Colorectal cancer in India: controversies, enigmas and primary prevention

Epigenetic differences in the tumor suppressor genes MLH1 and p16INK4a between Nepalese and Swedish patients with colorectal cancer

Objectives

Colorectal cancer (CRC) is one of the most prevalent cancer types worldwide, exhibiting significant variance in incidence rates across different ethnicities and geographical regions. Notably, there is a rising incidence of CRC among younger adults, particularly evident in advanced stages, with a more pronounced trend observed in developing nations. Epigenetic alterations potentially play a role in the early onset of CRC and could elucidate interpopulation disparities. This study aimed to examine DNA methylation levels in the tumor suppressor genes MLH1 and p16INK4a, comparing Nepalese and Swedish patients with CRC.

Methods

Patients who underwent CRC surgery at Tribhuvan University Teaching Hospital, Nepal (n=39), and Sahlgrenska University Hospital, Sweden (n=39) were included. Demographic and clinicopathological data were analyzed, and pyrosequencing was employed to determine methylation levels in the MLH1 promoter region and the first exon of p16INK4a in tumor tissues and adjacent mucosa located 10 cm from the tumor site. Subsequently, methylation status was compared between Nepalese and Swedish patients and correlated with clinicopathological parameters.

Results

Nepalese and Swedish patients displayed equal levels of MLH1 and p16INK4a methylation in tumors, but Nepalese patients exhibited a significantly higher level of MLH1 methylation in mucosa compared to Swedish patients (p=0.0008). Moreover, a greater proportion of Nepalese patients showed MLH1 methylation in mucosa compared to Swedish patients (31 vs. 2.6 %). Aberrant methylation of p16INK4a was also observed in the mucosa of Nepalese patients, characterized by high methylation at specific sites rather than uniform methylation across CpG sites. There were no significant differences in methylation levels based on tumor location among Nepalese patients, whereas Swedish patients exhibited higher methylation in right- compared to left-sided colon tumors. Swedish patients showed an increase in p16INK4a methylation in tumors with advancing age.

Conclusions

Nepalese and Swedish patients displayed equal levels of MLH1 and p16INK4a methylation in tumors. In contrast, Nepalese patients had a higher level of MLH1 methylation as well as aberrant methylation of p16INK4a in mucosa compared to Swedish patients. These epigenetic differences may be linked to environmental and lifestyle factors. Ongoing research will further explore whether hypermethylation in the mucosa of Nepalese patients is associated with tumorigenesis and its potential utility in screening high-risk patients or predicting recurrence.

Analysis of heavy metals and minerals in edible vegetable oils produced and marketed in Gondar City, Northwest Ethiopia

INTRODUCTION

Nowadays, food safety is regarded as one of the most critical global public health issues. Edible oil, a key ingredient in food processing, is widely used and consumed in every Ethiopian household. However, its safety is often overlooked. Currently, edible oil is produced in Ethiopia from small-scale operations to large industrial levels, as well as imported from other countries.

OBJECTIVE

This study aimed to determine the levels of heavy metals and essential minerals in edible vegetable oils produced and marketed in Gondar City, Northwest Ethiopia.

METHODS

A laboratory-based cross-sectional study was conducted from May to July 2021 in Gondar City. Seventeen edible oil samples were collected using simple random sampling techniques. Heavy metal content was determined using an atomic absorption spectrophotometer with the standard procedures and techniques after microwave digestion. The efficiency and validity of the method used were evaluated by determining the limit of detection (LOD), the limit of quantification (LOQ), accuracy, and precision. The collected data were entered into Microsoft Excel and transported to Stata for analysis.

RESULT

A total of seventeen vegetable oil samples were analyzed. The accuracy of the method was evaluated by recovery studies, which ranged from 81 to 115%, and the relative standard deviations were found to be below 15%. The concentrations of Zn, Cu, Fe, Cd, and Pb were in the range of 0.07 to 0.8 mg/l, 0.002 to 0.06 mg/l, 0.01 to 0.8 mg/l, 0.08 to 0.18 mg/l, and 0.003 to 0.27 mg/l, respectively. In general, the lead and cadmium content was higher than other metals in some of the investigated edible vegetable oils. Most values fell within the permissible quality limits for edibility as prescribed by the World Health Organization (WHO) and the National Agency for Food and Drug Administration and Control (NAFDAC). However, the levels of Pb and Cd exceeded the reference levels in some locally produced vegetable oils.

CONCLUSION

To address the exceeded levels of heavy metals, it is imperative to implement more careful handling, processing of raw materials, and filtering practices. Producers and marketers should take the necessary precautions to prevent contamination. Strict regulatory control from responsible bodies and stakeholders is recommended to ensure the safety and metal contents of vegetable oils originating from the study area.

Epidemiological trends of colorectal cancer cases in young population of Eastern India: A retrospective observational study

BACKGROUND

Colorectal cancer (CRC) is a disease of the older population in developed countries where the incidence among the young is rising despite the decline in the overall incidence. Contrary to this, in India, which is a low-incidence country for CRCs, the incidence among all age groups including the young is rising. This study aimed at describing the clinico-demographic profile of young CRC cases and the epidemiological trend of the proportion of young cases from 2014 to 2021 in a tertiary cancer center in Eastern India.

METHODS

This retrospective observational study was conducted at Department of Radiation Oncology, State Cancer Institute, IGIMS Patna, India a prominent tertiary cancer care center of Bihar. All histopathologically confirmed CRC cases in the 0-39 years age group were considered young and evaluated for the clinical, demographic profile as well as yearly trends in proportion out of total CRC cases. Microsoft Excel (2021) was used for statistical analysis. A P value of 0.05 was considered significant.

RESULTS

Young colorectal (less than 40 years) patients constituted a third (n = 344, 33.4%) of total colorectal (n = 1028) cases. The median age among the young CRC cases was 30 years (range: 12 to 39 years). Rectum was the most common subsite noted (n = 255,74.1%) among this group of young patients. The most commonly encountered stage of the disease was III (n = 107, 31.1%) and chemotherapy was the most common treatment offered (n = 153, 44.5%). The proportion of young (0-39 years) CRC cases ranged between 29.4 and 37.4 (mean 33.5 ± 2.77, P value = 0.725) over the calendar years of the study period.

CONCLUSION

The proportion of young (<40 years of age) cases out of total CRC cases in our study is higher than that in developed countries. However, the trends of this proportion have been consistent over the study period, i.e., from 2014 to 2021 without any significant change in our hospital-based cancer registry. Rectal cancer affected nearly three out of every four CRC patients in this age group. More advanced disease at presentation emphasizes the need for measures of screening, early diagnosis, and adequate infrastructure for treatment.

Molecular analysis to identify novel potential biomarkers as drug targets in colorectal cancer therapy: an integrated bioinformatics analysis

Colorectal cancer (CRC) is a heterogeneous disease that requires new diagnostic and prognostic markers. Integrated bioinformatics approach to identify novel therapeutic targets associated with CRC. Using GEO2R identified DEGs in CRC, and Funrich software facilitated the visualization of DEGs through Venn diagrams. From a total of 114 enhanced DEGs, potential hub genes were further filtered based on their nodal strength and edges using STRING database. To gain insights into the functional roles of these hub genes, gene ontology and pathway enrichment were conducted thorough g: profiler web server. Subsequently, overall survival plots from GEPIA and oncogenic predictive functions like mRNA expressions for stages and nodal metastasis were employed to identify hub genes in CRC patient samples. Additionally, the cBioPortal and HPA databases also revealed genetic alterations and expression levels in these hub genes in CRC patients, further supporting their involvement in colorectal cancer. Gene expression by RT-PCR shows upregulation of hub genes in HT-29 cells. Finally, our integrated bioinformatic analysis revealed that ABCE1, AURKA, HSPD1, PHKA1, CDK4, and YWHAE as hub genes with potential oncogenic roles in CRC. These genes hold promise as diagnostic and prognostic markers for colorectal tumorigenesis, providing insights into targeted therapies for improved patient outcomes.

Chemotherapeutic and Antiproliferative Effect of Purified Protein from Marine Catfish Tachysurus Dussumieri on Human Colon Cancer Cell Line

The present study aimed to investigate the purified protein from the epidermal mucus of marine catfish Tachysurus dussumieri on the human colon cancer cell line. The bioactive protein was purified with the Anion exchange chromatography and the collected fractions were then tested to assess cell viability in HT 29 cells through the MTT assay. The most responding active purified protein fraction (PPF III) was characterized with the MALDI-TOF/MS it shared a similar homology and sequence with 90% of antimicrobial peptides from external secretions of amphibians. Typical morphological changes of apoptotic cells, including cell shrinkage and detachment, DNA damage, and nuclear condensation were observed after the treatment of bioactive protein. PPF III triggered ROS, increasing the LDH activity, disruption of mitochondrial membrane potential, and upregulation of Cleaved caspase 3/9, Cytochrome-c, Bax, and downregulation of Bcl-2 protein and gene expression on HT 29 cells.

Colon Cancer: From Epidemiology to Prevention

Colorectal cancer (CRC) is one of the most prevalent cancers affecting humans, with a complex genetic and environmental aetiology. Unlike cancers with known environmental, heritable, or sex-linked causes, sporadic CRC is hard to foresee and has no molecular biomarkers of risk in clinical use. One in twenty CRC cases presents with an established heritable component. The remaining cases are sporadic and associated with partially obscure genetic, epigenetic, regenerative, microbiological, dietary, and lifestyle factors. To tackle this complexity, we should improve the practice of colonoscopy, which is recommended uniformly beyond a certain age, to include an assessment of biomarkers indicative of individual CRC risk. Ideally, such biomarkers will be causal to the disease and potentially modifiable upon dietary or therapeutic interventions. Multi-omics analysis, including transcriptional, epigenetic as well as metagenomic, and metabolomic profiles, are urgently required to provide data for risk analyses. The aim of this article is to provide a perspective on the multifactorial derailment of homeostasis leading to the initiation of CRC, which may be explored via multi-omics and Gut-on-Chip analysis to identify much-needed predictive biomarkers.

Risk Factors for Colorectal Cancer in Goa, India: A Hospital-based Case-Control Study

Introduction:

Colorectal cancer is the third most common cancer in men and the second in women worldwide. The objective of the present study was to determine and quantify important modifiable risk factors attributable to colorectal cancer, in order to explore the ways to reduce the incidence of colorectal cancer in this region.

Materials and Methods:

A case–control study was conducted at a tertiary care hospital in Goa, India. The study subjects were group matched for age and sex so as to include 110 cases and 110 controls. Only incident cases of colorectal cancer were recruited in the study. Predesigned structured questionnaire was utilized for data collection, while anthropometric measurements and laboratory investigations were conducted. Statistical analysis was conducted using SPSS software package. The study was approved by the Institutional Ethics Committee of the institute. Informed written consent was obtained from the study participants.

Results:

Smoking, smokeless tobacco use, alcohol consumption, red meat consumption, high body mass index (BMI), and the presence of Type 2 diabetes mellitus were found to be the risk factors for colorectal cancer on univariate analysis, while fruit and vegetable consumption were found to be the protective factors. Multiple logistic regression analysis identified Type 2 diabetes mellitus and high BMI as risk factors for colorectal cancer and consumption of fruits and vegetables as protective factors.

Conclusion:

Identification of risk factors for colorectal cancer would help in setting of colorectal cancer screening guidelines as well as for creating awareness regarding prevention of colorectal cancer among the general population.

Aberrant Promoter Hypermethylation of p16 and RASSF1a Genes in Colorectal Cancer - Significance in Young Patients

OBJECTIVE

The clinical profile of colorectal cancers (CRC) in India is different from that described in western countries. Microsatellite instability and APC mutation explain the molecular biology of up to 50% of colorectal cancers. Global genome hypermethylation may be the cause in at least 20% of cases. Few studies from India have examined the epigenetic profile of colorectal cancers. This study was designed to study aberrant promoter hypermethylation of two select tumour suppressor genes (p16, RASSF1a) in patients with colorectal cancer and their association with clinicopathologic features.

METHODS

A total of 41 samples including controls were collected from colorectal cancer patients. DNA was isolated from tumour tissue, and methylation-specific PCR was performed for the 2 genes.

RESULTS

p16 and RASSF1a promoter hypermethylation was found in 26% and 48% of CRC cases, respectively. RASSF1a promoter hypermethylation was more often seen in young CRC patients aged 40 years or less, and this was found to be statistically significant (p value = 0.037).

CONCLUSION

RASSF1a hypermethylation is peculiar to rectal cancers and left-sided colonic tumours in young patients. Large-scale population-based studies with extensive genetic and epigenetic characterization are required for a better understanding and further validation of our findings. For individuals diagnosed with sporadic CRC, these studies on specimen might help predict prognosis and response to therapy.

Adjuvant chemotherapy in stage II-III operated colon cancer patients from a nontrial cohort in a low colon cancer prevalence country with predominant use of modified CAPOX

BACKGROUND

Data regarding the practice of adjuvant chemotherapy, specifically with modified CAPOX, and survival outcomes in operated colon cancer patients from a nontrial cohort in a lower-middle income and low prevalence nation like India is scarce.

MATERIALS AND METHODS

Patients who underwent upfront curative resection for colon cancer from January 2013 to December 2016 were analyzed for baseline variables and outcomes.

RESULTS

A total of 491 patients underwent curative resection in the predefined time period. The median age of the patients was 53 years (range: 17-87). Patients with Stage I, Stage II, and Stage III disease comprised 7.9%, 44.8%, and 45.4% of the entire cohort, respectively. Patients with Stage I cancer were observed. Adjuvant chemotherapy was planned for 384 patients (78.2%), with the doublet regimens (capecitabine-oxaliplatin, or 5-fluorouracil-oxaliplatin) being used commonly (77.6%). Common toxicities were Hand-foot syndrome (Grade 2/3 - 21.4%) and peripheral neuropathy (Grade 2/3 - 20.1%). About 85% of patients receiving monotherapy (capecitabine or 5 fluorouracil) and 81.2% of patients receiving doublet chemotherapy (mCAPOX or modified FOLFOX-7) completed their planned adjuvant treatment. With a median follow-up of 22 months, estimated 3 years event-free survival was 86%, and overall survival (OS) was 93.6%. Stage, younger age (<50 years), underlying cardiovascular abnormalities, need for dose reductions and noncompletion of planned chemotherapy predicted for inferior estimated 3-year OS on multivariate analysis.

CONCLUSIONS

Adjuvant chemotherapy especially with modified CAPOX appears well tolerated in the Indian population and early survival outcomes appear to be comparable to published literature.

Serine Protease from Nereis virens Inhibits H1299 Lung Cancer Cell Proliferation via the PI3K/AKT/mTOR Pathway

This study explores the in vitro anti-proliferative mechanism between Nereis Active Protease (NAP) and human lung cancer H1299 cells. Colony formation and migration of cells were significantly lowered, following NAP treatment. Flow cytometry results suggested that NAP-induced growth inhibition of H1299 cells is linked to apoptosis, and that NAP can arrest the cells at the G0/G1 phase. The ERK/MAPK and PI3K/AKT/mTOR pathways were selected for their RNA transcripts, and their roles in the anti-proliferative mechanism of NAP were studied using Western blots. Our results suggested that NAP led to the downregulation of p-ERK (Thr 202/Tyr 204), p-AKT (Ser 473), p-PI3K (p85), and p-mTOR (Ser 2448), suggesting that NAP-induced H1299 cell apoptosis occurs via the PI3K/AKT/mTOR pathway. Furthermore, specific inhibitors LY294002 and PD98059 were used to inhibit these two pathways. The effect of NAP on the downregulation of p-ERK and p-AKT was enhanced by the LY294002 (a PI3K inhibitor), while the inhibitor PD98059 had no obvious effect. Overall, the results suggested that NAP exhibits antiproliferative activity by inducing apoptosis, through the inhibition of the PI3K/AKT/mTOR pathway.

Construing the Biochemical and Molecular Mechanism Underlying the In Vivo and In Vitro Chemotherapeutic Efficacy of Ruthenium-Baicalein Complex in Colon Cancer

In pursuit of a novel approach in colon cancer therapy, we explored the ability of ruthenium baicalein complex to eradicate colon cancer by efficiently targeting various apoptotic pathways on human colon cancer cell line and on a DMH and DSS induced murine model of colorectal cancer. In this study, we provide direct proof of the chemotherapeutic potential of the ruthenium baicalein complex by activating p-53 dependent intrinsic apoptosis and modulating the AKT/mTOR and WNT/β- catenin pathways. The ruthenium baicalein complex was synthesized and its characterizations were accomplished through various spectroscopic techniques followed by assessment of antioxidant potential by DPPH, FRAP, and ABTS methods. In vitro study established that the complex increased p53 and caspase-3 expressions while down regulating VEGF and mTOR expression, induced apoptosis, and DNA fragmentation in the HT-29 cells. Acute and sub-acute toxicity study was also considered and results from in vivo study revealed that complex was effective in suppressing ACF multiplicity and hyperplastic lesions and also raised the CAT, SOD, and glutathione levels. Furthermore, the complex decreased cell proliferation and increased apoptotic events in tumor cells correlated with the upregulation of Bax and downregulation of Bcl2, WNT and β- catenin expressions. Our findings from the in vitro and in vivo study provide robust confirmation that ruthenium baicalein complex possesses a potential chemotherapeutic activity against colon cancer and is competent in reducing ACF multiplicity, hyperplastic lesions in the colon tissues of rats by inducing apoptosis.

Physical Activity and Gastrointestinal Cancer Risk: A Review

Introduction: Western lifestyle characterized by increased consumption of red meat, fat, processed food, smoking, alcohol drinking, lower consumption of vegetables and physical inactivity has been associated with a higher gastrointestinal cancer risk. Digestive system cancers are diagnosed at late stages when they show poor response to treatment and are associated with a high mortality rate. Colorectal, gastric, esophageal and pancreatic cancers are among the most common cancers worldwide. Studies show that more than 50% of gastrointestinal cancers develop as a result of inappropriate lifestyle. An inverse association between physical activity and many chronic diseases has been proved so far. However, the association between physical activity and some gastrointestinal cancers is still controversial. This study was aimed to determine the association between physical activity and gastrointestinal cancers risk.

Methods: We conducted a comprehensive search of English and Persian databases from February 2007 till December 2017, for studies investigating the association of physical activity and risk of gastrointestinal cancers. Finally, after reading full text of articles, 123 studies were included.

Results: Physical activity can be helpful in reducing the risk of gastrointestinal cancer, especially colon and pancreatic cancers. The risk reduction is not similar for different types of gastrointestinal cancers and also among males and females.

Conclusion: Different types of physical activity are associated with a lower risk of gastrointestinal cancer. However, it is unknown which type and intensity of physical activity are associated with a protective effect against gastro-intestinal cancer.

Colorectal Cancer: How Familiar Are Our Future Doctors with the Cancer of Tomorrow?

Background

Colorectal cancer (CRC) is one of the common cancers affecting both genders. Although the incidence of CRC is low in India there has been an increase in the past few decades.

Objective

To assess the awareness regarding colorectal cancer and its screening among medical students and interns.

Methods

This cross-sectional study was conducted among 290 participants (final year medical students and interns) from Kasturba Medical College, Mangalore. A pretested semistructured questionnaire was used to collect information. Data was analyzed using SPSS 17.0.

Results

Majority of participants had satisfactory knowledge regarding CRC. 38% of them scored excellently, 64.8% had good knowledge, and 5.2% scored poorly. Knowledge regarding CRC symptoms was good (95%). 92% of the participants were aware of risk factors of CRC. Only 49% of the participants identified FOBT as a screening tool and 30.7% participants knew that 50 years is the recommended age to begin CRC screening. Interns and international students had better knowledge than final year medical students and Indian students and this was found to be statistically significant.

Conclusion

There is a need to improve participant's knowledge regarding CRC screening although majority of them are aware of CRC symptoms and risk factors.

Low prevalence of deficient mismatch repair (dMMR) protein in locally advanced rectal cancers (LARC) and treatment outcomes

Background

The available evidence in locally advanced rectal cancer (LARC) suggests a low prevalence of deficient mismatch repair (dMMR) protein status, approximating 1-3%.

Methods

Patients with LARC who were offered long course chemoradiation (LCRT), as per institution protocol during the period of 1st January 2014 to 31st December 2015 at Tata Memorial Hospital (TMH) in Mumbai were evaluated for outcomes and assessment of MMR status.

Results

A total of 419 patients were evaluated for LARC in TMH, of whom 354 were treated with LCRT. Of these 354 patients, 296 were assessable for MMR status based on tissue adequacy for testing. Three patients (1.01%) has dMMR status, while the remaining 293 patients had proficient MMR status. A total of 240 patients (67.8%) underwent curative intent resections. With a median follow-up of 32 months, estimated 3-year recurrence free survival (RFS) and overall survival (OS) for the resected group was 63.5% and 85.2%, respectively, while 3-year event free survival and OS for the unresected cohort was 15.2% and 15.8%, respectively. Signet ring histology, higher ypT stage, involved margin status post resection, and delays (>1 week) in LCRT were associated with inferior OS on multivariate analysis.

Conclusions

In a large LARC cohort, a majority of tumors had proficient MMR status, suggesting that MSI as a biomarker may have limited applicability in the management of rectal cancers. Signet ring histology, CRM involvement post resection, higher ypT stage and interruptions in LCRT predicted for inferior OS.

Topographic, histological and molecular study of aberrant crypt foci identified in human colon in different clinical groups

Background/Aims

Aberrant crypt foci (ACF) are early microscopic lesions of the colonic mucosa, which can be detected by magnified chromoendoscopy. Herein, we have investigated whether ACF identified in different clinical groups can be differentiated based on their characteristics.

Methods

Macroscopically unremarkable mucosal flaps were collected from 270 fresh colectomies and divided into 3 clinical groups: colorectal carcinoma (group A), disease controls having known pre-neoplastic potential (group Bc), and disease controls without risk of carcinoma development (group Bn). Topographic and histologic analysis, immunohistochemistry, and molecular studies (high-resolution melt curve analysis, real-time polymerase chain reaction, and Sanger sequencing) were conducted for certain neoplasia-associated markers.

Results

ACF were seen in 107 cases, out of which 72 were left colonic ACF and 35 right colonic ACF (67.2% vs. 32.7%, P=0.02). The overall density of left colonic ACF was 0.97/cm, which was greater than the right colonic ACF density of 0.81/cm. Hypercrinia was present in 41 out of 72 left colonic ACF and in 14 out of 35 right colonic ACF (P=0.01). Immunohistochemical expression of p53 was also greater in left colonic ACF than in right colonic ACF (60.5% vs. 38.2%, P=0.03). However, ACF identified among the 3 clinical groups did not show any distinguishing topographic, histological, or genetic changes.

Conclusions

Left colonic ACF appear to be high-risk based on their morphological and prototypic tumor marker signature. ACF identified in different clinical groups do not show significant genotypic or topographic differences. Further detailed genetic studies are required to elucidate them further.

Optimization of anticancer exopolysaccharide production from probiotic Lactobacillus acidophilus by response surface methodology

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths in the Western world. Recently, much attention has been focused on decreasing the risk of CRC by consuming probiotics. In the present study, exopolysaccharide (EPS) extracted from Lactobacillus acidophilus was found to inhibit the growth of CaCo2 colon cancer cell line in a dose-dependent manner. The experiment was performed in both normoxic and hypoxic conditions, and EPS was found to reduce the survival of CaCo2 cell line in both the conditions. Quantitative polymerase chain reaction (qPCR) studies demonstrated that EPS treatment upregulated the expression of peroxisome proliferator activator receptor-γ (PPAR-γ) in both normoxia and hypoxia conditions, whereas it upregulated the expression of erythropoietin (EPO) in the normoxic condition, but there was no significant expression under hypoxic conditions. Hence, the EPS production was optimized by Plackett-Burman design followed by central composite rotatory design. The optimized production of EPS at 24 hr was found to be 400 mg/L. During batch cultivation the production peaked at 21 hr, resulting in an EPS concentration of 597 mg/L.

MicroRNA-214 suppresses growth, migration and invasion through a novel target, high mobility group AT-hook 1, in human cervical and colorectal cancer cells

Background:

MicroRNA-214 (miR-214) has been shown to act as a tumour suppressor in human cervical and colorectal cancer cells. The aim of this study was to experimentally validate high mobility group AT-hook 1 as a novel target for miR-214-mediated suppression of growth and motility.

Methods:

HMGA1 and miR-214 expression levels were estimated in cervical and colorectal clinical specimens using qPCR. HMGA1 3′ untranslated region luciferase assays were performed to validate HMGA1 as a target of miR-214. Effect of altering the expression of miR-214 or HMGA1 on proliferation, migration and invasion of human cervical and colorectal cancer cells was investigated.

Results:

miR-214 expression was poor while that of HMGA1 was high in cervical and colorectal cancer tissues. miR-214-re-expression or HMGA1 downregulation inhibited proliferation, migration and invasion of cancer cells while miR-214 inhibition had opposite effects. miR-214 was demonstrated to bind to the wild-type 3′ untranslated region of HMGA1 but not with its mutant.

Conclusions:

Low expression of miR-214 concurrent with elevated levels of HMGA1 may contribute to cervical and colorectal cancer progression. miR-214-mediated regulation of HMGA1 is a novel mechanism for its tumour-suppressive actions in human cervical and colorectal cancer cells and opens up avenues for novel therapeutic strategies for these two cancers.

Evaluation of the deleterious health effects of consumption of repeatedly heated vegetable oil

Consumption of repeatedly heated cooking oil (RHCO) has been a regular practice without knowing the harmful effects of use. The present study is based on the hypothesis that, heating of edible oils to their boiling points results in the formation of free radicals that cause oxidative stress and induce damage at the cellular and molecular levels. Peroxide value of heated oil, histopathological alterations, antioxidant enzyme levels and blood biochemistry were determined in Wistar rats treated with the RHCO. RHCO revealed higher peroxide value in comparison to oil that has been unheated or singly heated. Histopathological observation depicted significant damage in jejunum, colon and liver of animals that received oil heated repeatedly for 3 times. The altered antioxidant status reflects an adaptive response to oxidative stress. Alteration in the levels of these enzymes might be due to the formation of reactive oxygen species (ROS) through auto oxidation or enzyme catalyzed oxidation of electrophilic components within RHCO. Analysis of blood samples revealed elevated levels of glucose, creatinine and cholesterol with declined levels of protein and albumin in repeatedly heated cooking oil group. Hematological parameters did not reveal any statistically significant difference between treated and control groups. Results of the present study confirm that the thermal oxidation of cooking oil generates free radicals and dietary consumption of such oil results in detrimental health effects.

Downregulation of HMGB1 by miR-34a is sufficient to suppress proliferation, migration and invasion of human cervical and colorectal cancer cells

High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein known to be highly expressed in human cervical (CaCx) and colorectal (CRC) cancers, and sustained high levels of HMGB1 contribute to tumourigenesis and metastasis. HMGB1-targeted cancer therapy is of recent interest, and there are not many studies on miRNA-mediated HMGB1 regulation in these cancers. Since miRNA-based therapeutics for cancer is gaining importance in recent years, it was of interest to predict miRNAs targeting HMGB1. Based on the identification of a potential miR-34a response element in HMGB1-3' untranslated region (3'UTR) and an inverse correlation between HMGB1 and miR-34a expression levels in CaCx and CRC tissues, from a subset of the local population as well as a large sampling from TCGA database, experiments were performed to validate HMGB1 as a direct target of miR-34a in CaCx and CRC cells. Ectopic expression of miR-34a decreased the wild-type HMGB1-3'UTR luciferase activity but not that of its mutant in 3'UTR luciferase assays. While forced expression of miR-34a in CaCx and CRC cells inhibited HMGB1 mRNA and protein levels, proliferation, migration and invasion, inhibition of endogenous miR-34a enhanced these tumourigenic properties. siRNA-mediated HMGB1 suppression imitated miR-34a expression in reducing proliferation and metastasis-related events. Combined with the disparity in expression of miR-34a and HMGB1 in clinical specimens, the current findings would help in not only understanding the complexity of miRNA-target regulatory mechanisms but also in designing novel therapeutic interventions in CaCx and CRC.

Cancer incidence among Asian American populations in the United States, 2009-2011

Cancer incidence disparities exist among specific Asian American populations. However, the existing reports exclude data from large metropoles like Chicago, Houston and New York. Moreover, incidence rates by subgroup have been underestimated due to the exclusion of Asians with unknown subgroup. Cancer incidence data for 2009 to 2011 for eight states accounting for 68% of the Asian American population were analyzed. Race for cases with unknown subgroup was imputed using stratified proportion models by sex, age, cancer site and geographic regions. Age-standardized incidence rates were calculated for 17 cancer sites for the six largest Asian subgroups. Our analysis comprised 90,709 Asian and 1,327,727 non-Hispanic white cancer cases. Asian Americans had significantly lower overall cancer incidence rates than non-Hispanic whites (336.5 per 100,000 and 541.9 for men, 299.6 and 449.3 for women, respectively). Among specific Asian subgroups, Filipino men (377.4) and Japanese women (342.7) had the highest overall incidence rates while South Asian men (297.7) and Korean women (275.9) had the lowest. In comparison to non-Hispanic whites and other Asian subgroups, significantly higher risks were observed for colorectal cancer among Japanese, stomach cancer among Koreans, nasopharyngeal cancer among Chinese, thyroid cancer among Filipinos, and liver cancer among Vietnamese. South Asians had remarkably low lung cancer risk. Overall, Asian Americans have a lower cancer risk than non-Hispanic whites, except for nasopharyngeal, liver and stomach cancers. The unique portrayal of cancer incidence patterns among specific Asian subgroups in this study provides a new baseline for future cancer surveillance research and health policy.

Comparative analysis of copy number variations in ulcerative colitis associated and sporadic colorectal neoplasia

Background

The incidence of and mortality from colorectal cancers (CRC) can be reduced by early detection. Currently there is a lack of established markers to detect early neoplastic changes. We aimed to identify the copy number variations (CNVs) and the associated genes which could be potential markers for the detection of neoplasia in both ulcerative colitis-associated neoplasia (UC-CRN) and sporadic colorectal neoplasia (S-CRN).

Methods

We employed array comparative genome hybridization (aCGH) to identify CNVs in tissue samples of UC nonprogressor, progressor and sporadic CRC. Select genes within these CNV regions as a panel of markers were validated using quantitative real time PCR (qRT-PCR) method along with the microsatellite instability (MSI) in an independent cohort of samples. Immunohistochemistry (IHC) analysis was also performed.

Results

Integrated analysis showed 10 overlapping CNV regions between UC-Progressor and S-CRN, with the 8q and 12p regions showing greater overlap. The qRT-PCR based panel of MYC, MYCN, CCND1, CCND2, EGFR and FNDC3A was successful in detecting neoplasia with an overall accuracy of 54 % in S-CRN compared to that of 29 % in UC neoplastic samples. IHC study showed that p53 and CCND1 were significantly overexpressed with an increasing frequency from pre-neoplastic to neoplastic stages. EGFR and AMACR were expressed only in the neoplastic conditions.

Conclusion

CNVs that are common and unique to both UC-associated and sporadic colorectal neoplasm could be the key players driving carcinogenesis. Comparative analysis of CNVs provides testable driver aberrations but needs further evaluation in larger cohorts of samples. These markers may help in developing more effective neoplasia-detection strategies during screening and surveillance programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2303-4) contains supplementary material, which is available to authorized users.

Risk factors for the development of colorectal carcinoma: A case control study from South India

AIM: To study the association of colorectal carcinoma (CRC) with diet, smoking, alcohol, physical activity, body mass index, family history and diabetes.

METHODS: All consecutive patients with CRC confirmed by histopathology diagnosis were included. Age (± 5 years) and gender matched controls were selected among the patients admitted in surgery ward for various conditions without any co-existing malignancy. Food frequency questionnaire (FFQ) was developed and validated after pretesting by investigator trained in data collection techniques. Cases and controls were interviewed ensuring privacy, in similar interview setting, with same duration of time for both cases and controls without any leading question. Biological variables like family history of CRC in first degree relatives, history of diabetes mellitus; behavioral factors like tobacco use both smoking and smokeless form, alcohol consumption and physical activity were recorded. Dietary details were recorded using a FFQ consisting 29 food items with seven categories. Analysis was done using appropriate statistical methods.

RESULTS: Ninety-four histopathologically confirmed cases of CRC and equal number of age and gender matched controls treated over a period of two years were studied. Age distribution, mean age, male to female ratio, education level and socioeconomic status were similar in cases and controls. Intake of food items was categorized into tertile due to skewed distribution of subjects as per recommended cut off for consumption of food item. On univariate analysis red meat [OR = 7.4 (2.935-18.732)], egg [OR = 5.1 (2.26-11.36)], fish, fried food and oil consumption were found to be risk factors for CRC. On multivariate analysis red meat consumption of more than 2-3 times a month (OR = 5.4; 95%CI: 1.55-19.05) and egg consumption of more than 2-3 times a week (OR = 3.67; 95%CI: 1.23-9.35) were found to be independent risk factors for the development of CRC.

CONCLUSION: Egg and red meat consumption found to be independent risk factors for CRC. Smoking, alcohol, physical activity and family history were not associated with increased risk.

Outcomes of Young Patients With Rectal Cancer From a Tertiary Cancer Care Centre in India

BACKGROUND

Carcinoma of the rectum is the fourth most common cancer in the world. The peak age of diagnosis is around the seventh decade. Rectal cancer presenting in those < 35 years old are very peculiar in that they present with adverse histologic features and more advanced stage compared with rectal cancer presenting in older patients.

MATERIALS AND METHODS

We retrospectively evaluated the patient records of young patients with rectal cancer (aged < 35 years) treated in our unit at the All India Institute from 2007 to 2013.

RESULTS

A total of 60 young patients with rectal cancer were registered in our unit during the study period. A family history of cancer was present in 3 patients. The median age at presentation was 27.5 years (range, 15-34 years). The male-to-female ratio was 1.5:1. Of the 60 patients, 52 (86.6%) presented with advanced-stage disease (stage III and IV). Mucinous, signet, papillary, and other poor-risk histologic features were seen in 33 patients (55%). The treatment intention was radical for 50 patients (83.3%). The median follow-up period was 7.3 months. Eighteen patients had documented disease progression. Distant metastasis was the most common type of failure, seen in 14 of 18 patients (77%). The median progression-free survival (PFS) was 1.4 years. The 1- and 3-year PFS rates were 66.5% and 42.0%, respectively. On univariate analysis, the Karnofsky performance status and histologic type were significant prognostic factors for PFS.

CONCLUSION

A greater proportion of poor histologic subtypes was found among young patients with rectal cancer. The high incidence of poor histologic subtypes confers a poor prognosis in these patients.

Sambar, an Indian Dish Prevents the Development of Dimethyl Hydrazine-Induced Colon Cancer: A Preclinical Study

Background:

Colon cancer (CC) is the third commonly diagnosed cancer and the second leading cause of mortality in the US when compared to India where prevalence is less. Possible reason could be the vegetarian diet comprising spices used in curry powders. Researchers believe that 70% of the cases are associated with diet. Spices have inherited a rich tradition for their flavor and medicinal properties. Researchers have been oriented towards spices present in food items for their antitumorigenic properties.

Objective:

We investigated the effects of sambar as a preventive measure for 1,2-dimethyl hydrazine (DMH)-induced CC in Wistar albino rats.

Materials and Methods:

The animals were divided into three groups (n = 6) namely control, DMH, and sambar. At the end of the experimental period, the animals were killed using anesthesia and the colons and livers were examined.

Results:

All the treatment groups exhibited a significant change in the number of aberrant crypt foci (ACF). Sambar group showed a significant change in the colonic GSH when compared to both normal and DMH groups. A significant reduction in the liver GSH was noted in the sambar group. Only sambar group showed a significant change in the liver catalase levels when compared to DMH. There was a significant reduction in the colonic nitrite in the sambar-treated group; 2.94 ± 0.29 when compared to DMH control at 8.09 ± 1.32. On the contrary, a significant rise in the liver nitrite levels was observed in the sambar-treated rats.

Conclusion:

Sambar may prevent the risk of CC when consumed in dietary proportions.

SUMMARY

Consumption of sambar significantly reduced aberrant crypt foci in DMH-induced colon cancer model

Sambar treatment prevented DMH-induced oxidative changes in the colonic tissue, indicating its antioxidant role

Sambar comprises a variety of spices that exhibited both pro- and antioxidant properties in different tissues, leading to its overall beneficial effect in this model.

Abbreviations used: ACF: aberrant crypt foci, CC: colon cancer, DMH: 1,2-dimethyl hydrazine, GSH: glutathione, IL-6: Interleukin-6, TNF-α: Tumor necrosis factor-alpha.

The Prognostic Significance of Neuroendocrine Differentiation in Colorectal Carcinomas: Our Experience

INTRODUCTION

Neuroendocrine differentiation in colorectal carcinomas, detected using immunohistochemistry and ultrastructural techniques, has been studied as a prognostic marker for invention of targeted therapy. There are a few studies done on this aspect which have shown conflicting results ranging from poor prognosis to no prognostic significance.

AIM

The aim of the study was to determine the clinical significance of neuroendocrine differentiation in colorectal carcinomas using immunohistochemical stains such as chromogranin A & synaptophysin in relation to its prognostic significance.

MATERIALS AND METHODS

A retrospective study was conducted wherein all the colorectal carcinomas, received in the Department of Pathology, over a period of 3 years, were reviewed. Neuroendocrine markers were done on 53 cases of moderately, poorly and undifferentiated adenocarcinomas. Based on the degree of immunoreactivity for these markers, tumours were divided into group 0, group 1, group 2, group 3 & group 4. Group 0 & 1 were categorized as neuroendocrine differentiation absent & group 2, 3 & 4 as present. Neuroendocrine differentiation was correlated with age, sex, grade, stage, diagnosis & survival. Follow up data of the cases was recorded.

RESULTS

Neuroendocrine differentiation was present in 18 cases (33.9%). The degree of immunoreactivity for neuroendocrine markers in present study were; group 0- 58%, 1- 7.5%, 2- 9%, 3- 13% & 4- 11%. The mean age of patients was 54 years with a slight male preponderance {M:F::1.6:1}. Most of the carcinomas with neuroendocrine differentiation belonged to Grade II (61%) & Stage II & III (83%). Neuroendocrine differentiation did not show any significant association with age, sex, location, histological type, grade, stage & survival.

CONCLUSION

The above results indicate that the presence of neuroendocrine differentiation cannot be recommended as a prognostic marker in colorectal carcinomas.

Ethnic variation in colorectal cancer risk following a positive faecal occult blood test in an English bowel cancer screening programme centre

BACKGROUND AND AIMS

The literature on colorectal cancer (CRC) screening and ethnic diversity is dominated by studies from the USA. There are no such published data from the UK bowel cancer screening programme (BCSP) population. The Wolverhampton Bowel Cancer Screening Centre serves a population of 900,000 in the Black Country and South Staffordshire. South Asians (SA) comprise 9% of the population. We aimed to determine the effects of ethnicity and sex on the risk for cancer or adenoma detected by colonoscopy following a positive faecal occult blood test over a 5-year period (2007-2011).

METHODS

Data were collected from the prospectively maintained BCSP cohort. South Asian patients were identified and compared with those of non-South Asian ethnicity, and colonoscopy outcomes were determined.

RESULTS

A total of 3552 participants underwent BCSP colonoscopy (non-South Asian=3363; SA=189). There were 271 cancers (7.6%) detected within the non-South Asian group and seven cancers (0.2%) in the South Asian population (P<0.05). The probability of colon cancer is higher [odds ratio (OR)=3.84, P<0.05] in non-South Asians compared with South Asians. Patients in the 65-70-year age group have the highest risk (OR=1.60; P<0.05) for CRC. During the study 1313 adenomas were detected. A total of 771 high-risk and intermediate-risk adenomas were detected in the non-South Asian group, and 14 were detected in the South Asian group. The risk of adenoma in non-South Asians is six times higher than in South Asians (OR=5.99, P<0.001) following positive faecal occult blood testing.

CONCLUSION

There are fewer colorectal cancers in South Asians compared with the non-South Asian population in this regional study. This is the first such study in the BCSP population.

Laparoscopic intersphincteric resection and hand-sewn coloanal anastomosis: a natural orifice specimen extraction technique

The incidence of rectal cancer in India is on the rise, and unlike in the West, predominantly younger individuals are affected. Surgery for rectal cancer has evolved over the years with the ultimate goals of sphincter preservation and better quality of life, besides oncological safety. With the routine use of magnetic resonance imaging for local staging, intersphincteric resection has become a viable alternative to abdominoperineal resection. Similarly, there is enough evidence to consider laparoscopic surgery as feasible and oncologically safe for rectal cancer. Thus laparoscopic intersphincteric resection fulfills all the objectives of modern-day rectal cancer surgery. Here we describe the technical points while performing the surgery as well as short-term results of our own series.

Dairy cattle serum and milk factors contributing to the risk of colon and breast cancers

The analysis of published epidemiological data on colon and breast cancer reveals a remarkable concordance for most regions of the world. A low incidence for both cancers has been recorded in Mongolia and Bolivia. Discrepant data, however, have been reported for India, Japan and Korea. In India, the incidence of breast cancer is significantly higher than for colon cancer, in Japan and Korea colon cancer exceeds by far the rate of breast cancer. Here, studies are summarized pointing to a species-specific risk for colon cancer after consumption of beef originating from dairy cattle. Uptake of dairy products of Bos taurus-derived milk cattle, particularly consumed at early age, is suggested to represent one of the main risk factors for the development of breast cancer. A recent demonstration of reduced breast cancer rates in individuals with lactose intolerance (Ji et al., Br J Cancer 2014; 112:149-52) seems to be in line with this interpretation. Species-specific risk factors for these cancers are compatible with the transmission of different infectious factors transferred via meat or dairy products. Countries with discordant rates of colon and breast cancer reveal a similar discordance between meat and milk product consumption of dairy cattle. The recent isolation of a larger number of novel presumably viral DNAs from serum, meat and dairy products of healthy dairy cows, at least part of them infectious for human cells, deserves further investigation. Systemic infections early in life, resulting in latency and prevention of subsequent infections with the same agent by neutralizing antibodies, would require reconsideration of ongoing prospective studies conducted in the adult population.

Intersphincteric resection and hand-sewn coloanal anastomosis for low rectal cancer: Short-term outcomes in the Indian setting

INTRODUCTION

The rectum remains a predominant subsite of colorectal cancer in the Indian population. Unique to the Indian setting are significant social repercussions associated with a permanent stoma. On account of this, many patients who are advised abdominal perineal excision of the rectum (APER) default treatment. Accurate demonstration of the intersphincteric plane with magnetic resonance imaging has made intersphincteric resection (ISR) a viable option. This study is aimed at determining the feasibility and oncological adequacy of ISR in the Indian scenario.

MATERIAL AND METHODS

All patients with low rectal cancer who underwent an ISR at the Tata Memorial Centre, from July 2013 to December 2013 were included. Patients with invasion of the external sphincter and suboptimal preoperative sphincter function were excluded. Following standard preoperative staging, patients with a threatened circumferential resection margin (CRM) and/or mesorectal nodes were given preoperative chemoradiotherapy. The oncological adequacy of the procedure was evaluated in terms of margin positivity (distal and CRMs) and lymph node yield. Short-term perioperative outcomes included 30-day mortality, postoperative morbidity, anastomotic leaks, and length of hospital stay.

RESULTS

Thirty-three patients with low rectal cancer and a median age of 38 years underwent ISR during the defined study period. Twenty-three patients (70 %) underwent open surgery whereas ten patients received a laparoscopic resection. The median blood loss and hospital stay was 300 mL and 7 days, respectively. Two patients had an involved CRM, but all distal margins were free of tumor. The quality of total mesorectal excision was satisfactory in all patients with a median lymph node yield of 9 nodes.

CONCLUSIONS

Intersphincteric resection is feasible and oncologically safe in selected patients with low rectal cancer. Long-term functional and oncological outcomes are essential before it can be considered a viable alternative to APER.

Immunohistochemical study of MUC1, MUC2 and MUC5AC in colorectal carcinoma and review of literature

BACKGROUND

A hallmark of colorectal carcinomas is their ability to secrete mucus. Aberrant expression of mucins and alterations in their glycosylation are associated with the development and progression of malignant diseases. Therefore, mucins can be used as markers of malignancy. Tumor-associated mucins are also used as immunotargets in the treatment of cancer. The present work aimed to study the patterns of expression of MUC1, MUC2 and MUC5AC in colorectal carcinoma using immunohistochemistry and their relationship with site, histological differentiation and stage.

METHODS

Fifty cases of colorectal carcinoma were chosen for the study. The histopathology slides were reviewed and blocks were retrieved. Using manual method, tissue microarray blocks were prepared. Immunostaining for MUC1, MUC2 and MUC5AC was performed on slides cut from the tissue microarray block.

RESULTS

We found that MUC1 expression was upregulated to 39 %, MUC2 expression was downregulated to 43 % and MUC5AC was aberrantly expressed in 24 % of colorectal cancer (CRC). There was a significant correlation between MUC1 positivity and tumor differentiation. As the grade increased from well to moderately differentiated, MUC1 expression increased from 11 % to 55 % (p-value 0.01). There was a statistically significant difference between MUC5AC positivity and grade of tumor (p-value 0.006). The percentage of cases showing MUC5AC expression increased as the stage of disease progressed from 1 to 4. However, there was no significant difference in MUC5AC positivity and stage of CRC (p-value 0.77).

CONCLUSION

We do not find any correlation between tumor stage or site and MUC1, MUC2 or MUC5AC expression. MUC1and MUC5AC expression showed significant correlation with tumor grade.

Rectal cancer profiling identifies distinct subtypes in India based on age at onset, genetic, epigenetic and clinicopathological characteristics

Rectal cancer is a heterogeneous disease that develops through multiple pathways characterized by genetic and epigenetic alterations. India has a comparatively higher proportion of rectal cancers and early-onset cases. We analyzed genetic (KRAS, TP53 and BRAF mutations, and MSI), epigenetic alterations (CpG island methylation detection of 10 tumor-related genes/loci), the associated clinicopathological features and survival trend in 80 primary rectal cancer patients from India. MSI was detected using BAT 25 and BAT 26 mononucleotide markers and mutation of KRAS, TP53, and BRAF V600E was detected by direct sequencing. Methyl specific polymerase chain reaction was used to determine promoter methylation status of the classic CIMP panel markers (P16, hMLH1, MINT1, MINT2, and MINT31) as well as other tumor specific genes (DAPK, RASSF1, BRCA1, and GSTP1). MSI and BRAF mutations were uncommon but high frequencies of overall KRAS mutations (67.5%); low KRAS codon 12 and a novel KRAS G15S mutation with concomitant RASSF1 methylation in early onset cases were remarkable. Hierarchical clustering as well as principal component analysis identified three distinct subgroups of patients having discrete age at onset, clinicopathological, molecular and survival characteristics: (i) a KRAS associated CIMP-high subgroup; (ii) a significantly younger MSS, CIMP low, TP53 mutant group having differential KRAS mutation patterns, and (iii) a CIMP-negative, TP53 mutated group. The early onset subgroup exhibited the most unfavorable disease characteristics with advanced stage, poorly differentiated tumors and had the poorest survival compared to the other subgroups. Genetic and epigenetic profiling of rectal cancer patients identified distinct subtypes in Indian population.

Molecular spectrum of KRAS, BRAF, and PIK3CA gene mutation: determination of frequency, distribution pattern in Indian colorectal carcinoma

Molecular evaluation of KRAS, BRAF, and PIK3CA mutation has become an important part in colorectal carcinoma evaluation, and their alterations may determine the therapeutic response to anti-EGFR therapy. The current study demonstrates the evaluation of KRAS, BRAF, and PIK3CA mutation using direct sequencing in 204 samples. The frequency of KRAS, BRAF, and PIK3CA mutations was 23.5, 9.8, and 5.9 %, respectively. Five different substitution mutations at KRAS codon 12 (G12S, G12D, G12A, G12V, and G12C) and one substitution type at codon 13 (G13D) were observed. KRAS mutations were significantly higher in patients who were >50 years, and were associated with moderate/poorly differentiated tumors and adenocarcinomas. All mutations in BRAF gene were of V600E type, which were frequent in patients who were ≤ 50 years. Unlike KRAS mutations, BRAF mutations were more frequent in well-differentiated tumors and right-sided tumors. PIK3CA-E545K was the most recurrent mutation while other mutations detected were T544I, Q546R, H1047R, G1049S, and D1056N. No significant association of PIK3CA mutation with age, tumor differentiation, location, and other parameters was noted. No concomitant mutation of KRAS and BRAF mutations was observed, while, interestingly, five cases showed concurrent mutation of KRAS and PIK3CA mutations. In conclusion, to our knowledge, this is the first study to evaluate the PIK3CA mutation in Indian CRC patients. The frequency of KRAS, BRAF, and PIK3CA was similar to worldwide reports. Furthermore, identification of molecular markers has unique strengths, and can provide insights into the pathogenic process and help optimize personalized prevention and therapy.

Feasibility of computed tomography colonography as a diagnostic procedure in colon cancer screening in India

Computed Tomography Colonography (CTC) is a medical imaging technology used in identifying polyps and colon cancer masses in the large intestine. The technique has evolved a great deal since its invention and has become a routine diagnostic procedure in Western countries due to its non invasiveness and ease of use. The objective of our study was to explore the possibility of CTC application in Indian hospitals. This paper gives an overview of the procedure and its commercial viability. The explanation begins with the domain aspects from gastroenterologist perspective, the new way of thinking in polyp classification, the technical components of CTC procedure, and how engineering solutions have helped clinicians in solving the complexities involved in colon diagnosis. The colon cancer statistics in India and the results of single institution study we carried out with retrospective data is explained. By considering the increasing number of patients developing colon malignancies, the practicality of CTC in Indian hospitals is discussed. This paper does not reveal any technical aspects (algorithms) of engineering solutions implemented in CTC.

Getting into the colon: approaches to target colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world and the second most common cause of cancer related deaths. Conventional treatment of CRC is comprised of drug (chemotherapeutic agents) administration by parenteral route, which delivers the drug to both normal as well as cancerous tissues, thus leading to numerous undesirable effects. Enormous research is going on worldwide for designing an alternative route of administration, among which oral colon-targeted drug delivery systems have gained immense attention amongst scientific community. Direct delivery of drugs at the site of action leads to an increase in the availability of drugs at the targeted region. This causes a reduction in the amount of drug required to exert same therapeutic effect, thus reducing the incidents of adverse effects. Various maneuvers (pH-dependent, time-dependent and microflora-activated systems) have been attempted by researchers for targeting drugs successfully to the colonic region by circumventing the upper part of gastrointestinal tract. This Editorial article aims to put forth an overview of the formulation technologies that have been developed for attaining colon specific drug delivery for the treatment of CRC.

Pathological stage significantly predicts survival in colorectal cancer patients: a study from two tertiary care centers in India

SUMMARY

Aims: An increase in incidence of early-onset colorectal cancer (EOCRC) in developing countries, including India, is reported recently; however, systematic analyses of clinico-pathological features and disease prognosis has seldom been undertaken. Materials & methods: We studied clinical data pertaining to 1259 colorectal adenocarcinoma patients from two tertiary cancer centers in south India. Results: Approximately 45% of patients were aged below 50 years and poor grade and late-stage tumors were significantly associated with early disease onset. Although tumor grade and stage significantly influenced disease-free survival independently, significant association between survival and age of onset or tumor location was not detected unlike previous observations. Conclusion: Given the sizeable proportion of EOCRC, implementation of the revised Bethesda guidelines may not be tenable in India. More importantly, the previous observation of EOCRC being significantly associated with poor survival could, in part, be due to a higher proportion of advanced-stage tumors.

The role of antioxidants and pro-oxidants in colon cancer

This review focuses on the roles antioxidants and pro-oxidants in colorectal cancer (CRC). Considerable evidence suggests that environmental factors play key roles in the incidence of sporadic CRC. If pro-oxidant factors play an etiological role in CRC it is reasonable to expect causal interconnections between the well-characterized risk factors for CRC, oxidative stress and genotoxicity. Cigarette smoking, a high dietary consumption of n-6 polyunsaturated fatty acids and alcohol intake are all associated with increased CRC risk. These risk factors are all pro-oxidant stressors and their connections to oxidative stress, the intestinal microbiome, intestinal microfold cells, cyclooxygenase-2 and CRC are detailed in this review. While a strong case can be made for pro-oxidant stressors in causing CRC, the role of food antioxidants in preventing CRC is less certain. It is clear that not every micronutrient with antioxidant activity can prevent CRC. It is plausible, however, that the optimal food antioxidants for preventing CRC have not yet been critically evaluated. Increasing evidence suggests that RRR-gamma-tocopherol (the primary dietary form of vitamin E) or other “non-alpha-tocopherol” forms of vitamin E (e.g., tocotrienols) might be effective. Aspirin is an antioxidant and its consumption is linked to a decreased risk of CRC.

Microsatellite instability and promoter hypermethylation in colorectal cancer in India

Microsatellite instability (MSI) is an important factor in tumor development and is a hypermutable phenotype caused by the loss of DNA mismatch repair activity. It is important to identify tumors with microsatellite instability as the patients have a better prognosis and differ with response to chemotherapy. Limited data are available on the incidence of MSI in Indian colorectal cancers (CRCs). The objectives of this study were to identify the extent of MSI in Indian CRC patients below 50 years and to determine promoter methylation status of hMLH1 and hMSH2 in relation to MSI. A total of 450 patients were diagnosed with CRC, out of which 91 individuals were recruited as per Bethesda guidelines and were tested for instability by the NCI-recommended Bethesda panel (BAT25, BAT26, D2S123, D5S346, and D17S2720) using labeled primers. The fragments were separated and analyzed on a Beckman GeXP sequencer. Promoter methylation status was determined by restriction enzyme digestion and PCR. MSI (high and low) was seen in 48.4% (44/91) of CRC patients, out of which microsatellite instability-high (MSI-H) was detected in 13.2% (12/91) and microsatellite instability-low (MSI-L) in 35.2% (32/91) and the rest were microsatellite stable (MSS), 51.6% (47/91). Majority of the MSI-H tumors were adenocarcinomas (10/12), in the rectum (8/12), and moderately or poorly differentiated (12/12). Promoter hypermethylation was seen in 75% of the MSI-H, 56.24% of MSI-L, and only 23.4% of MSS individuals. MSI (high and low) was associated with 48.4% of CRC patients, and a significantly higher proportion of promoter hypermethylation of hMLH1 and hMSH2 genes was associated with instable tumors.

Intestinal cell proliferation and senescence are regulated by receptor guanylyl cyclase C and p21

Guanylyl cyclase C (GC-C) is expressed in intestinal epithelial cells and serves as the receptor for bacterial heat-stable enterotoxin (ST) peptides and the guanylin family of gastrointestinal hormones. Activation of GC-C elevates intracellular cGMP, which modulates intestinal fluid-ion homeostasis and differentiation of enterocytes along the crypt-villus axis. GC-C activity can regulate colonic cell proliferation by inducing cell cycle arrest, and mice lacking GC-C display increased cell proliferation in colonic crypts. Activation of GC-C by administration of ST to wild type, but not Gucy2c(-/-), mice resulted in a reduction in carcinogen-induced aberrant crypt foci formation. In p53-deficient human colorectal carcinoma cells, ST led to a transcriptional up-regulation of p21, the cell cycle inhibitor, via activation of the cGMP-responsive kinase PKGII and p38 MAPK. Prolonged treatment of human colonic carcinoma cells with ST led to nuclear accumulation of p21, resulting in cellular senescence and reduced tumorigenic potential. Our results, therefore, identify downstream effectors for GC-C that contribute to regulating intestinal cell proliferation. Thus, genomic responses to a bacterial toxin can influence intestinal neoplasia and senescence.

Metastatic colorectal cancer-prolonging overall survival with targeted therapies

This review provides an updated overview of the management of metastatic colorectal cancer (CRC). With widespread application of personalized therapy based on specific patient and tumor characteristics, this will enable the oncologists to optimize overall survival while maintaining quality of life. The role of k-ras and braf testing in helping select systemic therapy that includes cetuximab or bevacizumab is clarified. Current management of metastatic CRC is based on careful attention to these finer points, explained in this article.

A review of controversies in the management of colorectal cancers

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Due to a higher incidence of CRC in the western hemisphere a significant amount of research was carried out and majority of the controversies could be resolved as far as management of CRC is concerned. Recently a number of significant advances were made in the field of CRC related to surgery, systemic therapy and radiotherapy. During the last decade we have witnessed introduction of minimally invasive surgery, incorporation of more effective newer chemotherapeutic regimes and targeted therapies and refinements in radiotherapy protocols. The demographics and clinical picture of CRC seems to be different in developing countries and there is paucity of CRC related studies from developing countries. In-order to update the practicing surgeons a review of conventional controversies of CRC surgery was performed and an update on the recent developments in the field of CRC was also presented in this article.

Modulatory efficacy of rosmarinic acid on premalignant lesions and antioxidant status in 1,2-dimethylhydrazine induced rat colon carcinogenesis

Colorectal cancer is one of the leading causes of cancer related deaths in Western countries and is becoming increasingly common in Asia. Rosmarinic acid (RA), one of the major components of polyphenol possesses attractive remedial features. The purpose of this study is to investigate the possible chemopreventive mechanism of action of RA against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the circulatory antioxidant status and colonic bacterial enzymes activities. Additionally, we analyzed the aberrant crypt foci (ACF) formation and multiplicity in the colon of experimental groups. Wistar male rats were divided into six groups. Group 1 was control rats, group 2 rats received RA (10 mg/kg b.w., p.o. everyday), rats in groups 3-6 received DMH (20 mg/kg b.w., s.c.) for the first 4 weeks. In addition to DMH, groups 4-6 received 2.5, 5, and 10 mg/kg b.w. RA respectively. The results revealed that supplementation with RA significantly reduced the formation of ACF and ACF multiplicity in DMH treated rats. Moreover RA supplementation prevented the alterations in circulatory antioxidant enzymes and colonic bacterial enzymes activities. Overall, our results showed that all three doses of RA inhibited carcinogenesis, though the effect of the intermediary dose of 5 mg/kg b.w. was more pronounced.