Dukes B colorectal cancer: distinct genetic categories and clinical outcome based on proximal or distal tumor location

Survival rates and prognostic factors in right- and left-sided colon cancer stage I-IV: an unselected retrospective single-center trial

PURPOSE

Colorectal cancer revealed over the last decades a remarkable shift with an increasing proportion of a right- compared to a left-sided tumor location. In the current study, we aimed to disclose clinicopathological differences between right- and left-sided colon cancer (rCC and lCC) with respect to mortality and outcome predictors.

METHODS

In total, 417 patients with colon cancer stage I-IV were analyzed in the present retrospective single-center study. Survival rates were assessed using the Kaplan-Meier method and uni/multivariate analyses were performed with a Cox proportional hazards regression model.

RESULTS

Our study showed no significant difference of the overall survival between rCC and lCC stage I-IV (p = 0.354). Multivariate analysis revealed in the rCC cohort the worst outcome for ASA (American Society of Anesthesiologists) score IV patients (hazard ratio [HR]: 16.0; CI 95%: 2.1-123.5), CEA (carcinoembryonic antigen) blood level > 100 µg/l (HR: 3.3; CI 95%: 1.2-9.0), increased lymph node ratio of 0.6-1.0 (HR: 5.3; CI 95%: 1.7-16.1), and grade 4 tumors (G4) (HR: 120.6; CI 95%: 6.7-2179.6) whereas in the lCC population, ASA score IV (HR: 8.9; CI 95%: 0.9-91.9), CEA blood level 20.1-100 µg/l (HR: 5.4; CI 95%: 2.4-12.4), conversion to laparotomy (HR: 14.1; CI 95%: 4.0-49.0), and severe surgical complications (Clavien-Dindo III-IV) (HR: 2.9; CI 95%: 1.5-5.5) were identified as predictors of a diminished overall survival.

CONCLUSION

Laterality disclosed no significant effect on the overall prognosis of colon cancer patients. However, group differences and distinct survival predictors could be identified in rCC and lCC patients.

Clinical and molecular characteristics and treatment outcomes of advanced right-colon, left-colon and rectal cancers: data from 1180 patients in a phase III trial of panitumumab with an extended biomarker panel

BACKGROUND

Primary tumour location (PTL) is being adopted by clinicians to guide treatment decisions in metastatic colorectal cancer (mCRC). Here we test PTL as a predictive marker for panitumumab efficacy, and examine its relationship with an extended biomarker profile. We also examine rectal tumours as a separate location.

PATIENTS AND METHODS

mCRC patients from the second-line PICCOLO trial of irinotecan versus irinotecan/panitumumab (IrPan). PTL was classified as right-PTL, left-PTL or rectal-PTL. PTL was assessed as a predictive biomarker for IrPan effect in RAS-wild-type (RAS-wt) patients (compared with irinotecan alone), then tested for independence alongside an extended biomarker profile (BRAF, epiregulin/amphiregulin (EREG/AREG) and HER3 mRNA expression).

RESULTS

PTL data were available for 1180 patients (98.5%), of whom 558 were RAS-wt. High HER3 expression was independently predictive of panitumumab overall survival improvement, but PTL and EREG/AREG were not. IrPan progression-free survival (PFS) improvement compared with irinotecan was seen in left-PTL [hazard ratio (HR) = 0.61, P = 0.002) but not right-PTL (HR = 0.98, P = 0.90) (interaction P = 0.05; RAS/BRAF-wt interaction P = 0.10), or in rectal-PTL (HR = 0.82, P = 0.20) (interaction P = 0.14 compared with left-PTL; RAS/BRAF-wt interaction P = 0.04). Patients with right-PTL and high EREG/AREG or HER3 expression, had IrPan PFS improvement (high EREG/AREG HR = 0.20, P = 0.04; high HER3 HR = 0.33, P = 0.10) compared with irinotecan. Similar effect was seen for rectal-PTL patients (high EREG/AREG HR = 0.44, P = 0.03; high HER3 HR = 0.34, P = 0.05).

CONCLUSIONS

RAS-wt patients with left-PTL are more likely to have panitumumab PFS advantage than those with right-PTL or rectal-PTL. However, an extended biomarker panel demonstrated significant heterogeneity in panitumumab PFS effect within a tumour location. AREG/EREG and HER3 mRNA expression identifies patients with right-PTL or rectal-PTL who achieve similar PFS effect with panitumumab as left-colon patients. Testing could provide a more reliable basis for clinical decision making. Further validation and development of these biomarkers is required to optimise routine patient care.

CLINICAL TRIAL REGISTRATION

ISRCTN identifier: ISRCTN93248876.

Overexpression of TP53 protein is associated with the lack of adjuvant chemotherapy benefit in patients with stage III colorectal cancer

TP53 mutations drive colorectal cancer development, with missense mutations frequently leading to accumulation of abnormal TP53 protein. TP53 alterations have been associated with poor prognosis and chemotherapy resistance, but data remain controversial. Here, we examined the predictive utility of TP53 overexpression in the context of current adjuvant treatment practice for patients with stage III colorectal cancer. A prospective cohort of 264 stage III patients was tested for association of TP53 expression with 5-year disease-free survival, grouped by adjuvant treatment. Findings were validated in an independent retrospective cohort of 274 stage III patients. Overexpression of TP53 protein (TP53+) was found in 53% and 52% of cases from the prospective and retrospective cohorts, respectively. Among patients receiving adjuvant chemotherapy, TP53+ status was associated with shorter disease-free survival (p ≤ 0.026 for both cohorts), while no difference in outcomes between TP53+ and TP53- cases was observed for patients treated with surgery alone. Considering patients with TP53- tumors, those receiving adjuvant treatment had better outcomes compared with those treated with surgery alone (p ≤ 0.018 for both cohorts), while no treatment benefit was apparent for patients with TP53+ tumors. Combined cohort-stratified analysis adjusted for clinicopathological variables and DNA mismatch repair status confirmed a significant interaction between TP53 expression and adjuvant treatment for disease-free survival (p_interaction = 0.030). For the combined cohort, the multivariate hazard ratio for TP53 overexpression among patients receiving adjuvant chemotherapy was 2.03 (95% confidence interval 1.41-2.95, p < 0.001), while the hazard ratio for adjuvant treatment among patients with TP53- tumors was 0.42 (95% confidence interval 0.24-0.71, p = 0.001). Findings were maintained irrespective of tumor location or when restricted to mismatch repair-proficient tumors. Our data suggest that adjuvant chemotherapy benefit in stage III colorectal cancer is restricted to cases with low-level TP53 protein expression. Identifying TP53+ tumors could highlight patients that may benefit from more aggressive treatment or follow-up.

IS THERE A DIFFERENCE BETWEEN RIGHT- VERSUS LEFT-SIDED COLON CANCERS? DOES SIDE MAKE ANY DIFFERENCE IN LONG-TERM FOLLOW-UP?

BACKGROUND

Since 1990 it was proposed that distal and proximal location of colon cancer might follow different biological, epidemiology, pathology and prognosis, probably due to embryologic different development of the two segments of the colon, which may represent two separate disease entities. These differences might have consequences for the treatment of patients with colorectal cancer.

AIM

To compare the characteristics between patients with right and left colon cancer, with severity and tumor characteristic that influence in the survival of these patients.

METHOD

Were evaluated the outcomes of surgical treatment of patients with colon cancer with data collected retrospectively from prospectively collected database.

RESULTS

The tumor's side did not influence survival time of patients with colon cancer (p=0.112) in the regression model. Only the diseases stage leads to influence on survival time; patients with right colon cancer have more advanced staging (III or IV) and present a risk of death greater in 3.23 times.

CONCLUSION

This analysis provides evidence that the prognosis of localized left-sided colon cancer is better compared to right-sided colon cancer. Also, the patients with right colon cancer have more advanced stage, mucinous tumor and are older.

Clinical significance and comparison of flotillin 1 expression in left and right colon cancer

Flotillin 1 (FLOT1) is increasingly implicated in various types of cancer, and has been reported to influence tumorigenesis and cancer progression, leading to poor prognosis for survival time; however, its expression in colorectal cancer (CRC) and its influence on various clinicopathological parameters of this disease remain unknown. In the present study, FLOT1 expression and its effect on different clinicopathological parameters were assessed immunohistochemically and histologically in 81 CRC and 81 non-tumorous colon tissue samples. The immunohistochemical staining was scored semi-quantitatively. The association of FLOT1 expression with various parameters and its effect on overall survival time was also assessed. FLOT1 was upregulated in the CRC tissue, with increased expression in the right colon tissue samples compared with those of left colon. Increased FLOT1 expression in CRC tissue samples was associated with tumor volume, differentiation, tumor grade and poor overall survival time. In the right colon tissue samples in particular, there was a notable association with tumor volume and grade, indicating its effect on proliferation and tumor stage at this site. A multivariate Cox regression hazard analysis revealed that only tumor grade and differentiation were the independent predictors of overall survival time in patients with CRC. Together, the results of the present study suggest that FLOT1 serves important functions in the proliferation and progression of CRC, contributes to decreased survival time, and may serve as a novel therapeutic target for the treatment of CRC.

Different Anatomical Subsites of Colon Cancer and Mortality: A Population-Based Study

Background

In terms of incidence and pathogenesis, right-sided colon cancer (RCC) and left-sided colon cancer (LCC) exhibit several differences. However, whether existing differences could reflect the different survival outcomes remains unclear. Therefore, we aimed to ascertain the role of location in the prognosis.

Methods

We identified colon cancer cases from the Surveillance, Epidemiology, and End Results database between 1973 and 2012. Differences among subsites of colon cancer regarding clinical features and metastatic patterns were compared. The Kaplan-Meier curves were conducted to compare overall and disease-specific survival in relation to cancer location. The effect of tumour location on overall and cancer-specific survival was analysed by Cox proportional hazards model.

Results

A total of 377,849 patients from SEER database were included in the current study, with 180,889 (47.9%) RCC and 196,960 (52.1%) LCC. LCC was more likely to metastasize to the liver and lung. Kaplan-Meier curves demonstrated that LCC patients had better overall and cancer-specific survival outcomes. Among Cox multivariate analyses, LCC was associated with a slightly reduced risk of overall survival (HR, 0.92; 95% CI, 0.92-0.93) and cancer-specific survival (HR, 0.92; 95% CI, 0.91-0.93), even after adjusted for other variables. However, the relationship between location and prognosis was varied by subgroups defined by age, year at diagnosis, stage, and therapies.

Conclusions

We demonstrated that LCC was associated with better prognosis, especially for patients with distant metastasis. Future trails should seek to identify the underlying mechanism.

Comparison of survival between right-sided and left-sided colon cancer in different situations

Mountain of studies has showed that right‐sided colon cancer (RSCC) and left‐sided colon cancer (LSCC) have different clinical presentation and biologic features and should be considered as two distinct disease entities. The survival difference between RSCC and LSCC remains controversial. Using Surveillance, Epidemiology, and End Results (SEER) database, we identified colon adenocarcinoma patients from 2004 to 2013. The 5‐year cause‐specific survival (CSS) was our primary endpoint. All statistical analyses were performed using the Intercooled Stata 13.0. All statistical tests were two‐sided. The study included 95,847 (58.72%) RSCC and 67,385 (41.28%) LSCC patients. RSCC patients were older, more often females, more Caucasian, more unmarried, more advanced T and N stage, larger tumor sizes, and more poorly differentiated tumor, while LSCC patients had more stage IV diseases. Location was an independent prognostic factor in the multivariable analysis. Compared with RSCC patients, the hazard ratio for LSCC was 0.87, 95% CI: 0.85–0.89 P < 0.001. There was no survival difference between RSCC and LSCC in the following situations: older than 68 years old, T3–4, N0, poorly differentiated, and undifferentiated diseases. We firstly reported that RSCC patients had a better prognosis than LSCC in mucinous adenocarcinoma/signet ring cell carcinoma patients. RSCC patients also had a better prognosis than LSCC in stage II disease. There is a need for further subdivisions when analyzing the survival difference between RSCC and LSCC patients. RSCC had lower mortality rate than LSCC in stage II disease and mucinous adenocarcinoma/signet ring cell carcinoma patients.

Tumor location as a novel high risk parameter for stage II colorectal cancers

Current studies do not accurately evaluate the influence of tumor location on survival of colorectal cancer patients. This study aimed to explore whether tumor location could be identified as another high-risk factor in stage II colorectal cancer by using data identified from the Surveillance, Epidemiology, and End Results database. All colorectal cancer patients between 2004 and 2008 were grouped into three according to tumor location. Of 33,789 patients diagnosed with stage II colorectal cancer, 46.8% were right colon cancer, 37.5% were left colon cancer and 15.7% were rectal cancer. The 5-year cancer specific survivals were examined. Right colon cancer was associated with the female sex, older age (> 50), and having over 12 lymph nodes resected. Conversely, rectal cancer was associated with the male sex, patients younger than 50 years of age and insufficient lymph node resection. The characteristics of left colon cancer were between them and associated with Asian or Pacific Islander populations, T4 stage, and Grade II patients. The prognostic differences between three groups were significant and retained after stratification by T stage, histological grade, number of regional nodes dissected, age at diagnose, race and sex. Furthermore, the significant difference of location was retained as an independent high-risk parameter. Thus, stage II colorectal cancers of different locations have different clinic-pathological features and cancer-specific survivals, and tumor location should be recognized as another high-risk parameter in stage II colorectal cancer.

Influence of primary site on metastatic distribution and survival in stage IV colorectal cancer

BACKGROUND

To assess pattern distribution and prognosis of the three anatomical entities of metastatic colorectal cancer, and influence of treatment of metastases on survival.

METHODS

Patients presenting with stage IV colorectal cancer (synchronous group), or who developed metastatic recurrence (metachronous group) after initial curative treatment between January 2005 and August 2015 were reviewed. Right sided (cecum to transverse colon), left sided (splenic flexure to sigmoid colon) and rectal cancers were identified. Distribution of metastases were noted as hepatic, lung or peritoneal.

RESULTS

Of 374 patients, 276 were synchronous, 98 were metachronous. Metachronous group had a better 3-year survival (54%, 95% CI: 42-64 versus 33%, 95% CI: 27-39, log rank P = 0.0038). There were equal numbers of right (n = 119), left (n = 115) and rectal cancers (n = 140). Rectal cancers had a higher metastatic recurrence, yet demonstrated better 3-year survival (right colon 45%, 95% CI: 19-67, left colon 49%, 95% CI: 27-68, rectum 59%, 95% CI: 42-72, P = 0.39) due to higher proportions of metachronous patients undergoing treatment for metastases (40 versus 14%). Over half of all organ metastases spread to liver, with equal distribution from all three anatomical groups. Rectal cancers showed highest preponderance for lung metastases.

CONCLUSION

Rectal cancers have a higher chance of recurring, with a higher metastatic rate to the lung, yet demonstrate better survival outcomes in metastatic colorectal cancer, reflecting the benefit of intervention for metastases.

Passive Smoking and Risk of Colorectal Cancer

We conducted this meta-analysis to explore the association between passive smoking and the risk of colorectal cancer. A literature search of online databases, including MEDLINE, EMBASE, the Cochrane Library, and Web of Science was performed up to June 30, 2015. A fixed-effects meta-analysis using Stata 12.0 was carried out to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for the associations. Eleven articles, including 6 case-control studies and 6 cohort studies, were included in our analysis according to inclusion and exclusion criteria. The pooled RR of all studies showed a statistically significant association between passive smoking and colorectal cancer (RR = 1.14; 95% CI = 1.05-1.24). Results of subgroup analysis showed a positive association between passive smoking and rectal cancer ((RR = 1.33; 95% CI = 1.15-1.53) and that male passive smokers were at greater risks of colorectal cancer (RR = 1.73; 95% CI = 1.37-2.19) than females. Results suggested that passive smoking is associated with an increased risk of colorectal cancer.

The influence of hormone therapies on colon and rectal cancer

Exogenous sex hormones seem to play a role in colorectal carcinogenesis. Little is known about the influence of different types or durations of postmenopausal hormone therapy (HT) on colorectal cancer risk. A nationwide cohort of women 50-79 years old without previous cancer (n = 1,006,219) were followed 1995-2009. Information on HT exposures was from the National Prescription Register and updated daily, while information on colon (n = 8377) and rectal cancers (n = 4742) were from the National Cancer Registry. Potential confounders were obtained from other national registers. Poisson regression analyses with 5-year age bands included hormone exposures as time-dependent covariates. Use of estrogen-only therapy and combined therapy were associated with decreased risks of colon cancer (adjusted incidence rate ratio 0.77, 95 % confidence interval 0.68-0.86 and 0.88, 0.80-0.96) and rectal cancer (0.83, 0.72-0.96 and 0.89, 0.80-1.00), compared to never users. Transdermal estrogen-only therapy implied more protection than oral administration, while no significant influence was found of regimen, progestin type, nor of tibolone. The benefit of HT was stronger for long-term hormone users; and hormone users were at lower risk of advanced stage of colorectal cancer, which seems supportive for a causal association between hormone therapy and colorectal cancer.

miRNA as markers for the diagnostic screening of colon cancer

Early screening for colon cancer (CC) allows for early stage diagnosis of the malignancy and potentially reduces disease mortality as the cancer is most likely curable at its earliest stages. Early detection would be desirable if accurate, practical and cost-effective diagnostic measures for this cancer were available. Mortality and morbidity from CC represent a major health problem involving a malignant disease that is theoretically preventable through screening. Current screening methods (e.g., the convenient and inexpensive immunological fecal occult blood test, FOBTi, obtained from patients' medical records) either lack sensitivity and require dietary restriction, which impedes compliance and use; are costly (e.g., colonoscopy), which decreases compliance; or could result in mortality. In comparison with the FOBT test, a non-invasive sensitive screen for which there is no requirement for dietary restriction would be a more convenient test. Colorectal cancer is the only cancer for which colonoscopy is recommended as a screening method. Although colonoscopy is a reliable screening tool, the invasive nature, abdominal pain, potential complications and high cost have hampered the application of this procedure worldwide. A screening approach using the stable miRNA molecules, which are relatively non-degradable when extracted from non-invasive stool and semi-invasive blood samples by commercially available kits and manipulated thereafter, would be preferable to a transcriptomic mRNA-, a mutation DNA-, an epigenetic- or a proteomic-based test. The approach uses reverse transcriptase, modified real-time quantitative PCR. Although exosomal RNA would be missed, using a restricted extraction of total RNA from stool or blood, a parallel test could also be carried out on RNA obtained from stool or plasma samples, and appropriate corrections for exsosomal loss can be made for accurate and quantitative test result. Eventually, a chip can be developed to facilitate diagnosis, as has been done for the quantification of genetically modified organisms in foods. The gold standard to which the molecular miRNA test is compared is colonoscopy, which can be obtained from patients' medical records. If performance criteria are met, as detailed herein, a miRNA test in human stool or blood samples based on high-throughput automated technologies and quantitative expression measurements commonly used in the diagnostic clinical laboratory should be advanced to the clinical setting, which will make a significant impact on CC prevention.

Microenvironment influence on human colon adenocarcinoma phenotypes and matrix metalloproteinase-2, p53 and β-catenin tumor expressions from identical monoclonal cell tumor in the orthotopic model in athymic nude rats

The present study aims to identify differences between left and right colon adenocarcinoma arising from identical clonal cell and to find out if microenvironment has any influence on matrix metalloproteinase-2 (MMP2), p53 and β-catenin tumor expressions. MATERIAL AND METHODS. Rats (RNU) were submitted to cecostomy to obtain the orthotopic model of right colon tumor (n = 10), while for the left colon model (n = 10), a colon diversion and distal mucous fistula in the descending colon was used. Cultivated human colon adenocarcinoma cells (WiDr) were inoculated in stomas submucosa. Histopathological analysis, real-time reverse transcription-PCR for β-catenin, p53 and MMP2, as well as immunohistochemical analysis for p53 and β-catenin expression were conducted. Central tendency, variance analysis and the Livak delta-delta-CT method were used for statistical analysis, adopting a 5% significance level. RESULTS. All tumors from the left colon exhibited infiltrative ulceration, while in the right colon tumor growth was predominantly exophytic (67%). In the left colon, tumor growth was undifferentiated (100%), while it was moderately differentiated in the right colon (83%). In right colon tumors, MMP2, p53, and β-catenin gene expressions were higher than compared to left colon (p = 4.59354E-05, p = 0.0035179, p = 0.00093798, respectively, for MMP2, p53 and β-catenin). β-catenin and p53 results obtained by real-time polymerase chain reaction were confirmed by immunohistochemistry assay (p = 0.01 and p = 0.001, respectively, for β-catenin and p53). CONCLUSION. Left and right human colon adenocarcinomas developed in animal models have distinct phenotypes even when they have the same clonal origin. Microenvironment has influenced p53, β-catenin, and MMP2 expression in animal models of colon cancer.

Clinicopathological significance of BTF3 expression in colorectal cancer

Basic transcription factor 3 (BTF3) is a general RNA polymerase II transcription factor and is also involved in apoptosis regulation. Increasing evidence shows that BTF3 is aberrantly expressed in several kinds of malignancies, but there is no study to analyze BTF3 expression in colorectal cancer (CRC) patients. Applying immunohistochemistry, we detected BTF3 in CRCs (n = 156), the corresponding distant (n = 42), adjacent normal mucosa (n = 96), lymph node metastases (n = 35), and analyzed its relationships with clinicopathological and biological variables. Our results showed that BTF3 staining significantly increased from distant or adjacent normal mucosa to primary CRCs (p < 0.0001) or metastases (p = 0.002 and p < 0.0001). BTF3 was higher in distal cancers than in proximal cancers (57 % vs. 39 %, p = 0.041). It also showed stronger staining in primary CRCs stage I and II than that in stage III and IV (64 % vs. 35 %, p = 0.0004), or metastases (64 % vs. 29 %, p = 0.004). Cancers with better differentiation had a higher expression than those with worse differentiation (56 % vs. 37 %, p = 0.031). There were positive correlations of BTF3 expression with nuclear factor kappa B (NF-κB), RAD50, MRE11, NBS1, and AEG-1 (p < 0.05). In conclusion, BTF3 overexpression may be an early event in CRC development and could be useful biomarker for the early stage of CRCs. BTF3 has positive correlations with NF-κB, RAD50, MRE11, NBS1 and AEG-1, and might influence complex signal pathways in CRC.

Somatic profiling of the epidermal growth factor receptor pathway in tumors from patients with advanced colorectal cancer treated with chemotherapy ± cetuximab

PURPOSE

To study the somatic molecular profile of the EGF receptor (EGFR) pathway in advanced colorectal cancer, its relationship to prognosis, the site of the primary and metastases, and response to cetuximab.

EXPERIMENTAL DESIGN

We used Sequenom and Pyrosequencing for high-throughput somatic profiling of the EGFR pathway in 1,976 tumors from patients with advanced colorectal cancer from the COIN trial (oxaliplatin and fluoropyrimidine chemotherapy ± cetuximab). Correlations between mutations, clinicopathologic, response, and survival data were carried out.

RESULTS

Sequenom and Pyrosequencing had 99.0% (9,961/10,063) genotype concordance. We identified 13 different KRAS mutations in 42.3% of advanced colorectal cancers, 2 BRAF mutations in 9.0%, 4 NRAS mutations in 3.6%, and 5 PIK3CA mutations in 12.7%. 4.2% of advanced colorectal cancers had microsatellite instability (MSI). KRAS and PIK3CA exon 9, but not exon 20, mutations cooccurred (P = 8.9 × 10(-4)) as did MSI and BRAF mutations (P = 5.3 × 10(-10)). KRAS mutations were associated with right colon cancers (P = 5.2 × 10(-5)) and BRAF mutations with right (P = 7.2 × 10(-5)) and transverse colon (P = 9.8 × 10(-6)) cancers. KRAS mutations were associated with lung-only metastases (P = 2.3 × 10(-4)), BRAF mutations with peritoneal (P = 9.2 × 10(-4)) and nodal-only (P = 3.7 × 10(-5)) metastases, and MSI (BRAF(WT)) with nodal-only metastases (P = 2.9 × 10(-4)). MSI (BRAF(WT)) was associated with worse survival (HR = 1.89, 95% CI 1.30-2.76, P = 8.5 × 10(-4)). No mutations, subsets of mutations, or MSI status were associated with response to cetuximab.

CONCLUSIONS

Our data support a functional cooperation between KRAS and PIK3CA in colorectal tumorigenesis and link somatic profiles to the sites of metastases. MSI was associated with poor prognosis in advanced disease, and no individual somatic profile was associated with response to cetuximab in COIN.

A novel model of distal colon cancer in athymic mice

PURPOSE

The present a novel adenocarcinoma model in athymic mice.

METHODS

Seven athymic mice were used. Colon diversion and distal fistula were made. Adenocarcinoma cells were inoculated in the submucosa of fistula. Tumor growth was monitored daily. Scintigraphy with 99mTc-MIBI was performed to identify the tumor.

RESULTS

The model of distal colon cancer is feasible. Tumor detection was possible by both, macroscopically and molecular imaging. All resections demonstrated poorly differentiated tumors. Colon obstruction occurred in one case, similarly to evolution in human tumors of distal colon.

CONCLUSION

The proposed model of distal colon cancer is feasible, allows for easy monitoring of tumoral growth by both, macroscopically and molecular imaging, and is suitable for studying the evolution of tumor with implementation of cytotoxic therapy in vivo.

NQO1 C609T polymorphism correlated to colon cancer risk in farmers from western region of Inner Mongolia

OBJECTIVE

To investigate the relationship between NAD(P)H:quinone oxidoreductase 1 (NQO1) C609T polymorphism and colon cancer risk in farmers from western region of Inner Mongolia.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to analyze NQO1 C609T polymorphism from 160 healthy controls and 76 colon cancer patients.

RESULTS

Among the colon cancer patients, the incidence of NQO1 T allele (53.29%) was significantly higher than it in control group (33.75%, P<0.001). The individuals with NQO1 T allele had higher risk [2.239 (95% CI: 
1.510-3.321) times] to develop colon cancer than individuals with NQO1 C allele. The incidence of NQO1
 (T/T) (34.21%) in colon cancer patients was higher than that in control group (15.62%, P<0.001). Odds ratios (OR) analysis suggested that NQO1 (T/T) and NQO1 (T/C) genotype carriers had 3.813 (95% CI: 1.836-7.920) times and 2.080 (1.026-4.219) times risk compared with wild-type NQO1 (C/C) gene carriers in developing colon cancer. Individuals with NQO1 (T/T) genotype had 2.541 (95% CI: 0.990-6.552) times, 3.713 (95% CI: 1.542-8.935) times, and 3.471 (95% CI: 1.356-8.886) times risk than individuals with NQO1 (T/C) or NQO1 (C/C) genotype in well-differentiated, moderately-differentiated, and poorly-differentiated colon cancer patients, respectively.

CONCLUSIONS

NQO1 gene C609T could be one of risk factors of colon cancer in farmers from western region of Inner Mongolia.

Differences in gene expression profiles and carcinogenesis pathways between colon and rectal cancer

OBJECTIVE

Colon cancer is more common in the USA and Europe than that in China, for reasons that are unclear. The aim of this study was to investigate the differences in gene expression profiles and carcinogenesis pathways between colon and rectal cancer.

METHODS

Expression profiling of primary tumor tissues from 12 colon and 12 rectal cancers was performed using oligonucleotide microarray analysis. All samples were strictly matched by clinical features. Bioinformatic analyses such as the Kyoto Encyclopedia of Genes and Genomes were used to identify genes and pathways specifically associated with colon or rectal cancers.

RESULTS

A total of 824 genes were differentially expressed in colon and rectal cancers. All differential gene interactions in the Signal-Net were analyzed. More genes were differentially expressed and included in the Signal-Net for rectal than colon cancer. Of the genes differentially expressed between colon and rectal cancer, S100P, the Reg family, ACTN1, CAMK2G and ACAT1 were the most significantly altered. Genes involved in the cell cycle pathway were present in rectal and colon cancers, but were more important in rectal cancer. The p53 and metabolic signaling pathways were significantly different in colon and rectal cancers. Gene expression profiles differed between colon and rectal cancer, with metabolic pathways being more important in rectal cancer.

CONCLUSION

The oncogenesis of rectal cancer may be more complex than that of colon cancer. Some genes could be new biomarkers for distinguishing between these two cancers.

Toward the prognostic significance and therapeutic potential of HER3 receptor tyrosine kinase in human colon cancer

PURPOSE

Abnormal accumulation and dysregulation of the epidermal growth factor receptor family member HER3 is associated with the development of various human cancers including those of the breast, lung, and ovary. We have previously shown that in melanoma HER3 is frequently overexpressed and is associated with poor prognosis. However, the importance of HER3 in colon cancer and its putative prognostic significance is still unknown.

EXPERIMENTAL DESIGN

HER3 expression was analyzed in primary colon tumors from 110 patients by immunohistochemistry and correlated with time of progression. Parallel to this, the influence of HER3 overexpression on cell proliferation, migration, invasion, and apoptosis was investigated in four different colon cancer cell lines including DLD-1, LoVo, CaCO2, and T-84.

RESULTS

HER3 was detected at high frequency and exclusively at the membrane of the primary tumors. Elevated HER3 expression levels may serve as a putative prognostic marker because it associates with cell proliferation and decreased time to disease progression. High HER3 protein expression as well as phosphorylation levels were detected in tested cells. HER3 downregulation by RNA interference abrogated cell proliferation, migration, and invasion. In addition, suppression of HER3 resulted in a G(2)-M cell-cycle arrest, induced apoptosis, and led to morphologic changes in colon cancer cell lines. Furthermore, application of a monoclonal antibody specific to the extracellular portion of the receptor reduced heregulin-β1-induced migration and invasion and also induced apoptosis in colon cancer cell lines.

CONCLUSION

We postulate that HER3 is critically involved in colon cancer progression and may serve as a novel target for therapeutic intervention.

Is diabetes mellitus an independent risk factor for colon cancer and rectal cancer?

OBJECTIVES

Diabetes mellitus (DM) has been associated with an increased risk of colorectal cancer (CRC). The American College of Gastroenterology Guidelines for Colorectal Cancer Screening 2008 recommend that clinicians be aware of an increased CRC risk in patients with smoking and obesity, but do not highlight the increase in CRC risk in patients with DM. To provide an updated quantitative assessment of the association of DM with colon cancer (CC) and rectal cancer (RC), we conducted a meta-analysis of case-control and cohort studies. We also evaluated whether the association varied by sex, and assessed potential confounders including obesity, smoking, and exercise.

METHODS

We identified studies by searching the EMBASE and MEDLINE databases (from inception through 31 December 2009) and by searching bibliographies of relevant articles. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with fixed- and random-effects models. Several subgroup analyses were performed to explore potential study heterogeneity and bias.

RESULTS

DM was associated with an increased risk of CC (summary RR 1.38, 95% CI 1.26-1.51; n=14 studies) and RC (summary RR 1.20, 95% CI 1.09-1.31; n=12 studies). The association remained when we limited the meta-analysis to studies that either controlled for smoking and obesity, or for smoking, obesity, and physical exercise. DM was associated with an increased risk of CC for both men (summary RR 1.43, 95% CI 1.30-1.57; n=11 studies) and women (summary RR 1.35, 95% CI 1.14-1.53; n=10 studies). For RC, there was a significant association between DM and cancer risk for men (summary RR 1.22, 95% CI 1.07-1.40; n=8 studies), but not for women (summary RR 1.09, 95% CI=0.99-1.19; n=8 studies).

CONCLUSIONS

These data suggest that DM is an independent risk factor for colon and rectal cancer. Although these findings are based on observational epidemiological studies that have inherent limitations due to diagnostic bias and confounding, subgroup analyses confirmed the consistency of our findings across study type and population. This information can inform risk models and specialty society CRC screening guidelines.

Adjuvant chemotherapy improves survival in patients with American Joint Committee on Cancer stage II colon cancer

BACKGROUND

It is unclear whether the administration of adjuvant chemotherapy improves survival in patients with American Joint Committee on Cancer (AJCC) stage II colon cancer.

METHODS

The authors used the State of California Cancer Surveillance Program (CSP) to assess patients ages 18 to 80 years with AJCC stage II colon cancer (ie, T3 or T4 and N0) who underwent surgical resection during 1991 and 2006. Patients who had rectal and rectosigmoid cancers were excluded. The cohort was stratified according to the receipt of adjuvant chemotherapy, and clinical and pathologic characteristics and outcomes were assessed.

RESULTS

From the CSP data, 3716 patients were identified who underwent curative-intent surgical resection for stage II colon cancer. When the 2 treatment groups (surgery plus adjuvant chemotherapy [n = 916] and surgery alone [n = 2800]) were compared, patients who received adjuvant chemotherapy were more likely to be younger and to have left-sided lesions with ≥ 12 lymph nodes examined. There was no difference in sex or tumor differentiation between the 2 groups. According to a Kaplan-Meier analysis, patients who received adjuvant chemotherapy had improved overall survival compared with patients who underwent surgery alone (median survival, 12 years vs 9.2 years, respectively; P < .001). In multivariate analysis, adjuvant chemotherapy was identified as an independent predictor of improved survival (hazard ratio, 0.88; 95% confidence interval, 0.78-0.99; P = .031).

CONCLUSIONS

To the authors' knowledge, this is the first population-based analysis to identify a survival advantage for adjuvant chemotherapy in patients with AJCC stage II colon cancer. On the basis of the current findings, the authors concluded that the administration of adjuvant chemotherapy improves survival in select patients with stage II disease.

Colon carcinoma--classification into right and left sided cancer or according to colonic subsite?--Analysis of 29,568 patients

BACKGROUND

It is common to distinguish between right and left colon cancer (RCC and LCC). But, little is known about the influence of its exact location on the tumor stage and characteristics when considering the colonic subsite within the right or left colon.

METHODS

During a five-year period, 29,568 consecutive patients were evaluated by data from the German multi-centered observational study "Colon/Rectal Carcinoma". Patients were split into 7 groups, each group representing a colonic subsite. They were compared regarding demographic factors, tumor stage, metastatic spread and histopathological characteristics.

RESULTS

Analysis of tumor differentiation and histological subtype revealed a linear correlation to the ileocecal valve, supporting the right and left side classification model. However, cancers arising from the RCC's cecum (52.3%) and LCC's splenic flexure (51.0%) showed the highest proportion of UICC stage III/IV tumors and lymphatic invasion, whereas the RCC's ascending colon (46.5%) and LCC's descending (44.7%) showed the lowest, which supports a more complex classification system, breaking down the right and left sides into colonic subsites.

CONCLUSIONS

Age, tumor grade and histological subtype support the right and left side classification model. However, gender, UICC stage, metastatic spread, T and N status, and lymphatic invasion correlated with a specific colonic subsite, irrespective of the side. The classification of RCC or LCC provides a general understanding of the tumor, but identification of the colonic subsite provides additional prognostic information. This study shows that the standard right and left side classification model may be insufficient.

A review of the most promising biomarkers in colorectal cancer: one step closer to targeted therapy

Rapidly growing insights into the molecular biology of colorectal cancer (CRC) and recent developments in gene sequencing and molecular diagnostics have led to high expectations for the identification of molecular markers to be used in optimized and tailored treatment regimens. However, many of the published data on molecular biomarkers are contradictory in their findings and the current reality is that no molecular marker, other than the KRAS gene in the case of epidermal growth factor receptor (EGFR)- targeted therapy for metastatic disease, has made it into clinical practice. Many markers investigated suffer from technical shortcomings, resulting from lack of quantitative techniques to capture the impact of the molecular alteration. This understanding has recently led to the more comprehensive approaches of global gene expression profiling or genome-wide analysis to determine prognostic and predictive signatures in tumors. In this review, an update of the most recent data on promising biological prognostic and/or predictive markers, including microsatellite instability, epidermal growth factor receptor, KRAS, BRAF, CpG island methylator phenotype, cytotoxic T lymphocytes, forkhead box P3-positive T cells, receptor for hyaluronic acid-mediated motility, phosphatase and tensin homolog, and T-cell originated protein kinase, in patients with CRC is provided.

Incorporating tumour pathology information into breast cancer risk prediction algorithms

INTRODUCTION

Mutations in BRCA1 and BRCA2 confer high risks of breast cancer and ovarian cancer. The risk prediction algorithm BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) may be used to compute the probabilities of carrying mutations in BRCA1 and BRCA2 and help to target mutation screening. Tumours from BRCA1 and BRCA2 mutation carriers display distinctive pathological features that could be used to better discriminate between BRCA1 mutation carriers, BRCA2 mutation carriers and noncarriers. In particular, oestrogen receptor (ER)-negative status, triple-negative (TN) status, and expression of basal markers are predictive of BRCA1 mutation carrier status.

METHODS

We extended BOADICEA by treating breast cancer subtypes as distinct disease end points. Age-specific expression of phenotypic markers in a series of tumours from 182 BRCA1 mutation carriers, 62 BRCA2 mutation carriers and 109 controls from the Breast Cancer Linkage Consortium, and over 300,000 tumours from the general population obtained from the Surveillance Epidemiology, and End Results database, were used to calculate age-specific and genotype-specific incidences of each disease end point. The probability that an individual carries a BRCA1 or BRCA2 mutation given their family history and tumour marker status of family members was computed in sample pedigrees.

RESULTS

The cumulative risk of ER-negative breast cancer by age 70 for BRCA1 mutation carriers was estimated to be 55% and the risk of ER-positive disease was 18%. The corresponding risks for BRCA2 mutation carriers were 21% and 44% for ER-negative and ER-positive disease, respectively. The predicted BRCA1 carrier probabilities among ER-positive breast cancer cases were less than 1% at all ages. For women diagnosed with breast cancer below age 50 years, these probabilities rose to more than 5% in ER-negative breast cancer, 7% in TN disease and 24% in TN breast cancer expressing both CK5/6 and CK14 cytokeratins. Large differences in mutation probabilities were observed by combining ER status and other informative markers with family history.

CONCLUSIONS

This approach combines both full pedigree and tumour subtype data to predict BRCA1/2 carrier probabilities. Prediction of BRCA1/2 carrier status, and hence selection of women for mutation screening, may be substantially improved by combining tumour pathology with family history of cancer.

Exposure to colorectal examinations before a colorectal cancer diagnosis: a case-control study

OBJECTIVES

To assess the prior exposure to colorectal examinations between colorectal cancer (CRC) patients and matched control participants to estimate the effect of these examinations on the development of CRC and to obtain insight into the background incidence of colorectal examinations.

METHODS

A population-based case-control study was conducted within the Dutch Integrated Primary Care Information database over the period 1996-2005. All incident CRC cases were matched with up to 18 controls (n=7,790) for age, sex, index date (date of CRC diagnosis) and follow-up before diagnosis. All colorectal examinations performed in symptomatic participants in the period 0.5-5 years before index date were considered in the analyses.

RESULTS

Within the source population of 457 024 persons, we identified 594 incident cases of CRC. In the period 0.5-5 years before index date 2.9% (17 of 594) of the CRC cases had undergone colorectal examinations, compared with 4.4% (346 of 7790) in the control population [odds ratio (ORadj): 0.56, 95% confidence interval (CI): 0.33-0.94]. For left-sided CRC, significantly more controls than cases had undergone a colorectal examination (4.7 vs. 2.0%, respectively, ORadj: 0.36, 95% CI: 0.17-0.76), which was not seen for right-sided CRCs (3.3 vs. 3.9%, respectively, ORadj: 0.98, 95% CI: 0.42-2.25).

CONCLUSION

Patients diagnosed with CRC were less likely than controls to have had a colorectal examination in previous years, being more pronounced in patients diagnosed with left-sided CRCs. If diagnostic examinations have a similar protective effect as screening examinations, this finding supports the concept that colorectal examination can have a major impact on the reduction of CRC risk.

Prognostic significance of matrix metalloproteinase-9 (MMP-9) in stage II colorectal carcinoma

BACKGROUND

Approximately 30% of all colorectal cancer patients are diagnosed with stage II disease. Adjuvant therapy is not widely recommended. However, it is well-established that a subgroup of patients with stage II is at high risk for recurrence within their life time and should be considered for adjuvant chemotherapy. The present work was designed to assess the value of matrix metalloproteinase-9 (MMP-9) as a predictor of disease outcome in a series of 202 stage II colorectal cancer (CRC) patients with long-term follow-up.

METHODS

The present study comprises a series of 202 patients who underwent bowel resection for stage II CRC at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with MMP-9 antibody.

RESULTS

Forty-eight percent of all CRC samples were positive for MMP-9. There was no significant correlation between MMP-9 expression and age, depth of invasion, and lymph node status. However, MMP-9 expression was significantly related to histological grade (p = 0.03) and location of the tumor (p = 0.01), therefore, being lower in high-grade tumors and most intense in carcinomas of the descending colon and rectum. Tumors with high MMP-9 expression showed a higher recurrence rate than tumors with low expression (p = 0.02). MMP-9 negative tumors had a more favorable disease-free survival (DFS) than those expressing MMP-9 (p = 0.03). The same was true with disease-specific survival (DSS; p = 0.02) as well, high expression of MMP-9 being associated with shorter survival rates. In multivariate (Cox) survival analysis, MMP-9 expression proved to be an independent predictor of DFS, but not DSS, which was predicted by age and sex only.

CONCLUSION

Quantification of MMP-9 expression seems to provide valuable prognostic information in stage II CRC, particularly, in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.

Comparison of 17,641 patients with right- and left-sided colon cancer: differences in epidemiology, perioperative course, histology, and survival

PURPOSE

There is a growing amount of data suggesting that carcinomas of the right and left colon should be considered as different tumor entities. Using the data and analysis compiled in the German multicentered study "Colon/Rectum Cancer," we aimed to clarify whether the existing differences influence clinical and histological parameters, the perioperative course, and the survival of patients with right- vs left-sided colon cancer.

METHODS

During a 3-year period data on all patients with colon cancer were evaluated. Right- and left-sided cancers were compared regarding the following parameters: demographic factors, comorbidities, and histology. For patients who underwent elective surgery with curative intent, the perioperative course and survival were also analyzed.

RESULTS

A total of 17,641 patients with colon carcinomas were included; 12,719 underwent curative surgery. Patients with right-sided colon cancer were significantly older, and predominantly women with a higher rate of comorbidities. Mortality was significantly higher for this group. Final pathology revealed a higher percentage of poorly differentiated and locally advanced tumors. Rate of synchronous distant metastases was comparable. However, hepatic and pulmonary metastases were more frequently found in left-sided, peritoneal carcinomatosis in right-sided carcinomas. Survival was significantly worse in patients with right-sided carcinomas on an adjusted multivariate model (odds ratio, 1.12).

CONCLUSIONS

We found that right- and left-sided colon cancers are significantly different regarding epidemiological, clinical, and histological parameters. Patients with right-sided colon cancers have a worse prognosis. These discrepancies may be caused by genetic differences that account for distinct carcinogenesis and biological behavior. The impact of these findings on screening and therapy remains to be defined.

More right-sided IBD-associated colorectal cancer in patients with primary sclerosing cholangitis

BACKGROUND

Patients with inflammatory bowel disease (IBD) and concurrent primary sclerosing cholangitis (PSC) have a higher risk of developing colorectal cancer (CRC) than IBD patients without PSC. The aim of this study was to investigate potential clinical differences between patients with CRC in IBD and those with CRC in IBD and PSC, as this may lead to improved knowledge of underlying pathophysiological mechanisms of CRC development.

METHODS

The retrospective study from 1980-2006 involved 7 Dutch university medical centers. Clinical data were retrieved from cases identified using the national pathology database (PALGA).

RESULTS

In total, 27 IBD-CRC patients with PSC (70% male) and 127 IBD-CRC patients without PSC (59% male) were included. CRC-related mortality was not different between groups (30% versus 19%, P = 0.32); however, survival for cases with PSC after diagnosing CRC was lower (5-year survival: 40% versus 75% P = 0.001). Right-sided tumors were more prevalent in the PSC group (67% versus 36%, P = 0.006); adjusted for age, sex, and extent of IBD, this difference remained significant (odds ratio: 4.8, 95% confidence interval [CI] 2.0-11.8). In addition, tumors in individuals with PSC were significantly more advanced.

CONCLUSIONS

The right colon is the predilection site for development of colonic malignancies in patients with PSC and IBD. When such patients are diagnosed with cancer they tend to have more advanced tumors than patients with IBD without concurrent PSC, and the overall prognosis is worse. Furthermore, the higher frequency of right-sided tumors in patients with PSC suggests a different pathogenesis between patients with PSC and IBD and those with IBD alone.

Survival of distinct Asian groups among colorectal cancer cases in California

BACKGROUND

It has been reported that Asian ethnicity confers a survival benefit in colorectal cancer (CRC) compared with other ethnicities, but it is not known if this is limited to specific Asian subsets. In the current study, the authors attempted to determine differences using data from the large, population-based California Cancer Registry (CCR).

METHODS

The authors conducted a case-only analysis of CCR data (1994-2003), including descriptive analysis of relevant clinical variables. Overall survival univariate analyses were conducted using the Kaplan-Meier method. Multivariate survival analyses were performed using Cox proportional hazards ratios (HR).

RESULTS

The 61,494 incident cases of colon and 24,350 incident cases of rectal cancer analyzed included 1905 Chinese, 1162 Filipino, 414 Vietnamese, 391 Korean, 1091 Japanese, 148 Asian Indian, and 77,554 Caucasians. After adjustment for age, sex, grade, histology, site within the colon, stage of disease, insurance status, socioeconomic status (SES), and therapy, Filipino (colon: HR, 0.85; 95% confidence interval [95% CI], 0.76-0.95) (rectum: HR, 0.82; 95% CI, 0.71-0.94) and Chinese ethnicity (colon: HR, 0.90; 95% CI, 0.92-0.98) had significantly decreased risk of death compared with Caucasians. Sigmoid lesions were independently associated with improved survival among all cases (HR, 0.92; 95% CI, 0.88-0.95) (referent group were proximal and transverse lesions), and among Asian-only cases in separate analysis (HR, 0.78; 95% CI, 0.70-0.87).

CONCLUSIONS

Although survival after CRC diagnosis is improved for Asians in general, significant survival differences are observed only in specific Asian subsets. Data from the current study suggest that survival among Asians is less affected by SES or treatment disparities, and may be because of biologic factors.

Colorectal cancer, one entity or three

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability (MSI). However, distal colon cancer is usually associated with specific chromosomal instability (CIN). The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. "Proximal shift" of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of colorectal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of colorectal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data concerning the site-specific mechanism of colorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception.

Survival after colorectal cancer diagnosis is associated with colorectal cancer family history

BACKGROUND

Colorectal cancer (CRC) family history is a known risk factor for CRC development; however, effects of CRC family history on survival after CRC diagnosis are less well-defined. Our population-based analysis investigates whether familial CRC cases exhibit improved survival compared with sporadic CRC cases.

METHODS

Cases enrolled in the University of California Irvine Gene-Environment Study of Familial Colorectal Cancer from 1994 to 1996 were analyzed, with follow-up through December 2006. Cases were categorized as familial or sporadic based on self-reported CRC family history in a first-degree relative. Univariate and multivariate survival analyses with Cox proportional hazards ratios were done for overall survival (OS) and CRC-SS (CRC-SS).

RESULTS

One thousand one hundred fifty-four CRC cases were analyzed, including 781 colon cancer and 373 rectal cancer cases. Nineteen percent of colon cases had family history of CRC in a first-degree relative, compared with 16% of rectal cancer cases. No statistically significant differences between familial and sporadic colon or rectal cancer cases were detected for age, gender, ethnicity, stage, tumor location, histology, tumor grade, or stage-specific treatment rendered. Among colon cancer cases, family history of CRC (versus no family history as a reference group) was associated with improved OS (adjusted hazard ratio, 0.760; 95% confidence interval, 0.580-0.997), but not with CRC-SS (hazard ratio, 0.880; 95% confidence interval, 0.621-1.246). No OS or CRC-SS differences were detected for rectal cancer cases.

CONCLUSIONS

CRC cases with family history of the disease have improved overall survival compared with sporadic CRC cases, a finding that is independent of other relevant clinical factors.

Evaluation of clinical, laboratory and morphologic prognostic factors in colon cancer

BACKGROUND

The long-term prognosis of patients with colon cancer is dependent on many factors. To investigate the influence of a series of clinical, laboratory and morphological variables on prognosis of colon carcinoma we conducted a retrospective analysis of our data.

METHODS

Ninety-two patients with colon cancer, who underwent surgical resection between January 1999 and December 2001, were analyzed. On survival analysis, demographics, clinical, laboratory and pathomorphological parameters were tested for their potential prognostic value. Furthermore, univariate and multivariate analysis of the above mentioned data were performed considering the depth of tumour invasion into the bowel wall as independent variable.

RESULTS

On survival analysis we found that depth of tumour invasion (P < 0.001; F-ratio 2.11), type of operation (P < 0.001; F-ratio 3.51) and CT scanning (P < 0.001; F-ratio 5.21) were predictors of survival. Considering the degree of mural invasion as independent variable, on univariate analysis, we observed that mucorrhea, anismus, hematocrit, WBC count, fibrinogen value and CT scanning were significantly related to the degree of mural invasion of the cancer. On the multivariate analysis, fibrinogen value was the most statistically significant variable (P < 0.001) with the highest F-ratio (F-ratio 5.86). Finally, in the present study, the tumour site was significantly related neither to the survival nor to the mural invasion of the tumour.

CONCLUSION

The various clinical, laboratory and patho-morphological parameters showed different prognostic value for colon carcinoma. In the future, preoperative prognostic markers will probably gain relevance in order to make a proper choice between surgery, chemotherapy and radiotherapy. Nevertheless, current data do not provide sufficient evidence for preoperative stratification of high and low risk patients. Further assessments in prospective large studies are warranted.

Influência da localização do tumor na expressão tecidual da proteína p53 em doentes com câncer colorretal: estudo de 100 casos

OBJETIVO: O objetivo do presente estudo foi verificar, se existem diferenças na expressão tecidual da proteína p53 segundo a localização do tumor em doentes com câncer colorretal. MÉTODO: Foram estudados 100 doentes (54 mulheres), com média de idade de 59,8 anos com adenocarcinoma colorretal. A expressão da proteína p53 foi analisada por imunoistoquímica, com anticorpo monoclonal anti-p53 pela técnica da estreptavidina-biotina-peroxidase. A expressão tecidual da proteína p53 foi relacionada às variáveis: gênero, idade, grau histológico, tipo histológico, tamanho do tumor, estadiamento TNM, profundidade de invasão da parede intestinal, comprometimento linfonodal, invasão angiolinfática, localização do tumor no intestino grosso em relação à flexura esplênica. Na avaliação estatística da relação entre expressão da proteína p53 e as variáveis consideradas empregou-se o teste qui-quadrado, estabelecendo-se nível de significância de 5% (p<0,05). RESULTADOS: A proteína p53 foi positiva em 77% dos casos. Com relação as diferentes variáveis consideradas verificou-se maior tendência de expressão da proteína mutante quando se considerava a idade (p=0,001), grau histológico (p=0,001), tipo histológico (p=0,001), estádios tardios da classificação TNM (p=0,001), maior profundidade de invasão na parede cólica (p=0,001), comprometimento linfonodal (p=0,001), invasão angiolinfática (p=0,02), localização após a flexura esplênica (p=0,001), não se encontrando relação com gênero (p=0,49) e tamanho do tumor (p=0,08). CONCLUSÃO: Os resultados do presente estudo permitem concluir que a expressão da proteína p53 mutante ocorre com maior freqüência nos tumores localizados a partir da flexura esplênica.

Predictive factors of years of potential life lost by colorectal cancer

OBJECTIVE

To evaluate the impact of colorectal cancer (CRC) by estimating the years of potential life lost (YPLL) by this neoplasm in a cohort of patients, as well as to define the predictive factors of YPLL.

METHODS

A descriptive cross-sectional study of 980 consecutive patients diagnosed and treated because of CRC in our institution between 1985 and 2002 was carried out. Demographic, clinical, pathological, surgical, hospital stay, complications, and mortality variables were recorded. The primary endpoint of this study was to calculate individual YPLL. Univariate analysis was performed to compare each independent variable with the variable YPLL. All clinically relevant variables significantly associated with YPLL were included in an ordinal regression model to identify independent factors prognostic of YPLL.

RESULTS

The final study sample was 794 patients, 413 (52%) men and 381 (48%) women, mean age 65.3 years [confidence interval (CI) 95%: 64.4-66.2 years; SD: 12.8]. The mean global YPLL for the 351 patients who died of CRC was 15.2 years (SD: 10.7; CI 95%: 14.1-16.3). Lower age [odds ratio (OR)=0.98; CI 95%: 0.97-0.98], male sex (OR=1.19; CI 95%: 1.00-1.43), lower tumor, nodes, metastasis (TNM) stage (OR=0.29; CI 95%: 0.24-0.35), and rectum localization of the tumor (OR=1.37; CI 95%: 1.14-1.64) were independent prognostic factors for YPLL.

CONCLUSION

In our community, the mean number of YPLL by CRC exceeds 15 years. Lower age, male sex, higher TNM stage, and rectum localization are negative predictors of YPLL.

Association of vitamin D receptor gene variants, adiposity and colon cancer

Vitamin D receptor (VDR) gene variants have been variably associated with risk of colon cancer in epidemiologic studies. We sought to further clarify the relationship between colon cancer and three single-nucleotide polymorphisms (SNPs) in the VDR gene (Cdx-2, FokI and TaqI) in a population-based case-control study of 250 incident cases and 246 controls. Colon cancer cases were more frequently homozygous for the Cdx-2 A allele (9.2 versus 4.1%, P = 0.06). Cdx-2 AA homozygotes were at increased risk with an unadjusted odds ratio (OR) of 2.47 [95% confidence interval (CI): 1.13-5.37, P = 0.022]; adjustment for age, sex, body mass index (BMI), non-steroidal anti-inflammatory use and family history of colorectal cancer yielded an OR of 2.27 (CI: 0.95-5.41, P = 0.065). Carriers of the FokI TT genotype were also at increased risk with an adjusted OR of 1.87 (CI: 1.03-3.38, P = 0.038). Haplotype analyses showed significant increased colon cancer risk for carriers of the Cdx-2-FokI A-T haplotype and the FokI-TaqI T-G haplotype. The three-SNP Cdx-2-FokI-TaqI (A-T-G) haplotype showed a similar association with an adjusted OR of 3.63 (CI: 1.01-13.07). A strong positive association was observed for the Cdx-2 variant among individuals with low BMI or low waist circumference. Our results suggest that genetic variation at the VDR locus, in particular Cdx-2 and FokI SNPs, may influence colon cancer risk and these associations may be modified by adiposity.

[Clinico-pathological characteristics of colonic carcinoma in relation to localization and histologic type]

BACKGROUND/AIM

A significant increase in colonic carcinoma has been analyzed in numerous clinico-pathological studies and genetics models. The aim of this study was to determinate the differences in clinico-pathological parameters of colonic carcinoma regarding localization and histological type.

METHODS

The study enrolled 124 patients who had undergone surgery for colorectal carcinoma at the Clinic of Surgery in the town of Nis within 2005. Paraffin sections were stained with Hematoxilin-eosin (H&E), High iron diamine-Alcian blue (HID-AB) (pH-2.5) and Alcian blue-Preiodic arid Shiff (AB-PAS) (pH-2.5) methods. From pathological report we used data regarding: localization (right or left colon), histological type, histological grade, and parameters which determinate the tumor stage.

RESULTS

The total number of patients with right-sided colonic carcinoma was 40 (32.36%) and 84 (67.74%) with left-sided colonic carcinoma. Histopathologically, 96 (77.42%) adenocarcinomas and 28 (22.58%) mucinous adenocarcinomas were verified. There were no statistically significant differences between the right-sided and left-sided colonic carcinoma regarding sex, age, histological grade and tumor stage (p > 0.05). Mucinous adenocarcinomas was statistically significantly more frequent in right-sided colon (35.00%) than in left-sided colon (16.67%) (p < 0.05). There were no statistically significant differences between adenocarcinomas and mucinous adenocarcinomas regarding sex and disease stage. In younger patients the percentage of mucinous adenocarcinomas (28.57%) compared to non-mucinous ones (11.46%) was significantlly higher (p < 0.05) than in older patients. Mucinous adenocarcinomas had statistically significantly more frequently poor differentiation in comparision to adenocarcinomas (46.43% versus 9.37%, p < 0.001).

CONCLUSION

According to the presented results it can be concluded that the lower grade of differentiation of the colon adenocarcinoma and mucinous secretion are significantly often present in younger patients.

Multidisciplinary management of patients with advanced rectal cancer

The chance of lymph node involvement in T(3) and T(4) rectal cancers is 20% to 60%, a risk sufficiently high that most clinicians favor mesorectal excision rather than less aggressive approaches. Patients who have a complete clinical response of the primary lesions to neoadjuvant therapy may represent a special case. Total mesorectal excision can be accomplished without sacrifice of the anal sphincters, and continence can be preserved. Evolving understanding of patterns of tumor spread and mechanisms of anal continence have resulted in increased use of continence-preserving procedures. Removal of the anal sphincters seems to be advantageous only if the sphincters are directly involved. A few small series suggest that a segmental sphincter resection could result in good local control and continence preservation, even if the sphincters are involved. Areas of controversy currently include the role of neoadjuvant therapy for high rectal lesions, the role of lateral lymph node dissection, and methods of improving anal continence after rectal resection.

The comparison of the risk factors and clinical manifestations of proximal and distal colorectal cancer

PURPOSE

Colorectal cancers in the proximal or distal site have distinct clinical characteristics. In this study, the authors compared the risk factors of proximal and distal colorectal cancer.

METHODS

A 16-page questionnaire was administered to 529 patients with colorectal cancer before operation. Cancers were classified as proximal or distal relative to the splenic flexure. Of these 529 patients, 6 patients were excluded because of the presence of synchronous colorectal cancers. Data of the 523 patients were analyzed.

RESULTS

Total numbers of proximal and distal cancers were 123 and 400. The proportion of patients with Type 2 diabetes was significantly higher for distal cancer (P = 0.034), whereas a greater proportion of patients with proximal cancer had a gallstone history (P = 0.005). Multivariate analysis revealed Type 2 diabetes to be a risk factor for distal colorectal cancer (P = 0.027) and cholelithiasis to be a risk factor for proximal cancer (P = 0.049). The odds ratio for distal colorectal cancer among males with Type 2 diabetes was 4.1 (95 percent confidence interval, 1.4-12.1). On the other hand, a gallstone history was more associated with proximal colon cancer, especially in females (odds ratio = 5.5; 95 percent confidence interval, 1.4-20.9).

CONCLUSIONS

A comparison of the risk factors of proximal and distal colorectal cancer showed that Type 2 diabetes is associated with distal colorectal cancer in males and that cholelithiasis is associated with proximal colon cancer in females.

Sensitivity of immunochemical fecal occult blood test to small colorectal adenomas

BACKGROUND

Although the immunochemical fecal occult blood test (FOBT) is reportedly more sensitive to large adenomas or colorectal cancer (CRC) than the guaiac-based FOBT, the sensitivity of the immunochemical FOBT to small adenomas has scarcely been reported. Previous reports have indicated that the guaiac-based FOBT can detect small adenomas only by serendipity.

OBJECTIVES

To investigate the sensitivity of immunochemical FOBT to small adenomas using a large-scale cohort.

METHODS

We analyzed 21,805 consecutively enrolled asymptomatic persons who underwent colonoscopy and immunochemical FOBT.

RESULTS

The sensitivity to adenomas </=9 mm was significantly higher than the false-positive rate as revealed by analysis of all eligible subjects (7.0%vs 4.5%, P < 0.001). In men, the sensitivity was superior to the false-positive rate and increased with age (<50 yr 6.1% and >60 yr 11.3%). On the other hand, the sensitivity in women was not significantly different from the false-positive rate in any generation (5.1%vs 4.7% for all eligible women, P= 0.72).

CONCLUSIONS

Immunochemical FOBT detected a small percentage of small adenomas in men at a rate that is significantly higher than the false-positive rate. Studies comparing the guaiac and immunochemical FOBTs using the end point of CRC-related death are expected.

Diet and vitamin or mineral supplementation and risk of colon cancer by subsite in Canada

The study assesses the association of diet and vitamin or mineral supplementation with risk of proximal or distal colon cancer. Mailed questionnaires were completed by 1723 newly diagnosed, histologically confirmed colon cancer cases and 3097 population controls between 1994 and 1997 in seven Canadian provinces. Measurement included information on socio-economic status, physical activity, smoking habits, alcohol use, diet and vitamin or mineral supplementation. Odds ratios and 95% confidence intervals were derived through unconditional logistic regression. Linear regression was used to examine that dietary factors affect body mass index. The strongest positive associations between colon cancer risk and increasing total fat intake were observed for proximal colon cancer in men and for distal colon cancer in both men and women. Increased consumption of vegetables, fruit and whole-grain products did not reduce the risk of colon cancer. A modest reduction in distal colon cancer risk was noted in women who consumed yellow-orange vegetables. Significant positive associations were observed between proximal colon cancer risk in men and consumption of red meat and dairy products, and between distal colon cancer risk in women and total intake of meat and processed meat. We also saw strong associations between bacon intake and both subsites of colon cancer in women. When men were compared with women directly by subsite however, the results did not show a corresponding association. A significantly reduced risk of distal colon cancer was noted in women only with increasing intake of dairy products and of milk. Among men and women taking vitamin and mineral supplements for more than 5 years, significant inverse associations with colon cancer were most pronounced among women with distal colon cancer. These findings suggest that dietary risk factors for proximal colon cancer may differ from those for distal colon cancer.

Prognostic significance of matrix metalloproteinases-1, -2, -7 and -13 and tissue inhibitors of metalloproteinases-1, -2, -3 and -4 in colorectal cancer

Strong expression of many matrix metalloproteinases (MMPs) has been related to poor survival of colorectal cancer (CRC) patients. The expression of tissue inhibitors of metalloproteinases (TIMPs) has been associated with both a beneficial and a poor outcome and there is thus a need to further clarify the significance of MMPs and TIMPs in CRC. The prognostic significance of 4 MMPs and TIMPs in CRC was evaluated. Formalin-fixed, paraffin-embedded tissue arrayed samples of 351 patients with primary colon or rectal cancer of Dukes' stages A-D were selected for immunohistochemical staining of MMP-1, -2, -7 and -13, and TIMP-1, -2, -3 and -4. High expression of MMP-2 in the malignant epithelium as well as in the surrounding stroma was associated with reduced survival of colon cancer patients. Strong epithelial and stromal cytoplasmic staining of TIMP-3 was associated with a longer survival in rectal cancer patients, and here the interobserver variation for evaluating the degree of staining was lower than for epithelial staining. Strong stromal cytoplasmic staining of TIMP-4 predicted longer survival of rectal cancer patients. Multivariate analysis showed that stromal cytoplasmic TIMP-3 staining was the only marker of independent prognostic value. MMP-2 might be a useful prognostic marker in colon cancer, and TIMP-3 and TIMP-4 in rectal cancer, but the findings associated with stromal staining should be interpreted with some caution. Different biologic behavior or different genetic development may explain the differences between colon and rectal cancers regarding the expression of MMP-2, TIMP-3 and TIMP-4.

Fatty acid synthase hyperactivation in human colorectal cancer: relationship with tumor side and sex

OBJECTIVE

Fatty acid synthase (FAS) is a multienzyme protein required for the conversion of acetyl coenzyme A and malonyl coenzyme A to palpitate. High levels of FAS expression have been found in many human cancers, including breast, prostate and colon. In this study, we evaluated FAS activity levels and the expression of its mRNA in normal colorectal mucosa and cancer tissue from patients operated for colorectal carcinoma. In addition, the hypothesis of a relation between FAS activity and p53 mutation status of patients was tested.

METHODS

Forty-two patients were enrolled in the study. FAS activity was measured by using a radiometric assay. FAS gene expression was determined using quantitative reverse-transcription polymerase chain reaction and p53 mutations by polymerase chain reaction single-strand conformation polymorphism.

RESULTS

FAS activity levels were significantly higher in cancer than in the corresponding normal mucosa. Tumors located on the left side of the colon showed higher levels of FAS activity and tumors from male patients showed higher FAS activity than tumors from females. No difference was detected in mRNA FAS levels according to tumor side and gender. Moreover, lower levels of FAS activity were detected in patients carrying the p53 mutation.

CONCLUSIONS

This study suggests that biological factors including sex and gene mutation status, as well as stratification of patients with colorectal cancer into right- and left-sided subsets, may be important in patient selection for targeted therapies and for the subsequent assessment of objective therapeutic responses.

Câncer colorretal: características clínicas e anatomopatológicas em pacientes com idade inferior a 40 anos

O câncer colorretal (CCR) é a quarta neoplasia maligna mais incidente no Brasil. Seu diagnóstico em pacientes jovens é geralmente subestimado pelos médicos por ser frequentemente considerada como condição clínica de pacientes idosos. O presente trabalho tem como objetivo avaliar variáveis clínico-patológicas em pacientes com menos de 40 anos, no que diz respeito a idade, sexo e raça do paciente, história familiar, tabagismo, sinais e sintomas, tempo entre início dos sintomas e o diagnóstico, e localização da lesão primária, através de estudo retrospectivo de 11 casos de CCR atendidos no Hospital Universitário - HUUFMA no período de 1995 a 2005. Os pacientes incluídos representaram 11 (3,27%) dos casos, sendo mais freqüente o sexo feminino (54,5%). A idade média ao diagnóstico foi de 30,5 anos. Os sinais e sintomas mais prevalentes foram dor abdominal, alteração do hábito intestinal, perda ponderal, dor retal e hematoquezia. O tempo médio entre o início da sintomatologia e o aparecimento dos sintomas foi de 9,09 meses. A maioria das lesões encontrava-se no retossigmóide e reto (81,8%). Cerca de 80% dos pacientes apresentaram carcinoma estágios C e D da classificação de Dukes Astler-Coller. Pacientes jovens portadores de CCR apresentam, geralmente, sintomatologia rica, com doença avançada ao diagnóstico, portanto, com menor possibilidade de cura e prognóstico mais reservado.

Predictive poor prognostic factors in colonic carcinoma

INTRODUCTION

Five-year survival in rectal cancer has been steadily improving since the introduction of neoadjuvant chemoradiation and total mesorectal excision surgery. In contrast, 5-year survival rates and management of colonic carcinoma remain relatively unchanged. This study aims to identify poor prognostic factors in colonic cancer patients that could potentially be predicted pre-operatively to identify a subset of patients amenable to neoadjuvant treatment strategies.

METHODS

Database compilation of all operable rectal and colonic cancer patients presenting to a single district general hospital over 5 years. Data were documented on presentation and site of tumour, TNM staging, differentiation and extramural venous invasion.

RESULTS

There was no significant difference in 4-year survival between rectal (57.5%) and right (57%) or left sided (52.5%) colonic cancers (p=0.4689). On multivariate analysis, N2-stage, T4-stage and emergency presentation were identified as independent prognostic factors. On univariate analysis, in addition to the above factors, presence of venous invasion (p=0.001) and poor differentiation (p=0.0003) of tumour also predicted for poor 5-year survival.

CONCLUSION

T4-stage and N2-stage and extramural venous invasion are poor prognostic factors that could be identified pre-operatively with suitably accurate imaging. Such patients could then be considered for a pre-operative treatment strategy.

Expression of the p53 protein and clinical and pathologic correlation in adenocarcinoma of the rectum

BACKGROUND

p53 is a tumor suppressor gene that has been implicated in the pathogenesis of a wide range of tumors, including colorectal cancer.

AIM

To evaluate the prognostic significance of p53 protein expression, and to correlate with clinical and pathologic variables as well as survival.

PATIENTS AND METHODS

Immunohistochemical staining for p53 protein was performed in a series of 83 patients with rectal cancer with a follow-up of at least 5 years.

RESULTS

Expression of nuclear protein was positive in 36 (43.4%) of the tumors. We found association between positive p53 and death, local recurrence, distant metastasis and overall recurrence and we also found association between p53 and death, local recurrence, metastasis and overall recurrence when analysis was adjusted to Astler-Coller stage and grade of differentiation.

CONCLUSION

p53 immunoexpression has shown to be an independent prognostic factor in these series.