Colorectal cancer or colon and rectal cancer? Clinicopathological comparison between colonic and rectal carcinomas

SPLICE - Streamlining Digital Pathology Image Processing

Digital pathology and the integration of artificial intelligence (AI) models have revolutionized histopathology, opening new opportunities. With the increasing availability of Whole Slide Images (WSIs), there's a growing demand for efficient retrieval, processing, and analysis of relevant images from vast biomedical archives. However, processing WSIs presents challenges due to their large size and content complexity. Full computer digestion of WSIs is impractical, and processing all patches individually is prohibitively expensive. In this paper, we propose an unsupervised patching algorithm, Sequential Patching Lattice for Image Classification and Enquiry (SPLICE). This novel approach condenses a histopathology WSI into a compact set of representative patches, forming a "collage" of WSI while minimizing redundancy. SPLICE prioritizes patch quality and uniqueness by sequentially analyzing a WSI and selecting nonredundant representative features. We evaluated SPLICE for search and match applications, demonstrating improved accuracy, reduced computation time, and storage requirements compared to existing state-of-the-art methods. As an unsupervised method, SPLICE effectively reduces storage requirements for representing tissue images by 50%. This reduction enables numerous algorithms in computational pathology to operate much more efficiently, paving the way for accelerated adoption of digital pathology.

Immune Response and Immune Checkpoint Molecules in Patients with Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy: A Review

It is well-established that tumor antigens and molecules expressed and secreted by cancer cells trigger innate and adaptive immune responses. These two types of anti-tumor immunity lead to the infiltration of the tumor's microenvironment by immune cells with either regulatory or cytotoxic properties. Whether this response is associated with tumor eradication after radiotherapy and chemotherapy or regrowth has been a matter of extensive research through the years, mainly focusing on tumor-infiltrating lymphocytes and monocytes and their subtypes, and the expression of immune checkpoint and other immune-related molecules by both immune and cancer cells in the tumor microenvironment. A literature search has been conducted on studies dealing with the immune response in patients with rectal cancer treated with neoadjuvant radiotherapy or chemoradiotherapy, assessing its impact on locoregional control and survival and underlying the potential role of immunotherapy in the treatment of this cancer subtype. Here, we provide an overview of the interactions between local/systemic anti-tumor immunity, cancer-related immune checkpoint, and other immunological pathways and radiotherapy, and how these affect the prognosis of rectal cancer patients. Chemoradiotherapy induces critical immunological changes in the tumor microenvironment and cancer cells that can be exploited for therapeutic interventions in rectal cancer.

Association Between Socioeconomic and Insurance Status and Delayed Diagnosis of Gastrointestinal Cancers

INTRODUCTION

Association between socioeconomic status (SES) and stage at diagnosis in gastrointestinal (GI) cancers is poorly described. Relationship between low SES and stage at diagnosis as well as the mediating role of insurance status (IS) was examined.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for esophageal, gastric, liver, biliary, pancreatic, colon, and rectal cancers diagnosed in 2012-2016. Relationship between census-tract SES index quintiles and late diagnosis (distant disease at diagnosis) was examined. Uni and multivariable logistic regressions were performed. Mediation analyses were conducted to determine the degree to which IS (private/Medicare versus Medicaid/uninsured) mediates the relationship between SES and late diagnosis of cancer.

RESULTS

Analysis included 236,713 adult patients from 18 Surveillance, Epidemiology, and End Results areas. In univariable analysis, lowest SES quintile was significantly associated with late diagnosis for all cancers except gastric and biliary cancers. In multivariable analysis controlling for age, gender, marital status and race, this association remained significant for liver (odds ratio (OR) 1.41 [95% confidence interval (CI) 1.25-1.58]), pancreatic (OR 1.13 [95% CI 1.06-1.21]), and rectal (OR 1.31 [95% CI 1.20-1.42]) cancers. Further controlling for IS showed the largest effect size reduction for rectal cancer (OR 1.18 [95% CI 1.09-1.29]), with IS mediating 36.5% (P < 0.0001) of SES effect.

CONCLUSIONS

Low SES is an independent risk factor for late diagnosis in liver, pancreas, and rectal cancers. Insurance is not a critical mediator of difference by SES for most GI cancers, with the exception of rectal cancer. Further research is needed to understand factors beyond IS that can account for SES differences in late diagnosis for GI cancers. Insurance related differences for rectal cancer deserves further attention.

Risk of colon cancer-related death in people who had cancer in the past

BACKGROUND

The rate of second primary malignancies (SPM) is gradually increasing. Yet, the risk of death from primary cancer vs. SPM is still not well understood. In this study, we investigated the survival of patients with colorectal cancer (as SPM) who had cancer in the past (prior cancer) and the risk factors of SPM death in this population.

MATERIALS AND METHODS

Based on the Surveillance, Epidemiology, and End Results (SEER) database, we identified 1866 colon cancer patients with prior cancer in our main cohort and 43,959 colon cancer patients, including 37,440 patients with colon cancer as only malignancy and 6519 patients with colon cancer as subsequent colon cancer (SCC), in a second cohort and 3429 colon cancer patients, including 2371 patients with prior colon cancer (PCC) and 1058 patients with colon cancer as SPM, in a third cohort. After propensity score matching, 6519 pairs of subjects were identified in second cohort.

RESULTS

Patients with prior prostate and breast cancer had a higher risk of developing colon cancer compared to those with gastrointestinal cancer. Also, colon cancer patients with different prior cancer had different survival rates. Furthermore, except for prior lung cancer (52.78 vs. 25.93%), most subjects died due to colon cancer complications. The ratio of colon cancer deaths to prior cancer deaths in patients with a low stage and high stage was 1.51 and 6.64, respectively. In addition, colon cancer-specific survival (CSS) and OS rates were significantly lower in subjects with colon cancer as the SPM than in those with PCC. Also, compared with PCC, SPM was associated with OS and CSS with HR 1.59 (95 CI 1.43-1.78) and HR 2.00 (95% CI 1.70-2.36). Furthermore, compared with only colon cancer, SCC was associated with OS and CSS with HR 1.23 (95 CI 1.17-1.29) and HR 1.13 (95% CI 1.06-1.21).

CONCLUSIONS

Prior cancer was found to have an adverse impact on OS in patients with colon cancer (secondary cancer), most of whom died due to colon cancer as secondary cancer itself rather than prior cancer. Early detection and treatment strategies should be investigated in this population.

Skeletal muscle wasting and long-term prognosis in patients undergoing rectal cancer surgery without neoadjuvant therapy

BACKGROUND

Derangement of body composition has been associated with dismal long-term survival in several gastrointestinal cancers including rectal tumors treated with neoadjuvant therapies. The role of specific preoperative anthropometric indexes on the oncologic outcomes of patients undergoing upfront surgery for rectal cancer has not been investigated. The aim of the study is to evaluate the association of body composition and overall survival in this specific cohort.

METHODS

Lumbar computed tomography images, obtained within the 30 days previous to surgery, between January 2009 and December 2016, were used to calculate population-specific thresholds of muscle mass (sarcopenia), subcutaneous and visceral adiposity, visceral obesity, sarcopenic obesity, and myosteatosis. These body composition variables were related with overall survival (OS), tumor-specific survival (TSS), and disease-free survival (DFS). OS, TSS, and DFS were evaluated by the Kaplan-Meier method. Cox regression analysis was used to identify independent predictors of mortality, tumor-specific mortality, and recurrence, and data were presented as hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

During the study period, 411 patients underwent rectal resection for cancer, and among these, 129 were without neoadjuvant chemoradiation. The median follow-up was 96.7 months. At the end of the follow-up, 41 patients (31.8%) had died; of these, 26 (20.1%) died for tumor-related reasons, and 36 (27.1%) experienced disease recurrence. One-, three-, and five-year OS was 95.7%, 86.0%, and 76.8% for non-sarcopenic patients versus 82.4%, 58.8%, and 40.0% for sarcopenic ones respectively (p < 0.001). Kaplan-Meier survival curves comparing sarcopenic and non-sarcopenic patients showed a significant difference in terms of OS (log-rank < 0.0001). Through multivariate Cox regression, overall mortality risk was associated only with sarcopenia (HR 1.96; 95%CI 1.03-3.74; p = 0.041). Disease stage IV and III (HR 13.75; 95% CI 2.89-65.6; p < 0.001 and HR 4.72; 95% CI 1.06-21.1; p = 0.043, respectively) and sarcopenia (HR 2.62; 95% CI 1.22-5.6; p = 0.013) were independently associated with TSS. The other body composition indexes investigated showed no significant association with prognosis.

CONCLUSIONS

These results support the inclusion of body composition assessment for prognostic stratification of rectal cancer patients undergoing upfront resection.

Relation between skeletal muscle volume and prognosis in rectal cancer patients undergoing neoadjuvant therapy

The prognostic role of body composition indexes, and specifically sarcopenia, has recently been explored in different cancer types. However, conflicting results have been reported. Heterogeneity in cancer type, cancer stage or oncological treatments, as well as different methodology and definition of sarcopenia, could be accounted for different conclusions retrieved from literature. When focusing on colorectal cancer, it clearly appears that colon and rectal cancers are often treated as a single entity though they have different behaviors and treatments. Particularly, patients with advanced rectal cancer represent a peculiar group of patients that according to current guidelines are treated with neoadjuvant chemotherapy and radiotherapy followed by radical surgery. This review was restricted to a homogeneous group of patients with advanced lower rectal cancer and the aim of exploring whether there is a correlation between skeletal muscle depletion and prognosis. Literature was searched for articles related to patients with advanced rectal cancer undergoing neoadjuvant chemo-radiotherapy (NCRT) followed by radical surgery, in whom muscle mass and/or change in muscle mass during neoadjuvant treatment were measured. Eight full-text articles were selected and included in the present review. The main findings of our review were: (1) The majority of the studies defined sarcopenia as muscle mass alone over muscle strength or physical performance; (2) There was a great deal of heterogeneity in the definition and measures of sarcopenia, in the definition of cut-off values, and in the method to measure change in muscle mass; (3) There was not full agreement on the association between sarcopenia at baseline and/or after chemo-radiotherapy and prognosis, and only few studies found a significance in the multivariate analysis; and (4) It seems that a loss in skeletal muscle mass during NCRT is associated with the worst outcomes in terms of disease-free survival. In conclusion, analysis of muscle mass might provide prognostic information on patients with rectal cancer, however more robust evidence is needed to define the role of muscle depletion and/or muscle change during neoadjuvant treatments, related to this specific group of patients. If a prognostic role would be confirmed by future studies, the role of preoperative intervention aimed at modifying muscle mass could be explored in order to improve outcomes.

Time trends in colorectal cancer incidence in four regions of Latin America: 1983-2012

This study aimed to assess time trends in colorectal cancer incidence from 1983 to 2012 in Latin America. This was an ecological time-series study whose population consisted of individuals aged 20 years or older diagnosed with colorectal cancer. Data from population-based cancer registries in Cali (Colombia), Costa Rica, Goiânia (Brazil), and Quito (Ecuador), were used for rates estimation, while time trends estimations were proceeded by the Joinpoint Regression Program. The study showed an increase in colorectal cancer incidence in men and women in Cali (2.8% and 3.2%, respectively), Costa Rica (3.1% and 2.1%, respectively), and Quito (2.6% and 1.2%, respectively), whereas in Goiânia, only women showed an increase in colorectal cancer rates (3.3%). For colon cancer, we observed an increasing trend in incidence rates in men and women in Cali (3.1% and 2.9%, respectively), Costa Rica (3.9% and 2.8%, respectively), and Quito (2.9% and 1.8%). For rectal cancer, we observed an increasing trend in incidence in men and women in Cali (2.5% and 2.6%, respectively), Costa Rica (2.2% and 1%, respectively), and Goiânia (5.5% and 4.6%, respectively), while in Quito only men showed an upward trend (2.8%). The study found increases in colorectal cancer, colon cancer, and rectal cancer in four Latin America regions. This findings reflect lifestyle, such as dietary changes, following the economic opening, and the prevalence variations of colorectal cancer risk factors by sex and between the four studied regions. Finally, the different strategies adopted by regions for colorectal cancer diagnosis and screening seem to influence the observed variation between anatomical sites.

Prognostic Factors Affecting Disease-Free Survival and Overall Survival in T4 Colon Cancer

PURPOSE

It is known that as the T stage of a carcinoma progresses, the prognosis becomes poorer. However, there are few studies about factors that affect the prognosis of T4 advanced colon cancer. This study aimed to identify the prognostic factors associated with disease-free survival (DFS) and overall survival (OS) in T4 colon cancer.

METHODS

Patients diagnosed with stage T4 on histopathology after undergoing curative surgery for colon cancer between March 2009 and March 2018 were retrospectively analyzed for factors related to postoperative survival. Primary outcomes were DFS and OS.

RESULTS

Eighty-two patients were included in the study. DFS and OS of the pathologic (p) T4b group were not inferior to that of the pT4a group. Multivariate analysis showed that differentiation (hazard ratio [HR], 4.994; P = 0.005), and laparoscopic surgery (HR, 0.323; P = 0.008) were significant prognostic factors for DFS, while differentiation (HR, 7.904; P ≤ 0.001) and chemotherapy (HR, 0.344; P = 0.038) were significant prognostic factors for OS.

CONCLUSION

Tumor differentiation, laparoscopic surgery, and adjuvant chemotherapy were found to be significant prognostic factors in patients with T4 colon cancer. Adjuvant chemotherapy and curative resections by laparoscopy might improve the prognosis in these patients.

Adjuvant Chemotherapy Benefits on Patients with Extramural Vascular Invasion in Stages II and III Colon Cancer

INTRODUCTION

Extramural vascular invasion (EMVI) is a poor prognostic factor in colon cancer. However, the benefit of adjuvant chemotherapy in patients with EMVI is not well defined. The objective of this study is to determine if there is a survival benefit for using adjuvant chemotherapy in patients with EMVI-positive colon cancers.

METHODS

We performed a retrospective review of all patients with stages II and III colon adenocarcinoma who underwent surgical resection between 2004 and 2015. Cox regression was used to determine the effect of chemotherapy on EMVI-positive patients while adjusting for the extent of invasion, regional lymph node metastasis, histologic grade, age, site of tumor, and ASA score.

RESULTS

A total of 750 patients were included in this study. Extramural vascular invasion was present in 93 out of 387 stage II patients (24%) and 187 out of 363 stage III patients (52%). The Cox regression model showed that in patients with EMVI, those who did not receive adjuvant chemotherapy had a 1.6-fold (1.1-2.3) increase in the hazard of death compared with those who received chemotherapy.

CONCLUSIONS

Patients who were EMVI-negative fared better than those who were EMVI-positive. In patients who were EMVI-positive, adjuvant chemotherapy improved overall survival.

A comprehensive analysis of SNPs and CNVs identifies novel markers associated with disease outcomes in colorectal cancer

We aimed to examine the associations of a genome-wide set of single nucleotide polymorphisms (SNPs) and 254 copy number variations (CNVs) and/or insertion/deletions (INDELs) with clinical outcomes in colorectal cancer patients (n = 505). We also aimed to investigate whether their associations changed (e.g., appeared, diminished) over time. Multivariable Cox proportional hazards and piece-wise Cox regression models were used to examine the associations. The Cancer Genome Atlas (TCGA) datasets were used for replication purposes and to examine the gene expression differences between tumor and nontumor tissue samples. A common SNP (WBP11-rs7314075) was associated with disease-specific survival with P-value of 3.2 × 10^-8 . Association of this region with disease-specific survival was also detected in the TCGA patient cohort. Two expression quantitative trait loci (eQTLs) were identified in this locus that were implicated in the regulation of ERP27 expression. Interestingly, expression levels of ERP27 and WBP11 were significantly different between colorectal tumors and nontumor tissues. Three SNPs predicted the risk of recurrent disease only after 5 years postdiagnosis. Overall, our study identified novel variants, one of which also showed an association in the TCGA dataset, but no CNVs/INDELs, that associated with outcomes in colorectal cancer. Three SNPs were candidate predictors of long-term recurrence/metastasis risk.

Distinguishing Rectal Cancer from Colon Cancer Based on the Support Vector Machine Method and RNA-sequencing Data

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Several studies have indicated that rectal cancer is significantly different from colon cancer in terms of treatment, prognosis, and metastasis. Recently, the differential mRNA expression of colon cancer and rectal cancer has received a great deal of attention. The current study aimed to identify significant differences between colon cancer and rectal cancer based on RNA sequencing (RNA-seq) data via support vector machines (SVM). Here, 393 CRC samples from the The Cancer Genome Atlas (TCGA) database were investigated, including 298 patients with colon cancer and 95 with rectal cancer. Following the random forest (RF) analysis of the mRNA expression data, 96 genes such as HOXB13, PRAC, and BCLAF1 were identified and utilized to build the SVM classification model with the Leave-One-Out Cross-validation (LOOCV) algorithm. In the training (n=196) and the validation cohorts (n=197), the accuracy (82.1 % and 82.2 %, respectively) and the AUC (0.87 and 0.91, respectively) indicated that the established optimal SVM classification model distinguished colon cancer from rectal cancer reasonably. However, additional experiments are required to validate the predicted gene expression levels and functions.

Age and Lymph Node Positivity in Patients With Colon and Rectal Cancer in the US Military Health System

BACKGROUND

Young age may be associated with an increased risk of lymph node involvement at diagnosis of colorectal cancer. Accessibility to care, which is related to cancer detection, tumor stage, and therefore lymph node positivity, may vary by age and thus influence research results.

OBJECTIVE

The purpose of this study was to investigate whether young patients had an increased risk of lymph node-positive colon and rectal cancers in the Department of Defense Military Health System, which provides universal health care to its beneficiaries.

DESIGN

This was a retrospective, cross-sectional study.

SETTINGS

Patients were identified from the US Department of Defense Automated Central Tumor Registry.

PATIENTS

Included patients were diagnosed with histologically confirmed primary stage I to III colon and rectal adenocarcinomas between 1989 and 2013, had surgery and ≥1 lymph node examined, and did not receive preoperative radiotherapy. Logistic regression was used to examine the relationships between age at diagnosis (18-49, 50-59, 60-69, and ≥70 y) and lymph node positivity overall and stratified by tumor T stage and number of lymph nodes examined.

MAIN OUTCOME MEASURES

Lymph node positivity of colon and rectal cancers was measured.

RESULTS

The youngest patients (aged 18-49 y) were more likely to have lymph node-positive colon and rectal cancers compared with those who were aged ≥70 years after adjustment for potential confounders (OR = 2.04 and 95% CI, 1.63-2.56 for colon cancer; OR = 1.73 and 95% CI, 1.11-2.70 for rectal cancer). A similar tendency was shown in most colon and rectal cancer subgroups stratified by tumor T stage and number of lymph nodes examined.

LIMITATIONS

This study was limited by its small sample size for certain subgroup analyses. No information on comorbidities, BMI, or other indicators of health status was available.

CONCLUSIONS

In a universal healthcare system, young age was associated with increased lymph node positivity of colon and rectal cancers, suggesting that factors other than access to care may play a role in this association. See Video Abstract at http://links.lww.com/DCR/B90. EDAD Y POSITIVIDAD DE GANGLIOS LINFÁTICOS EN PACIENTES CON CÁNCER DEL COLON Y EL RECTO EN EL SISTEMA DE SALUD MILITAR DE EE UU: La edad temprana puede estar asociada con un mayor riesgo de compromiso de los ganglios linfáticos en el momento del diagnóstico de cáncer colorrectal. La accesibilidad a la atención medica, que está relacionada con la detección del cáncer, el estadio del tumor y, por lo tanto, la positividad de los ganglios linfáticos, puede variar según la edad y, por lo tanto, influir en los resultados de la investigación.Investigar si los pacientes jóvenes tenían un mayor riesgo de cáncer del colon y el recto con ganglios linfáticos positivos en el Sistema de Salud Militar del Departamento de Defensa, que brinda atención médica universal a sus beneficiarios.Estudio transversal retrospectivo.Se identificaron pacientes del Registro Automático Central de Tumores del Departamento de Defensa de los Estados Unidos.Fueron diagnosticados con adenocarcinomas del colon y el recto en estadio I-III confirmados histológicamente entre 1989-2013, se les realizó una cirugía y se examinaron ≥ 1 ganglio linfático, y no recibieron radioterapia preoperatoria. La regresión logística se utilizó para examinar las relaciones entre la edad al momento del diagnóstico (18-49, 50-59, 60-69 y ≥70 años) y la positividad de los ganglios linfáticos en general y fue estratificada por el estadio T tumoral y el número de ganglios linfáticos examinados.Positividad de ganglios linfáticos de cáncer del colon y el recto.Los pacientes más jóvenes (18-49 años) tenían más probabilidades de tener cáncer del colon y el recto con ganglios linfáticos positivos en comparación con aquellos que tenían 70 años o más después del ajuste por posibles factores de confusión (odds ratio: 2.04, intervalo de confianza del 95%: 1.63 -2.56 para el cáncer de colon; odds ratio: 1.73, intervalo de confianza del 95%: 1.11-2.70 para el cáncer de recto). Se mostró una tendencia similar en la mayoría de los subgrupos de cáncer del colon y el recto estratificados por el estadio T tumoral y el número de ganglios linfáticos examinados.Tamaño de muestra pequeño para ciertos análisis de subgrupos. No hay información sobre comorbilidades, índice de masa corporal u otros indicadores del estado de salud.En un sistema de salud universal, la edad joven se asoció con un aumento de la positividad de los ganglios linfáticos del cáncer del colon y el recto, lo que sugiere que otros factores además del acceso a la atención medica pueden desempeñar un papel en esta asociación. Consulte Video Resumen en http://links.lww.com/DCR/B90.

Impact of intramural and extramural vascular invasion on stage II-III colon cancer outcomes

BACKGROUND AND OBJECTIVES

Vascular invasion, in particular extramural venous invasion (EMVI), is a pathologic characteristic that has been extensively studied in rectal cancer but rarely in colon cancer. This study aims to evaluate its prognostic role in stage II-III colon cancer.

METHODS

All stage II-III colon cancer patients who underwent surgery between 2004 and 2015 were reviewed. We compared patients without invasion, with intramural invasion only (IMVI), EMVI only, and both IMVI/EMVI (n = 923).

RESULTS

EMVI was associated with other high-risk features, including T4, N+ disease, lymphatic, and perineural invasion (P < 0.001). EMVI+ patients had higher rates of locoregional and distant recurrence and subsequently disease-specific mortality (stage-II, odds ratio [OR] 3.64; P = 0.001; stage-III OR, 1.94; P = 0.009), whereas outcomes were comparable between IMVI and no vascular invasion (OR, 1.21; P = 0.764; OR, 1.28, P = 0.607, respectively). The adjusted HRs for EMVI+ patients on disease-free survival, and disease-specific survival were 2.07 ( P < 0.001) and 1.67 ( P = 0.027), respectively. Moreover, EMVI+ stage-II patients fared worse than EMVI- stage-III patients, even after adjusting for adjuvant chemotherapy.

CONCLUSION

EMVI is a strong predictor for worse oncologic outcomes in stage II-III colon cancer patients, whereas IMVI is not. It is also associated with worse outcomes compared in patients with higher stage disease who are EMVI negative.

Do clinicopathologic features of rectal and colon cancer guide us towards distinct malignancies?

Background

Unlike developed countries where studies on all aspects of colorectal cancers are widely numerous, Iran as a Middle Eastern country show very few studies especially ones comparing the differences between colon and rectal cancer. In this study, firstly we report demographic, clinical and pathologic characteristics of patients with rectum and colon cancer and secondly compare these findings in order to investigate probable differences.

Methods

In this cross-sectional study, 238 patients were divided into two groups: the rectal cancer group and the colonic cancer group. Demographic, clinical and pathologic information of patients were statistically compared using Stata version 12.

Results

There were no statistical differences between the two groups regarding age and gender and BMI. Regarding clinical presentation, the proportion of rectal bleeding was significantly higher in colon cancer group (P<0.001). Moreover, abdominal pain was significantly more frequent in colon cancer group (P<0.001). Tumor stage showed statistically difference between the two groups (P=0.02).

Conclusions

We did not find enough evidences to conclude that rectal cancer and colon cancer should be investigated as two distinct malignancies but findings showed significant differences such as stage at diagnosis encouraged us in order to conduct other appropriate studies for better evaluation of this issue.

Survival Rate of Colorectal Cancer in Iran: A Systematic Review and Meta-Analysis

Background: Different studies have been conducted to estimate the survival rate of colorectal cancer in Iran but there is no overall estimate of the survival rate. The aim of this study was to calculate the pooled 1, 3, and 5-year survival rate of the patients with colorectal cancer in Iran. Methods: To retrieve relevant studies, we conducted a systematic search in Iranian databases, including Iran Medex, Magiran, SID, and international databases such as Medlin/PubMed, Scopus, and Google scholar using “Colorectal Neoplasms” and “Survival Rate” as keywords up to December 1st, 2017. We used random effect model to estimate pooled 1, 3, and 5-year survival rates of the patients with colorectal cancer in Iran. To assess the heterogeneity, we used Chi-squared test at the 5 % significance level (p <0.05) and I2 Index. We used meta-regression and subgroup analysis to find a potential source of heterogeneity. Results: After a systematic search, 196 articles were found, of the 38 studies met the eligibility criteria and are included in our meta-analysis. The pooled 1, 3, and 5-year survival rates in patient with colorectal cancer were 0.84 (95% CI: 0.81-0.87), 0.64 (95%CI: 0.59-0.70), and 0.54 (95%CI: 0.49-0.58) respectively. The 5-year survival rate in the subgroup of women was 0.5 (0.44-0.56) and in male subgroup was 0.44 (0.40-0.48). In a subgroup of the tumor site, the 5-year survival rate in colon cancer was 0.6 (0.49-0.75) and rectum cancer was 0.54 (0.36-0.69). In multivariable models, there was a significant association between years of study and 5-year survival rate as a source of heterogeneity (β = 18.9, P=0.01). Conclusion: According to the results of this study, women had a better survival rate than men, and according to the tumor site, the 5-year survival rate in colon cancer was better than the rectum cancer.

Rectal Cancer in Asian vs. Western Countries: Why the Variation in Incidence?

OPINION STATEMENT

Colorectal cancer (CRC) is the third most common cancer worldwide. CRC has been thought to be less common in Asia compared to Western countries. However, the incidence rates of CRC in Asia are high and there is an increasing trend in the Asian population. Furthermore, colorectal cancer accounts for the greatest number of all incidences of CRC in Asia. The increasing adoption of a Western lifestyle, particularly in dietary habits, is likely the most important factor contributing to the rapid increase in colon cancer incidence; it is noteworthy that trends for rectal cancer were flat. The etiology of colon and rectal cancer is a bit different. The risks of distal colon and rectal cancers are more likely to be related to environmental factors, such as polluted surface water sources, alcohol consumption, and habitual smoking. The lack of great change in the incidence of rectal cancer might be due to weaker associations with such lifestyle factors. Therefore, it has been hypothesized that proximal and distal sections of the colon and rectum are two different organs in terms of function and genetic background. It may mean differences in differential sensitivities and exposures to carcinogens. However, despite the decrease in whole incidence, the CRC incidence in young adults in Western countries are reversely increasing, especially in rectal cancer, due to reasons largely unknown. Although the treatment algorithm is different between Asia and western countries, globally, the survival rate for patients with rectal cancer has risen during the past 10 years. Screening contributes a great deal to reducing the incidence and improving survival. Most countries in Asia, such as China, need nationwide registration and screening systems to provide better data.

Does tumor size have its prognostic role in colorectal cancer? Re-evaluating its value in colorectal adenocarcinoma with different macroscopic growth pattern

BACKGROUND

Few previous studies have taken the growth pattern into consideration when analyzing the prognostic value of tumor size in colorectal cancer (CRC).

OBJECTIVE

We sought to reveal the prognostic role of tumor size in different macroscopic growth patterns of CRC.

MATERIALS AND METHODS

Using Cancer Center datasets, we identified 4057 cases with colorectal adenocarcinoma treated with curative resection. Macroscopic growth patterns of tumors were classified into three types: infiltrative, ulcerative and expansive types based on tumor gross appearance. Univariate and multivariate Cox regression analyses were performed to evaluate the prognostic factors for overall survival (OS) and disease-free survival (DFS).

RESULTS

In whole cohort, tumor size was an independent factor for OS (HR 1.10, 95%CI 1.04-1.16, p < 0.001). Subgroup analysis based on macroscopic growth pattern suggested that tumor size was an independent factor for OS both in the infiltrative (HR 1.37, 95%CI 1.12-1.66, p = 0.002) group and ulcerative group (HR 1.08, 95%CI 1.00-1.16, p = 0.044) and tumor size (HR 1.22, 95%CI 1.06-1.40, p = 0.004) was found as an independent factor for DFS only in infiltrative group.

CONCLUSIONS

Tumor size is an independent factor for OS and DFS in patients with colorectal adenocarcinoma of infiltrative type, while only for OS in patients of ulcerative type.

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.

Colon cancer with unresectable synchronous metastases: the AAAP scoring system for predicting the outcome after primary tumour resection

AIM

The aim of this study was to develop a prognostic scoring system to predict the outcome of patients with unresectable metastatic colon cancer who received primary colon tumour resection.

METHOD

Patients with confirmed metastatic colon cancer treated at the Peking University Cancer Hospital between 2003 and 2012 were reviewed retrospectively. The correlation of clinicopathological factors with overall survival was analysed using the Kaplan-Meier method and the log-rank test. Independent prognostic factors were identified using a Cox proportional hazards regression model and were then combined to form a prognostic scoring system.

RESULTS

A total of 110 eligible patients were included in the study. The median survival time was 10.4 months and the 2-year overall survival (OS) rate was 21.8%. Age over 70 years, an alkaline phosphatase (ALP) level over 160 IU/l, ascites, a platelet/lymphocyte ratio (PLR) above 162 and no postoperative therapy were independently associated with a shorter OS in multivariate analysis. Age, ALP, ascites and PLR were subsequently combined to form the so-called AAAP scoring system. Patients were classified into high, medium and low risk groups according to the score obtained. There were significant differences in OS between each group (P < 0.001).

CONCLUSION

Age, ALP, ascites, PLR and postoperative therapy were independent prognostic factors for survival of patients with metastatic colonic cancer who underwent primary tumour resection. The AAAP scoring system may be a useful tool for surgical decision making.

Immunological Landscape and Clinical Management of Rectal Cancer

The clinical management of rectal cancer and colon cancer differs due to increased local relapses in rectal cancer. However, the current molecular classification does not differentiate rectal cancer and colon cancer as two different entities. In recent years, the impact of the specific immune microenvironment in cancer has attracted renewed interest and is currently recognized as one of the major determinants of clinical progression in a wide range of tumors. In colorectal cancer, the density of lymphocytic infiltration is associated with better overall survival. Due to the need for biomarkers of response to conventional treatment with chemoradiotherapy in rectal tumors, the immune status of rectal cancer emerges as a useful tool to improve the management of patients.

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.

Increased lymphangiogenesis in lung metastases from colorectal cancer is associated with early lymph node recurrence and decreased overall survival

Pulmonary metastasectomy (PM) is an accepted treatment modality in colorectal cancer (CRC) patients with pulmonary tumor spread. Positive intrathoracic lymph nodes at the time of PM are associated with a poor prognosis and 5-year survival rates of <20 %. Increased lymphangiogenesis in pulmonary metastases might represent an initial step for a subsequent lymphangiogenic spreading. We aimed to evaluate the presence of lymphangiogenesis in clinically lymph node negative patients undergoing PM and its impact on outcome parameters. 71 patients who underwent PM for CRC metastases were included in this dual-center study. Tissue specimens of pulmonary metastases and available corresponding primary tumors were assessed by immunohistochemistry for lymphatic microvessel density (LMVD) and lymphovascular invasion (LVI). Results were correlated with clinical outcome parameters. LMVD was 13.9 ± 8.1 and 13.3 ± 8.5 microvessels/field (mean ± SD) in metastases and corresponding primary CRC; LVI was evident in 46.5 and 58.6 % of metastases and corresponding primary CRC, respectively. Samples with high LMVD had a higher likelihood of LVI. LVI was associated with early tumor recurrence in intrathoracic lymph nodes and a decreased overall survival (p < 0.001 and p = 0.029). Herein, we present first evidence in a well-defined patient collective that increased lymphangiogenesis is already present in a subtype of pulmonary metastases of patients staged as N0 at the time of PM. This lymphangiogenic phenotype has a strong impact on patients' prognosis. Our findings may have impact on the post-surgical therapeutic management of CRC patients with pulmonary spreading.

The conundrum of the young colon cancer patient

BACKGROUND

Colonoscopy has had a major impact on the incidence and survival of colon cancer for patients who are screened, usually beginning at the age of 50. Meanwhile, the incidence rate of colon cancer is actually increasing in the patients younger than 50 while no routine screening is implemented for this age group.

METHODS

All patients surgically treated for colon cancer (2004-2011) without preexisting high-risk characteristics (hereditary nonpolyposis colorectal cancer, inflammatory bowel disease) were included (n = 1,015). Age-related disparities in baseline disease and outcomes were reviewed.

RESULTS

Patients younger than 50 years of age (n = 108; 10.6%) had the greatest baseline rates of metastatic (20.4% vs 8.0%; P < .001), node-positive disease (54.6% vs 39.4%; P = .002), and greater rates of extramural vascular invasion (38.9 vs 29.4%; P = .043). Cancer-related mortality also was greatest in this group (28.7 vs 18.4%; P = .011). Multivariable Cox regression shows that patients younger than 50 are still at significantly greater risk of mortality after adjustment for effects of age, baseline AJCC staging, smoking, and comorbidity (hazard ratio: 1.57, 95% confidence interval 1.01-2.45; P = .049).

DISCUSSION

Patients younger than 50 present with the most advanced and aggressive disease, giving them the worst stage-independent prognosis of all age groups. Potential causes include age-related differences in tumor biology and underdetection by current screening efforts. This raises the question of how to address the conundrum of the young colon cancer patient, who often is the proverbial needle in a haystack of young patients, with nonspecific gastrointestinal symptoms but who would benefit considerably from early detection.

Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study

The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) after adjusting for various confounders. A strong inverse association was found between freshwater fish intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 53% (OR 0.47, 95% CI = 0.36-0.60, Ptrend < 0.01) after adjustment for various confounders. The inverse association were also observed for sea fish (OR 0.79, 95%CI = 0.62-0.99, Ptrend < 0.01) and fresh fish (OR 0.49, 95%CI = 0.38-0.62, Ptrend < 0.01). No statistically significant association was found between dried/salted fish and shellfish intake and colorectal cancer risk. These results indicate that higher consumption of freshwater fish, sea fish and fresh fish is associated with a lower risk of colorectal caner.

Variations in Metastasis Site by Primary Location in Colon Cancer

OBJECTIVE

The purpose of this paper is to determine whether sites of distant recurrence are associated with specific locations of primary disease in colon cancer.

METHODS

A cohort including all patients (n = 947) undergoing a segmental colonic resection for colon cancer at our center (2004-2011) comparing site-specific metastatic presentation and recurrence rates, as well as their respective multivariable American Joint Committee on Cancer (AJCC) stage-adjusted hazard ratios (mHR).

RESULTS

Right-sided colectomies (n = 557) had a lower overall metastasis rate (24.8% vs. 31.8%; P = 0.017; mHR = 1.24 [95% CI: 0.96-1.60]; P = 0.011) due to significantly lower pulmonary metastasis in follow-up (2.7% vs. 9%; P < 0.001; mHR = 0.32 [95% CI: 0.17-0.58]; P = 0.001) and lower overall liver metastasis rate (15.6 vs. 22.1%; P = 0.012; mHR = 0.74 [95% CI: 0.55-0.99];P = 0.050). Left colectomies (n = 127) had higher rates of liver metastasis during follow-up (9.4% vs. 4.8%; P = 0.029; mHR = 1.64 [95% CI: 0.86-3.15]; P = 0.134). Sigmoid resections (n = 238) had higher baseline rates of liver metastasis (17.1% vs. 11.3%; P = 0.015) and higher cumulative rates of lung (12.2% vs. 5.4%; P < 0.001; mHR = 2.26 [95% CI: 1.41-3.63]; P = 0.001) and brain metastases (2.3% vs. 0.6%; P = 0.033; mHR = 4.03 [95% CI: 1.14-14.3]; P = 0.031). Other sites of metastasis, including the (retro) peritoneum, omentum, ovary, and bone, did not yield significant differences.

CONCLUSIONS

Important variations in site-specific rates of metastatic disease exist within major resection regions of colon cancer. These variations may be important to consider when evaluating options for adjuvant treatment and surveillance after resection of the primary disease.

Type 2 diabetes mellitus and colorectal neoplasia risk in Hispanics: a case-control study

AIMS

There is inconclusive evidence regarding the potential link between diabetes mellitus (DM) and colorectal cancer (CRC). Associations between type 2 DM and colorectal neoplasia (CRN; colorectal cancer and/or adenomas) have not been well studied in Hispanics, an ethnic minority at high risk for type 2 DM. This study aims to assess the association between type 2 DM and CRN in Hispanics.

METHODS

Hispanics with incident CRN and colonoscopy-negative controls from 2005 to 2009 were evaluated. Diagnosis of type 2 DM was established by previous medical diagnosis and/or use of DM treatments. Unconditional logistic regression was performed to estimate odds ratios for the association between type 2 DM and CRN.

RESULTS

A total of 451 participants (mean age 61.1±11.9years, 59.6 % men) were evaluated (218 with incident CRC, 77 with colorectal adenomas, and 156 colonoscopy-negative controls). The prevalence of type 2 DM in this study was 25.1%. After adjusting for potential confounding variables, women with type 2 DM were 2.74 (95% CI: 0.94-7.99) times more likely to have CRN and 4.83 times more likely to present with proximal colonic CRN (95% CI: 1.25-18.58) than women without type 2 DM. No statistically significant associations were found between type 2 DM and CRN among men.

CONCLUSIONS

An increased odds for CRN and proximal location of CRN was observed among Hispanic women with type 2 DM. Since DM is a highly prevalent disease in this population, adherence to routine CRC screening is of outmost importance.

Colon cancer stem cell markers CD44 and CD133 in patients with colorectal cancer and synchronous hepatic metastases

CD44 and CD133 mRNA expression as cancer stem cell markers in colorectal cancer were correlated with synchronous hepatic metastases and the clinicopathological factors, including patient survival. The CD44 and CD133 mRNA levels in 36 primary colorectal adenocarcinomas with synchronous hepatic metastasis were analyzed by reverse transcriptase polymerase chain reaction, with normalization relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Immunohistochemical analysis was performed on samples with typical mRNA expression patterns to investigate protein expression. Both CD44 and CD133 gene expressions were highest in hepatic metastasis tissue, followed by colorectal cancer and normal mucosa. The differences were statistically significant among groups of normal mucosa, colorectal cancer and hepatic metastasis tissue. CD44 mRNA expression was significantly associated with the tumor location (P=0.019) and histology (P=0.026). With a median follow-up period of 38 months, the 5-year disease-free survival rate of the patients with high CD44 mRNA expression in the CD44 hepatic metastasis tissue group was significantly lower than that of the patients with low expression (P=0.002). While the mRNA expressions in groups of CD44 colorectal tumor, CD133 colorectal tumor, and CD133 hepatic metastasis tissue were not significant. CD44 and CD133 mRNA were highly correlatively co-expressed in colorectal cancer with hepatic metastases. CD44 expression was an independent factor associated with patient survival, while CD133 did not show this pattern. Thus, CD44 is a more reliable marker for predicting hepatic metastases and survival. Larger prospective studies are required to confirm these findings.

Prognostic and predictive values of the immunoscore in patients with rectal cancer

PURPOSE

To determine whether the tumor immune infiltrate, as recently evaluated with the Immunoscore methodology, could be a useful prognostic marker in patients with rectal cancers.

EXPERIMENTAL DESIGN

The influence of the immune infiltrate on patient's outcome was investigated in patients with or without preoperative chemoradiation therapy (pCRT). The density of total (CD3(+)) and cytotoxic (CD8(+)) T lymphocytes was evaluated by immunohistochemistry and quantified by a dedicated image analysis software in surgical specimens of patients with rectal cancer (n = 111) who did not receive pCRT and in tumor biopsies performed before pCRT from additional 55 patients. The results were correlated with tumor recurrence, patient's survival, and response to pCRT.

RESULTS

The densities of CD3(+) and CD8(+) lymphocytes and the associated Immunoscore (from I0 to I4) were significantly correlated with differences in disease-free and overall survival (HR, 1.81 and 1.72, respectively; all P < 0.005). Cox multivariate analysis supports the advantage of the Immunoscore compared with the tumor-node-metastasis (TNM) staging in predicting recurrence and survival (all P < 0.001). Lymph node ratio added information in a prognostic model (all P < 0.05). In addition, high infiltration of CD3(+) and CD8(+) lymphocytes in tumor biopsies was associated with downstaging of the tumor after pCRT (CD3(+) cells; Fisher exact test P = 0.01).

CONCLUSIONS

The Immunoscore could be a useful prognostic marker in patients with rectal cancer treated by primary surgery. The determination of the immune infiltrate in biopsies before treatment could be a valuable information for the prediction of response to pCRT.

Prevalence of local recurrence of colorectal cancer at the Iranian Cancer Institute

BACKGROUND

Although a great deal of progress has been made in the management of colorectal cancer in terms of neoadjuvant modalities, surgical techniques and adjuvant therapies, the recurrence of tumors remains an enigmatic complication in patients. A better understanding of colorectal cancer and of factors that lead to recurrence of disease can provide helpful information for designing more effective screening and surveillance methods.

AIM

To investigate the factors that may lead to local recurrence of colorectal cancers.

MATERIALS AND METHODS

The current retrospective case study evaluated 617 patients admitted to the Iranian Cancer Institute (the largest referral cancer center in the country) from 1995 to 2009 with confirmed colorectal cancer. Patients with distant metastasis, or with pathology other than adenocarcinoma and no follow-up, were excluded (175 patients). The remainder (442) included 294 (66.5%) with rectal cancer and 148 (33.5%) with colon cancer. The median duration of follow-up was 26 months.

RESULTS

The total rate of recurrence was 17.4%, comprising 19.6% and 16.3% recurrence rates in colon and rectal cancer, respectively.

CONCLUSIONS

Recurrence of colorectal cancer was significantly correlated to tumor grade (p<0.008).

Fish consumption and risk of gastrointestinal cancers: A meta-analysis of cohort studies

AIM: To assess quantitatively the relationship between fish intake and the incidence of gastrointestinal cancers in a meta-analysis of cohort studies.

METHODS: We searched MEDLINE, Embase, Science Citation Index Expanded, and the bibliographies of retrieved articles. Prospective cohort studies were included if they reported relative risks (RRs) and corresponding 95% confidence intervals (CIs) of various cancers with respect to fish intake. When RRs were not available in the published article, they were computed from the exposure distributions. Two investigators extracted the data independently and discrepancies were resolved by discussion with a third investigator. We performed random-effect meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of cancer associated with a 20-g/d increment of fish consumption.

RESULTS: Forty-two studies, comprising 27 independent cohorts, met our inclusion criteria. The studies included 2325040 participants and 24115 incident cases of gastrointestinal cancer, with an average follow-up of 13.6 years. Compared with individuals who did not eat, or seldom ate, fish, the pooled RR of gastrointestinal cancers was 0.93 (95%CI: 0.88-0.98) for regular fish consumers, 0.94 (0.89-0.99) for low to moderate fish consumers, and 0.91 (0.84-0.97) for high fish consumers. Overall, a 20-g increase in fish consumption per day was associated with a 2% reduced risk of gastrointestinal cancers (RR = 0.98; 95%CI: 0.96-1.01). In subgroup analyses, we noted that fish consumption was associated with reduced risk of colorectal (RR = 0.93; 95%CI: 0.87-0.99; P < 0.01), esophageal (RR = 0.91; 95%CI: 0.83-0.99; P < 0.05) and hepatocellular cancers (RR = 0.71; 95%CI: 0.48-0.95; P < 0.01).

CONCLUSION: This meta-analysis suggested that fish consumption may reduce total gastrointestinal cancer incidence. Inverse relationships were also detected between fish consumption and specific types of cancers.

Colon cancer surgery following emergency presentation: effects on admission and stage-adjusted outcomes

BACKGROUND

Emergency presentation with colon cancer is intuitively related to advanced disease. We measured its effect on outcomes of surgically treated colon cancer.

METHODS

A retrospective cohort of 1,071 surgical colon cancer patients (2004 to 2011), with 102 emergency cases requiring surgery within the index admission, was analyzed.

RESULTS

Emergency patients required longer surgeries (median 141 vs 124 minutes; P = .04), longer median admissions (8% vs 5%; P < .001), more readmissions (12.7% vs 7.1%; P = .040), and perioperative mortality (7.8% vs .8%; P < .001). Surgical pathology displayed higher rates of node-positive disease (56.6% vs 38.6%; P < .001), extramural vascular invasion (39.6% vs 29.1%; P = .021), and metastatic disease (19.6% vs 8%; P < .001). Consequently, adjusting for staging, emergency presentations had considerably higher mortality (odds ratio = 2.07; P = .003) and shorter disease-free survival (hazard ratio = 1.39; P = .042).

CONCLUSIONS

Emergency presentation is a stage-independent poor prognostic factor associated with aggressive tumor biology, resulting in longer surgeries and admissions, frequent readmissions, worsening outcomes, and increasing healthcare costs.

Gimeracil and oteracil porassium capsules as a single drug in adjuvant treatment of patients with advanced colorectal cancer: A randomized clinical study

AIM: To evaluate the efficacy and safety of gimeracil and oteracil porassium capsules (S-1) as a single drug in the adjuvant treatment of patients with advanced colorectal cancer.

METHODS: Eligible patients with advanced colorectal cancer were randomly assigned to either a control group or an experimental group. The patients of the control group received routine symptomatic treatment, while the experimental group was additionally given S-1 [60 mg/(m²•d), bid, P.O. on days 1-14, then drug withdrawal for 1 wk, repeated every 3 wk, stopped until disease progression or unacceptable toxicity occurred] beside the routine symptomatic treatment.

RESULTS: A total of 83 eligible patients were enrolled, including 4 in the control group and 41 in the experimental arm. Median follow-up period was 54 wk. The baseline characteristics were comparable between the two groups. S-1 treatment improved the progression-free survival (PFS), though there was no statistical difference (HR = 0.52, 95%CI: 0.22-1.23, P = 0.1384). For all patients with advanced colorectal cancer, the 1-year PFS for the control arm and experimental arm was 78.6% and 97.6%, respectively, favoring the S-1 regimen. For patients with advanced colon cancer, the improvement of PFS did not differ significantly between the two arms (HR = 0.62, 95%CI: 0.20-1.95, P = 0.4156). The 1-year PFS for the control arm and experimental arm was 76.2% and 95.0%, favoring the S-1 regimen. For patients with advanced rectal cancer, the improvement of PFS did not differ significantly between the two arms (HR = 0.42, 95%CI: 0.11-1.58, P = 0.2005). The 1-year PFS for the control arm and experimental arm was 76.2% and 95.2%, respectively. Three cases developed S-1-induced adverse reactions, including one case of grade Ⅱ and two cases of grade Ⅰ, which, however, did not cause treatment discontinuation.

CONCLUSION: S-1 can improve the PFS in patients with advanced colorectal cancer, indicating that such patients may benefit from S-1 regimen in the adjuvant setting.

Rectal Site and Suboptimal Nodal Yield Predict Systemic Recurrence in Resected Colorectal Carcinoma

We assessed the contribution of histopathological features to systemic recurrence (SR) in patients with colorectal cancer, using a case-control design: 71 cases and 184 controls were included, with a mean time until SR of 1.4 ± 0.1 years and a mean follow-up of controls of 1.6 ± 0.06 years. Cases had significantly greater odds of rectal site (odds ratio [OR] = 1.82), stage ≥pT3 (OR = 2.11), suboptimal (<12) lymph node yield (OR = 4.6), stage ≥pN1 (OR = 2.46), KRAS mutation (OR = 2.76), and extramural venous invasion (OR = 1.97). By multiple regression analysis, rectal site, stage ≥pT3, suboptimal lymph node yield, and lymph node positivity independently predicted SR. Rectal cancers were more likely to have a suboptimal node yield than nonrectal cancers (relative risk = 1.6) among the entire cohort. We conclude that rectal cancers have greater risk of SR than colon cancers. A lower yield of lymph nodes in rectal cancer specimens may contribute to this.

Differences in carcinoembryonic antigen levels between colon and rectal cancer

The aim of the present study was to investigate the levels of the serum tumor biomarker carcinoembryonic antigen (CEA) in patients with carcinoma of the colon and rectum in different clinical stages. Colorectal cancer (CRC) is one of the most commonly diagnosed types of cancer worldwide and previous studies have reported rapidly updated therapeutic regimes. While the majority of studies focus on CRC as a single entity, certain studies distinguish colon cancer (CC) from rectal cancer (RC), as there is a hypothesis stating that CC and RC are two naturally different entities. CEA is reported to be an important tumor-associated antigen overexpressed in CRC, which is routinely detected as a significant indicator of CRC. Our study aimed to identify potential differences in the expression of CEA between CC and RC, which may, to some degree, reflect the natural differences between the two. We investigated 240 CRC cases between July, 2010 and December, 2012 from The First and Second Affiliated Hospitals of Dalian Medical University, including 117 CC and 123 RC patients with tumors classified by Duke's staging as A-D. The serum CEA level was measured preoperatively by radioimmunoassays as a routinely used auxiliary indicator. The expression of CEA differed between CC and RC, with the former exhibiting variation among the four stages, whereas no variation was observed in RC. In addition, there were differences between CC and RC regarding the CEA level in stage C and D. Furthermore, the CEA level in stage C of CC was significantly lower compared to that in any other stage. In conclusion, the intrinsic distribution of the CEA level between CC and RC suggests that CC and RC may be two naturally different entities; the significantly low CEA level in stage C of CC indicates that stage C may be crucial in the evolution of CC.

Gender and ethnic disparities in colon cancer presentation and outcomes in a US universal health care setting

OBJECTIVE

Access to care is a pillar of U.S. healthcare reform and could potentially challenge existing ethnic and gender disparities in care. We present a snapshot of these disparities in surgical colon cancer patients in the largest public hospital in Massachusetts, a state leading in providing universal healthcare, to indicate potential changes that might result from universal care access.

METHODS

All surgical colon cancer patients at Massachusetts General Hospital (2004-2011) were included. Baseline characteristics, perioperative, and long-term outcomes were compared.

RESULTS

Among 1,071 patients, the 110 (10.3%) minority patients presented with more comorbid (mean Charlson score 0.84 vs. 0.71; P = 0.039), metastatic (21.8% vs. 14%; P = 0.026), and node-positive disease (50% vs. 38.8%; P = 0.014). Women (n = 521; 48.6%) had less screening diagnoses (overall: 17.8% vs. 22.6%; P = 0.049, screening age: 26.4% vs. 32.7%; P = 0.036) with subsequently higher rates of metastatic disease on pathology (11.3% vs. 7.1%, P = 0.02). Multivariate adjustment for baseline staging makes outcome disparities no longer statistically significant.

CONCLUSIONS

Significant gender and ethnic disparities subsist at baseline despite long-standing low-threshold healthcare access, although seemingly mitigated by enrollment into high-level care, empowering equal chances for underprivileged groups. The outcomes are also a reminder that universal healthcare will not be a panacea for the deeply rooted and dynamic causes of presentation inequalities.

Differences in survival between colon and rectal cancer from SEER data

Background

Little is known about colorectal cancer or colon and rectal cancer. Are they the same disease or different diseases?

Objectives

The aim of this epidemiology study was to compare the features of colon and rectal cancer by using recent national cancer surveillance data.

Design and setting

Data included colorectal cancer (1995–2008) from the Surveillance, Epidemiology, and End Results Program (SEER) database. Only adenocarcinoma was included for analysis.

Patients

A total of 372,130 patients with a median follow-up of 32 months were analyzed.

Main outcome measures

Mean survival of patients with the same stage of colon and rectal cancer was evaluated.

Results

Around 35% of patients had stage information. Among them, colon cancer patients had better survival than those with rectal cancer, by a margin of 4 months in stage IIB. In stage IIIC and stage IV, rectal cancer patients had better survival than colon cancer patients, by about 3 months. Stage IIB colorectal cancer patients had a poorer prognosis than those with stage IIIA and IIIB colorectal cancer. After adjustment of age, sex and race, colon cancer patients had better survival than rectal cancer of stage IIB, but in stage IIIC and IV, rectal cancer patients had better survival than colon cancer.

Limitations

The study is limited by its retrospective nature.

Conclusion

This was a population-based study. The prognosis of rectal cancer was not worse than that of colon cancer. Local advanced colorectal cancer had a poorer prognosis than local regional lymph node metastasis. Stage IIB might require more aggressive chemotherapy, and no less than that for stage III.

Opposite variation tendencies of serum CA724 levels in patients with colon and rectal carcinoma

The aim of this study was to investigate tumor biomarker carbohydrate antigen 724 (CA724) in the serum of patients with carcinomas of the colon and rectum at various clinical stages. Serum was collected from 51 patients with colon carcinoma (CC) and 49 patients with rectal carcinoma (RC). CA724 levels were then measured in the different groups according to site, TNM classification, gender, age and metastastic status of the patients. The statistical significance of the differences between the groups was calculated by non-parametric statistics (Mann-Whitney and Kruskall-Wallis tests). We observed a close association between the serum CA724 levels and tumor migration in colorectal carcinoma (CRC) and opposite variation tendencies of CA724 in the evolution of CC and RC. In conclusion, we identified a close association between the serum levels of CA724 and tumor migration in CRC. The opposite variation tendencies of CA724 in the different evolution groups of CC and RC may reflect the differences between these two types of cancer. The evaluation of serum CA724 may be of monitoring and and predictive value and may also assist in the development of treatment strategies for CRC patients.

Differential lymph node retrieval in rectal cancer: associated factors and effect on survival

BACKGROUND

Recent publications have identified positive associations between numbers of lymph nodes pathologically examined and five-year overall survival (5-yr OS) in colon cancer. However, focused examinations of relationships between survival of rectal cancer and lymph node counts are less common. We conducted a single institution, retrospective review of rectal cancer resections to determine whether lymph node counts correlated with 5-yr OS and to explore the relationship between lymph node counts and various clinical and pathologic factors.

METHODS

A retrospective review of our institutional tumor registry identified 159 patients with AJCC Stage 1, 2, or 3 rectal cancers that underwent surgical resection at our institution over eleven years. Univariate analysis was used to explore the relationship between lymph node counts and age, AJCC Stage, time period of diagnosis, preoperative radiotherapy, and performance of TME. Survival analysis was performed by the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

In univariate analysis, there was an association between increased lymph node counts and age <70, higher stage, and diagnosis during the later portion of the study period [all P-values <0.05]. Lymph node counts were not associated with survival in Kaplan-Meier analysis or in multivariate Cox proportional hazards analysis.

CONCLUSIONS

Increasing lymph node counts improve survival and the accuracy of colorectal cancer staging. The body of literature recommends identical minimum lymph node counts in both colon and rectal cancer. In our study, which exclusively examined rectal cancer, we could not demonstrate that increased lymph node counts were associated with improved survival.

Prognostic value of microsatellite instability in sporadic locally advanced rectal cancer following neoadjuvant radiotherapy

AIMS

This study was conducted to investigate the clinicopathological significance and prognostic value of microsatellite instability (MSI) in locally advanced rectal cancer (LARC) following neoadjuvant radiotherapy.

METHODS AND RESULTS

A total of 316 consecutive patients with LARC who underwent neoadjuvant radiotherapy and curative surgery were included retrospectively. Microsatellite instability in pretreatment biopsy tissue was assessed using the pentaplex panel of mononucleotides. Twenty-five tumours (7.9%) were assessed as high-frequency MSI (MSI-H) and 291 were low-frequency MSI (MSI-L; n = 42) or microsatellite stable (MSS; n = 249). There were no significant differences in terms of gender, age, tumour location or pretreatment serum carcinoembryonic antigen between the MSI-H and MSI-L + MSS groups. Microsatellite instability was not associated statistically with pathological stage, radiation-induced tumour regression or downstaging. No significant difference was found in disease-free survival (DFS) between the two groups but, within the subgroup of ypN0 stage, patients with MSI-H tumours presented a significantly improved DFS compared with those with MSI-L or MSS tumours (100% versus 79.8%, P < 0.05), whereas no DFS improvement was observed for patients with MSI-H tumours in the ypN + subgroup.

CONCLUSIONS

Microsatellite instability could not predict a histopathological response to neoadjuvant radiotherapy, but was a good prognostic marker for patients without lymph node metastasis after neoadjuvant radiotherapy.

Impact of diabetes on oncologic outcome of colorectal cancer patients: colon vs. rectal cancer

Background

To evaluate the impact of diabetes on outcomes in colorectal cancer patients and to examine whether this association varies by the location of tumor (colon vs. rectum).

Patients and methods

This study includes 4,131 stage I-III colorectal cancer patients, treated between 1995 and 2007 (12.5% diabetic, 53% colon, 47% rectal) in South Korea. Cox proportional hazards modeling was used to determine the prognostic influence of DM on survival endpoints.

Results

Colorectal cancer patients with DM had significantly worse disease-free survival (DFS) [hazard ratio (HR) 1.17, 95% confidence interval (CI): 1.00–1.37] compared with patients without DM. When considering colon and rectal cancer independently, DM was significantly associated with worse overall survival (OS) (HR: 1.46, 95% CI: 1.11–1.92), DFS (HR: 1.45, 95% CI: 1.15–1.84) and recurrence-free survival (RFS) (HR: 1.32, 95% CI: 0.98–1.76) in colon cancer patients. No association for OS, DFS or RFS was observed in rectal cancer patients. There was significant interaction of location of tumor (colon vs. rectal cancer) with DM on OS (P = 0.009) and DFS (P = 0.007).

Conclusions

This study suggests that DM negatively impacts survival outcomes of patients with colon cancer but not rectal cancer.

Fish consumption and colorectal cancer risk in humans: a systematic review and meta-analysis

BACKGROUND

Fish consumption may protect against colorectal cancer, but results from observational studies are inconsistent; therefore, a systematic review with a meta-analysis was conducted.

METHODS

Relevant studies were identified by a search of MEDLINE and EMBASE databases to May 2011, with no restrictions. Reference lists from retrieved articles also were reviewed. Studies that reported odds ratio (OR) or relative risk estimates with 95% confidence intervals (CIs) for the association between the consumption of fish and the risk of colorectal, colon, or rectal cancer were included. Two authors independently extracted data and assessed study quality. The risk estimate (hazard ratio, relative risk, or OR) of the highest and lowest reported categories of fish intake were extracted from each study and analyzed using a random-effects model.

RESULTS

Twenty-two prospective cohort and 19 case-control studies on fish consumption and colorectal cancer risk met the inclusion criteria and were included in the meta-analysis. Our analysis found that fish consumption decreased the risk of colorectal cancer by 12% (summary OR, 0.88; 95% CI, 0.80-0.95). The pooled ORs of colorectal cancer for the highest versus lowest fish consumption in case-control studies and cohort studies were 0.83 (95% CI, 0.72-0.95) and 0.93 (95% CI, 0.86-1.01), respectively. There was heterogeneity among case-control studies (P<.001) but not among cohort studies. A significant inverse association was found between fish intake and rectal cancer (summary OR, 0.79; 95% CI, 0.65-0.97), and there was a modest trend seen between fish consumption and colon cancer (summary OR, 0.96; 95% CI, 0.81-1.14). This study had no publication bias.

CONCLUSION

Our findings from this meta-analysis suggest that fish consumption is inversely associated with colorectal cancer.

Long-term follow-up of preoperative pelvic radiation therapy and concomitant boost irradiation in locally advanced rectal cancer patients: a multi-institutional phase II study (KROG 04-01)

PURPOSE

To perform a prospective phase II study to investigate the efficacy and safety of preoperative pelvic radiation therapy and concomitant small-field boost irradiation with 5-fluorouracil and leucovorin for 5 weeks in locally advanced rectal cancer patients.

METHODS AND MATERIALS

Sixty-nine patients with locally advanced, nonmetastatic, mid-to-lower rectal cancer were prospectively enrolled. They had received preoperative chemoradiation therapy and total mesorectal excision. Pelvic radiation therapy of 43.2 Gy in 24 fractions plus concomitant boost radiation therapy of 7.2 Gy in 12 fractions was delivered to the pelvis and tumor bed for 5 weeks. Two cycles of 5-fluorouracil and leucovorin were administered for 3 days in the first and fifth week of radiation therapy. The pathologic response, survival outcome, and treatment toxicity were evaluated for the study endpoints.

RESULTS

Of 69 patients, 8 (11.6%) had a pathologically complete response. Downstaging rates were 40.5% for T classification and 68.1% for N classification. At the median follow-up of 69 months, 36 patients have been followed up for more than 5 years. The 5-year disease-free survival (DFS) and overall survival rates were 66.0% and 75.3%, respectively. Higher pathologic T (P=.045) and N (P=.032) classification were significant adverse prognostic factors for DFS, and high-grade histology was an adverse prognostic factor for both DFS (P=.025) and overall survival (P=.031) on the multivariate analysis. Fifteen patients (21.7%) experienced grade 3 or 4 acute toxicity, and 7 patients (10.1%) had long-term toxicity.

CONCLUSION

Preoperative pelvic radiation therapy with concomitant boost irradiation with 5-fluorouracil and leucovorin for 5 weeks showed acceptable acute and long-term toxicities. However, the benefit of concomitant small-field boost irradiation for 5 weeks in rectal cancer patients was not demonstrated beyond conventional irradiation for 6 weeks in terms of tumor response and survival.

Prognosis of mucinous histology for patients with radically resected stage II and III colon cancer

BACKGROUND

Previous studies investigating the prognostic role of mucinous histology of colorectal cancer produced conflicting results. This retrospective analysis was carried out in order to explore whether mucinous adenocarcinoma (MC) is associated with a comparatively worse prognosis than that of nonmucinous adenocarcinoma (NMC) for patients undergoing curative resection for stage II and III colon cancer.

PATIENTS AND METHODS

This study involved 1025 unselected patients who underwent curative surgery for sporadic colon cancer and follow-up procedures at six different oncology departments.

RESULTS

MCs accounted for 17.4% (n=178) of tumours. Patients with MC had 5- and 8-year overall survival rates of 78.6% and 68.8%, respectively, compared with 72.3% and 63.8%, respectively, for patients with nonmucinous tumours. Multivariate analysis using the Cox proportional hazards model showed that the clinically significant prognostic factors were stage of disease and adjuvant chemotherapy. No statistically significant interaction between mucinous histology and adjuvant chemotherapy was found.

CONCLUSIONS

For patients with stage II and III colon cancer who underwent curative surgery, mucinous histology has no significant correlation with prognosis compared with NMC. This retrospective analysis suggests a comparable benefit from adjuvant chemotherapy for MC compared with NMC.

Influence of pT3 subgroups on outcome of R0-resected colorectal tumors

OBJECTIVE

Evaluate whether depth of infiltration within T3 colorectal tumors influences long-term oncologic outcome.

PATIENTS AND METHODS

Patients with stage pT3 colon and rectal tumors were divided into four subgroups according to the depth of infiltration. The influence on overall and disease-free survival was tested for each subgroup and compared in univariate and multivariate analyses.

RESULTS

A total of 368 patients were evaluated, with a median follow-up time of 92.5 months. In 181 patients with colon cancer 5- and 10-year overall survival rates were 82.7% and 65.0%, respectively, and 5- and 10-year disease-free survival rates were 80.9% and 64.4%, respectively. For 187 patients, rectal cancer 5- and 10-year overall survival rates were 69.0% and 50.5%, respectively, and disease-free survival rates were 61.3% and 47.5%, respectively. In either colon or rectal cancer, different pT3 categories showed neither a statistically significant influence on survival nor the occurrence of local or distant recurrence in univariate and multivariate analyses; however, higher pT3 subgroups had a significant influence on lymph node involvement and vessel invasion in patients with rectal cancer.

CONCLUSIONS

Subdivision of pT3 tumors in colon cancer based on depth of infiltration does not provide additional information about prognosis. In rectal cancer, T3 substages were associated with lymph node involvement; however, we could not demonstrate an impact on recurrence or survival.

Matrix metalloproteinase-2 and -7 expression in colorectal cancer

Purpose

Matrix metalloproteinase-2 (MMP-2) and MMP-7 have been implicated in tumor growth and metastasis. This study aimed to investigate the expressions of MMP-2 and -7 in colorectal cancer and to evaluate their values as prognostic markers.

Methods

Immunohistochemical staining for MMP-2 and -7 was done in 144 resected colorectal cancer specimens. Clinicopathological data and survival results were compared with regard to the expression results.

Results

The expression rates of MMP-2 in tumor cells in the tumor center and the tumor border were 16.7% and 38.9%, respectively. That of MMP-2 in stromal cells was 27.8%. MMP-7 immunoreactivities of tumor cells in the tumor center and the tumor border were 6.9% and 23.6%. The expressions of MMP-2 and MMP-7 were correlated. MMP-2 expression in stromal cells was more increased in the distal part of the colorectum: 8.8% in right colon cancer, 29.5% in left colon cancer and 36.4% in rectal cancer. MMP-2 expression of tumor cells in the tumor border was correlated with T-stage. MMP-7 expression of tumor cells in the tumor border was increased in case of infiltrative cancer compared with fungating tumor. The expression patterns of MMP-2 and -7 were not correlated with other clinicopathological factors, including tumor markers, node metastasis, distant metastasis, lymphatic invasion, tumor differentiation, and recurrence. No significant associations between the overall and disease-free survival rates and the MMP-2 and -7 expression patterns were noted.

Conclusion

The high expression rates of MMP-2 and -7 in tumor borders suggest that MMP-2 and -7 have some role in tumor invasion, but in this study, MMP-2 and -7 did not appear to be significant predictors of prognosis in colorectal cancer.