Epidemiology and prevention of colorectal cancer

Long-term Oncological Results After Laparoscopic Sigmoidectomy for Adenocarcinoma

Purpose: Sigmoidectomy is performed in most cases for benign pathologies and mainly in cases of diverticulitis. Few studies in the literature report oncological results after sigmoidectomy for adenocarcinoma. The aim of this study was to report the long-term oncological outcomes after elective laparoscopic sigmoidectomy (LS) for adenocarcinoma. Methods: This study is a retrospective analysis of prospectively collected data. From January 2003 to February 2021, 173 patients underwent elective LS for adenocarcinoma. Twenty-four patients with a diagnosis of preoperative distant metastases were excluded (13.9%). Results: Seven postoperative complications were observed (7.1%). Of these, 2 (2%) anastomotic leakages were treated surgically by the Hartmann procedure (Clavien-Dindo grade III-b). The mean number of harvested lymph nodes with the specimen was 14.2 ± 7.1. At a median follow-up of 115 months (interquartile range 133.8), 2 (2%) and 9 patients (9.2%) had developed recurrence and metastases, respectively. During follow-up, 6 patients (6.1%) with metastases died due to disease progression and 6 other patients (6.1%) died due to causes other than cancer related. At the 5- and 10-year follow-ups, the overall survival rates were 90.5% ± 3.4% and 83.8% ± 4.5%, respectively, while the disease-free survival rates were 87.1% ± 4.1% and 83.5% ± 4.7%, respectively. Conclusion: LS is a safe and feasible technique both in terms of the number of harvested lymph nodes and oncological results. The possibility of sparing the colon without mobilizing the splenic flexure and dividing the left colic artery could reduce intra- and postoperative complications. Further studies with larger samples of patients are required to confirm these data.

TiaochangXiaoliu decoction inhibits azomethane (AOM)/dextran sulfate sodium (DSS)-induced colorectal cancer by regulating immune response

Background

TiaochangXiaoliu decoction (TXD) has an anti-tumor effect in clinical practice. We further investigated the role of TXD in colorectal cancer (CRC).

Methods

Mouse models of CRC were induced by azomethane (AOM)/dextran sulfate sodium (DSS), with sixty male C57BL/6 mice randomly divided into six groups (10 mice/group): a control group, AOM/DSS group, TXD at low dose (L-dose) group, middle dose (M-dose) group, high dose (H-dose) group, and Celecoxib (Cel) group. The colorectum, serum, and plasma of mice in each group was collected following sacrifice to record the number of tumors. HE staining was utilized for observing pathological damage to colorectal tissues, ELISA used for detecting INF-γ, IL-2, and TNF-α expression in serum, and flow cytometry used for measuring the proportion of CD4⁺, CD8⁺, CD4⁺/CD8⁺, and NK cells in plasma.

Results

Compared with the control group, the AOM/DSS group showed tumor masses in the colorectum and different degrees of pathological damage in the intestine. AOM/DSS induction also resulted in an increase in INF-γ, IL-2, and TNF-α expression in serum, and a decrease in the percentages of CD4⁺, CD8⁺, CD4⁺/CD8⁺, and NK cells(P<0.05). In comparison with the AOM/DSS group, with the increase of TXD dose, the number of tumors decreased significantly, and intestinal structure and mucosal inflammatory cell infiltration also improved. Further, in comparison with the AOM/DSS group, all three doses of TXD and celecoxib caused an increase in the contents of CD4⁺, CD8⁺, CD4⁺/CD8⁺, and NK cells in plasma. In addition, in the M-dose, H-dose, and Cel groups, INF-γ, IL-2, and TNF-α expression showed a marked decrease, and the reduction in these two groups treated with TXD was dose-dependent.

Conclusions

TXD leads to a marked reduction in the number of tumors and inflammatory cell infiltration in CRC mice. This decoction significantly decreased the levels of INF-γ, IL-2, and TNF-α in serum, and increased the contents of CD4⁺, CD8⁺, CD4⁺/CD8⁺, and NK cell in the plasma of mice with AOM/DSS-induced CRC.

Pemetrexed/Erlotinib as a Salvage Treatment in Patients with High EGFR-Expressing Metastatic Colorectal Cancer Following Failure of Standard Chemotherapy: A Phase II Single-Arm Prospective Study

BACKGROUND

Despite new agents to treat metastatic colorectal cancer (CRC), patients eventually progress and additional therapies are needed.

OBJECTIVE

We intended to evaluate the combination of pemetrexed/erlotinib in patients with high epidermal growth factor receptor (EGFR)-expressing (2+ or 3 on immunohistochemistry) metastatic CRC who experienced disease progression after standard chemotherapy.

PATIENTS AND METHODS

We investigated pemetrexed and erlotinib (pemetrexed 500 mg/m² on Day 1 and erlotinib 100 mg/m² on Days 1-21) as a salvage treatment, given every 3 weeks, until disease progression or intolerable toxicity. The primary outcome was overall response rate (RR).

RESULTS

From May 2017 to April 2018, 29 metastatic CRC patients with high EGFR expression who had previously received standard therapies were enrolled into this trial. The regimen was well tolerated. Skin rash, vomiting, fatigue, and anorexia were common toxic effects but were mostly manageable and controllable side effects of grades 1 or 2 only. In an intent-to-treat analysis, three partial responses (PRs) were observed in enrolled patients, revealing an overall RR of 10.3%. This value supported the statistical hypothesis of this study. Fifteen patients had stable disease and the disease control rate (DCR) was 62.1%. All three patients who achieved a PR had a tumor EGFR expression of 3+. Among the eight patients with EGFR 3+ expression, the RR and DCR were 37.5% and 75.0%, respectively.

CONCLUSION

This phase II trial using pemetrexed/erlotinib in metastatic CRC with high EGFR expression met the primary endpoint of tumor response.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov (number NCT03086538).

Malignant colo-duodenal fistula: management based on proposed classification

Duodenal involvement in colonic malignancy is a rare event and poses challenge to surgeons as it may entail major resection in a malnourished patient. Nine patients with malignant colo-duodenal fistula were reviewed retrospectively. Depending on the pattern of duodenal involvement, it was classified as-type I involving lateral duodenal wall less than half circumference; type II involving more than half circumference away from papilla; type III involving more than half circumference close to papilla. Type I was managed with sleeve resection, type II with segmental and type III with pancreaticoduodenectomy. Median age was 47 years, with male to female ratio of 2:1. Eight patients had anemia and seven had hypoproteinemia. Tumor was located in right colon in eight patients and distal transverse colon in one. Diagnosis of fistula was established by CT abdomen in seven (78%), foregut endoscopy in three and intraoperatively in two patients. Two patients had metastatic disease. Elective resection was done in seven while two required emergence surgery. Five patients underwent sleeve resection of the duodenum, two underwent segmental resection and two required pancreaticoduodenectomy. All patients had negative resection margin. One patient died. Median survival was 14 months in eight survivors. Duodenal resection in malignant colo-duodenal fistula should be tailored based on the extent and pattern of duodenal involvement. Negative margin can be achieved even with sleeve resection. En bloc pancreaticoduodenectomy is sometimes required due to extensive involvement. Resection with negative margin can achieve good survival.

A meta-analysis of short-term outcome of laparoscopic surgery versus conventional open surgery on colorectal carcinoma

OBJECTIVE

The aim of this article is to study the superiority and safety of laparoscopic surgery for colorectal carcinoma.

SUMMARY BACKGROUND DATA

Laparoscopy in rectal cancer is still not recommended as the treatment of choice by National Comprehensive Cancer Network guidelines. Laparoscopic rectal surgery is more complex and technically demanding, especially for mid and low rectal cancer.

METHODS

A computer-based online research of retrospective or prospective studies addressing laparoscopic surgery versus conventional open surgery for colorectal carcinoma published in the last 11 years was performed in electronic database (Wangfang Database, China National Knowledge Infrastructure, Chinese Medical Current Contents, Pubmed, Medline, Ovid, Elsevier, ISI Web of Knowledge, Cohrane Database of Systematic Reviews). Selective trials were analyzed by the Review Manager 5.2 software.

RESULTS

A total of 9 clinical trials, involving a total of 4747 patients, were identified. A meta-analysis showed that operating time was not significantly different between the 2 groups [WMD = 0.46, 95% confidence interval (95% CI): -55.68 to 56.60, P = .99], intraoperative blood loss in laparoscopic surgery group was less than conventional open surgery group (WMD = -64.66, 95% CI: -87.31 to 42.01, P < .01); No significant difference in the number of lymph node retrieved from postoperative pathologic specimens was found between the 2 groups (WMD = -0.75, 95% CI: -1.72 to 0.23, P = .14); Postoperative time to flatus in laparoscopic surgery group was earlier than that in open surgery significantly (WMD = -1.22, 95% CI: -1.53 to -0.91, P < .01). The cases of postoperative complications were significantly different between the 2 groups, which showed that the cases of laparoscopic surgery group were less than those of open surgery group [odds ratio (OR) = 0.62, 95% CI: 0.52∼0.72, P < .01]; Moreover, hospital stay of laparoscopic surgery group was shorter than that of open surgery that showed significant difference (WMD = -2.38, 95% CI:-3.30 to -1.46, P < .01).

CONCLUSION

Short-term outcomes of laparoscopic surgery are superior than conventional open surgery that include more safety and feasibility, and is expected to be a standardization operation method for colorectal carcinoma.

Are there differences in outcome after elective sigmoidectomy for diverticular disease and for cancer? A national inpatient study

AIM

The postoperative outcome after elective sigmoidectomy for diverticulitis has not been compared to that for cancer. The study aimed to evaluate the differences in the postoperative outcome after sigmoidectomy for diverticular disease and cancer.

METHOD

The National Inpatient Sample Database was used to identify patients who underwent elective sigmoid resection for diverticular disease or cancer between 2004 and 2011. After excluding patients with metastatic cancer and preoperative weight loss, sigmoid cancer and diverticulitis patients were matched using propensity score, controlling for age, gender, race, type of operation (open vs laparoscopic) and comorbidities. The end-points of interest were infective complications, reoperation, anastomotic leakage, rebleeding, length of hospital stay and in-hospital mortality.

RESULTS

After propensity score matching (diverticulitis 11 192 patients, sigmoid cancer 11 192 patients), the mean age was 65 ± 12.5 years, 53.8% were male and 61.5% were Caucasian. Only 18.0% of the operations were done by laparoscopy. The overall complication rate was 17.7% and the in-hospital mortality rate was 0.9%. The diverticulitis group had a higher rate of surgical site infection (3.2% vs 2.6%, P = 0.004), intra-abdominal abscess formation (1.2% vs 0.4%, P < 0.0001) and reoperation (6.1% vs 4.1%, P < 0.0001) compared with the cancer group. The cancer group had a higher incidence of pneumonia (1.9% vs 1.5%, P = 0.01) and anastomotic leakage (9.2% vs 8.3%, P = 0.001). There was no difference in sepsis, deep vein thrombosis, respiratory failure, renal failure, rebleeding, overall complication rate or length of hospital stay. Subgroup analysis showed a higher in-hospital mortality for cancer than for diverticulitis patients whether resected by open or by laparoscopic surgery.

CONCLUSION

Although elective sigmoidectomy for diverticular disease has a higher risk of infective complications, elective sigmoidectomy for cancer has a higher risk of anastomotic leakage.

Colorectal Cancer: Genetics is Changing Everything

Cancer is fundamentally a genetic disease caused by mutational or epigenetic alterations in DNA. There has been a remarkable expansion of the molecular understanding of colonic carcinogenesis in the last 30 years and that understanding is changing many aspects of colorectal cancer care. It is becoming increasingly clear that there are genetic subsets of colorectal cancer that have different risk factors, prognosis, and response to treatment. This article provides a general update on colorectal cancer and highlights the ways that genetics is changing clinical care.

Association between dietary fibre intake with cancer and all-cause mortality among 15 740 adults: the National Health and Nutrition Examination Survey III

BACKGROUND

Few prospective studies have examined the longitudinal associations of total dietary fibre intake and water insoluble and soluble fibres with cancer and all-cause mortality. The present study aimed to examine these associations.

METHODS

We studied the effects of total dietary fibre intake and water insoluble and soluble fibres on cancer and all-cause mortality, using data from 15 740 adult participants [mean (SD) age: 44.53 (19.22) years, 46.60% male] in the National Health and Nutrition Examination Survey (NHANES) III, 1988-1994, who had completed a 24-h dietary recall. Death certificate data were obtained up to 2006. Participants had been followed for 13.74 years on average. Cox regression was used to estimate the hazard ratios (HRs) of total dietary, insoluble and soluble fibres on cancer and all-cause mortality, with the first quartile as the reference group, adjusted for demographics, lifestyle and dietary factors.

RESULTS

Relative to those in the first quartile of total fibre intake, only the third quartile was associated with all-cause mortality, with an adjusted HR of 0.87 [95% confidence interval (CI) = 0.79, 0.97, P = 0.021], and cancer mortality, with an adjusted HR of 0.77 (95% CI = 0.61, 0.99, P = 0.05). The third quartile of insoluble fibre intake was associated with cancer mortality, with an adjusted HR of 0.76 (95% CI = 0.60, 0.96, P = 0.023), and colorectal-anal cancer mortality (in grouped data as provided for public use), with an adjusted HR of 0.42 (95% CI = 0.19, 0.91, P = 0.03).

CONCLUSIONS

Dietary fibre showed protective benefits in terms of mortality risk. Investigating the mechanisms and components of dietary fibres underlying the different protective benefits remains an important consideration for research on fibre-mortality risk.

Dietary fibre and the risk of colorectal cancer: a case- control study

BACKGROUND

Colorectal cancer is one of the most commonly occurring cancers in China. Dietary fibre has been thought to decrease the risk of colorectal cancer in Western countries. However, studies investigating the association between dietary fibre (particularly soluble and insoluble fibres) and colorectal cancer have hitherto been lacking in China.

OBJECTIVE

This case-control study examined the effect of dietary fibre intake on the risk of colorectal cancer, stratified by tumour site.

MATERIALS AND METHODS

The study included 265 cases (colon cancer, 105; rectal cancer, 144; colon and rectal cancer, 16) and 252 controls residing in Qingdao. A food frequency questionnaire that included 121 food items was used to collect dietary information. Odds ratio (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis.

RESULTS

For food groups, controls in the study consumed more vegetables, soy food and total fibre than did colorectal cancer patients (p<0.05). The intakes of fruit, meat and sea-food did not differ significantly between cases and controls. However, we did not find any association between soy food intake and colon cancer. We observed inverse associations between total fibre intake and colorectal, colon and rectal cancer (Q4 vs Q1: OR=0.44, 95%CI, 0.27- 0.73; OR=0.40, 95%CI, 0.21-0.76; OR=0.52, 95%CI, 0.29-0.91). Vegetable fibre intake showed similar inverse associations (Q4 vs Q1: OR=0.51, 95%CI, 0.31-0.85; OR=0.48, 95%CI, 0.25-0.91; OR=0.53, 95%CI, 0.29-0.97). In addition, inverse associations were observed between soluble fibre and insoluble fibre and both colorectal cancer and colon cancer. No relationship was found between colorectal cancer and fruit, soy or grain fibre intakewhen the results were stratified by tumour site.

CONCLUSIONS

The present study suggests that vegetable fibre and total fibre play very important roles in protecting against colorectal cancer. Soluble and insoluble fibres were inversely associated with only colorectal cancer and colon cancer.

Biomarkers of Inflammation and Immune Function and Risk of Colorectal Cancer

A substantial number of prospective epidemiological studies have been conducted to investigate the association between biomarkers of inflammation and immune function and risk of colorectal cancer. Although pre-diagnostic concentrations of these biomarkers, especially C-reactive protein, have been associated with a higher risk of colorectal cancer in some studies, this association does not seem to have a robust support without hints of bias. Future prospective studies should evaluate multiple inflammatory biomarkers with longitudinal measures over the follow-up taking advantage of new multiplex cytokine quantification arrays and use more sophisticated joint or biomarker pattern statistical approaches to capture the complex and dynamic interplay between biomarkers and risk of colorectal cancer. Large collaborative consortia and Mendelian randomization studies should be encouraged to diminish the threat of biases and improve the reliability of this literature.

Practical opportunities to improve early detection and prevention of colorectal cancer (CRC) in members of high-risk families

Colorectal cancer (CRC) incidence and mortality are steadily declining and CRC screening rates are increasing in the United States. Although this a very good news, several definable groups still have very low screening rates including younger (under age 50) members of high-risk CRC families. This opinion piece describes five strategies that could be incorporated into routine practice to improve identification and guideline-based screening in members of high-risk families. Routine incorporation of a simple family history screening tool and outreach to high-risk family members could substantially improve guideline-based screening in this population. Identification of CRCs and advanced adenomas in the endoscopy suite defines another group of high-risk families for similar outreach. Lynch syndrome families can be identified by testing CRCs and selected adenomas for microsatellite instability or loss of DNA repair protein expression. Finally, selective addition of aspirin to surveillance endoscopy can decrease the risk of new adenomas and CRCs. The rationale for these strategies as well as mechanisms for their implementation and evaluation in clinical practice is described.

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.

Laparoscopic versus open surgery for rectal cancer: Results of a systematic review and meta-analysis on clinical efficacy

Colorectal cancer is one of the main malignant tumors threatening human health. Surgery plays a pivotal role in treating colorectal cancer. The present study aimed to compare the clinical effect in patients with rectal cancer undergoing laparoscopic versus open surgery by meta-analysis of the randomized controlled trials (RCTs) published in the past 20 years. The data showed that 14 RCTs comparing laparoscopic surgery with conventional open surgery for rectal cancer matched the selection criteria and reported on 2,114 subjects, of whom 1,111 underwent laparoscopic surgery and 1,003 underwent open surgery for rectal cancer. Blood loss (P<0.00001), days to passage of flatus (P=0.0003), first bowel movement (P=0.0006), fluids intake (P<0.00001), walking independently (P<0.00001), length of hospital duration (P=0.003) and the rate of wound infection (P=0.04) were all significantly reduced following laparoscopic surgery. The incidence of complications, such as ureteric injury (P=0.33), urinary retention (P=0.43), ileus (P=0.05), anastomotic leakage (P=0.09) and incisional hernia (P=0.88), were not significantly different between the two groups. There were no significant differences in lymph nodes harvested (P=0.88), length of specimen (P=0.60), circumferential resection margin (CRM) (P=0.86), regional recurrence ((P=0.08), port site or wound metastasis (P=0.67), distant metastasis (P=0.12), 3-year overall survival (OS) (P=0.42), 3-year disease-free survival (DFS) (P=0.44), 5-year OS (P=0.60) and 5-year DFS (P=0.70). Therefore, laparoscopy for the treatment of patients with rectal cancer has the advantage of recovery and the same complications and prognosis as laparotomy, which indicates that laparoscopy may provide a potential survival benefit for patients with rectal cancer.

MiR-5000-3p, miR-5009-3P and miR-552: potential microRNA biomarkers of side population cells in colon cancer

Colon cancer is one of the most common cancers in the world. Multidrug resistance is related to poor prognosis of advanced colon cancer. The side population plays an important role in multiple drug resistance (MDR) of colon cancer. MicroRNA biomarkers of the side population of colon cancer is still unknown. In the present study, we aimed to explore miRNA markers of side population (SP) cells of colon cancer. The side population was sorted by flow cytometry. Cell viability was measured using an MTT assay. MicroRNA profiling analysis was performed to compare microRNA expression levels in the SP cells of colon cancer with levels in the non-SP cells of colon cancer. RT-PCR was applied to verify the result obtained from the microRNA profiling analysis. miR-5000-3p, miR-5009-3P and miR-552 were all found to be upregulated in SP cells of the colon cancer cell lines HCT-15, HT-29 and LoVo. RT-PCR confirmed the result from the microRNA profiling analysis. This implied that miR-5000-3p, miR-5009-3P and miR-552 may be potential microRNA biomarkers of the side population in colon cancer, which may provide new specific targets of the side population for the reversal of MDR of colon cancer.

Colorectal cancer in patients seen at the teaching hospitals of Guadeloupe and Martinique: discrepancies, similarities in clinicopathological features, and p53 status

BACKGROUND

In Guadeloupe and Martinique, two French Overseas Departments, colorectal cancer (CRC) has become an essential public health issue. However, little is known about CRC characteristics and the p53 status in these populations, particularly in Guadeloupe, whereas certification of a cancer registry has been recently validated.

METHODS

This was a descriptive retrospective study of 201 patients who, between 1995 and 2000, underwent surgery for CRC in the Guadeloupe Teaching Hospital (GlpeTH; 83 patients) and in the Martinique Teaching Hospital (MqueTH; 118 patients). The clinicopathological features and the p53 expression, evaluated with immunohistochemistry, were compared at the time of diagnosis. A relationship between these parameters and the p53 expression was also studied. Data were analysed, using the SPSS computer software version 17.0.

RESULTS

No statistical difference was found between the two groups of patients regarding age (p = 0.60), percentage of young patients (≤50 years; p = 0.94)), sex (p = 0.47), histological type (p = 0.073) and tumour sites (p = 0.65), although the GlpeTH patients were diagnosed with more distal colon cancers (54.2%) than the Mque TH patients (47.4%). By contrast, a significant difference was found regarding the tumour grade (p < 0.0001), the pTNM stage (p = 0.045) and the pT stage (p < 0.0001). Regarding p53 expression, solely for the MqueTH patients, nuclear expression was associated with pTNM, the percentage of p53 negative tumours increasing with the progression of the pTNM stages (p = 0.029).

CONCLUSIONS

For the first time, this study reveals discrepancies in clinicopathological features and in the p53 status between the two groups of patients. The GlpeTH patients were diagnosed with more moderated CRCs but with few CRCs at pTNM IV stage. By contrast, the MqueTH patients were diagnosed with more differentiated tumours, but with many more CRCs at pTNM IV stage. This paradox may be due to differences in tumour location (distal vs proximal), multiplicity of the genetic profiles of patients, or patients getting treatment elsewhere. Although our study is limited due to its small size, it emphasizes the originality of our results.

Increased Tumor Ascorbate is Associated with Extended Disease-Free Survival and Decreased Hypoxia-Inducible Factor-1 Activation in Human Colorectal Cancer

Ascorbate is a co-factor for the hydroxylases that regulate the transcription factor hypoxia-inducible factor (HIF)-1, which provides cancer cells with a metabolic and survival advantage in the hypoxic environment of solid tumors. However, whether ascorbate affects tumor development is a highly debated issue. We aimed to determine whether tumor ascorbate was associated with HIF-1 activation and patient disease-free survival. In this study, we undertook a retrospective observational analysis of tissue-banked tumor and paired normal tissue from 49 colorectal cancer patients, measuring ascorbate levels, HIF-1α and its downstream gene products BNIP3, and vascular endothelial cell growth factor (VEGF). Patient survival was monitored for the first 6 years after surgery. We found that ascorbate levels were lower in tumor tissue compared to normal tissue (p < 0.001) but overall levels varied considerably. HIF-1α, VEGF, and BNIP3 were elevated in tumor samples (p < 0.01). There was an inverse relationship between tumor ascorbate content and HIF-1 pathway activation (p = 0.002) and tumor size (p = 0.018). Higher tumor ascorbate content was associated with significantly improved disease-free survival in the first 6 years after surgery (p = 0.006), with 141–1,094 additional disease-free days. This was independent of tumor grade and stage. Survival advantage was associated with the amount of ascorbate in the tumor, but not with the amount in adjacent normal tissue. Our results demonstrate that higher tumor ascorbate content is associated with decreased HIF-1 activation, most likely due to the co-factor activity of ascorbate for the regulatory HIF hydroxylases. Our findings support the need for future studies to determine whether raising tumor ascorbate is possible with clinical intervention and whether this results in modification of hydroxylase-dependent pathways in the tumor.

Overexpression of epidermal growth factor receptor as a prognostic factor in colorectal cancer on the basis of the Allred scoring system

BACKGROUND

Overexpression of epidermal growth factor receptor (EGFR) is found in many types of neoplasms. The aim of the study was to evaluate EGFR expression in colorectal cancer (CRC) specimens and to determine whether EGFR expression correlates with clinicopathological data and overall survival.

PATIENTS AND METHODS

Tissue specimens from 181 consecutive CRC patients treated at the Military Institute of Medicine in 2006-2010 were collected and examined for EGFR expression, by immunohistochemistry staining. The staining intensity and percentage of cells with membranous EGFR expression were scored and then grouped according to the parameters of the Allred Scoring system. Cutoff values were subjected to further statistical analysis. Univariate tests and a multivariate Cox proportional hazards model were used in data analysis.

RESULTS

EGFR was overexpressed in 96 of 181 CRC specimens (53%). EGFR expression was not correlated with other clinicopathological variables. On univariate analysis, overexpression of EGFR, determined by PS (percentage score) (>3) and total score (sum of PS and intensity score) (>4), was associated with poor overall survival. On multivariate analysis, EGFR overexpression (PS > 3) was an independent adverse prognostic factor (hazard ratio [HR] 1.62; 95% confidence interval [CI]: 1.03-2.53). Elevated carcinoembryonic antigen (CEA) serum concentration before treatment, performance status (Word Health Organization [WHO]-2), and tumor localized in colon and liver metastases were also independent unfavorable prognostic factors.

CONCLUSION

EGFR overexpression (PS > 3) in a CRC patient population was an independent adverse prognostic factor. Implementation of the Allred Scoring system criteria into clinical practice might facilitate treatment decisions in CRC patients.

Strategies to evaluate synchronous carcinomas of the colon and rectum in patients that present for emergent surgery

It is not always possible to evaluate patients that present acutely with carcinoma of the colon and rectum for synchronous lesions. Patients that require emergent surgery necessitate urgent and efficient operation. Patients with lower gastrointestinal bleeding, perforation, or obstruction represent a challenging subset of patients with colorectal cancer. An organized approach to these patients in the effort not to overlook a synchronous carcinoma is important. The present paper provides an evidenced-based approach to this special situation.

Low Mmp 9 and VEGF levels predict good oncologic outcome in mid and low rectal cancer patients with neoadjuvant chemoradiation

Background

The aim of this study was to evaluate apoptotic (Bcl-2, Bax expression, caspase-3 activity, and cytochrome-c) and angiogenic (MMP-9 levels and VEGF expression) markers in operable rectal cancer patients who were treated with preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME). Understanding these factors will facilitate the identification of potential pathological responders before treatment, leading to better local control and survival rates.

Methods

Between March 2006 and March 2008, 29 patients withTNM Stage III (cT3 N+) mid or low rectal cancer were included in this study. Our sample consisted of 17 males (58.6%) and 12 females (41.4%). The median age was 60 years (range 24-88 years). Biopsy samples were taken from different portions of the tumors using flexible endoscopy before neoadjuvant CRT. Preoperatively, all patients received radiation (45-50.4 gray (Gy) in 25 cycles with concurrent 5-florouracil (5-FU) chemotherapy.

Results

A complete response was observed in 7 of 29 patients (24%). Bax staining was negative in 1 of the 7 patients (14%) in the pathological complete response (PCR) group and in 18 of the 22 patients (82%) in the no pathological complete response (noPCR) group (p = 0.001). MMP-9 and VEGF levels were higher in the noPCR group than the PCR group (p = 0.04, p = 0.05 respectively). No statistically significant differences were found between VEGF and MMP-9 levels in nodal downstaging. No statistically significant relationships were found between the other apoptotic factors (Bcl 2, cytochrome-c, and caspase-3 activity) and pathological response rate (p > 0.05).

Conclusion

In neoadjuvant CRT patients, high levels of Bax expression and low levels of VEGF and MMP-9 expression on preoperative biopsies indicate that the patient will potentially be a good pathological responder.

Secreted protein acidic and rich in cysteines-like 1 suppresses aggressiveness and predicts better survival in colorectal cancers

PURPOSE

Secreted protein acidic and rich in cysteines-like 1 (SPARCL1) is an extracellular matrix glycoprotein with malignancy-suppressing potential. The hypothesis that SPARCL1 reduces cancer invasiveness and predicts better survival in colorectal cancers (CRC) was investigated.

EXPERIMENTAL DESIGN

Stable SPARCL1 transfectants, RKO-SPARCL1, and corresponding vector control were constructed and implanted into nude mice to generate a mouse xenograft model of liver metastasis. Also, a retrospective outcome study was conducted on the COH set (222 CRCs) and ZJU set (412 CRCs). The protein expression level of SPARCL1 was determined by immunohistochemistry. The Kaplan-Meier and Cox analyses were used for survival analysis. The association of SPARCL1 with mesenchymal-epithelial transition (MET) was examined by reverse transcription PCR (RT-PCR) and Western blot analysis.

RESULTS

The ectopic expression of SPARCL1 significantly reduced the potential for anchorage-independent growth, migration, invasion and induced cell differentiation in RKO and SW620 cells. In mouse xenograft model, the expression of SPARCL1 significantly reduced the liver metastasis (P < 0.01). The patient-based studies revealed that the expression of SPARCL1 was related to better differentiation (P < 0.01), less lymph node involvement [OR, 0.67; 95% confidence interval (CI), 0.45-1.00], and less distant metastasis (OR, 0.38; 95% CI, 0.18-0.79). The Kaplan-Meier and Cox analysis showed that the expression of SPARCL1 was associated with better overall survival (log-rank: P < 0.01; HR, 0.57; 95% CI, 0.39-0.84). Transfection of SPARCL1 induced MET of colon cancer cells.

CONCLUSION

SPARCL1 functions as a tumor suppressor promoting differentiation possibly via MET, which inhibits the aggressiveness of CRCs.

Chemoprevention for advanced CR neoplasia

Colorectal cancer (CRC) is a major health concern worldwide. In 2011 1,200,000 new cases are predicted and half of them are going to die from the disease. CRC carcinogenesis is a multi-step process that spans over 10-20 years, providing a window of opportunity for effective intervention. CRC can be prevented by life style modification and screening program. However, although these strategies are standard clinical practice, their impact is limited due to low adherence. The number of deaths due to CRC remains alarming high, and makes CRC prevention a paramount. Chemoprevention interferes with the carcinogenesis process by targeting key molecular pathways. It involves the use of a variety of natural or chemical compounds that can delay, prevent or even reverse the adenoma to carcinoma sequence. Numerous chemopreventive agents have been studied but the most efficient are the NSAID group of agents. Much of their efficacy and toxicity has been attributed to their potent inhibition of the cyclooxygenase (COX) enzymes. Chemoprevention has the potential to represent a cost-effective intervention, particularly when targeted at intermediate-risk populations, ages 61-70, following polypectomy. Chemoprevention in this setting is as very important as polyp recurrence in this population can be as high as 50%, even with surveillance colonoscopy every 1-3 years. The most challenging task is to find the proper place for these interventions in the entire effort of general wellbeing. Subjects are likely to be more adherent to prescribed regimens if cancer prevention may be combined with a cardiovascular and Alzheimer prophylaxis. Subjects with a normal colon or non advanced adenomas can be safely monitored with surveillance colonoscopy every 5-10 years. The ideal chemopreventive agent remains to be discovered with great emphasis on the need not to harm. Possibly, combinations of agents will maximize effectiveness while limiting drug toxicity. Finally, personalized approaches would include the ability to predict risk, as well as benefit for a specific individual based on specific SNP's or other genetic profiles.

Thermostable direct hemolysin downregulates human colon carcinoma cell proliferation with the involvement of E-cadherin, and β-catenin/Tcf-4 signaling

BACKGROUND

Colon cancers are the frequent causes of cancer mortality worldwide. Recently bacterial toxins have received marked attention as promising approaches in the treatment of colon cancer. Thermostable direct hemolysin (TDH) secreted by Vibrio parahaemolyticus causes influx of extracellular calcium with the subsequent rise in intracellular calcium level in intestinal epithelial cells and it is known that calcium has antiproliferative activity against colon cancer.

KEY RESULTS

In the present study it has been shown that TDH, a well-known traditional virulent factor inhibits proliferation of human colon carcinoma cells through the involvement of CaSR in its mechanism. TDH treatment does not induce DNA fragmentation, nor causes the release of lactate dehydrogenase. Therefore, apoptosis and cytotoxicity are not contributing to the TDH-mediated reduction of proliferation rate, and hence the reduction appears to be caused by decrease in cell proliferation. The elevation of E-cadherin, a cell adhesion molecule and suppression of β-catenin, a proto-oncogene have been observed in presence of CaSR agonists whereas reverse effect has been seen in presence of CaSR antagonist as well as si-RNA in TDH treated cells. TDH also triggers a significant reduction of Cyclin-D and cdk2, two important cell cycle regulatory proteins along with an up regulation of cell cycle inhibitory protein p27(Kip1) in presence of CaSR agonists.

CONCLUSION

Therefore TDH can downregulate colonic carcinoma cell proliferation and involves CaSR in its mechanism of action. The downregulation occurs mainly through the involvement of E-cadherin-β-catenin mediated pathway and the inhibition of cell cycle regulators as well as upregulation of cell cycle inhibitors.

Dietary patterns and the risk of colorectal adenomas: the Black Women's Health Study

BACKGROUND

Colorectal adenomas are benign lesions that may be precursors to colorectal cancer. No studies of African American women have investigated dietary patterns and the risk of developing colorectal adenomas. We examined data from the Black Women's Health Study to determine whether dietary patterns are associated with the risk of developing colorectal adenomas.

METHODS

This is a prospective cohort study of 59,000 participants followed biennially since 1995. During 155,414 person-years of follow-up from 1997 to 2007 among women who had had at least one screening colonoscopy, 620 incident cases of colorectal adenomas were identified. By using Cox regression models, we obtained incidence rate ratios (IRR) for colorectal adenoma in relation to quintiles of each of two dietary patterns, adjusting for other colorectal adenoma risk factors.

RESULTS

Two dietary patterns, Western and prudent, were utilized to assess the association between dietary intake and adenoma risk. The highest quintile of prudent diet, relative to the lowest quintile, was significantly associated with 34% lower colorectal adenoma risk overall (IRR = 0.66; 95% CI, 0.50-0.88; P(trend) < 0.01). Higher scores on the Western pattern were associated with a higher risk of developing colorectal adenoma (IRR = 1.42; 95% CI, 1.09-1.85 for the highest quintile relative to the lowest; P(trend) = 0.01).

CONCLUSION

Our findings suggest that African American women may be able to reduce their risk of developing colorectal adenomas by following a prudent dietary pattern and avoiding a more Western pattern.

IMPACT

A dietary modification could have a strong impact in colorectal adenoma prevention in African American women.

The association of Streptococcus bovis/gallolyticus with colorectal tumors: the nature and the underlying mechanisms of its etiological role

Streptococcus bovis (S. bovis) bacteria are associated with colorectal cancer and adenoma. S. bovis is currently named S. gallolyticus. 25 to 80% of patients with S. bovis/gallolyticus bacteremia have concomitant colorectal tumors. Colonic neoplasia may arise years after the presentation of bacteremia or infectious endocarditis of S. bovis/gallolyticus. The presence of S. bovis/gallolyticus bacteremia and/or endocarditis is also related to the presence of villous or tubular-villous adenomas in the large intestine. In addition, serological relationship of S. gallolyticus with colorectal tumors and direct colonization of S. gallolyticus in tissues of colorectal tumors were found. However, this association is still under controversy and has long been underestimated. Moreover, the etiological versus non-etiological nature of this associationis not settled yet. Therefore, by covering the most of up to date studies, this review attempts to clarify the nature and the core of S. bovis/gallolyicus association with colorectal tumors and analyze the possible underlying mechanisms.

Primary prevention of colorectal cancer: are we closer to reality?

Colorectal cancer is one of the leading causes of morbidity and mortality worldwide. An early detection of colorectal cancer determines therapeutic outcomes, while primary prevention remains a challenge. Our aim was to review the dietary, geographical and genetic factors in the causation and their possible role in the primary prevention of colorectal cancer. Data from experimental and clinical studies and population screening programmes were analysed to determine the factors responsible for causation of colorectal cancer. The role of dietary constituents, including the consumption of fat, red meat, fibre content, alcohol consumption, and other lifestyle issues, including obesity, lack of exercise and geographical variations in cancer prevalence were reviewed. The role of genetic and lifestyle factors in causation of colorectal cancer is evident from the experimental, clinical and population-based studies. Dietary factors, including the consumption of fat, fibre, red meat and alcohol, seem to have a significant influence in this regard. The role of micronutrients, vitamins, calcium may be relevant but remain largely unclear. In conclusion, there is ample evidence favouring the role of various dietary and lifestyle factors in the aetiology of colorectal cancer. Modification of these factors is an attractive option, which is likely to help in the primary prevention and reduced disease burden.

Expression of HIF-1alpha and VEGF in colorectal cancer: association with clinical outcomes and prognostic implications

Background

Hypoxia-inducible factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) are frequently overexpressed in numerous types of cancers and are known to be important regulators of angiogenesis. Until now, few studies have been carried out to investigate the prognostic role of these factors in solid tumors, especially in colorectal cancer (CRC). The purpose of this study was to evaluate the expression of HIF-1α and VEGF in CRC tissues, and to analyze the association of these two factors with several clinical and pathological characteristics, and patients' survival.

Methods

Paraffin-embedded tissue samples were retrospectively collected from 71 CRC patients, who received surgical resection between 2001 and 2002, with a median follow-up of 5 years. We examined the patterns of expression of HIF-1α and VEGF by immunohistochemistry method. Statistical analysis was performed with univariate tests and multivariate Cox proportional hazards model to evaluate the differences.

Results

Expression of HIF-1α and VEGF was positively observed in 54.93% and 56.34% among the patients, respectively. HIF-1α and VEGF status were significantly associated with tumor stage, lymph nodes and liver metastases (P < 0.05). Expression of both HIF-1α and VEGF remained significantly associated with overall survival (OS) (P < 0.01), and HIF-1α was positively correlative to VEGF in CRC (r = 0.72, P < 0.001).

Conclusions

HIF-1α and VEGF could be used as biomarkers indicating tumors in advanced stage and independently implied poor prognosis in patients with CRC. Treatment that inhibits HIF-1α might be a promising targeted approach in CRC to exhibit its potential to improve outcomes in future perspective, just as VEGF targeting has proved to be.

Can calcium chemoprevention of adenoma recurrence substitute or serve as an adjunct for colonoscopic surveillance?

OBJECTIVES

The aim of this study was to examine the potential cost-effectiveness of calcium chemoprevention post-polypectomy as a substitute or adjunct for surveillance.

METHODS

We constructed a Markov model of post-polypectomy adenoma recurrence and colorectal cancer (CRC) development, calibrated to data from prospective chemoprevention trials of fiber, calcium, antioxidants, and aspirin. We modeled four scenarios for 50-year-old patients immediately after polypectomy: (i) natural history with no further intervention; (ii) elemental calcium 1,200 mg/day from age 50-80; (iii) surveillance colonoscopy from age 50-80 every 5 years, or 3 years for large adenoma; (iv) calcium + surveillance. Patients were followed up until age 100 or death.

RESULTS

Calcium was cost-effective compared to natural history ($49,900/life-year gained). However, surveillance was significantly more effective than calcium (18.729 versus 18.654 life-years/patient; 76 percent versus 14 percent reduction in CRC incidence) at an incremental cost of $15,900/life-year gained. Calcium + surveillance yielded a very small benefit (0.0003 incremental life-years/patient) compared with surveillance alone, at a substantial incremental cost of $3,090,000/life-year gained.

CONCLUSION

Post-polypectomy calcium chemoprevention is unlikely to be a reasonable substitute for surveillance. It may be cost-effective in patients unwilling or unable to undergo surveillance.

American Society of Clinical Oncology policy statement: the role of the oncologist in cancer prevention and risk assessment

Oncologists have a critical opportunity to utilize risk assessment and cancer prevention strategies to interrupt the initiation or progression of cancer in cancer survivors and individuals at high risk of developing cancer. Expanding knowledge about the natural history and prognosis of cancers positions oncologists to advise patients regarding the risk of second malignancies and treatment-related cancers. In addition, as recognized experts in the full spectrum of cancer care, oncologists are afforded opportunities for involvement in community-based cancer prevention activities. Although oncologists are currently providing many cancer prevention and risk assessment services to their patients, economic barriers exist, including inadequate or lack of insurance, that may compromise uniform patient access to these services. Additionally, insufficient reimbursement for existing and developing interventions may discourage patient access to these services. The American Society of Clinical Oncology (ASCO), the medical society representing cancer specialists involved in patient care and clinical research, is committed to supporting oncologists in their wide-ranging involvement in cancer prevention. This statement on risk assessment and prevention counseling, although not intended to be a comprehensive overview of cancer prevention describes the current role of oncologists in risk assessment and prevention; provides examples of risk assessment and prevention activities that should be offered by oncologists; identifies potential opportunities for coordination between oncologists and primary care physicians in prevention education and coordination of care for cancer survivors; describes ASCO's involvement in education and training of oncologists regarding prevention; and proposes improvement in the payment environment to encourage patient access to these services.

Intense cytoplasmic ezrin immunoreactivity predicts poor survival in colorectal cancer

Ezrin is a membrane-cytoskeleton anchor, which, in experimental models, regulates tumor cell invasion and metastatic ability. We carried out immunohistochemical analysis of ezrin in 74 advanced colorectal cancer patients and correlated it to clinicopathologic variables and disease outcome. In contrast to the predominantly membraneous immunoreactivity of normal colorectal epithelium, ezrin expression in the colorectal cells was typically cytoplasmic. Altogether, 16.2% (12/74) of the tumors showed negative/weak ezrin staining, 35.1% (26/74) had moderate staining, and 48.6% (36/74) had intense staining. The expression was more intense in colon than in rectal carcinomas (P = .003). Increased ezrin expression was associated with adverse outcome, that is, shorter disease-specific survival; 48.3 months and 36.6 months for negative-weak versus intense expression (P = .041) as well as shorter survival with metastases at 36 months (P = .030); the metastases(36) rates in ezrin(neg/weak), ezrin(moderate), ezrin(intense) are 58.3%, 25.0%, and 18.4%, respectively. In univariate survival analysis, dichotomized (negative/weak versus moderate/strong) ezrin expression significantly predicted both the 5-year disease specific survival (P = .035) and 5-year metastases (P = .018) but lost this predictive power in multivariate (Cox) analysis. High ezrin expression was also related to high E-cadherin (cytoplasmic) expression, DNA aneuploidy, and high thymidylate synthase expression (P = .046, P = .042, P = .046, respectively). These results suggest that ezrin may play a role in colorectal cancer progression and that ezrin expression might provide clinically valuable information in predicting the biological behavior of colorectal cancer.

Previous cancer screening behavior as predictor of endoscopic colon cancer screening among women aged 50 and over, in NYC 2002

Colon cancer screening rates in women are low. Whether screening for breast and cervical cancer is associated with colon cancer screening behavior is unknown but could provide linkage opportunities. To identify the extent to which both breast and cervical cancer screening increases uptake of colon cancer screening among women in New York City. Women at least 50 years old completed questionnaires for the New York Cancer Project. Analyses compared rates of endoscopic colon cancer screening with adherence to screening recommendations for breast and cervical cancer. Of the 3,386 women, 87.8% adhered to breast and cervical cancer screening guidelines, yet only 42.1% had received endoscopic colon cancer screening. Most women with colon cancer screening (95%) also reported past mammogram and Pap-smear. In multivariable analysis, women who adhered to the other two procedures were more likely to have had colon cancer screening than women with no prior history (OR = 4.4; CI = 2.36, 8.20), after accounting for age, race/ethnicity, insurance status, family history of cancer and income. Significant predictors of endoscopic colon cancer screening included: age over 65 years (OR = 1.63; CI = 1.23, 2.15) with 50-65 years old as the reference, any health insurance (OR = 2.18; CI = 1.52, 3.13) and a family history of cancer (OR = 1.38; CI = 1.17, 1.61). Colorectal cancer screening remains low, even among women who undergo other cancer screening tests. Opportunities to link cancer screening tests to encourage colon cancer screening merit closer attention.

The polyp prevention trial continued follow-up study: no effect of a low-fat, high-fiber, high-fruit, and -vegetable diet on adenoma recurrence eight years after randomization

The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial to evaluate the effects of a high-fiber (18 g/1,000 kcal), high-fruit and -vegetable (3.5 servings/1,000 kcal), and low-fat (20% of total energy) diet on the recurrence of adenomatous polyps in the large bowel over a period of 4 years. Although intervention participants reported a significantly reduced intake of dietary fat, and increased fiber, fruit, and vegetable intakes, their risk of recurrent adenomas was not significantly different from that of the controls. Since the PPT intervention lasted only 4 years, it is possible that participants need to be followed for a longer period of time before treatment differences in adenoma recurrence emerge, particularly if diet affects early events in the neoplastic process. The PPT-Continued Follow-up Study (PPT-CFS) was a post-intervention observation of PPT participants for an additional 4 years from the completion of the trial. Of the 1,905 PPT participants, 1,192 consented to participate in the PPT-CFS and confirmed colonoscopy reports were obtained on 801 participants. The mean time between the main trial end point colonoscopy and the first colonoscopy in the PPT-CFS was 3.94 years (intervention group) and 3.87 years (control group). The baseline characteristics of 405 intervention participants and 396 control participants in the PPT-CFS were quite similar. Even though the intervention group participants increased their fat intake and decreased their intakes of fiber, fruits, and vegetables during the PPT-CFS, they did not go back to their prerandomization baseline diet (P < 0.001 from paired t tests) and intake for each of the three dietary goals was still significantly different from that in the controls during the PPT-CFS (P < 0.001 from t tests). As the CFS participants are a subset of the people in the PPT study, the nonparticipants might not be missing completely at random. Therefore, a multiple imputation method was used to adjust for potential selection bias. The relative risk (95% confidence intervals) of recurrent adenoma in the intervention group compared with the control group was 0.98 (0.88-1.09). There were no significant intervention-control group differences in the relative risk for recurrence of an advanced adenoma (1.06; 0.81-1.39) or multiple adenomas (0.92; 0.77-1.10). We also used a multiple imputation method to examine the cumulative recurrence of adenomas through the end of the PPT-CFS: the intervention-control relative risk (95% confidence intervals) for any adenoma recurrence was 1.04 (0.98-1.09). This study failed to show any effect of a low-fat, high-fiber, high-fruit and -vegetable eating pattern on adenoma recurrence even with 8 years of follow-up. (Cancer Epidemiol Biomarkers Prev 2007;16(9):1745-52).

Magnifying colonoscopy: interobserver agreement in the assessment of colonic pit patterns and its correlation with histopathological findings

BACKGROUND AND STUDY AIMS

Magnifying colonoscopy (MC) is recognized as an aid to the differential diagnosis between neoplastic and nonneoplastic lesions. This study evaluated interobserver agreement of experienced endoscopists in the assessment of colonic pit patterns through the Kudo's classification and correlated morphological aspects with histopathological findings.

MATERIALS AND METHODS

A total of 213 magnification chromoendoscopic pictures of colonic lesions were collected from 161 consecutive patients and presented to three independent observers who expressed opinion about predominant pit pattern. All lesions were excised and sent for histopathological study.

RESULTS

Kappa statistics showed that the general agreement index with respect to the aspects of the pits was good among the three observers (0.561). Regarding prediction of histopathology according to the pit pattern diagnosis, overall accuracy was 84%, sensitivity was 91.4%, specificity was 67.2%, positive predictive value was 86.6%, and negative predictive value was 79.3%.

CONCLUSION

Although the interobserver reproducibility of the colonic pit pattern is good for experienced endoscopists, MC must not be used to replace the histopathological analysis, since it does not differentiate with the necessary safety neoplastic from nonneoplastic lesions.

Role of BRAF-V600E in the serrated pathway of colorectal tumourigenesis

There is increasing evidence for an alternative pathway of sporadic colorectal tumourigenesis that is associated with DNA microsatellite instability (MSI), due to methylation and loss of expression of the mismatch repair gene MLH1. Recent studies have highlighted a serrated pathway of colorectal cancer (CRC) in which serrated polyps with activating mutations in BRAF progress to CRCs with MSI following methylation and silencing of MLH1. The present study provides a novel mechanistic experimental model for these clinical observations. We investigated the role of BRAF activating mutation (BRAF-V600E) in colorectal tumourigenesis by studying the effects of forced expression of BRAF-V600E in the 'normal' colon epithelial NCM460 cell line and by targeting endogenous BRAF-V600E in MSI-High (MSI-H) colon cancer cell lines. The findings indicate that BRAF mutation in colon epithelial cells contributes to a gain in resistance towards apoptotic stimuli, which is likely to be an important characteristic of pre-malignant serrated lesions. BRAF-V600E also plays a role in the development and maintenance of transformed and invasive phenotypes in colon epithelial cells. Our findings also suggest that BRAF mutation potentiates promoter hypermethylation of the MLH1 gene promoter. Together, these results highlight BRAF as a potential target for therapeutic intervention in sporadic MSI-H colorectal cancers.

Dietary fiber and risk of colorectal cancer in the Japan collaborative cohort study

To examine the association of dietary fiber with the risk of colorectal cancer in a population with a high incidence of cancer and a low fiber intake, we analyzed the data from the Japan Collaborative Cohort Study. From 1988 to 1990, 43,115 men and women aged 40 to 79 years completed a questionnaire on dietary and other factors. Intake of dietary fiber was estimated using a food frequency questionnaire. Rate ratios (RR) were computed by fitting proportional hazards models. During the mean follow-up of 7.6 years, 443 colorectal cancer cases were recorded. In all participants, we found a decreasing trend in risk of colorectal cancer with increasing intake of total dietary fiber; the multivariate-adjusted RRs across quartiles were 1.00, 0.96 [95% confidence interval (95% CI), 0.72-1.27], 0.72 (0.53-0.99), and 0.73 (0.51-1.03; P(trend) = 0.028). This trend was exclusively detected for colon cancer: the corresponding RRs were 1.00, 0.90 (95% CI, 0.64-1.26), 0.56 (0.38-0.83), and 0.58 (0.38-0.88; P(trend) = 0.002). The decrease in RRs with increasing intake of dietary fiber was larger in men than in women. No material differences appeared in the strength of associations with the risk between water-soluble and insoluble dietary fiber. For food sources of fiber, bean fiber intake was somewhat inversely correlated with colorectal cancer risk. This prospective study supported potential protective effects of dietary fiber against colorectal cancer, mainly against colon cancer. The role of dietary fiber in the prevention of colorectal cancer seems to remain inconsistent, and further investigations in various populations are warranted. (

Prognostic and predictive value of baseline and posttreatment molecular marker expression in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

PURPOSE

To evaluate expression of a panel of molecular markers, including p53, p21, MLH1, MSH2, MIB-1, thymidylate synthase, epidermal growth factor receptor (EGFR), and tissue vascular endothelial growth factor (VEGF), before and after treatment in patients treated with neoadjuvant chemoradiotherapy for locally advanced rectal cancer, to correlate the constitutive profile and dynamics of expression with pathologic response and outcome.

METHODS AND MATERIALS

Expression of biomarkers was evaluated by immunohistochemistry in tumor samples from 91 patients with clinical Stage II and III rectal cancer treated with preoperative pelvic radiotherapy (50 Gy) plus concurrent 5-fluorouracil by continuous intravenous infusion.

RESULTS

A pathologic complete remission was observed in 14 patients (15.4%). Patients with MLH1-positive tumors had a higher pathologic complete response rate (24.3% vs. 9.4%; p = 0.055). Low expression of constitutive p21, absence of EGFR expression after chemoradiotherapy, and high Dworak's tumor regression grade (TRG) were significantly associated with improved disease-free survival and overall survival. A high MIB-1 value after chemoradiotherapy was significantly associated with worse overall survival. Multivariate analysis confirmed the prognostic value of constitutive p21 expression as well as EGFR expression and MIB-1 value after chemoradiotherapy among patients not achieving TRG 3-4.

CONCLUSIONS

In our study, we observed the independent prognostic value of EGFR expression after chemoradiotherapy on disease-free survival. Moreover, our study suggests that a constitutive high p21 expression and a high MIB-1 value after neoadjuvant chemoradiotherapy treatment could predict worse outcome in locally advanced rectal cancer.

Clinical application of pharmacogenetics in gastrointestinal diseases

As knowledge of the human genome grows, there will be a direct impact on the management of specific diseases. Within gastroenterology and hepatology, there has been a change in the understanding of how variations or mutations in genes involved in drug metabolism or disease pathophysiology affect response to therapy. This review discusses the application of clinical pharmacogenetics to the following diseases and disorders: inflammatory bowel disease, Helicobacter pylori infections, gastroesophageal reflux disease, irritable bowel syndrome, functional dyspepsia, liver transplantation and colon cancer. Although only a few genotyping tests are regularly used in clinical practice, it is anticipated that studies will propel the routine use of many of the tests described in this review, in the future.

E-cadherin expression pattern in primary colorectal carcinomas and their metastases reflects disease outcome

AIM: To investigate the changes that occur in E-cadherin expression during the process of metastasis in colorectal cancer.

METHODS: E-cadherin expression was detected by immunohistochemistry and two indices of expression were calculated which reflected the level of expression and the locations (membrane and cytoplasm). Univariate and multivariate survival analyses were used to assess the value of these two E-cadherin indices as predictors of both disease-free (DFS) and disease-specific (DSS) survival.

RESULTS: E-cadherin membrane index (MI), but not cytoplasmic index (CI), was significantly higher in primary tumors than their metastases (P = 0.0001). Furthermore, both primary tumor MI and CI were higher among the patients who developed subsequent metastasis (P = 0.022 and P = 0.007, respectively). Interestingly, both indices were higher in liver metastase compared to other anatomic sites (MI, P = 0.034 and CI, P = 0.022). The CI of the primary tumors was a significant predictor of DFS (P = 0.042, univariate analysis), with a strong inverse correlation between CI and DFS (P = 0.006, multivariate analysis). Finally, the MI of primary tumor proved to be a significant independent predictor of DSS, with higher indices being associated with a more favorable outcome (P = 0.016).

CONCLUSION: Examination of E-cadherin expression and distribution in colorectal tumors can be extremely valuable in predicting disease recurrence. The observation that aberrant cytoplasmic expression of E-cadherin can predict disease recurrence is obviously of great importance for both patients and clinicians, and significantly affects decisions concerning the therapy and management of the patients.

Can patient satisfaction with quality of life predict survival in advanced colorectal cancer?

GOALS OF WORK

The goal of this study was to evaluate the association between patient satisfaction with quality of life (QoL) and survival in colorectal cancer patients undergoing care in a community hospital comprehensive cancer center.

MATERIALS AND METHODS

A consecutive case series of 177 cases of histologically confirmed colorectal cancer treated at Cancer Treatment Centers of America at Midwestern Regional Medical Center between April 2001 and November 2004. The quality of life index (QLI) was utilized to assess patient satisfaction with QoL. QLI measures global QoL and the QoL in four major subscales: health and physical functioning, social and economic, psychological/spiritual, and family. All scores range from 0 to 30 with higher scores indicating a better QoL. Kaplan-Meier method was used to calculate survival. Log-rank test was used to study the equality of survival distributions. Multivariate Cox regression analyses were then performed to evaluate the joint prognostic significance of those QoL and clinical factors that were shown to be prognostic in univariate analyses.

RESULTS

Of the 177 patients, 46 were newly diagnosed and 131 have treatment history. The median age was 53 years (range 25-85 years). Eight patients had stage I disease, 16 had stage II, 51 had stage III, and 77 had stage IV. Health and physical subscale was significantly associated with survival (p=0.0003), with the median survival for low scores being 8.3 and 20.6 months for high scores. Health and physical subscale was found to be predictive of survival independent of the effects of tumor stage at diagnosis and treatment history.

CONCLUSIONS

We found that baseline patient satisfaction with QoL, as measured by the QLI, provides useful prognostic information in patients with colorectal cancer independent of tumor stage at diagnosis and treatment history. While these findings require further investigation in large patient cohorts, they may have important implications for patient stratification in clinical trials and aid in clinical decision-making.

La cirugía en el cáncer de colon complicado

Colorectal cancer continues to have a serious social impact. A large proportion of patients are diagnosed at an advanced stage of the disease. Approximately one-third of patients with colorectal cancer will undergo emergency surgery for a complicated tumor, with a high risk of mortality and poorer long-term prognosis. The most frequent complications are obstruction and perforation, while massive hemorrhage is rare. The curative potential of surgery, whether urgent or elective, depends on how radical the resection is, among other factors. In the literature on the management of urgent colorectal disease, there are few references to the oncological criteria for resection. Uncertainly about the optimal treatment has led to wide variability in the treatment of this entity. The present article aims to provide a critical appraisal of the controversies surrounding the role of surgery and its impact on complicated colorectal cancer.

Duration of adjuvant chemotherapy for colon cancer and survival among the elderly

PURPOSE

In randomized trials, patients with stage III colon cancer who received 6 months of fluorouracil (FU)-based adjuvant chemotherapy had better survival than patients who did not. However, little is known about the predictors of, or the survival associated with, duration of chemotherapy in the community.

PATIENTS AND METHODS

The linked Surveillance, Epidemiology, and End Results-Medicare database was used to identify individuals > or = 65 years of age diagnosed with stage III colon cancer between 1995 and 1999. We used logistic and Cox proportional hazards regression models to analyze factors associated with early discontinuation of FU-based chemotherapy among these elderly colon cancer patients.

RESULTS

Among 1,722 patients who received 1 to 7 months of FU-based chemotherapy, older age, being unmarried, and having comorbid conditions were associated with receiving less than 5 months of treatment. Among the 1,579 patients who survived > or = 8 months, the 1,091 (69.1%) who received 5 to 7 months of treatment had lower overall (hazard ratio [HR], 0.59; 95%, CI 0.49 to 0.71) and colon cancer-specific (HR, 0.53; 95% CI, 0.43 to 0.66) mortality than the 488 (30.9%) who received 1 to 4 months of treatment.

CONCLUSION

More than 30% of elderly patients who initiated FU-based chemotherapy for stage III colon cancer and survived for at least 8 months discontinued treatment early. Mortality rates among such patients were nearly twice as high as among patients who completed 5 to 7 months of treatment. If the association we observed between duration of treatment and survival is confirmed, additional investigation is warranted to determine whether dose-intensity, cumulative dose, or other factors related to receipt of full adjuvant treatment are responsible.

Colorectal carcinoma among Indigenous people: a public hospital-based study in Townsville and Cairns, North Queensland, Australia

INTRODUCTION

There are very little clinical and pathological data on colorectal cancer among Indigenous people in Australia.

METHODS

A retrospective study on Indigenous patients treated for colorectal cancer at the Townsville and Cairns Base Hospitals from 1999 to 2004 was carried out in order to better characterise this disease in the Indigenous population.

RESULTS

There were 25 patients (12 M, 13 F) with a median age of 57.3 years. The majority (56%) of the tumours were left-sided, being in the sigmoid colon, rectosigmoid junction and rectum. Of the patients, 60% had American Joint Committee on Cancer (AJCC) staging system Stage I and II disease at presentation. There was a relatively high proportion of poorly differentiated adenocarcinomas (40%). Six patients died of the disease. The median follow-up was 20.5 months (range 2-51).

CONCLUSIONS

Comparisons were made with available data on colorectal cancer in the general Australian population. The limitations and deficiencies of the study, as well as problems of data collection on Indigenous people were discussed.