and specificity as biomarkers. The use of the 11 metabolites on a new set of samples was able to differentiate CRC from normal samples with 80% accuracy. These metabolites were hypoxanthine, acetylcarnitine, xanthine, uric acid, tyrosine, methionine, lysoPC, lysoPE, citric acid, 5-oxoproline, and pipercolic acid. The data also showed that the most perturbed pathways in CRC were purine, catecholamine, and amino acid metabolisms. Conclusion: Serum metabolomics profiling can be used to identify distinguishing biomarkers for CRC as well as to further our knowledge of its pathophysiological mechanisms.

A Prospective Interventional Study on LigaSureTM Haemorrhoidectomy as a Daycare Procedure.

OBJECTIVE: This study was designed as a prospective and interventional study that evaluated LigaSure™ haemorrhoidectomies with regional anaesthesia as a daycare procedure. METHODS: Patients with third- and fourth-degree haemorrhoids were recruited from the clinic from January 2018 to December 2019. The procedure was performed as a day case under regional anaesthesia. Using a LigaSureTM device, excisional haemorrhoidectomies (Milligan-Morgan haemorrhoidectomy) were performed without sutures or an anal sponge. We evaluated wound bleeding, pain and urinary retention per daycare protocols. RESULTS: A total of 264 patients were enrolled. There were 153 males (57.9%) with a median age of 30 years old (range 16 years old-80 years old). A total of 142 patients (54%) had third-degree haemorrhoids, while the rest had fourth-degree haemorrhoids. The median operating time was 8 min (range 4 min-17 min) and minimal blood loss was observed. During follow-up, the complications were one case (0.3%) had anal stenosis, one case (0.3%) had minimal bleeding and one case (0.3%) had urine retention. Upon discharge, four patients (1.5%) required additional analgesia and another four (1.5%) developed post-spinal headaches. No incontinence was encountered. CONCLUSION: LigaSure™ excisional haemorrhoidectomy is a safe and effective daycare procedure with acceptable re-admission and complication rates.

Acquiring Advanced Laparoscopic Colectomy Skills - The Issues.

Colorectal surgery has been revolutionised towards minimally invasive surgery with the emergence of enhanced recovery protocol after surgery initiatives. However, laparoscopic colectomy has yet to be widely adopted, due mainly to the steep learning curve. We aim to review and discuss the methods of overcoming these learning curves by accelerating the competency level of the trainees without compromising patient safety. To provide this mini review, we assessed 70 articles in PubMed that were found through a search comprised the keywords laparoscopic colectomy, minimal invasive colectomy, learning curve and surgical education. We found England's Laparoscopic Colorectal National Training Programme (LAPCO-NTP) England to be by far the most structured programme established for colorectal surgeons, which involves pre-clinical and clinical phases that end with an assessment. For budding colorectal trainees, learning may be accelerated by simulator-based training to achieve laparoscopic dexterity coupled with an in-theatre proctorship by field experts. Task-specific checklists and video recordings are essential adjuncts to gauge progress and performance. As competency is established, careful case selections with the proctor are essential to maintain motivation and ensure safe performances. A structured programme to establish competency is vital to help both the proctor and trainee gauge real-time progress and performance. However, training systems both inside and outside the operating theatre (OT) are equally useful to achieve the desired performance.

A Randomized Controlled Trial of Novel Treatment for Hemorrhagic Radiation Proctitis.

BACKGROUND: Various methods have been used for treatment of hemorrhagic radiation proctitis (HRP) with variable results. Currently, the preferred treatment is formalin application or endoscopic therapy with argon plasma coagulation. Recently, a novel therapy with colonic water irrigation and oral antibiotics showed promising results and more effective compared to 4% formalin application for HRP. The study objective is to compare the effect of water irrigation and oral antibiotics versus 4% formalin application in improving per rectal bleeding due to HRP and related symptoms such as diarrhoea, tenesmus, stool frequency, stool urgency and endoscopic findings. METHODS: We conducted a study on 34 patients with HRP and randomly assigned the patients to two treatment arm groups (n=17). The formalin group underwent 4% formalin dab and another session 4 weeks later. The irrigation group self-administered daily rectal irrigation at home for 8 weeks and consumed oral metronidazole and ciprofloxacin during the first one week. We measured the patients' symptoms and endoscopic findings before and after total of 8 weeks of treatment in both groups. RESULTS: Our study showed that HRP patients had reduced per rectal bleeding (p = 0.003) in formalin group, whereas irrigation group showed reduced diarrhoea (p=0.018) and tenesmus (p=0.024) symptoms. The comparison between the two treatment arms showed that irrigation technique was better than formalin technique for tenesmus (p=0.043) symptom only. CONCLUSION: This novel treatment showed benefit in treating HRP. It could be a new treatment option which is safe and conveniently self-administered at home or used as a combination with other therapies to improve the treatment outcome for HRP.
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Incorporation of Smooth Muscle Cells Derived from Human Adipose Stem Cells on Poly(Lactic-co-Glycolic Acid) Scaffold for the Reconstruction of Subtotally Resected Urinary Bladder in Athymic Rats.

BACKGROUND: The urinary tract can be affected by both congenital abnormalities as well as acquired disorders, such as cancer, trauma, infection, inflammation, and iatrogenic injuries, all of which may lead to organ damage requiring eventual reconstruction. As a gold standard, gastrointestinal segment is used for urinary bladder reconstruction. However, one major problem is that while bladder tissue prevents reabsorption of specific solutes, gastrointestinal tissue actually absorbs them. Therefore, tissue engineering approach had been attempted to provide an alternative tissue graft for urinary bladder reconstruction. METHODS: Human adipose-derived stem cells isolated from fat tissues were differentiated into smooth muscle cells and then seeded onto a triple-layered PLGA sheet to form a bladder construct. Adult athymic rats underwent subtotal urinary bladder resection and were divided into three treatment groups (n = 3): Group 1 ("sham") underwent anastomosis of the remaining basal region, Group 2 underwent reconstruction with the cell-free scaffold, and Group 3 underwent reconstruction with the tissue-engineered bladder construct. Animals were monitored on a daily basis and euthanisation was performed whenever a decline in animal health was detected. RESULTS: All animals in Groups 1, 2 and 3 survived for at least 7 days and were followed up to a maximum of 12 weeks post-operation. It was found that by Day 14, substantial ingrowth of smooth muscle and urothelial cells had occurred in Group 2 and 3. In the long-term follow up of group 3 (tissue-engineered bladder construct group), it was found that the urinary bladder wall was completely regenerated and bladder function was fully restored. Urodynamic and radiological evaluations of the reconstructed bladder showed a return to normal bladder volume and function.Histological analysis revealed the presence of three muscular layers and a urothelium similar to that of a normal bladder. Immunohistochemical staining using human-specific myocyte markers (myosin heavy chain and smoothelin) confirmed the incorporation of the seeded cells in the newly regenerated muscular layers. CONCLUSION: Implantation of PLGA construct seeded with smooth muscle cells derived from human adipose stem cells can lead to regeneration of the muscular layers and urothelial ingrowth, leading to formation of a completely functional urinary bladder.

Genome-Wide Open Chromatin Methylome Profiles in Colorectal Cancer.

The methylome of open chromatins was investigated in colorectal cancer (CRC) to explore cancer-specific methylation and potential biomarkers. Epigenome-wide methylome of open chromatins was studied in colorectal cancer tissues using the Infinium DNA MethylationEPIC assay. Differentially methylated regions were identified using the ChAMP Bioconductor. Our stringent analysis led to the discovery of 2187 significant differentially methylated open chromatins in CRCs. More hypomethylated probes were observed and the trend was similar across all chromosomes. The majority of hyper- and hypomethylated probes in open chromatin were in chromosome 1. Our unsupervised hierarchical clustering analysis showed that 40 significant differentially methylated open chromatins were able to segregate CRC from normal colonic tissues. Receiver operating characteristic analyses from the top 40 probes revealed several significant, highly discriminative, specific and sensitive probes such as OPLAH cg26256223, EYA4 cg01328892, and CCNA1 cg11513637, among others. OPLAH cg26256223 hypermethylation is associated with reduced gene expression in the CRC. This study reports many open chromatin loci with novel differential methylation statuses, some of which with the potential as candidate markers for diagnostic purposes.

Colorectal screening using the immunochemical faecal occult blood test kit among the Malaysian cohort participants.

BACKGROUND: There has been a rapid increase in colorectal cancer (CRC) cases in Asian countries, including Malaysia. CRC is usually diagnosed at a late stage, and early detection of CRC is vital in improving survival. This study was conducted to determine the uptake rate of the immunochemical faecal occult blood test (iFOBT), the response rate to colonoscopy, and the CRC detection rate. We also wanted to identify the association between colorectal neoplasia and the Asia Pacific Colorectal Cancer Screening (APCS) scoring system. METHODS: We recruited 2264 individuals from The Malaysian Cohort participants aged 35-65 years who consented to colorectal screening using the iFOBT kit from July 2017 until January 2019. RESULTS: The response rate and positive iFOBT test rate of this study were 79.6% and 13.1% respectively. Among those with positive results, 125 individuals (52.7%) underwent colonoscopy; CRC was detected in six of them while 45 others (36.0%) had polyps. The overall CRC detection rate was 0.3% while the colorectal neoplasia detection rate (both colorectal cancer and colorectal polyps) was 2.3%. The APCS scoring indicated a significant association with colorectal neoplasia risk, with increasing trend by severity from moderate to high risk (3.46-11.14) compared to low risk. Most of the participants who were positive for iFOBT were those at high risk. CONCLUSIONS: The awareness of CRC risk and iFOBT screening are important strategies for early detection of CRC. We showed a CRC detection rate of 0.3 % among those who volunteered to have the iFOBT screening.

Validation of immunogenic PASD1 peptides against HLA-A*24:02 colorectal cancer.

Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8+ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8+ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.

A four-decade analysis of the incidence trends, sociodemographic and clinical characteristics of inflammatory bowel disease patients at single tertiary centre, Kuala Lumpur, Malaysia.

BACKGROUND: Inflammatory bowel disease (IBD) was once considered as a Western disease. However, recent epidemiological data showed an emerging trend of IBD cases in the Eastern Asia countries. Clinico-epidemiological data of IBD in Malaysia is scarce. This study aimed to address this issue. METHODS: Retrospective analysis of ulcerative colitis (UC) and Crohn's disease (CD), diagnosed from January 1980 till June 2018 was conducted at our centre. RESULTS: A total of 413 IBD patients (281 UC, 132 CD) were identified. Mean crude incidence of IBD has increased steadily over the first three decades: 0.36 (1980-1989), 0.48 (1990-1999) and 0.63 per 100,000 person-years (2000-2009). In the 2010 to 2018 period, the mean crude incidence has doubled to 1.46 per 100,000 person-years. There was a significant rise in the incidence of CD, as depicted by reducing UC:CD ratio: 5:1 (1980-1989), 5:1 (1990-1999), 1.9:1 (2000-2009) and 1.7:1 (2010-2018). The prevalence rate of IBD, UC and CD, respectively were 23.0, 15.67 and 7.36 per 100,000 persons. Of all IBD patients, 61.5% (n = 254) were males. When stratified according to ethnic group, the highest prevalence of IBD was among the Indians: 73.4 per 100,000 persons, followed by Malays: 24.8 per 100,000 persons and Chinese: 14.6 per 100,000 persons. The mean age of diagnosis was 41.2 years for UC and 27.4 years for CD. Majority were non-smokers (UC: 76.9%, CD: 70.5%). The diseases were classified as follows: UC; proctitis (9.2%), left-sided colitis (50.2%) and extensive colitis (40.6%), CD; isolated ileal (22.7%), colonic (28.8%), ileocolonic (47.7%) and upper gastrointestinal (0.8%). 12.9% of CD patients had concurrent perianal disease. Extra intestinal manifestations were observed more in CD (53.8%) as compared to UC (12%). Dysplasia and malignancy, on the other hand, occurred more in UC (4.3%, n = 12) than in CD (0.8%, n = 1). Over one quarter (27.3%) of CD patients and 3.6% of UC patients received biologic therapy. CONCLUSION: The incidence of IBD is rising in Malaysia, especially in the last one decade. This might be associated with the urbanization and changing diets. Public and clinicians' awareness of this emerging disease in Malaysia is important for the timely detection and management.

Molecular Characterization of Somatic Alterations in Dukes' B and C Colorectal Cancers by Targeted Sequencing.

Despite global progress in research, improved screening and refined treatment strategies, colorectal cancer (CRC) remains as the third most common malignancy. As each type of cancer is different and exhibits unique alteration patterns, identifying and characterizing gene alterations in CRC that may serve as biomarkers might help to improve diagnosis, prognosis and predict potential response to therapy. With the emergence of next generation sequencing technologies (NGS), it is now possible to extensively and rapidly identify the gene profile of individual tumors. In this study, we aimed to identify actionable somatic alterations in Dukes' B and C in CRC via NGS. Targeted sequencing of 409 cancer-related genes using the Ion AmpliseqTM Comprehensive Cancer Panel was performed on genomic DNA obtained from paired fresh frozen tissues, cancer and normal, of Dukes' B (n = 10) and Dukes' C (n = 9) CRC. The sequencing results were analyzed using Torrent Suite, annotated using ANNOVAR and validated using Sanger sequencing. A total of 141 somatic non-synonymous sequence variations were identified in 86 genes. Among these, 64 variants (45%) were predicted to be deleterious, 38 variants (27%) possibly deleterious while the other 39 variants (28%) have low or neutral protein impact. Seventeen genes have alterations with frequencies of ≥10% in the patient cohort and with 14 overlapped genes in both Dukes' B and C. The adenomatous polyposis coli gene (APC) was the most frequently altered gene in both groups (n = 6 in Dukes' B and C). In addition, TP53 was more frequently altered in Dukes' C (n = 7) compared to Dukes' B (n = 4). Ten variants in APC, namely p.R283∗, p.N778fs, p.R805∗, p.Y935fs, p.E941fs, p.E1057∗, p.I1401fs, p.Q1378∗, p.E1379∗, and p.A1485fs were predicted to be driver variants. APC remains as the most frequently altered gene in the intermediate stages of CRC. Wnt signaling pathway is the major affected pathway followed by P53, RAS, TGF-ß, and PI3K signaling. We reported the alteration profiles in each of the patient which has the potential to affect the clinical decision. We believe that this study will add further to the understanding of CRC molecular landscape.