Colorectal cancer in the Kingdom of Saudi Arabia: need for screening

The sensitivity, specificity, predictive values, and likelihood ratios of fecal occult blood test for the detection of colorectal cancer in hospital settings

Objectives

To study the performance of a single test using two fecal occult blood tests with colonoscopy for the detection of colorectal cancer (CRC) for the first time in Saudi Arabia to determine possible implications for the anticipated colorectal screening program.

Materials and methods

We compared the performance of guaiac and immunochemical fecal occult blood tests for the detection of CRC among patients of 50–74 years old attending two hospitals in the Eastern Region of Saudi Arabia. Samples of feces were collected from 257 asymptomatic patients and 20 cases of confirmed CRC, and they were tested simultaneously by the guaiac-based occult blood test and monoclonal antibody-based immunoassay kit. Colonoscopy was performed on all participants and the results were statistically analyzed with both positive and negative occult blood tests of both methods.

Results

Of the 277 subjects, 79 tested positive for occult blood with at least one method. Overall, the number of those with an occult blood-positive result by both tests was 39 (14.1%), while for 198 (71.5%), both tests were negative (P<0.0001); 40 (14.4%) samples showed a discrepant result. Colonoscopy data were obtained for all 277 patients. A total of three invasive cancers were detected among the screening group. Of the three, the guaiac test detected two cases, while the immunochemical test detected three of them. Of the 20 control cases, the guaiac test detected 13 CRC cases (P=0.03), while the immunochemical test detected 16 of them (P<0.0001). The sensitivity of guaiac and immunochemical tests for the detection of CRC in the screening group was 50.00% (95% confidence interval [CI] =6.76–93.24) and 75.00% (95% CI =19.41–99.37), respectively. For comparison, the sensitivity of the guaiac fecal occult blood test for detecting CRC among the control group was 65.00% (95% CI =40.78–84.61) while that of FIT was 80.00% (95% CI =56.34–94.27). The specificity of the guaiac and immunoassay tests was 77.87% (95% CI =72.24–82.83) and 90.12% (95% CI =85.76–93.50), respectively. The positive likelihood ratio of guaiac and immunochemical tests for the detection of CRC was 2.26 (95% CI =0.83–6.18) and 7.59 (95% CI =3.86–14.94), whereas the negative likelihood ratio was 0.64 (95% CI =0.24–1.71) and 0.28 (95% CI =0.05–1.52), respectively. The positive predictive values of guaiac and immunochemical tests were 3.45% (95% CI =0.426–11.91) and 10.71% (95% CI =2.27–28.23), respectively. There was no marked difference in the negative predictive values for both methods. The sensitivity of the fecal occult blood test by FIT was significantly higher for stages III and IV colorectal cancer than for stages I and II (P=0.01) and it was insignificant for the guaiac fecal occult blood test (P=0.07).

Conclusion

In areas where other advance screening methods of CRC are not feasible, the use of FIT can be considered.

Moringa oleifera as an Anti-Cancer Agent against Breast and Colorectal Cancer Cell Lines

In this study we investigated the anti-cancer effect of Moringa oleifera leaves, bark and seed extracts. When tested against MDA-MB-231 and HCT-8 cancer cell lines, the extracts of leaves and bark showed remarkable anti-cancer properties while surprisingly, seed extracts exhibited hardly any such properties. Cell survival was significantly low in both cells lines when treated with leaves and bark extracts. Furthermore, a striking reduction (about 70–90%) in colony formation as well as cell motility was observed upon treatment with leaves and bark. Additionally, apoptosis assay performed on these treated breast and colorectal cancer lines showed a remarkable increase in the number of apoptotic cells; with a 7 fold increase in MD-MB-231 to an increase of several fold in colorectal cancer cell lines. However, no significant apoptotic cells were detected upon seeds extract treatment. Moreover, the cell cycle distribution showed a G2/M enrichment (about 2–3 fold) indicating that these extracts effectively arrest the cell progression at the G2/M phase. The GC-MS analyses of these extracts revealed numerous known anti-cancer compounds, namely eugenol, isopropyl isothiocynate, D-allose, and hexadeconoic acid ethyl ester, all of which possess long chain hydrocarbons, sugar moiety and an aromatic ring. This suggests that the anti-cancer properties of Moringa oleifera could be attributed to the bioactive compounds present in the extracts from this plant. This is a novel study because no report has yet been cited on the effectiveness of Moringa extracts obtained in the locally grown environment as an anti-cancer agent against breast and colorectal cancers. Our study is the first of its kind to evaluate the anti-malignant properties of Moringa not only in leaves but also in bark. These findings suggest that both the leaf and bark extracts of Moringa collected from the Saudi Arabian region possess anti-cancer activity that can be used to develop new drugs for treatment of breast and colorectal cancers.

Increasing Trend in Colorectal Cancer Incidence in the Southeast of Iran 2003-2013: A Population Based Cancer Registry Study

Rates based on age-adjusted incidence of colorectal cancers over a 10-year period in Kerman, the biggest province of Iran, were estimated from 2003 to 2013. Data were obtained from the population-based cancer registry unit of Kerman University of Medical Sciences (CR-KMU). Information included age, sex, city, ICD-O and year of registry. Our trend analyses cover 3.91% of the Iranian population. The data set comprised cases diagnosed from 2003 to 2013.The population of over 20 years was interpolated using 2003 and 2010 censuses. Then, truncated age-adjusted incidence rates were calculated. Increase was noted from 2003-2009 to 2010-2013 for 731 cancer cases considered in the analysis. The increases was most prominent in 2009. Totally, the frequency of the cancer was greater in males. Moreover, calculating truncated age-adjusted incidence rate indicated that the most prevalent age of colorectal incidence was in the 50-59 year age group except in 2007-2008 and 2012- 2013, when greatest incidences occurred in people aged 60-69 years. Our data revealed that the incidence rates of colorectal cancer have increased over the past decade in our region of Iran.

Accuracy of self-checked fecal occult blood testing for colorectal cancer in Thai patients

PURPOSE

Colorectal cancer (CRC) screening with fecal occult blood testing (FOBT) has been associated with a reduction in CRC incidence and CRC-related mortality. However, a conventional FOBT requires stool collection and handling, which may be inconvenient for participants. The EZ-DetectTM (Siam Pharmaceutical Thailand) is a FDA-approved chromogen-substrate based FOBT which is basically a self-checked FOBT (no stool handling required). This study aimed to evaluate the accuracy of EZ-Detect for CRC detection.

METHODS

This prospective study was conducted in the Faculty of Medicine, Siriraj Hospital, Bangkok, Thailand between November 2013 and May 2014. Some 96 patients with histologically-proven CRC and 101 patients with normal colonoscopic findings were invited to perform self-checked FOBT according to the manufacturer's instructions. RESULTS were compared with endoscopic and pathologic findings. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CRC detection were calculated.

RESULTS

The present study revealed the sensitivity, specificity, PPV and NPV of this self-checked FOBT for CRC detection to be 41% (95% CI: 31-51), 97% (95% CI: 92-99), 93% (95% CI: 81-98) and 63% (95% CI: 55-70), respectively. The overall accuracy of the self-checked FOBT for identifying CRC was 70%. The sensitivity for CRC detection based on 7th AJCC staging was 29% for stage I, 32% for stage II and 50% for stage III/IV (P=0.19). The sensitivity was 33% for proximal colon and 42% for distal colon and rectal cancer (P=0.76). Notably, none of nine infiltrative lesions gave a positive FOBT.

CONCLUSIONS

The self-checked FOBT had an acceptable accuracy of CRC detection except for infiltrative tumors. This home-administrated or 'DIY' do-it-yourself FOBT could be considered as one non-invasive and convenient tool for CRC screening.

Clinico-pathological patterns and survival outcome of colorectal cancer in young patients: western Saudi Arabia experience

BACKGROUND

The prognosis of young colorectal cancer (CRC) patients has been addressed by several studies but with contradictory results. The aim of the present study was to evaluate the clinico-pathological features of young Saudi patients with CRC in addition to displaying their survival outcome.

MATERIALS AND METHODS

In this retrospective study, young CRC patients (≤ 40 years) diagnosed between 2007 and 2011 from 4 centres in western Saudi Arabia, were included. Clinico-pathological features, tumor markers, dates of disease relapse and death were collected. Survival parameters were compared with those of older Saudi patients, reported in previous studies.

RESULTS

One hundred and sixteen young patients with CRC were identified (32.2% rectal, 67.8% colon). Some 44% were metastatic while 32.7% had stage III at diagnosis. Patients with grade 3 tumors made up 29.4% of the total while 49.5% had positive lymphovascular invasion (LVI), 56% had a lymph node (LN) ratio ≥ 0.2 and 40.2% were K-ras mutant. Median disease-free survival (DFS) and overall survival (OS) in non-metastatic cases were 22.8 and 49.6 months respectively with better median DFS in K-ras wild compared to mutant patients (28.5 vs 20.9 months, p=0.005). In metastatic cases, median OS was 19.5 months. These survival outcomes are inferior compared to those of older Saudi patients reported in prior studies.

CONCLUSIONS

Young CRC patients present more commonly with advanced stage and a high incidence of adverse prognostic factors such as LVI and high LN ratio. Young CRC patients seem to have worse survival compared to older Saudi patients.

Genome-wide mRNA and miRNA expression profiling reveal multiple regulatory networks in colorectal cancer

Despite recent advances in cancer management, colorectal cancer (CRC) remains the third most common cancer and a major health-care problem worldwide. MicroRNAs have recently emerged as key regulators of cancer development and progression by targeting multiple cancer-related genes; however, such regulatory networks are not well characterized in CRC. Thus, the aim of this study was to perform global messenger RNA (mRNA) and microRNA expression profiling in the same CRC samples and adjacent normal tissues and to identify potential miRNA-mRNA regulatory networks. Our data revealed 1273 significantly upregulated and 1902 downregulated genes in CRC. Pathway analysis revealed significant enrichment in cell cycle, integrated cancer, Wnt (wingless-type MMTV integration site family member), matrix metalloproteinase, and TGF-β pathways in CRC. Pharmacological inhibition of Wnt (using XAV939 or IWP-2) or TGF-β (using SB-431542) pathways led to dose- and time-dependent inhibition of CRC cell growth. Similarly, our data revealed up- (42) and downregulated (61) microRNAs in the same matched samples. Using target prediction and bioinformatics, ~77% of the upregulated genes were predicted to be targeted by microRNAs found to be downregulated in CRC. We subsequently focused on EZH2 (enhancer of zeste homolog 2 ), which was found to be regulated by hsa-miR-26a-5p and several members of the let-7 (lethal-7) family in CRC. Significant inverse correlation between EZH2 and hsa-miR-26a-5p (R²=0.56, P=0.0001) and hsa-let-7b-5p (R²=0.19, P=0.02) expression was observed in the same samples, corroborating the belief of EZH2 being a bona fide target for these two miRNAs in CRC. Pharmacological inhibition of EZH2 led to significant reduction in trimethylated histone H3 on lysine 27 (H3K27) methylation, marked reduction in cell proliferation, and migration in vitro. Concordantly, small interfering RNA-mediated knockdown of EZH2 led to similar effects on CRC cell growth in vitro. Therefore, our data have revealed several hundred potential miRNA-mRNA regulatory networks in CRC and suggest targeting relevant networks as potential therapeutic strategy for CRC.

Novel mutations of the PARP-1 gene associated with colorectal cancer in the Saudi population

BACKGROUND

Colorectal cancer (CRC) is the third most common type of cancers and the fourth leading cause of death worldwide. In Saudi Arabia, CRC accounts for 8.5% of all tumors; it ranks first among all cancers in males and third among females. The aim of this study was to link between different PARP-1 mutations and risk of CRC in Saudi population and to determine common variants of PARP-1 in Saudi CRC patients and normal individuals.

MATERIALS AND METHODS

DNA samples were isolated from fifty CRC patients and from a comparable number of control subjects then sequenced to detect different variations present in exons 3, 17, and 21 of the PARP-1 gene.

RESULTS AND CONCLUSIONS

When comparing the genotype and allele frequencies of all detected SNPs in CRC patients with those in controls, we found none were significantly different for all variants even the most common SNP in PARP-1 gene (Val762Ala). However, two novel alterations in exon 21 were found to be associated with increased risk of CRC. The variants identified as (1) Lys933Asn [p-value 0.0318] and (2) Lys945Asn [p-value 0.0257]. Our results suggest that PARP-1 Lys933Asn and Lys945Asn alterations could be associated with increased risk of CRC in the Saudi population.

Public awareness of colorectal cancer in Saudi Arabia: A survey of 1070 participants in Riyadh

BACKGROUND/AIMS

The aim of this study was to investigate colorectal cancer (CRC) awareness in healthy individuals in Saudi Arabia in order to identify segments of the population that would most benefit from targeted education programs.

SETTING AND DESIGN

Survey/questionnaire.

PATIENTS AND METHODS

Random, healthy individuals from Riyadh, Saudi Arabia, were approached to participate in a 10-question multiple choice survey about CRC. Data were analyzed by demographic criteria, including age, gender, marital status, and level of education, to determine if members of these groups displayed differential knowledge.

STATISTICAL ANALYSIS

Differences in responses by demographic data were analyzed using Pearson's Chi-square test. A P < 0.05 was considered statistically significant.

RESULTS

In total, 1070 participants completed the survey. Most respondents believe that screening for colon cancer should begin at symptom onset (42.9%). Less than 20% of all respondents believe that polyps are a risk factor for CRC, which varied significantly according to level of education; however, even the most educated answered correctly less than 50% of the time. Similarly, only 34.8% of all respondents knew that a family history of CRC imparted a personal risk for CRC.

CONCLUSIONS

Although older individuals and those with higher education tended to answer questions correctly more often, there were some misconceptions regarding universally accepted screening protocols, symptoms, and general understanding of CRC in Saudi Arabia. A national education/screening program in Saudi Arabia is recommended to improve CRC knowledge.

Does the increasing trend of colorectal cancer incidence in jeddah reflect a rise in the Kingdom of Saudi Arabia?

BACKGROUND

The aim of this study was to outline the trend in the incidence of colorectal cancer (CRC) in the city of Jeddah, Kingdom of Saudi Arabia (KSA), for comparison with previously published national CRC data.

MATERIALS AND METHODS

A retrospective data analysis was performed on all cases of CRC diagnosed between January 2000 and December 2006 amongst Saudi patients in Jeddah using data retrieved from the Saudi Cancer Registry (SCR). Descriptive analysis was performed and results were compared to national CRC data from the SCR.

RESULTS

In Jeddah, 644 cases of CRC were diagnosed during the time period, accounting for 15% of all CRC cases in KSA. Males were more commonly affected than females (58% versus 42%). The male preponderance of CRC was similar to that observed at a national level. In Jeddah, the incidence was higher among those >45 years (77.0%), and the mean age at diagnosis was 57 years. At diagnosis, 10% of patients presented with localized disease; 25% presented with distant metastasis and the remaining patients had various stages of regional extension. Adenocarcinomas accounted for 72% of cases. Statistical analysis did not reveal any clinically significant differences between cases diagnosed in Jeddah and those diagnosed throughout KSA.

CONCLUSIONS

The increased trend in the incidence of CRC in Jeddah between 2000 and 2006 mirrors the recent trend in KSA. This highlights the magnitude of this healthcare hazard, not only in Jeddah, but also across the country and supports the need for preventive measures and early detection of the disease.

Knowledge, Attitude, Practice, and Perceived Barriers of Colorectal Cancer Screening among Family Physicians in National Guard Health Affairs, Riyadh

Objectives. The objective of this study is to explore the current knowledge, attitude, and practice of family physicians working in family medicine clinics in National Guard Health Affairs (NGHA), Riyadh, toward colorectal cancer (CRC) screening and to identify the barriers of the screening. Methods. Data were collected using a validated self-administered questionnaire adopted from the National Cancer Institute in USA, customized by adding and eliminating questions to be in line with the institution (NGHA) characteristics. Results. Of the 130 physicians, 56.2% of the physicians were not practicing CRC screening although 94.6% considered CRC screening effective. Board certified physicians had higher knowledge score and were practicing CRC screening more when compared to other physicians. Physicians who reported practicing CRC screening scored more on the knowledge score than those not practicing. Male physicians scored better on attitude score than female physicians. The study found that barriers were cited in higher rates among physicians not practicing CRC screening compared with practicing physicians. Lack of patients' awareness was the most cited barrier. Conclusion. Large percentage of family physicians in this study do not practice CRC screening, despite the knowledge level and the positive attitude.

Incidence trends of colorectal cancer in the West of Iran during 2000-2005

BACKGROUND

Colorectal cancer is a main leading cause of cancer death in western countries. Although many studies have been conducted on incidence trends all over the world in recent years, information regarding changes in incidence of colorectal cancer in Iran is insufficient. The present study of colorectal cancer in the west of Iran during recent years was therefore performed.

MATERIALS AND METHODS

The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Ministry of Health and Medical Education, Center for Disease Control and Management. The codes from 18-21 among cancers were selected for colon and rectum cancers. Incidence rates were standardized directly using WHO population. The significance of incidence rate trends during 2000-2005 was tested through Poisson regression.

RESULTS

762 cases of colorectal cancer were observed during 6 years in this region, with a gender ratio of men to women of 1.2. It increased from 65 cases in 2000 to 213 cases in 2005 or from 1.5 per100,000 per persons per year to 4.8. Significant increasing trends were evident in Kermanshah and Hamadan provinces; however, change did not reach significance in Ilam and Kurdistan provinces.

CONCLUSIONS

Colorectal cancer has an increasing trend in the west of Iran. Although it seems that the increasing rate of colorectal cancer is due to increasing of cancer risk factors, some proportion may be related to the improvement of surveillance systems in Iran.

Prevalence and characteristics of colonic polyps and adenomas in 2654 colonoscopies in Saudi Arabia

BACKGROUND/AIMS

Colorectal cancer (CRC) is the second most common malignancy in the Saudi population, with an increasing incidence over the past 20 years. We aim to determine the baseline polyp as well as adenoma prevalence in a large cohort of patients and to find the possible age in which, if deemed appropriate, a CRC screening program should be initiated.

PATIENTS AND METHODS

A retrospective cohort study was conducted using an endoscopic reporting database of individuals seen at a major tertiary care university hospital (King Khalid University Hospital) in Riyadh, Saudi Arabia. Consecutive Saudi patients who underwent a colonoscopy between August 2007 and April 2012 were included. Patients were excluded if the indication for the colonoscopy was colon cancer, colonic resection, active colitis, active diverticulitis, inflammatory bowel disease, or if the patient was referred for polypectomy.

RESULTS

2654 colonoscopies were included in the study. The mean age of the study population was 50.5 years [standard deviation (SD) 15.9] and females represented 57.7%. The polyp detection rate in completed colonoscopies was 20.8% (95% CI: 19.2-22.5). Adenomas were found in 8.1% (95% CI: 7.1-9.1), while advanced adenomas were found in only 0.5% (95% CI: 0.2-0.7). Adenomas were found in the left side of the colon in 33.9%, followed by the rectum in 14.6%, ascending colon and cecum in 14.2%, transverse colon in 8.7%, and in multiple locations in 28.7%. Those with a prior history of polyps or CRC were more likely to have an adenoma at colonoscopy than those who did not (14.3% vs. 6.6%; P < 0.01). The adenoma prevalence varied between age groups and ranged from 6.2% to 13.6% with a higher proportion in older individuals; this trend was seen both in males (6.0-14.5%) and females (6.4-14.6%) as well as in those who had screening colonoscopies (6.3-18.4%). No age could be found at which a CRC screening program would be appropriate to initiate.

CONCLUSION

The prevalence of polyps and adenomas in this cohort is less than that reported in the Western populations. But as this cohort included younger and symptomatic patients with only a small proportion undergoing screening, further studies in an asymptomatic population are needed.