April Camilla Roslani

Microbiota organization is a distinct feature of proximal colorectal cancers

Significance We demonstrate, to our knowledge for the first time, that bacterial biofilms are associated with colorectal cancers, one of the leading malignancies in the United States and abroad. Colon biofilms, dense communities of bacteria encased in a likely complex matrix that contact the colon epithelial cells, are nearly universal on right colon tumors. Most remarkably, biofilm presence correlates with bacterial tissue invasion and changes in tissue biology with enhanced cellular proliferation, a basic feature of oncogenic transformation occurring even in colons without evidence of cancer. Microbiome profiling revealed that biofilm communities on paired normal mucosa cluster with tumor microbiomes but lack distinct taxa differences. This work introduces a previously unidentified concept whereby microbial community structural organization exhibits the potential to contribute to disease progression. Environmental factors clearly affect colorectal cancer (CRC) incidence, but the mechanisms through which these factors function are unknown. One prime candidate is an altered colonic microbiota. Here we show that the mucosal microbiota organization is a critical factor associated with a subset of CRC. We identified invasive polymicrobial bacterial biofilms (bacterial aggregates), structures previously associated with nonmalignant intestinal pathology, nearly universally (89%) on right-sided tumors (13 of 15 CRCs, 4 of 4 adenomas) but on only 12% of left-sided tumors (2 of 15 CRCs, 0 of 2 adenomas). Surprisingly, patients with biofilm-positive tumors, whether cancers or adenomas, all had biofilms on their tumor-free mucosa far distant from their tumors. Bacterial biofilms were associated with diminished colonic epithelial cell E-cadherin and enhanced epithelial cell IL-6 and Stat3 activation, as well as increased crypt epithelial cell proliferation in normal colon mucosa. High-throughput sequencing revealed no consistent bacterial genus associated with tumors, regardless of biofilm status. However, principal coordinates analysis revealed that biofilm communities on paired normal mucosa, distant from the tumor itself, cluster with tumor microbiomes as opposed to biofilm-negative normal mucosa bacterial communities also from the tumor host. Colon mucosal biofilm detection may predict increased risk for development of sporadic CRC.

ALEXIS O-Ring wound retractor vs conventional wound protection for the prevention of surgical site infections in colorectal resections 1

Aim  Surgical site infection (SSI) remains a common postoperative morbidity, particularly in colorectal resections, and poses a significant financial burden to the healthcare system. The omission of mechanical bowel preparation, as is performed in enhanced recovery after surgery programmes, appears to further increase the incidence. Various wound protection methods have been devised to reduce the incidence of SSIs. However, there are few randomized controlled trials assessing their efficacy. The aim of this study is to investigate whether ALEXIS wound retractors with reinforced O‐rings are superior to conventional wound protection methods in preventing SSIs in colorectal resections.

Redundant Innate and Adaptive Sources of IL17 Production Drive Colon Tumorigenesis

IL17-producing Th17 cells, generated through a STAT3-dependent mechanism, have been shown to promote carcinogenesis in many systems, including microbe-driven colon cancer. Additional sources of IL17, such as γδ T cells, become available under inflammatory conditions, but their contributions to cancer development are unclear. In this study, we modeled Th17-driven colon tumorigenesis by colonizing Min(Ap) (c+/-) mice with the human gut bacterium, enterotoxigenic Bacteroides fragilis (ETBF), to investigate the link between inflammation and colorectal cancer. We found that ablating Th17 cells by knocking out Stat3 in CD4(+) T cells delayed tumorigenesis, but failed to suppress the eventual formation of colonic tumors. However, IL17 blockade significantly attenuated tumor formation, indicating a critical requirement for IL17 in tumorigenesis, but from a source other than Th17 cells. Notably, genetic ablation of γδ T cells in ETBF-colonized Th17-deficient Min mice prevented the late emergence of colonic tumors. Taken together, these findings support a redundant role for adaptive Th17 cell- and innate γδT17 cell-derived IL17 in bacteria-induced colon carcinogenesis, stressing the importance of therapeutically targeting the cytokine itself rather than its cellular sources. Cancer Res; 76(8); 2115-24. ©2016 AACR.

Is laparoscopic colectomy as cost beneficial as open colectomy

Background:  Laparoscopic colectomy has yet to gain widespread acceptance in cost‐conscious health‐care institutions. The aim of the present study was to define the cost–benefit relationship of laparoscopic versus open colectomy.

Hand-assisted laparoscopic colectomy versus standard laparoscopic colectomy: a cost analysis.

Objective  There is a relative dearth of literature comparing hand‐assisted (HALC) to standard (SLC) laparoscopic colectomies. HALC seems beneficial in terms of shorter operative times and lower conversion rates, but this is counterbalanced by a greater inflammatory response, larger incisions and higher direct costs. Nevertheless, these results are not consistent throughout existing studies and there are to date no detailed cost comparisons. Our hypothesis was that HALC would not incur significantly higher institutional costs compared with standard laparoscopic techniques.

Sociodemographic Predictors of Recall and Recognition of Colorectal Cancer Symptoms and Anticipated Delay in Help- Seeking in a Multiethnic Asian Population

BACKGROUND Colorectal cancer is the second most common cancer in Malaysia. The prognosis of the disease is excellent if detected at an early stage, but the majority of Malaysian patients present at late stages. We aimed to assess the awareness of cancer warning signs and anticipated delay in help-seeking as possible contributors to this phenomenon. MATERIALS AND METHODS A population-based cross-sectional survey using the Colorectal Cancer Awareness Measure was initiated in Perak, Malaysia. A total of 2,379 respondents aged 18 years and above were recruited using a multi-stage sampling in five locations. Analysis of covariance was used to examine independent sociodemographic predictors of scores for symptom awareness. RESULTS Younger age, being female, a higher education, and higher income were significantly associated with better scores for both recall and recognition of warning symptoms. Among the ethnic groups, Malays had better recognition of symptoms whereas Chinese recalled the most symptoms. Passing bloody stool was associated with the least anticipated delay and unexplained anal pain had the highest anticipated delay. CONCLUSIONS The level of awareness across all ethnicities in Malaysia is generally low, especially among minorities. Targeted public education, which is culturally and linguistically appropriate, should be developed to encourage early help-seeking and improve clinical outcomes.

Advantage of using colonic washouts for Blastocystis detection in colorectal cancer patients

BackgroundThere have been previous studies associating microorganisms to cancer and with our recent findings of Blastocytsis antigen having a higher in vitro proliferation of cancer cells strengthens the suspicion. Collecting faecal samples alone to associate this parasite with cancer may not be accurate due to the phenomenon of irregular shedding and the possible treatment administrated to the cancer patients. Hence, this become the basis to search for an alternate method of sample collection. Colonic washout is an almost complete washed up material from colon and rectum which includes various microorganisms such as Blastocystis and other lodged material within the villi. The detection of parasite in colonic washouts will give a better reflection on the association between Blastocystis and CRC.MethodsBlastocytsis detection was made by in vitro culture method using Jones’ medium, formal ether concentration technique and conventional polymerase chain reaction (PCR) on faecal samples and colonic washouts of 204 CRC patients from colonoscopy procedure. Faecal samples and colonic washouts from 221 normal individuals served as control.ResultsWe observed an increased detection of Blastocystis using colonic washouts (n = 53, 12.47%) than faecal samples (n = 26, 6.12%). Eleven faecal samples showed positive results for Blastocystis which were also found in colonic washouts using the PCR technique. This study for the first time showed a significant Blastocystis infection among CRC patients (n = 43, 21.08%) compared to the asymptomatic normal individuals (n = 22, 9.95%). Blastocystis subtype 3 infection was found to be significantly more prevalent (n = 26, 12.75%) compared to other subtypes namely subtype 1: n = 9 (4.41%), subtype 2: n = 1 (0.49%), subtype 5: n = 1 (0.49%) and mixed subtype: n = 6 (2.94%) among the CRC patients.ConclusionThe study showed that colonic washouts provide a better alternative for Blastocystis detection in CRC patients compared to faecal samples as this prevents treatment regime and the phenomenon of irregular shedding from influencing the detection results obtained from faecal samples.

Health-related quality of life among colorectal cancer patients in Malaysia: a study protocol

BackgroundColorectal cancer is a major public health problem in Malaysia. However, it is also one of the most treatable cancers, resulting in significant numbers of survivors. Therefore, the impact of surviving treatment for colorectal cancer on health related quality of life is important for the patients, clinicians and policy makers, and may differ in different cultures and populations. The aim of this study was to validate the Malaysian versions of the European Organization for Research and Treatment of Cancer quality of life instruments among colorectal cancers patients.Methods/designThis is a cross sectional multi centre study. Three hospitals were included, the University of Malaya Medical Centre, the Universiti Kebangsaan Malaysia Medical Centre and Hospital Tuanku Jaafar Seremban. Malaysian citizens and permanent residence were studied and demographic and clinical information obtained from hospital records. The European Organization for Research and Treatment of Cancer Quality of life Core 30, colorectal cancer CR29, and the colorectal cancer liver metastasis LMC 21 were used and an observer assessment of performance obtained with the Karnofsky Performance Scale. Questionnaires were translated into three most commonly spoken languages in Malaysia (Bahasa Malaysia, Chinese and Tamil), then administered, scored and analyzed following the developers’ guidelines. Ethical approval was obtained from the participating centres. Tests of reliability and validity were performed to examine the validity of these instruments.ConclusionThe result of pilot testing shows that the use of the Malaysian versions of EORTC QLQ C30, CR29 instruments is feasible in our sample of colorectal cancer patients. Instructions for completion as well as questions were well understood except the questions on the overall quality of life, overall health status and sexual activity. Thus we anticipate obtaining good psychometric properties for the instruments at the end of the study.

Development of a risk score to stratify symptomatic adults referred for colonoscopy.

With an increasing burden on overstretched colonoscopy services, a simple risk score for significant pathology in symptomatic patients may aid in the prioritization of patients.

Heterogeneity in cancer cells: variation in drug response in different primary and secondary colorectal cancer cell lines in vitro

Tumor heterogeneity may give rise to differential responses to chemotherapy drugs. Therefore, unraveling tumor heterogeneity has an implication for biomarker discovery and cancer therapeutics. To test this phenomenon, we investigated the differential responses of three secondary colorectal cancer cell lines of different origins (HCT116, HT29, and SW620 cells) and four novel primary cell lines obtained from different colorectal cancer patients to 5-fluorouracil (5-FU) and oxaliplatin (L-OHP) and explored the differences in gene expression among the primary cell lines in response to exposure to cytotoxic drugs. Cells were exposed to different doses of 5-FU and L-OHP separately or in combinations of equitoxic drug or equimolar drug ratios (median effect of Chou-Talalay principle). Cell viability was assessed using MTT assay and the respective IC50 values were determined. Changes in gene expression in primary cell lines after exposure to the same drug doses were compared using real-time PCR array. The sensitivities (IC50) of different cell lines, both secondary and primary, to 5-FU and L-OHP were significantly different, whether in monotherapy or combined treatment. Primary cell lines needed higher doses to reach IC50. There were variations in gene expression among the primary cell lines of different chemosensitivities to the challenge of the same combined dose of 5-FU and L-OHP. The results confirm the heterogeneous nature of colorectal cancer cells from different patient tumors. Studies using primary cancer cells established from patient’s tumors rather than secondary cell lines will more closely reflect the actual character of the disease.