Epidemiology of colorectal cancer

Risk of Gastric and Colorectal Cancer After Tamoxifen Use for Breast Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

It is still controversial whether tamoxifen use for breast cancer will simultaneously cause gastric and colorectal cancer. In this study, we aimed to evaluate the association between tamoxifen use and the risk of gastric and colorectal cancer by performing a systematic review and meta-analysis.

MATERIALS AND METHODS

A comprehensive literature search for relevant studies published from 1969 to October 2013 was performed in PubMed, MEDLINE, and ISI Web of Science. Only articles in which gastric and colorectal cancer was reported after tamoxifen therapy for breast cancer were included. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using both the random-effects and fixed-effects models.

RESULTS

We found a total of 9 studies that met the inclusion criteria for the analysis of tamoxifen use and incidence of gastric and colorectal cancer. Among these studies, 7 were involved with both gastric and colorectal cancer, 1 with gastric cancer and 1 with colorectal cancer. The random-effects model results showed that tamoxifen use for breast cancer was not a risk factor for either gastric cancer (RR=0.92; 95% CI, 0.41-2.07, P=0.84) or colorectal cancer (RR=1.05; 95% CI, 0.90-1.21, P=0.54). Sensitivity analysis indicated that the duration or dose of tamoxifen use had no effect on these 2 gastrointestinal tumors (P>0.05). Stratified analysis showed that tamoxifen use was not associated with the increased risk of gastric and colorectal cancer regardless of whether the latency interval after breast cancer diagnosis was <5 or ≥5 years.

CONCLUSION

Our meta-analysis results indicate that there was no substantial increase in gastric and colorectal cancer among the tamoxifen-treated female patients.

An evaluation of treatment results of emergency versus elective surgery in colorectal cancer patients

OBJECTIVE

Colorectal cancer is still one of the most common causes of cancer related deaths in the world despite improvements in diagnosis and treatment modalities, and application of community-based screening methods. Symptoms of colorectal cancer are non-specific and usually manifest following local progression. A number of patients with advanced stage colorectal cancer present to emergency departments with obstruction as the first sign of disease without any previous symptoms. This presentation is an indication for emergency surgery that has a high rate of morbidity and mortality. In this study, we aimed to determine the factors associated with early diagnosis and survival by comparing postoperative results of colorectal cancer patients who underwent surgery under emergency or elective situation.

MATERIAL AND METHODS

Files of colorectal patients treated between 2009-2013 were retrospectively analyzed. Data on patient age, gender, operation type, intraoperative results, length of hospital stay, co-morbidities, postoperative complications and pathological results were evaluated and compared.

RESULTS

There was no statistical difference between groups in terms of age, gender, and pathology results (p>0.05). The difference between groups in terms of postoperative length of hospital stay, presence of co-morbid diseases, pathological stage, and postoperative complications was statistically significant (p<0.05). Length of hospital stay, advanced stage on admission, complications such as surgical site infection, evisceration, and anastomosis leakage rates were higher in patients in the emergency surgery group.

CONCLUSION

Risk groups should be determined in order to diagnose colorectal cancer patients at an early stage while they are still asymptomatic, and this information should be incorporated into effective screening programs. This approach will be beneficial to treatment outcomes, complication rates, length of hospital stay, and survival and treatment results.

Fruit and vegetable intake among Jordanians: results from a case-control study of colorectal cancer

BACKGROUND

Diets that include fruits and vegetables have been suggested as one way to reduce the risk of developing colorectal cancer (CRC); however, the association between consuming fruits and vegetables and CRC risk is not clear. The objective of the present study is to compare fruit and vegetable intake between 2 groups of Jordanians and further investigate this possible relationship.

METHODS

A history of fruit and vegetable consumption was obtained from 220 people with CRC and 281 healthy controls, all of whom were from Jordan. Both groups were matched for age, sex, occupation, and marital status. Fruit and vegetable consumption was quantified for the previous 12 months in both groups.

RESULTS

Total vegetable intake was associated with the risk of developing CRC. Consuming 5 servings of vegetables a day decreased the risk of developing CRC when compared with no more than 1 serving a day (odds ratio [OR] = 0.23; 95% confidence interval [CI]: 0.55-0.97). A significant direct relationship between CRC risk and consuming cauliflower and cabbage was found; however, no association was found for raw or cooked leafy vegetable and other vegetable types. Consuming several types of fruits also revealed no association with risk of CRC, although an increased intake of dates and figs was associated with a reduced risk of developing CRC. The ORs for the highest intake of servings compared with the lowest intake were 0.48 (95% CI: 0.27-0.87; P = .004) for dates and 0.604 (95% CI: 0.35-1.06; P = .003) for figs.

CONCLUSIONS

Consuming fruits and vegetables did not significantly correlate with a lowered incidence of CRC. However, a trend of protection was detected for several types of fruits and vegetables.

Optimal delivery of colorectal cancer follow-up care: improving patient outcomes

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. With population aging and increases in survival, the number of CRC survivors is projected to rise dramatically. The time following initial treatment is often described as a period of transition from intensive hospital-based care back into "regular life." This review provides an overview of recommended follow-up care for people with CRC who have been treated with curative intent, as well as exploring the current state of the research that underpins these guidelines. For patients, key concerns following treatment include the development of recurrent and new cancers, late and long-term effects of cancer and treatment, and the interplay of these factors with daily function and general health. For physicians, survivorship care plans can be a tool for coordinating the surveillance, intervention, and prevention of these key patient concerns. Though much of the research in cancer survivorship to date has focused on surveillance for recurrent disease, many national guidelines differ in their conclusions about the frequency and timing of follow-up tests. Most CRC guidelines refer only briefly to the management of side effects, despite reports that many patients have a range of ongoing physiological, psychosocial, and functional needs. Guidance for surveillance and intervention is often limited by a small number of heterogeneous trials conducted in this patient group. However, recently released survivorship guidelines emphasize the potential for the effectiveness of secondary prevention strategies, such as physical activity, to improve patient outcomes. There is also emerging evidence for the role of primary care providers and nurse coordinated care to support the transition and increase the cost-effectiveness of follow-up. The shift in focus from recurrence alone to the assessment and management of a range of survivorship issues will be important for ensuring that this growing group of patients achieves optimal outcomes.

Comparing survival and recurrence in curative stage I to III colorectal cancer in transfused and nontransfused patients

Evidence of the association between blood transfusions and its impact on prognostic outcomes in patients who undergo curative resection of colorectal cancer remains controversial. The aim of this study was to determine whether receiving peri-operative blood transfusions during curative colorectal cancer resection affected overall survival, cancer-related survival, and cancer recurrence. This retrospective study was undertaken at The Royal Brisbane and Women's Hospital, Australia, between 1984 and 2004. The outcomes of 1370 patients undergoing curative colorectal cancer resection for TNM stage I to III were analyzed. Four hundred twenty three patients (30.9%) required transfusion and 947 patients (69.1%) did not. Peri-operative transfusion was associated with higher rates of cancer recurrence on multivariate analysis (P = 0.024, RR, 1.257, 95% CI, 1.03-1.53); however, it was not independently associated with poorer overall or cancer-related survival. Where the aim is curative resection, this study contributes to a body of evidence that blood transfusions may be associated with poorer outcomes.

Survival and tolerability of liver radioembolization: a comparison of elderly and younger patients with metastatic colorectal cancer

AIM

To evaluate the outcomes among elderly (≥70 years) and younger patients (<70 years) with liver-dominant metastatic colorectal cancer (mCRC) who received radioembolization (RE) as salvage therapy.

METHODS

A retrospective review of 107 consecutive patients with unresectable mCRC treated with RE after failing first- and second-line chemotherapy.

RESULTS

From 2002 to 2012, 44 elderly and 63 younger (<70 years) patients received RE. Patients had similar previous extensive chemotherapy and liver-directed interventions. Using modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria, either a stable or a partial radiographical response was seen in 65.8% of the younger compared with 76.5% of the elderly patients. RE was equally well tolerated in both groups and common procedure-related adverse events were predominantly grade 1-2 and of short duration. No significant difference was found with regard to overall median survival between younger [8.4 months; 95% confidence interval (CI) = 6.2-10.6] or elderly patients (8.2 months; 95% CI = 5.9-10.5, P = 0.667). The presence of extrahepatic disease at the time of RE was associated with a significantly worse median survival in both groups.

CONCLUSION

Radioembolization appears to be as well tolerated and effective for the elderly as it is for younger patients with mCRC. Age alone should not be a discriminating factor for the use of radioembolization in the management of mCRC patients.

Efficacy and complications in the use of self-expanding colonic stents: an analysis of 15 years' experience

OBJECTIVE

To analyze the efficacy and safety of the procedure for placing self-expanding stents in the colon. To evaluate the factors associated with complications. To analyze the dose of radiation delivered in the procedure.

MATERIAL AND METHODS

This was a retrospective descriptive study of 478 procedures done at a single center to place self-expanding metallic stents in the colon. A total of 423 nitinol stents and 79 stainless steel stents were placed. We included all colonic obstructions, of which 446 had malignant causes and 8 had benign causes. We excluded patients with intestinal perforation, severe colonic bleeding, short life expectancy, or lesions located less than 5 cm from the anus. We collected the dosimetric data and analyzed the technical success, clinical success, and complications during follow-up.

RESULTS

The procedure was a technical success in 92.26% of cases (n=441) and a clinical success in 78.45% (n=375); complications occurred during follow-up in 18.5% of cases. Complications occurred more frequently with the stainless steel stents than with the nitinol stents (OR: 3.2; 95% CI: 1.8-5.7). The mean value of the dose area product was 35 Gy*cm(2). When instead of being done by the interventional radiologist working together with an endoscopist the procedure was done exclusively by the interventional radiologist, the time under fluoroscopy (p=0.001), dose area product (p=0.029), and kinetic energy released per unit mass (p=0.001) were greater.

CONCLUSION

The procedure for placing self-expanding colonic stents is efficacious and safe with an acceptable rate of complications. The doses of radiation delivered were low, and the radiation doses and time under fluoroscopy were lower when the procedure was done together with an endoscopist.

The surgical treatment of patients with colorectal cancer and liver metastases in the setting of the "liver first" approach

A surgical resection is the only curative method in the therapy of colorectal carcinoma and liver metastases. Along with the development of interventional radiological techniques the indications for surgery widen. The number of metastases and patients age should not present a contraindication for surgical resection. However, there are still some doubts concerns what to resect first in cases of synchronous colorectal carcinoma and liver metastases and how to ensure the proper remnant liver volume in order to avoid postoperative liver failure and achieve the best results. Through this review the surgical therapy of colorectal carcinoma and liver metastases was revised in the setting of "liver-first" approach and the problem of ensuring of remnant liver volume.

Epidemiology and clinical findings of colorectal carcinoma in two tertiary care hospitals in Benghazi, Libya

AIM

The aim is to determine the pattern of patients with colorectal cancer (CRC) seen in two tertiary hospitals in Benghazi, Libya.

MATERIALS AND METHODS

The cohort includes all patients of CRC who were presented between January 2007 and December 2009 to the Oncology Department, Aljomhoria Hospital and 7(th) October Hospital, Benghazi. Patient's age, gender, clinical presentation, location of cancer involvement, and histopathologic diagnosis were reviewed. Tumor staging was carried out according to Astler Coller modification of Duke's system, dividing it into stage A to C depending upon the extent of local involvement and regional node spread. Stage D was added to account for distant metastasis in accordance with Turnbull modification.

RESULTS

A total of 152 patients with CRC were included, 84 males (55%) and 68 females (45%) with a male to female ratio of 1.2:1.0. The mean age was 57.4 ± 12.92 years (range 21-87 years). 18 (11.8%) patients were below 40 years of age. The most common presenting symptoms were rectal bleeding and abdominal pain and were together present in 71% of the patients. The majority (67.8%) of tumors arise from rectum and sigmoid colon. More than one-third of the patients had poorly differentiated adenocarcinoma. Sixty patients (39.5%) presented in stage D, whereas 30.9% (47/152) and 29.6% (45/152) of patients were in stage B and stage C, respectively. None of the patients had stage A at presentation. The radiological evaluation showed presence of liver metastasis in 14 patients (9.2%) and pulmonary metastasis in two patients (1.3%). Anemia was found in 56 patients (36.8%). It was more common in females (P = 0.01) and in the right sided tumors (66.7%) than left sided tumors (29.5%) (P = 0.001).

CONCLUSION

The majority of CRC patients in Benghazi were diagnosed in locally advanced or metastatic stage. In order to achieve early detection of CRC, a comprehensive cancer education program and screening of high risk population for CRC should be considered in this part of Libya.

Immune response, safety, and survival and quality of life outcomes for advanced colorectal cancer patients treated with dendritic cell vaccine and cytokine-induced killer cell therapy

Purpose. To determine the immune response after dendritic cell (DC) vaccine and cytokine-induced killer cells (CIK) therapy and assess its associated toxicity, survival benefit, and changes in the quality of life (QOL) of advanced colorectal cancer (CRC) patients. Methods. We recruited 100 patients with unresectable CRC orrelapsed CRC after surgery who received DC vaccine and CIK cells (group immunotherapy, group I), and, as a control, 251 patients who had similar characteristics and underwent similar treatments, except for this immunotherapy (group nonimmunotherapy, group NI). After a follow-up period of 489.2 ± 160.4 days, overall survival (OS) of the two groups was compared using the Kaplan-Meier method. Results. In group I, 62% of patients developed a positive delayed type hypersensitivity response, and most patients showed an improvement in physical strength (75.2%), appetite (74.2%), sleeping (72.1%), and body weight (70.1%). Adverse events were fever (29.5%), insomnia (19.2%), anorexia (9.1%), sore joints (5.4%), and skin rash (1.0%). No toxicity was observed in patients treated with DC vaccine and CIK therapy. OS was significantly longer in group I than in group NI (P = 0.043). Conclusion. DC vaccine and CIK therapy were safe and could induce an immune response against CRC, thereby improving QOL and prolonging OS.

The detection of the methylated Wif-1 gene is more accurate than a fecal occult blood test for colorectal cancer screening

BACKGROUND

The clinical benefit of guaiac fecal occult blood tests (FOBT) is now well established for colorectal cancer screening. Growing evidence has demonstrated that epigenetic modifications and fecal microbiota changes, also known as dysbiosis, are associated with CRC pathogenesis and might be used as surrogate markers of CRC.

PATIENTS AND METHODS

We performed a cross-sectional study that included all consecutive subjects that were referred (from 2003 to 2007) for screening colonoscopies. Prior to colonoscopy, effluents (fresh stools, sera-S and urine-U) were harvested and FOBTs performed. Methylation levels were measured in stools, S and U for 3 genes (Wif1, ALX-4, and Vimentin) selected from a panel of 63 genes; Kras mutations and seven dominant and subdominant bacterial populations in stools were quantified. Calibration was assessed with the Hosmer-Lemeshow chi-square, and discrimination was determined by calculating the C-statistic (Area Under Curve) and Net Reclassification Improvement index.

RESULTS

There were 247 individuals (mean age 60.8±12.4 years, 52% of males) in the study group, and 90 (36%) of these individuals were patients with advanced polyps or invasive adenocarcinomas. A multivariate model adjusted for age and FOBT led to a C-statistic of 0.83 [0.77-0.88]. After supplementary sequential (one-by-one) adjustment, Wif-1 methylation (S or U) and fecal microbiota dysbiosis led to increases of the C-statistic to 0.90 [0.84-0.94] (p = 0.02) and 0.81 [0.74-0.86] (p = 0.49), respectively. When adjusted jointly for FOBT and Wif-1 methylation or fecal microbiota dysbiosis, the increase of the C-statistic was even more significant (0.91 and 0.85, p<0.001 and p = 0.10, respectively).

CONCLUSION

The detection of methylated Wif-1 in either S or U has a higher performance accuracy compared to guaiac FOBT for advanced colorectal neoplasia screening. Conversely, fecal microbiota dysbiosis detection was not more accurate. Blood and urine testing could be used in those individuals reluctant to undergo stool testing.

Interaction of dietary fatty acids with tumour necrosis factor family cytokines during colon inflammation and cancer

Intestinal homeostasis is precisely regulated by a number of endogenous regulatory molecules but significantly influenced by dietary compounds. Malfunction of this system may result in chronic inflammation and cancer. Dietary essential n-3 polyunsaturated fatty acids (PUFAs) and short-chain fatty acid butyrate produced from fibre display anti-inflammatory and anticancer activities. Both compounds were shown to modulate the production and activities of TNF family cytokines. Cytokines from the TNF family (TNF- α, TRAIL, and FasL) have potent inflammatory activities and can also regulate apoptosis, which plays an important role in cancer development. The results of our own research showed enhancement of apoptosis in colon cancer cells by a combination of either docosahexaenoic acid (DHA) or butyrate with TNF family cytokines, especially by promotion of the mitochondrial apoptotic pathway and modulation of NF κ B activity. This review is focused mainly on the interaction of dietary PUFAs and butyrate with these cytokines during colon inflammation and cancer development. We summarised recent knowledge about the cellular and molecular mechanisms involved in such effects and outcomes for intestinal cell behaviour and pathologies. Finally, the possible application for the prevention and therapy of colon inflammation and cancer is also outlined.

Genetic unraveling of colorectal cancer

Colorectal cancer is a common disease in both men and women (being the third most common cancer in men and the second most common among women) and thus represents an important and serious public health issue, especially in the western world. Although it is a well-established fact that cancers of the large intestine produce symptoms relatively earlier at a stage that can be easily cured by resection, a large number of people lose their lives to this deadly disease each year. Recent times have seen an important change in the incidence of colorectal cancer in different parts of the world. The etiology of colorectal cancer is multifactorial and is likely to involve the actions of genes at multiple levels along the multistage carcinogenesis process. Exhaustive efforts have been made out in the direction of unraveling the role of various environmental factors, gene mutations, and polymorphisms worldwide (as well as in Kashmir-"a valley of gastrointestinal cancers") that have got a role to play in the development of this disease so that antitumor drugs could be developed against this cancer, first, and, finally, the responsiveness or resistance to these agents could be understood for combating this global issue.

Effects of honey and its mechanisms of action on the development and progression of cancer

Honey is a natural product known for its varied biological or pharmacological activities-ranging from anti-inflammatory, antioxidant, antibacterial, antihypertensive to hypoglycemic effects. This review article focuses on the role of honey in modulating the development and progression of tumors or cancers. It reviews available evidence (some of which is very recent) with regards to the antimetastatic, antiproliferative and anticancer effects of honey in various forms of cancer. These effects of honey have been thoroughly investigated in certain cancers such as breast, liver and colorectal cancer cell lines. In contrast, limited but promising data are available for other forms of cancers including prostate, bladder, endometrial, kidney, skin, cervical, oral and bone cancer cells. The article also underscores the various possible mechanisms by which honey may inhibit growth and proliferation of tumors or cancers. These include regulation of cell cycle, activation of mitochondrial pathway, induction of mitochondrial outer membrane permeabilization, induction of apoptosis, modulation of oxidative stress, amelioration of inflammation, modulation of insulin signaling and inhibition of angiogenesis. Honey is highly cytotoxic against tumor or cancer cells while it is non-cytotoxic to normal cells. The data indicate that honey can inhibit carcinogenesis by modulating the molecular processes of initiation, promotion, and progression stages. Thus, it may serve as a potential and promising anticancer agent which warrants further experimental and clinical studies.

Radiation risks associated with serial imaging in colorectal cancer patients: Should we worry?

To provide an overview of the radiation related cancer risk associated with multiple computed tomographic scans required for follow up in colorectal cancer patients. A literature search of the PubMed and Cochrane Library databases was carried out and limited to the last 10 years from December 2012. Inclusion criteria were studies where computed tomographic scans or radiation from other medical imaging modalities were used and the risks associated with ionizing radiation reported. Thirty-six studies were included for appraisal with no randomized controlled trials. Thirty-four of the thirty-six studies showed a positive association between medical imaging radiation and increased risk of cancer. The radiation dose absorbed and cancer risk was greater in children and young adults than in older patients. Most studies included in the review used a linear, no-threshold model to calculate cancer risks and this may not be applicable at low radiation doses. Many studies are retrospective and ensuring complete follow up on thousands of patients is difficult. There was a minor increased risk of cancer from ionizing radiation in medical imaging studies. The radiation risks of low dose exposure (< 50 milli-Sieverts) are uncertain. A clinically justified scan in the context of colorectal cancer is likely to provide more benefits than harm but current guidelines for patient follow up will need to be revised to accommodate a more aggressive approach to treating metastatic disease.

Aberrant methylation of NPY, PENK, and WIF1 as a promising marker for blood-based diagnosis of colorectal cancer

Background

DNA methylation is a well-known epigenetic mechanism involved in epigenetic gene regulation. Several genes were reported hypermethylated in CRC, althought no gene marker was proven to be individually of sufficient sensitivity or specificity in routine clinical practice. Here, we identified novel epigenetic markers and assessed their combined use for diagnostic accuracy.

Methods

We used methylation arrays on samples from several effluents to characterize methylation profiles in CRC samples and controls, as established by colonoscopy and pathology findings, and selected two differentially methylated candidate epigenetic genes (NPY, PENK). To this gene panel we added WIF, on the basis of being reported in literature as silenced by promoter hypermethylation in several cancers, including CRC. We measured their methylation degrees by quantitative multiplex-methylation specific PCR (QM-MSP) on 15 paired carcinomas and adjacent non-cancerous colorectal tissues and we subsequently performed a clinical validation on two different series of 266 serums, subdivided in 32 CRC, 26 polyps, 47 other cancers and 161 with normal colonoscopy. We assessed the results by receiver operating characteristic curve (ROC), using cumulative methylation index (CMI) as variable threshold.

Results

We obtained CRC detection on tissues with both sensitivity and specificity of 100%. On serum CRC samples, we obtained sensitivity/specificity values of, e.g., 87%/80%, 78%/90% and 59%/95%, and negative predictive value/positive predictive value figures of 97%/47%, 95%/61% and 92%/70%. On serum samples from other cancers we obtained sensitivity/specificity of, e.g, 89%/25%, 43%/80% and 28%/91%.

Conclusions

We showed the potential of NPY, PENK, and WIF1 as combined epigenetic markers for CRC diagnosis, both in tissue and serum and tested their use as serum biomarkers in other cancers. We optimized a QM-MSP for simultaneously quantifying their methylation levels. Our assay can be an effective blood test for patients where CRC risk is present but difficult to assess (e.g. mild symptoms with no CRC family history) and who would therefore not necessarily choose to go for further examination. This panel of markers, if validated, can also be a cost effective screening tool for the detection of asymptomatic cancer patients for colonoscopy.

The functional significance of microRNA-29c in patients with colorectal cancer: a potential circulating biomarker for predicting early relapse

BACKGROUND

The recurrence of colorectal cancer (CRC) is frequent within the first year of curative resection surgery and may be unavoidable. microRNAs have been suggested to play roles in carcinogenesis and cancer recurrence. We recently identified microRNA-29c (miRNA-29c) as a predictor of early recurrence in CRC. In the present study, we further investigated the functions and serum level of miRNA-29c in relation to early recurrence of CRC.

METHODS

First we further confirmed overexpression of miRNA-29c in non-early relapse subjects. Gain-of-function in vitro studies were used to evaluate the effect of miRNA-29c on cell proliferation, migration, invasion, and cell cycle progression. The colon cancer cell line Caco2 and a stable clone overexpressing miRNA-29c were xenografted to evaluate the in vivo effect of miRNA-29c in null mice. Finally, circulating miRNA-29c was investigated as a potential biomarker for identifying early relapse.

RESULTS

miRNA-29c expression significantly decreased during early relapse compared to non-early relapse in UICC stage II and III CRC patients (P = 0.021). In vitro studies showed that overexpression of miRNA-29c inhibited cell proliferation and migration. The cell cycle studies also revealed that miRNA-29c caused an accumulation of the G1 and G2 population. In vivo, miRNA-29c suppressed tumor growth in null mice. The serum miRNA-29c increased significantly in early relapsed patients compared to non-early elapsed patients (P = 0.012).

CONCLUSIONS

miRNA-29c shows anti-tumorigenesis activity, and preoperative circulating miRNA-29c levels can be used to predict postoperative early relapse of CRC.

Recent advances and significance of intra-arterial infusion chemotherapy in non-resectable colorectal liver metastasis

In era of systemic chemotherapy for colorectal liver metastasis (CLM), role of hepatic intraarterial infusion chemotherapy (HAIC) remains important. We examined treatment effects of HAIC in 36 patients with non-resectable CLM using 5-FU or CPT-11. Tumor response was complete response (CR) in 4, partial response (PR) in 19, stable disease (SD) in 6, and progressive disease (PD) in 7. Tumor control rate was 81% and response rate was 64%. Six patients showed catheter-related complications. Median survival period was 62 months in CR, and 25 with PR. HAIC has a major impact in high chemotherapy response and prolonging survival.

Changing trends of colorectal carcinoma in Nepalese young adults

INTRODUCTION

Colorectal carcinoma (CRC) is the most common gastrointestinal malignancy in the older population, but it is also quite frequent among young adults in developing countries. The aim of this study was to update the trends of clinicopathological features of CRC in young Nepalese.

METHODS

A retrospective comparative study on the data retrieved from the surgical records of all patients between 20 to 39 years of age with CRC was carried out for periods of 5 years each from 1999 to 2003 (early) and 2004 to 2008 (recent), treated at Tribhuvan University Teaching Hospital, Kathmandu, Nepal.

RESULTS

The number of young adults with CRC increased from 28 to 34. However, the proportion of young patients in both groups was 28% of all CRC patients. The mean ages were 34±4.7 and 31.8±5.1 years in early and recent 5 years, respectively, and the male female ratio changed from 2:3 to 4:3. Abdominal pain as the most common presenting symptom was replaced by bleeding per rectum in recent years. The mean duration from onset of symptoms to seeking medical advice decreased from 7.8 months to 5.6 months in recent years. More patients (85.3%) were subjected to endoscopic examination in recent years than early years (60.7%) and right colonic cancer increased from 10.7% to 26.5%. However, the rectum was the commonest site in both early (71.4%) and recent (50%) groups. CRC was detected significantly at an earlier stage (7.1% vs 32.4%) in recent years with large proportion of modified Dukes B stage. Poorly differentiated adenocarcinoma was the predominant histology in both groups (50% vs 60.7%). Curative resection had risen in recent years (39.3% vs 73.6%).

CONCLUSION

CRC among Nepalese young adults accounts for a high incidence (28%) of all CRC cases. Although right sided colonic cancer has been increasing, rectum is the commonest site. There is also an increasing trend for diagnosis at earlier stages of the disease which can be treated with curative intent.

Potent anticancer activity of cystine-based dipeptides and their interaction with serum albumins

BACKGROUND

Cancer is a severe threat to the human society. In the scientific community worldwide cancer remains a big challenge as there are no remedies as of now. Cancer is quite complicated as it involves multiple signalling pathways and it may be caused by genetic disorders. Various natural products and synthetic molecules have been designed to prevent cell proliferation. Peptide-based anticancer drugs, however, are not explored properly. Though peptides have their inherent proteolytic instability, they could act as anticancer agents.

RESULTS

In this present communication a suitably protected cystine based dipeptide and its deprotected form have been synthesized. Potent anticancer activities were confirmed by MTT assay (a laboratory test and a standard colorimetric assay, which measures changes in colour, for measuring cellular proliferation and phase contrast images. The IC50 value, a measure of the effectiveness of a compound in inhibiting biological or biochemical function, of these compounds ranges in the sub-micromolar level. The binding interactions with serum albumins (HSA and BSA) were performed with all these molecules and all of them show very strong binding at sub-micromolar concentration.

CONCLUSIONS

This study suggested that the cystine-based dipeptides were potential anticancer agents. These peptides also showed very good binding with major carrier proteins of blood, the serum albumins. We are currently working on determining the detailed mechanism of anticancer activity of these molecules.

Meta-analyses of colorectal cancer risk factors

PURPOSE

Demographic, behavioral, and environmental factors have been associated with increased risk of colorectal cancer (CRC). We reviewed the published evidence and explored associations between risk factors and CRC incidence.

METHODS

We identified 12 established non-screening CRC risk factors and performed a comprehensive review and meta-analyses to quantify each factor's impact on CRC risk. We used random-effects models of the logarithms of risks across studies: inverse-variance weighted averages for dichotomous factors and generalized least squares for dose-response for multi-level factors.

RESULTS

Significant risk factors include inflammatory bowel disease (RR = 2.93, 95 % CI 1.79-4.81); CRC history in first-degree relative (RR = 1.80, 95 % CI 1.61-2.02); body mass index (BMI) to overall population (RR = 1.10 per 8 kg/m(2) increase, 95 % CI 1.08-1.12); physical activity (RR = 0.88, 95 % CI 0.86-0.91 for 2 standard deviations increased physical activity score); cigarette smoking (RR = 1.06, 95 % CI 1.03-1.08 for 5 pack-years); and consumption of red meat (RR = 1.13, 95 % CI 1.09-1.16 for 5 servings/week), fruit (RR = 0.85, 95 % CI 0.75-0.96 for 3 servings/day), and vegetables (RR = 0.86, 95 % CI 0.78-0.94 for 5 servings/day).

CONCLUSIONS

We developed a comprehensive risk modeling strategy that incorporates multiple effects to predict an individual's risk of developing CRC. Inflammatory bowel disease and history of CRC in first-degree relatives are associated with much higher risk of CRC. Increased BMI, red meat intake, cigarette smoking, low physical activity, low vegetable consumption, and low fruit consumption were associated with moderately increased risk of CRC.

Four years incidence rate of colorectal cancer in Iran: a survey of national cancer registry data - implications for screening

INTRODUCTION

Design and implementation of screening programs in each country must be based on epidemiological data. Despite the relatively high incidence of CRC, there is no nationwide comprehensive program for screening in Iran. This study was designed to investigate national CRC data and help to determine guidelines for screening.

METHODS

Incidence data used in this study were obtained from Iranian annual of National Cancer Registration report. Age standardized rates (ASR)were calculated using world standard population and were categorized by age, sex, anatomic subsite and morphology of tumor. Data were analyzed using SPSS.V.13 and Open Source Epidemiologic Statistics for Public Health software (OpenEpi v.2.3.1).

RESULTS

A quarter of cases were less than 50 years of age. The majority of tumors were detected in the colon. The overall ASR in the four years period was 38.0 per 100000 and was higher for men compared women (P<0.05). Incidence rate of colorectal cancer increased with age.

CONCLUSION

Results of present study indicated that incidence of colorectal cancer is relatively high in Iran. Incidence of CRC in people under 50 years and in rectum were reported higher than other countries that related etiologic factors should be investigate in further studies. According to the increasing of ASR after age 50 years, it seems that onset of screening at age 50 would be appropriate.

Probiotic metabolites as epigenetic targets in the prevention of colon cancer

Dietary interventions for preventing colon cancer have recently attracted increased attention from researchers and clinicians. The probiotics have emerged as potential therapeutic agents but are also regarded as healthy dietary supplements for nutrition and health applications. The probiotic metabolome may interfere with various cellular and molecular processes, including the onset and progression of colon cancer. Probiotic metabolites may lead to the modulation of diverse cellular signal transduction and metabolic pathways. The gut microbial metabolites (organic acids, bacteriocins, peptides, etc.) have been noted to interact with multiple key targets in various metabolic pathways that regulate cellular proliferation, differentiation, apoptosis, inflammation, angiogenesis, and metastasis. Progress in this field suggests that epigenetic alterations will be widely used in the near future to manage colon cancer. The present review provides insights into the molecular basis of the therapeutic applications and the chemopreventive activities of certain probiotic metabolites, with emphasis on the interaction between these metabolites and the molecular signaling cascades that are considered to be epigenetic targets in preventing colon cancer.

Loss of expression of DNA mismatch repair proteins in aberrant crypt foci identified in vivo by magnifying colonoscopy in subjects with hereditary nonpolyposic and sporadic colon rectal cancer

PURPOSE

The aims of this study are to characterize the frequency, density, and distribution of aberrant crypt foci (ACF) and its histological features and to determine the frequency of loss of expression of DNA mismatch repair (MMR) proteins of subjects with hereditary nonpolyposic colorectal cancer (HNPCC) and sporadic colon rectal cancer (CRC).

METHODS

Patients with HNPCC, first-degree relatives of subjects with HNPCC, sporadic CRC, and average risk subjects of sporadic CRC were included prospectively. Total colonoscopy with chromoendoscopy using methylene blue 0.5% and magnification in the right colon (cecum and 20 cm of the ascending colon) and in the left colon (rectum) was performed; loss of expression of MLH1 and MSH2 was evaluated by immunohistochemistry in confirmed ACF.

RESULTS

Fifty-two subjects were included. Thirty-eight of the 119 ACF detected by endoscopy were biopsied. In 14 of the 38 specimens (36.8%), ACF were confirmed by histology (Cohen's kappa, 0.44). In subjects with HNPCC, ACF were identified more frequently in the right segment of the colon than in the left (73.1% vs. 26%); in contrast, ACF predominated in the left segment of the colon (89.3% vs. 10.6%) in subjects with sporadic CRC. There was a loss of MLH1 expression in ACF in subjects with HNPCC.

CONCLUSIONS

In HNPCC, we found a greater density of ACF in the right colon, and in sporadic CRC, greater density in the left. ACF present loss in the expression of DNA MMR protein and can be used as an early marker in patients with a risk of HNPCC in whom carcinogenesis appears to be accelerated.

Bax expression is a candidate prognostic and predictive marker of colorectal cancer

OBJECTIVE

Since the anti-tumor activity of 5-fluorouracil (5-FU) is due to induction of apoptosis, we assessed the value of expression of key apoptotic molecules (Bax, Bcl-2 and p53) in predicting the efficacy of 5-FU therapy for colorectal adenocarcinomas (CRCs).

METHODS

Archival tissues of CRCs from 56 patients who received a complete regimen of 5-FU-based chemotherapy after surgery, and 56 patients matched for age, gender, ethnicity, tumor stage, tumor location, and tumor differentiation who had undergone only surgery (without any pre- or post-surgery therapy), were evaluated for immunophenotypic expression of Bax, Bcl-2, and p53. Also, these CRCs were evaluated for Bax mutations. The predictive capacity or prognostic value of these markers was assessed by estimating overall survival.

RESULTS

The majority of low Bax expressing CRCs have exhibited mutations at the G (8) tract. There was no significant difference in overall survival rates between the categories of surgery alone and 5-FU-treated patients. However, a better survival was observed for patients who received chemotherapy when their CRCs had low Bax/Bcl2 ratio (HR, 1.55; 95% CI: 1.46-31.00). Patients who received surgery alone and whose CRCs lacked Bax expression had 5.33 times higher mortality than those with high Bax expression (95% CI: 1.78-15.94), when controlled for tumor stage and other confounders. Bcl-2 and nuclear p53 accumulation had no predictive value in either patient group.

CONCLUSION

These findings are the first to demonstrate that high Bax expression is a good prognosticator for patients who underwent surgery alone, and that patient with low Bax/Bcl-2 expression ratio benefit from 5-FU-based adjuvant therapies.

Characterization of a large panel of patient-derived tumor xenografts representing the clinical heterogeneity of human colorectal cancer

PURPOSE

Patient-derived xenograft models are considered to represent the heterogeneity of human cancers and advanced preclinical models. Our consortium joins efforts to extensively develop and characterize a new collection of patient-derived colorectal cancer (CRC) models.

EXPERIMENTAL DESIGN

From the 85 unsupervised surgical colorectal samples collection, 54 tumors were successfully xenografted in immunodeficient mice and rats, representing 35 primary tumors, 5 peritoneal carcinoses and 14 metastases. Histologic and molecular characterization of patient tumors, first and late passages on mice includes the sequence of key genes involved in CRC (i.e., APC, KRAS, TP53), aCGH, and transcriptomic analysis.

RESULTS

This comprehensive characterization shows that our collection recapitulates the clinical situation about the histopathology and molecular diversity of CRC. Moreover, patient tumors and corresponding models are clustering together allowing comparison studies between clinical and preclinical data. Hence, we conducted pharmacologic monotherapy studies with standard of care for CRC (5-fluorouracil, oxaliplatin, irinotecan, and cetuximab). Through this extensive in vivo analysis, we have shown the loss of human stroma cells after engraftment, observed a metastatic phenotype in some models, and finally compared the molecular profile with the drug sensitivity of each tumor model. Through an experimental cetuximab phase II trial, we confirmed the key role of KRAS mutation in cetuximab resistance.

CONCLUSIONS

This new collection could bring benefit to evaluate novel targeted therapeutic strategies and to better understand the basis for sensitivity or resistance of tumors from individual patients.

Impact of preoperative targeted therapy on postoperative complications after resection of colorectal liver metastases

PURPOSE

The impact of chemotherapy (CTx) on morbidity after liver resection for colorectal metastases (CRC-LM) has been increasingly investigated during recent years. Biologic agents like bevacizumab (BEV) or cetuximab (CET) are now added as "targeted therapy" (TT), also in neoadjuvant settings. Initial series could demonstrate the safety of those regimens in liver resection but data are still scarce. We evaluated the impact of CTx with BEV or CET (CTx + TT) on perioperative morbidity and mortality.

METHODS

Two hundred thirty-seven patients who underwent liver resections for CRC-LM after chemotherapy before surgery since 1999 were included. One hundred eighty-five patients (78%) had preoperative CTx regimen without biologic agents (fluoropyrimidine-, oxaliplatin-, or irinotecan-based) and 52 (22%) had CTx + TT (39 BEV, 11 CET, 2 CET/BEV). After preoperative CTx + TT, a time interval of at least 4-6 weeks and a residual liver volume of >35% before surgery were required.

RESULTS

Hemihepatectomy or more was performed in about half of the patients. The median amount of intraoperatively transfused blood was 0 ml in both groups (p = 0.34). Overall mortality was 1.7% and slightly elevated in patients with CTx + TT (3.8% vs. 1.1%, p = 0.17). Any complication occurred in (CTx + TT vs. CTx) 52% and 46%, respectively (p = 0.47). The rates of liver failure (9.6% vs. 9.7%, p = 0.98), infectious complications such as wound infection (19% vs. 16%, p = 0.62) and abdominal abscess (8% vs. 6.5%, p = 0.71), as well as the rate of relaparotomies (11.5% vs. 7.0%, p = 0.29) showed no significant differences between the groups with TT or without. In multivariate analyses, neither type nor duration of CTx nor the time interval between CTx and surgery showed any influence on complication rates.

CONCLUSIONS

Our data confirm the safety of targeted therapy before liver resection for CRC-LM. This effect may in part be due to our treatment policy (time interval to resection and residual liver volume) after intensive preoperative CTx.

Thermostable direct hemolysin diminishes tyrosine phosphorylation of epidermal growth factor receptor through protein kinase C dependent mechanism

BACKGROUND

Adequate evidence mounts to the fact that several bacteria and their toxins have protective or curative roles in colorectal cancers. Thermostable direct hemolysin (TDH), produced by Vibrio parahaemolyticus, down regulates cell proliferation in colon carcinoma cell lines. TDH induces Ca2+ influx from an extracellular environment accompanied by protein kinase C phosphorylation. Activated protein kinase C inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR), the rational target of anti-colorectal cancer therapy.

METHODS

Immunoblotting analyses were performed to ascertain protein kinase C activation, EGFR status, EGFR phosphorylation and mitogen activated protein kinase (MAPK) activity. Flow cytometry analysis and ELISA reconfirmed tyrosine phosphorylation of EGFR and ERK activations, respectively. PKC-α siRNA knockdown was done to corroborate the involvement of PKC-α in the undertaken study.

RESULTS

Our study showed the translocation of PKC-α from cytosol to the membrane fraction in colon carcinoma cell lines on incubation with TDH. The EGFR tyrosine kinase activity exhibited a down regulation on TDH treatment which involved PKC-α, as confirmed by siRNA knockdown. Also ERK phosphorylation occurred on PKC-α activation.

CONCLUSION

TDH activated PKC-α down regulates EGFR tyrosine kinase activity by MEK dependent mechanism involving MAPK.

GENERAL SIGNIFICANCE

In this study we have seen that TDH has an implication in EGFR based therapeutic approach in colorectal cancer via PKC mediated mechanism.

High extracellular matrix metalloproteinase inducer/CD147 expression is strongly and independently associated with poor prognosis in colorectal cancer

As in most solid tumors, colorectal cancer prognosis strongly depends on the extent of local invasion and lymph node and distant metastases. Extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that activates matrix metalloproteinases, a group of enzymes that play an important role in tumor invasion and metastasis formation. This study investigates the EMMPRIN expression in a large cohort of patients with colorectal cancer. Immunohistochemical analysis of tissue microarrays from 285 patients shows that increased EMMPRIN protein expression does not correlate with clinicopathologic parameters and is an independent prognostic factor of poor survival, with mean survival times of 103 months in EMMPRIN negative/low versus 57 months in EMMPRIN intermediate/high patients (P < .001). This pronounced association of increased EMMPRIN levels and--on average--a 45% reduction in overall survival could help improve the risk stratification in patients with colorectal cancer; moreover, the lack of correlations with classical measures of cancer invasion/spreading may suggest the relevance of alternative EMMPRIN pathways beyond matrix metalloproteinase activation.

DNA repair genes XPC, XPG polymorphisms: relation to the risk of colorectal carcinoma and therapeutic outcome with Oxaliplatin-based adjuvant chemotherapy

Xeroderma pigmentosum complementation group C and G (XPC, XPG) play important roles in DNA damage repairing machinery. Genetic variations in the XPC and XPG may be associated with increased risk for colorectal carcinoma (CRC). In this study, we evaluated the relation between the XPC Lys939Gln, XPG Asp1104His polymorphisms, and CRC susceptibility in a population-based case-control study, which included 1,028 CRC cases and 1,085 controls. Compared with the corresponding wild genotypes, we found that individuals with at least one copy of the XPC Lys939Gln (AC or CC genotype) and XPG Asp1104His (GC or CC genotype) had an increased risk for CRC. In addition, the variant genotypes of the XPC Lys939Gln AC/CC (P = 0.027) or XPG Asp1104His GC/CC (P = 0.003) reduced the elevation of preoperative carcinoembryonic antigen (CEA) level. Moreover a significantly longer progression-free survival (PFS) after Oxaliplatin-based adjuvant chemotherapy was observed in patients with XPG Asp1104His wide-type GG genotype (n = 432, Log-rank test: P = 0.033). Cox proportional hazards analyses demonstrated that variant genotypes of XPG Asp1104His [hazard ratio (HR) = 1.692, 95% confidence interval (95%CI): 1.202-2.383, P = 0.003] as well as pathology grade (HR = 2.545, 95%CI: 2.139-3.030, P < 0.001), and lymph node metastases (HR = 1.851, 95%CI: 1.306-2.625, P < 0.001) were predictive of shorter PFS for the CRC patients with Oxaliplatin-based adjuvant chemotherapy. In conclusion, the current data suggested that XPC Lys939Gln and XPG Asp1104His polymorphisms might contribute to the identification of patients with increased risk for CRC.

Elective resection of rectal cancer primary tumor in patients with stage IV disease--own experiences

Optimal management of asymptomatic generalized rectal cancer is still the matter of debate. The aim of the study was to review stage IV rectal cancer patients who were treated in our clinic since 2000 till 2008 in order to evaluate the effectiveness of surgery.

MATERIAL AND METHODS

Fifty-two generalized rectal cancer patients treated with elective resection of primary tumor were identified. Patients' age, sex, duration of hospital stay, modality of surgery, complications, postoperative mortality rate and survival rate were assessed.

RESULTS

Median survival was 16.3 months. Postoperative complications occurred in 29% patients. Postoperative mortality rate was 1.9%.

CONCLUSIONS

In properly selected group of patients elective resection of primary tumor may cause low mortality rate and acceptable morbidity rate. This surgical modality allows to avoid potential complications of tumor local growth.

Trends in incidence of gastrointestinal tract cancers in Western iran, 1993-2007

BACKGROUND

Few studies have addressed the secular trend of malignancies in developing countries such as Iran. This study aimed to determine the trend in the incidence of gastrointestinal cancers during a period of 15 years in Kermanshah, Iran.

METHODS

All of the confirmed positive pathologic reports for esophageal, gastric and colorectal cancers from 1993 to 2007 were collected and compared with the data compiled in the provincial health center. The incidence rate was standardized for world population using a direct method. The Fay and Feuer method was used to calculate the 95% confidence intervals for each cancer in each year. Trends were investigated using linear regression.

RESULTS

Over the period, 2951 cases of gastrointestinal cancer were reported in Kermanshah Province. The age-standardized incidence rates for gastric, esophageal and colorectal cancers were 9.2, 8.1 and 4.5 per 100,000 respectively over 15 years. In all types, the incidence increased with age. The study showed that the incidence of gastric and esophageal cancers decreased annually by 0.28 (-0.67-0.11) and 0.36 (-0.70 - (-0.02)), respectively. Colorectal cancer demonstrated an increase in the incidence [0.14 (95% CI: -0.01-0.29) annually].

CONCLUSION

A decrease in the incidence of gastric and esophageal cancers and an increase in the incidence of colorectal cancer are in line with reports from other developing countries in epidemiologic transition. Such trends warrant in depth investigation for the exact reasons.

Prognostic significance of cytosolic phospholipase A2 expression in patients with colorectal cancer

PURPOSE

Cyclooxygenase-2 is believed to be an important enzyme in the pathogenesis of colorectal cancer (CRC). Cytosolic phospholipase A2 (cPLA2), also, have been suggested to be related to the carcinogenesis of CRC. The aim of this study was to investigate cPLA2 expression and its relationship with prognostic significance in CRC.

METHODS

Eighty-eight patients with colorectal cancer who underwent curative surgery were enrolled in this study. cPLA2 was examined in 88 primary CRCs by immunohistochemistry and we compared their expression with clinicopathologic findings, recurrence and survival in patients with CRC.

RESULTS

The expression of cPLA2 was positive in 54.5% (48/88). The expression of cPLA2 was not correlated with clinicopathologic parameters. However, cPLA2 expression was significantly related with vascular endothelial growth factor expression. Kaplan-Meier analysis didn't show any clinical significance in disease-free survival and overall survival according to cPLA2 expression.

CONCLUSION

These results suggest that cPLA2 expression was not associated with the prognosis of CRC. However, further large-scale studies are needed to clarify the prognostic effect of cPLA2 in CRC.

Prevalence of colonic adenomas in patients with nonalcoholic fatty liver disease

BACKGROUND

Epidemiologic data suggest that colonic adenomas have an increased tendency to occur in patients who are obese, African American, or have a positive family history of colon cancer, or diabetes mellitus. Recent data suggest that impaired glucose tolerance, dyslipidemia, and metabolic syndrome are associated with a higher risk for colonic adenomas. Patients with nonalcoholic fatty liver disease (NAFLD) often share several of the aforementioned risk factors for colonic adenomas. However, data are lacking about the relationship between NAFLD and colonic adenomas. The aim of this study was to systematically evaluate whether NAFLD is an independent risk factor for colonic adenomas.

METHODS

We performed a retrospective cohort observational study on 233 patients who underwent screening colonoscopies at Brooke Army Medical Center from November 2007 to March 2010 to assess for the association between NAFLD and colonic adenomas. Patients who had previously been found to have biopsy-proven simple steatosis (n = 65) or nonalcoholic steatohepatitis (NASH) (n = 29) were compared with a control group without fatty liver disease on sonographic imaging (n = 139). Patients were stratified based on gender, race, body mass index (BMI), and family history and adjusted for variables previously known to be associated with increased adenoma risk.

RESULTS

The mean age was 54.7 ± 6.0 years (48.5% women). Racial demographics were: 62.7% White, 18.5% Hispanic, 13.7%, African American, and 5.2% other. The mean BMI was 29.7 ± 5.8. The prevalence of colonic adenomas was 25.1% in the control group and 24.4% in the NAFLD group to include simple steatosis and NASH (p = 1.00). Furthermore, when adjusting for known confounders to include race, BMI, and family history no significant differences were found (p = 0.33). However, the ultrasound-negative patients ranked lower in the number of adenomas per person (p = 0.016).

CONCLUSIONS

There was no difference in the prevalence of colonic adenomas when comparing the NAFLD group who had undergone colonoscopy with a group of control patients without NAFLD who had undergone colonoscopy. However, patients with negative ultrasounds appeared to have a lower polyp burden.

Predictive factors of the response of rectal cancer to neoadjuvant radiochemotherapy

Locally advanced rectal cancer is currently treated with pre-operative radiochemotherapy (pRCT), but the response is not uniform. Identification of patients with higher likelihood of responding to pRCT is clinically relevant, as patients with resistant tumors could be spared exposure to radiation or DNA-damaging drugs that are associated with adverse side effects. To highlight predictive biomarkers of response to pRCT, a systematic search of PubMed was conducted with a combination of the following terms: "rectal", "predictive", "radiochemotherapy", "neoadjuvant", "response" and "biomarkers". Genetic polymorphisms in epithelial growth factor receptor (EGFR) and thymidylate synthase (TS) genes, the expression of several markers, such as EGFR, bcl-2/bax and cyclooxygenase (COX)-2, and circulating biomarkers, such as serum carcinoembryonic antigen (CEA) level, are promising as predictor markers, but need to be further evaluated. The majority of the studies did not support the predictive value of p53, while the values of Ki-67, TS and p21 is still controversial. Gene expression profiles of thousands of genes using microarrays, microRNA studies and the search for new circulating molecules, such as human telomerase reverse transcriptase mRNA and cell-free DNA, are providing interesting results that might lead to the identification of new useful biomarkers. Evaluation of biomarkers in larger, prospective trials are required to guide therapeutic strategies.

Inhibition of fried meat-induced colorectal DNA damage and altered systemic genotoxicity in humans by crucifera, chlorophyllin, and yogurt

Dietary exposures implicated as reducing or causing risk for colorectal cancer may reduce or cause DNA damage in colon tissue; however, no one has assessed this hypothesis directly in humans. Thus, we enrolled 16 healthy volunteers in a 4-week controlled feeding study where 8 subjects were randomly assigned to dietary regimens containing meat cooked at either low (100°C) or high temperature (250°C), each for 2 weeks in a crossover design. The other 8 subjects were randomly assigned to dietary regimens containing the high-temperature meat diet alone or in combination with 3 putative mutagen inhibitors: cruciferous vegetables, yogurt, and chlorophyllin tablets, also in a crossover design. Subjects were nonsmokers, at least 18 years old, and not currently taking prescription drugs or antibiotics. We used the Salmonella assay to analyze the meat, urine, and feces for mutagenicity, and the comet assay to analyze rectal biopsies and peripheral blood lymphocytes for DNA damage. Low-temperature meat had undetectable levels of heterocyclic amines (HCAs) and was not mutagenic, whereas high-temperature meat had high HCA levels and was highly mutagenic. The high-temperature meat diet increased the mutagenicity of hydrolyzed urine and feces compared to the low-temperature meat diet. The mutagenicity of hydrolyzed urine was increased nearly twofold by the inhibitor diet, indicating that the inhibitors enhanced conjugation. Inhibitors decreased significantly the mutagenicity of un-hydrolyzed and hydrolyzed feces. The diets did not alter the levels of DNA damage in non-target white blood cells, but the inhibitor diet decreased nearly twofold the DNA damage in target colorectal cells. To our knowledge, this is the first demonstration that dietary factors can reduce DNA damage in the target tissue of fried-meat associated carcinogenesis.

Trial Registration

ClinicalTrials.gov NCT00340743.

Ten-year retrospective study of treatment of malignant colonic obstructions with self-expandable stents

PURPOSE

To describe the use of self-expandable metallic stents to manage malignant colorectal obstructions and to compare the radiation dose between fluoroscopic guidance of stent placement and combined endoscopic and fluoroscopic guidance.

MATERIALS AND METHODS

From January 1998 to December 2007, 467 oncology patients undergoing colorectal stent placement in a single center were included in the study. Informed consent was obtained in all cases. All procedures were performed with fluoroscopic or combined fluoroscopic and endoscopic guidance. Inclusion criteria were total or partial colorectal obstruction of neoplastic origin. Exclusion criteria were life expectancy shorter than 1 month, suspicion of perforation, and/or severe colonic neoplastic bleeding. Procedure time and radiation dose were recorded, and technical and clinical success were evaluated. Follow-up was performed by clinical examination and simple abdominal radiographs at 1 day and at 1, 3, 6, and 12 months.

RESULTS

Of 467 procedures, technical success was achieved in 432 (92.5%). Thirty-five treatments (7.5%) were technical failures, and the patients were advised to undergo surgery. Significant differences in radiation dose and clinical success were found between the fluoroscopy and combined-technique groups (P < .001). Total decompression was achieved in 372 cases, 29 patients showed remarkable improvement, 11 showed slight improvement, and 20 showed clinical failure. Complications were recorded in 89 patients (19%); the most significant were perforation (2.3%) and stent migration (6.9%). Mean interventional time and radiation dose were 67 minutes and 3,378 dGy·cm(2), respectively.

CONCLUSIONS

Treatment of colonic obstruction with stents requires a long time in the interventional room and considerable radiation dose. Nevertheless, the clinical benefits and improvement in quality of life justify the radiation risk.

Up-regulated EMMPRIN/CD147 protein expression might play a role in colorectal carcinogenesis and its subsequent progression without an alteration of its glycosylation and mRNA level

PURPOSE

Extracellular matrix metalloproteinase inducer (EMMPRIN) was reported to involve in the invasion and metastasis of malignancies by regulating the expression of vascular endothelial growth factor (VEGF) in stromal and cancer cells. The study aimed to clarify the role of EMMPRIN expression in tumorigenesis and progression of colorectal carcinomas (CRC).

METHODS

EMMPRIN expression was examined on tissue microarray containing colorectal carcinomas, adenoma and non-neoplastic mucosa (NNM) by immunohistochemistry and in situ hybridization (ISH). Colorectal carcinoma cell lines (DLD-1, HCT-15, SW480 and WiDr) and tissues were studied for EMMPRIN expression by Western blot or RT-PCR, followed by sequencing.

RESULTS

All carcinoma cell lines showed EMMPRIN expression at both mRNA and protein levels. Two synonymous mutations were found in carcinoma cell lines at codon109 (GCT → GCC: Ala) or 179 (GAT → GAC: Asp). Frozen CRC tissues displayed higher EMMPRIN expression than paired NNM (P < 0.05). EMMPRIN expression was immunohistochemically stronger in colorectal high-grade adenoma, adenocarcinoma and metastatic carcinoma than non-neoplastic superficial epithelium and low-grade adenoma (P < 0.05). In contrast, its mRNA level was similar from colorectal NNM, adenoma to adenocarcinoma by ISH, in line with the findings of RT-PCR (P > 0.05). Immunohistochemically, EMMPRIN expression was positively correlated with tumor size, depth of invasion, vascular or lymphatic invasion, grade of infiltration (INF), ki-67 and VEGF expression of CRCs (P < 0.05). Among them, depth of invasion was an independent associated factor for EMMPRIN expression in CRCs (P < 0.05).

CONCLUSIONS

Up-regulated EMMPRIN protein expression might contribute to colorectal carcinogenesis without the alteration of its glycosylation and mRNA level. Aberrant EMMPRIN protein expression might promote growth or invasion of CRCs possibly through increased ki-67 expression and inducible angiogenesis via up-regulating VEGF expression.

Incidence of colorectal cancer in Kashmir valley, India

BACKGROUND

There is wide variation in the incidence of colorectal cancer globally and also within the same country among different racial or ethnic groups. The present population-based study was undertaken to determine the incidence of colorectal cancer in Kashmiri population which is non-migratory and ethnically homogeneous having stable food habits.

METHODS

Over a period of one year, all newly diagnosed and histological proved cases of colorectal cancer in all possible areas, where such patients are diagnosed and treated were prospectively registered.

RESULTS

A total of 212 cases of colorectal cancers were registered; of them 113 (53.3%) originated in the colon and other 99 (46.7%) in rectum. Male to female ratio was 1.2:1. The crude incidence rate of colorectal cancer was 3.65/100,000; it was 3.78 in males, and 3.50/100,000 in females. The incidence rates for colorectal cancer in Muslims and Hindus were different. The crude incidence rate for colorectal carcinoma was highest for district Srinagar 6.19/100,000 (urban area) and lowest for district Kupwara (rural area) 1.59/100,000. The highest numbers of cases were detected in the age group 55-59 years (n = 34). The age-specific rate for colorectal carcinoma was highest in the age group 55-59 years (17.21/100,000), followed by 65-69 years (14.86/100,000). The age standardized incidence rate was 4.52/100,000 per year. The truncated age adjusted incidence rates in age group 35-64 years was 8.31/100,000; while that for colorectal carcinoma was 8.77/100,000 in males and 7.66/100,000 in females.

CONCLUSION

We conclude that the incidence of colorectal cancer in Kashmir valley is similar to that reported in the rest of India.

Gene mutations in epidermal growth factor receptor signaling network and their association with survival in Chinese patients with metastatic colorectal cancers

Mutations of the KRAS, BRAF, and PIK3CA genes have been reported in colorectal cancer (CRC), associated with resistance to epidermal growth factor receptor (EGFR)-targeted monoclonal antibody therapy. These reports have mainly emanated from Western countries, however, and little is known about the mutation frequencies of these genes and their prognostic value in Asian patients with CRC. In this study, we analyzed the mutation frequencies of these three genes together with EGFR, and their association with overall survival in 61 Chinese patients with metastatic CRC (mCRC). Gene mutations were examined using pyrosequencing. Kaplan-Meier survival analysis and multivariate Cox proportional hazard analysis were used to assess the prognostic significance of mutations of these four genes for patients' survival. We found that the mutations of KRAS, BRAF, PIK3CA, and EGFR were present in 12 (19.7%), 3 (4.9%), 3 (4.9%), and 0 patients, respectively. Kaplan-Meier survival analysis showed that none of these gene mutations correlated significantly with patients' overall survival. Multivariate Cox proportional hazard analysis showed only treatment regimens and age to be independent prognostic factors. Our findings indicate that EGFR signaling network genes are frequently mutated in Chinese mCRC patients, and these gene mutations do not seem to be associated with patients' overall survival.

Role of surgery in colorectal liver metastases: Too early or too late?

As colorectal cancer and colorectal liver metastases become a serious public health problem, new treatment modalities are needed in order to achieve better results. In the last decade there has been very important progress in oncology, with new and more effective chemotherapeutic agents administered alone or in combination improving the resectability rate in up to 40% of patients with colorectal liver metastases. Advances in interventional radiology, in particular, with the use of portal vein embolization and radiofrequency thermal ablation are new strategies allowing major liver resections and treatment of small liver metastases or early recurrences. Surgery, however, remains the gold standard strategy with intention to treat. In this review article we will describe the advanced role of surgery in the multidisciplinary approach to colorectal liver metastases, and the clinical problems the liver surgeon has to deal with, such as the resectability of the metastases, the presence of bilobar liver lesions and extrahepatic disease, the impact of chemotherapy in already resectable liver metastases, the problem of vanishing metastases after chemotherapy and the dilemma of staged or combined liver and colon operations and which organ first in the clinical scenario of synchronous colorectal liver metastases.

SMAD4--molecular gladiator of the TGF-beta signaling is trampled upon by mutational insufficiency in colorectal carcinoma of Kashmiri population: an analysis with relation to KRAS proto-oncogene

BACKGROUND

The development and progression of colorectal cancer has been extensively studied and the genes responsible have been well characterized. However the correlation between the SMAD4 gene mutations with KRAS mutant status has not been explored by many studies so far. Here, in this study we aimed to investigate the role of SMAD4 gene aberrations in the pathogenesis of CRC in Kashmir valley and to correlate it with various clinicopathological variables and KRAS mutant genotype.

METHODS

We examined the paired tumor and normal tissue specimens of 86 CRC patients for the occurrence of aberrations in MCR region of SMAD4 and exon 1 of KRAS by PCR-SSCP and/or PCR-Direct sequencing.

RESULTS

The overall mutation rate of mutation cluster region (MCR) region of SMAD4 gene among 86 patients was 18.6% (16 of 86). 68.75% (11/16) of the SMAD4 gene mutants were found to have mutations in KRAS gene as well. The association between the KRAS mutant genotype with SMAD4 mutants was found to be significant (P = or < 0.05). Further more, we found a significant association of tumor location, tumor grade, node status, occupational exposure to pesticides and bleeding PR/Constipation with the mutation status of the SMAD4 gene (P = or < 0.05).

CONCLUSION

Our study suggests that SMAD4 gene aberrations are the common event in CRC development but play a differential role in the progression of CRC in higher tumor grade (C+D) and its association with the KRAS mutant status suggest that these two molecules together are responsible for the progression of the tumor to higher/advanced stage.

Meta-analysis of survival of patients with stage IV colorectal cancer managed with surgical resection versus chemotherapy alone

BACKGROUND There is no consensus regarding the appropriate management of asymptomatic and minimally symptomatic patients with stage IV colorectal cancer and irresectable metastases. METHODS A literature search was conducted on Medline and Embase. Outcome measures included: survival; postoperative morbidity and mortality; complications from the primary tumor and the need for surgery to manage complications; the likelihood of curative surgery after initial response to primary therapy; and length of hospital stay. Quantitative meta-analysis was performed where appropriate. RESULTS Eight retrospective studies, including 1,062 patients, met the criteria for inclusion in this study. Meta-analysis has shown an improvement in the survival of patients managed with palliative resection of their primary tumor, with an estimated standardized median difference of 6.0 months (standardized difference, 0.55; 95% confidence interval (CI), 0.29, 0.82; p < 0.001). Patients managed with chemotherapy alone were 7.3 times more likely to have a complication from the primary tumor (95% CI, 1.7, 34.4; p = 0.008). There was no difference in the response rates to chemotherapy, making metastatic disease amendable to curative resection (0.85; 95% CI 0.40, 1.8; p = 0.662). CONCLUSIONS To date, only retrospective data are available, showing that palliative resection of the primary tumor in asymptomatic or minimally symptomatic patients with stage IV colorectal cancer is associated with longer survival. Resection of the primary tumor reduces the likelihood of complications from the primary tumor and avoids the need for emergency procedures.

Cytokeratin 20 and vascular endothelial growth factor as molecular markers in Egyptian patients with colorectal cancer

PURPOSE

To investigate the expression of cytokeratin 20 (CK20) and vascular endothelial growth factor (VEGF) in the peripheral blood of colorectal cancer (CRC) patients, and correlate the findings with the pathologic data of the patients.

METHODS

This study was carried out on 50 subjects, 40 patients with histologically confirmed colorectal carcinoma undergoing elective surgery and 10 healthy individuals matched for age and sex. Total RNA extraction followed by real time quantitative RT-PCR and real time TaqMan quantitative assay for peripheral blood expression of CK20 and VEGF was done for both patients and controls.

RESULTS

(1) Statistically significant high levels of CK20,VEGF, CEA (p = 0.000 each) and CA19-9 (p = 0.002) in CRC patients when compared with controls; (2) Statistically significant increase in the expression of CK20 in advancing CRC stage C (p = 0.001) and with LN metastasis (p = 0.000); (3) Statistically significant increase in the expression of VEGF in advancing CRC stage C (p = 0.002), pathologic grade (p = 0.038), and with LN metastasis (p = 0.004); and (4) statistically positive correlation between CK20 and VEGF expressions, and also between these markers and CEA level.

CONCLUSION

CK20 and VEGF expressions in peripheral blood of CRC patients are promising molecular markers for CRC progression and metastasis.

TP53 Pro47Ser and Arg72Pro polymorphisms and colorectal cancer predisposition in an ethnic Kashmiri population

Two TP53 gene polymorphisms at codon 47 (TP53 Pro47Ser) and at codon 72 (TP53 Arg72Pro) have been associated with susceptibility to various cancers. We carried out a case-control study and examined the genotype distribution of TP53 Pro47Ser and Arg72Pro single nucleotide polymorphisms (SNPs), using a PCR-RFLP approach, to determine if these two SNPs are risk factors for colorectal cancer (CRC) development and to look for a possible correlation of these two SNPs with clinicopathological variables of CRC. We investigated the genotype distribution of these SNPs in 86 CRC cases in comparison with 160 healthy subjects in an ethnic Kashmiri population. TP53 Arg72Pro SNP genotype frequencies differed significantly (P = 0.000001) between the groups; the frequency of the Pro/Pro mutant was almost 20% in the general population. We also found significant association of the Pro/Pro mutant with tumor location, nodal status/higher tumor grade and bleeding per rectum/constipation. We conclude that Arg72Pro SNP is associated with susceptibility to developing CRC in this ethnic Kashmiri population.

Molecular predictive and prognostic markers in colon cancer

Colorectal cancer remains one of the major cancer related death despite progress in the cytotoxic treatment of colorectal cancer (CRC) over the past decade. The introduction of targeted agents has improved the progression free and overall survival of metastatic disease. However, 40-50% of patients do not experience beneficial effects and it remains a challenge to select patients likely to respond to therapy. Several new molecular predictive and prognostic markers have been identified and are now being translated into routine clinical practice. K-Ras mutation is the first established molecular marker with a lack of response in K-Ras mutated patients treated with an epidermal growth factor receptor (EGFR)-targeted therapy. The validation of predictive and prognostic markers will result in more successful and less toxic therapeutic regimens for cancer patients. This review aims to summarize the most important currently available predictive and prognostic molecular markers in colorectal cancer.