Survival for colon and rectal cancer in a population-based cancer registry

Complete Obstruction, a Real Risk Factor: A Comprehensive Study on Obstruction in Stage IIA Colon Cancer With Propensity Score Matching Analysis

MICROABSTRACT

This study evaluates the prognostic significance of obstructions in stage IIA colon cancer, distinguishing between partial and complete obstructions. It employs a retrospective review of 1914 patients with propensity score matching to analyze oncologic outcomes. Findings reveal complete obstruction as a significant risk factor for poorer outcomes, emphasizing the necessity for further research to refine treatment strategies, particularly regarding the efficacy of adjuvant chemotherapy across obstruction types.

BACKGROUND

This study examined the prognostic impact of obstructions in stage IIA colon cancer. The analysis specifically differentiated partial and complete obstructions, analyzing their distinct influences of both on oncologic outcomes.

MATERIALS AND METHODS

A retrospective review was conducted of stage IIA colon cancer cases with the presence of an obstruction. Patients were stratified by whether it was partial or complete based on the severity of obstruction. Propensity score matching was employed to control for confounders.

RESULTS

Among 1914 consecutive patients diagnosed with stage IIA colon cancer, 758 patients (597 patients with partial obstruction, 161 patients with complete obstruction) exhibited obstruction, while 1156 patients had no obstruction. The median follow-up period was 126 months. Complete obstruction was associated with poorer disease-free survival (Hazard ratio (HR) = 1.785, P < .001) and overall survival (HR = 1.853, P = .001). This trend persisted after propensity score matching, patients with complete obstruction showing a worsened disease-free survival (HR = 1.666, P = .028) and overall survival (HR = 1.732, P = .041). Adjuvant chemotherapy showed improved outcomes overall, but its efficacy varied across obstruction types.

CONCLUSION

Differentiating between complete and partial obstructions in stage IIA colon cancer is an important clinical distinction, as our findings suggest that complete obstruction is a significant risk factor for poorer oncologic outcomes. While adjuvant chemotherapy generally improves prognosis in stage IIA colon cancer, the correlation of obstruction type with its efficacy remains uncertain, necessitating further research to refine treatment strategies.

Prognostic value of primary tumor location in colorectal cancer: an updated meta-analysis

The clinical, histological, and molecular differences between right-sided colon cancer (RCC) and left-sided colon cancer (RCC) have received considerable attention. Over the past decade, many articles have been published concerning the association between primary tumor location (PTL) of colorectal cancer and survival outcomes. Therefore, there is a growing need for an updated meta-analysis integrating the outcomes of recent studies to determine the prognostic role of right vs left-sidedness of PTL in patients with colorectal cancer. We conducted a comprehensive database review using PubMed, SCOPUS, and Cochrane library databases from February 2016 to March 2023 for prospective or retrospective studies reporting data on overall survival (OS) and cancer-specific survival (CSS) of RCC compared with LCC. A total of 60 cohort studies comprising 1,494,445 patients were included in the meta-analysis. We demonstrated that RCC is associated with a significantly increased risk of death compared with LCC by 25% (hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.19-1.31; I2 = 78.4%; Z = 43.68). Results showed that patients with RCC have a worse OS compared with LCC only in advanced stages (Stage III: HR, 1.275; 95% CI 1.16-1.4; P = 0.0002; I2 = 85.8%; Stage IV: HR, 1.34; 95% CI 1.25-1.44; P < 0.0001; I2 = 69.2%) but not in primary stages (Stage I/II: HR, 1.275; 95% CI 1.16-1.4; P = 0.0002; I2 = 85.8%). Moreover, a meta-analysis of 13 studies including 812,644 patients revealed that there is no significant difference in CSS between RCC and LCC (HR, 1.121; 95% CI 0.97-1.3; P = 0.112). Findings from the present meta-analysis highlight the importance of PTL in clinical decision-making for patients with CRC, especially in advanced stages. We provide further evidence supporting the hypothesis that RCC and LCC are distinct disease entities that should be managed differently.

Prognostic Factors for Survival of Colorectal Adenocarcinoma Patients in Uganda

Background

In Uganda, similar to other countries in East Africa, the incidence of colorectal cancer (CRC) has been steadily increasing. This increase in incidence is accompanied by a poor prognosis. There is limited knowledge on factors responsible for the poor outcome of patients with CRC in Uganda. Cancer survival analysis is one way of determining some of these prognostic factors. The aim of this study was to determine prognostic factors associated with CRC survival in Ugandan patients.

Methods

This was a retroprospective cohort study involving patients with linked data in the Kampala cancer registry and medical records from hospitals in Uganda. Participants with a diagnosis of colorectal adenocarcinoma between 1st January 2008 and 31st December 2018 were included. Variables included patients’ demographic data, grade, stage and location of CRC, data on whether a patient was operated on, type of operation, treatment modalities and date of diagnosis. Our outcome variable was time to death after diagnosis. We computed and compared survival using the Log rank test and used Cox proportional hazards regression to determine factors associated with survival.

Results

A total of 247 patients were included in the study with a mean (SD) age of 53.3 (15.7) years and a female: male ratio of 1.14:1. The proportions of patients surviving at 1, 2 and 3 years were 65.2% (95% CI: 58.8–70.9), 42.0% (95% CI:35.6–48.3) and 33.3% (95% CI:27.3–39.4) respectively. In multivariate analysis, factors associated with increased mortality included clinical stage II (aHR = 2.44, 95% CI: 1.10–5.41, p=0.028), stage III (aHR=2.65, 95% CI: 1.31–5.39, p=0.007) and stage IV (aHR=5.47, 95% CI: 2.40–12.48, p<0.001). Curative surgery alone (aHR=0.63, 95% CI: 0.39–1.01, p=0.057) and curative surgery with chemotherapy (aHR=0.53, 95% CI: 0.32–0.88, p=0.015) were associated with a better survival.

Conclusion

The survival rate among CRC patients in Uganda is low. Advanced stage CRC accelerates mortality, while surgery alone or in combination with chemotherapy improves survival. Implementation of national screening programmes for early diagnosis of CRC and increasing surgery and oncology infrastructure is recommended to improve the CRC survival rate in the Ugandan population.

Long non-coding RNA DCST1-AS1/hsa-miR-582-5p/HMGB1 axis regulates colorectal cancer progression

Long non-coding RNAs (lncRNAs) are related to the initiation and progression of tumor and regulate various cellular processes including growth, invasion, migration, and apoptosis. Understanding the roles and mechanisms of lncRNAs in regulating cancer progression is crucial for formulating novel therapeutic strategies. Although lncRNA DCST1-antisense RNA 1(AS1) has been implicated in several cancers, its role in the progression of colorectal cancer (CRC) remains to be explored. This study focuses on elucidating the function of lncRNA DCST1-AS1 in CRC development and its underlying mechanism. We found that the expression of lncRNA DCST1-AS1 was up-regulated in CRC tissues and cell lines, and CRC patients with high lncRNA DCST1-AS1 expression were associated with a poor prognosis. Loss-of-function and gain-of-function experiment in CRC cell lines confirmed that lncRNA DCST1-AS1 promoted the malignant phenotype of CRC cells, including cell proliferation, colony formation, migration, and invasion. In addition, we identified the binding sites between lncRNA DCST1-AS1 and hsa-miR-582-5p, and between hsa-miR-582-5p and High Mobility Group Box 1 (HMGB1) through DIANA Tools and TargetScan database, which was further confirmed by dual-luciferase reporter assay. Functional assay further confirmed the crucial role of lncRNA DCST1-AS1/hsa-miR-582-5p/HMGB1 axis in modulating the malignant phenotype of CRC cells. Collectively, our data suggest that lncRNA DCST1-AS1 regulates the aggressiveness of CRC cells through hsa-miR-582-5p/HMGB1 axis. Our study provides novel insight into the mechanism of lncRNA DCST1-AS1 in CRC cells for targeted therapy.

The Clinical Significance of Microsatellite Instability in Patients with Right-sided Colorectal Cancer

Background/Aims

Colorectal cancer (CRC) with microsatellite instability (MSI) has a better prognosis than CRC with microsatellite stable (MSS). Recent studies have reported biological differences according to tumor location in CRC. In this study, we investigated the clinical significance of MSI in patients with right-sided CRC.

Methods

The medical records of 1,009 CRC patients diagnosed at our institute between October 2004 and December 2016 with MSI test results were retrospectively reviewed. The long-term outcomes of CRC patients with MSI were assessed with respect to tumor location using Kaplan-Meier curves and Cox regression models.

Results

The median follow-up duration for all 1,009 study subjects was 25 months (interquartile range, 15-38). One hundred twenty-four of the study subjects had MSI (12.3%) and 250 had right-sided CRC (24.8%). The patients with MSI and right-sided CRC had better disease-free survival (DFS) than those with MSS as determined by the log-rank test (p=0.013), and this result was significant in females (p=0.035) but not in males with right-sided CRC. Multivariate Cox regression analysis showed MSS significantly predicted poor DFS in patients with right-sided CRC (hazard ratio 3.97, 95% CI 1.30-12.15, p=0.016) and in female patients (hazard ratio 4.69, 95% CI 1.03-21.36, p=0.045).

Conclusions

The study shows MSI is a useful predictor of DFS in patients with right-sided CRC, especially in female patients.

The long-term survival characteristics of a cohort of colorectal cancer patients and baseline variables associated with survival outcomes with or without time-varying effects

BACKGROUND

Colorectal cancer is the third most common cancer in the world. In this study, we assessed the long-term survival characteristics and prognostic associations and potential time-varying effects of clinico-demographic variables and two molecular markers (microsatellite instability (MSI) and BRAF Val600Glu mutation) in a population-based patient cohort followed up to ~ 19 years.

METHODS

The patient cohort included 738 incident cases diagnosed between 1999 and 2003. Cox models were used to analyze the association between the variables and a set of survival outcome measures (overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS), metastasis-free survival (MFS), recurrence/metastasis-free survival (RMFS), and event-free survival (EFS)). Cox proportional hazard (PH) assumption was tested for all variables, and Cox models with time-varying effects were used if any departure from the PH assumption was detected.

RESULTS

During the follow-up, ~ 61% patients died from any cause, ~ 26% died from colorectal cancer, and ~ 10% and ~ 20% experienced recurrences and distant metastases, respectively. Stage IV disease and post-diagnostic recurrence or metastasis were strongly linked to risk of death from colorectal cancer. If a patient had survived the first 6 years without any disease-related event (i.e., recurrence, metastasis, or death from colorectal cancer), their risks became very minimal after this time period. Distinct sets of markers were associated with different outcome measures. In some cases, the effects by variables were constant throughout the follow-up. For example, MSI-high tumor phenotype and older age at diagnosis predicted longer MFS times consistently over the follow-up. However, in some other cases, the effects of the variables varied with time. For example, adjuvant radiotherapy treatment was associated with increased risk of metastasis in patients who received this treatment after 5.5 years post-diagnosis, but not before that.

CONCLUSIONS

This study describes the long-term survival characteristics of a prospective cohort of colorectal cancer patients, relationships between baseline variables and a detailed set of patient outcomes over a long time, and time-varying effects of a group of variables. The results presented advance our understanding of the long-term prognostic characteristics in colorectal cancer and are expected to inspire future studies and clinical care strategies.

Colorectal cancer survival rates in Ghana: A retrospective hospital-based study

Background

Colorectal cancer (CRC) is one of the commonest cancers associated with diverse prognosis times in different parts of the world. Despite medical interventions, the overall clinical outcomes and survival remains very poor for most patients in developing countries. This study therefore investigated the survival rate of colorectal cancer and its prognostic factors among patients at Komfo Anokye Teaching Hospital, Ghana.

Methodology

In this retrospective cohort study, a total of 221 patients diagnosed with CRC from 2009 to 2015 at the Surgical and Oncological units of Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana were employed. The survival graphs were obtained using the Kaplan–Meier method and compared by the Log-rank test. Cox regression analysis was used to assess prognostic factors. All analyses were performed by SPSS version 22.

Results

The median survival time was 15 months 95% CI (11.79–18.21). The overall survival rate for CRC over the 5 years period was 16.0%. The survival rates at the 1^st, 2^nd, 3^rd, 4^th and 5^th years were 64% 95% CI (56.2–71.1), 40% 95% CI (32.2–50.1), 21% 95% CI (11.4–30.6) 16% 95% CI (8.9–26.9) and 16% 95% CI (7.3–24.9). There was a significant difference in the survival rate of colorectal cancer according to the different stages (p = 0.0001). Family history [HR = (3.44), p = 0.029)], Chemotherapy [HR = (0.23), p = <0.0001)], BMI [HR = (1.78), p = 0.017)] and both chemo/radiotherapy (HR = (3.63), p = 0.042)] were the significant social and clinical factors influencing the overall survival. Pathological factors such as TNM tumour stage (p = 0.012), depth of tumour invasion (p = 0.036), lymph node metastasis (p = 0.0001), and distance metastasis (p = 0.001) were significantly associated with overall survival.

Conclusion

The study has clearly demonstrated that survival rate for CRC patients at KATH, Ghana is very low in a 5 years period. This is influenced by significant number of clinical and pathological prognostic factors. Identification of prognostic factors would be a primary basis for early prediction and treatment of patients with colorectal cancer.

Cancer Patient Survival in the Elderly in Italy

Aims and background

Italy, like most western populations, is sharply aging and changing its age structure with a striking increase in the oldest segment of the elderly. Since age is related to an exponential growth of cancer incidence rates and to a worsening of prognosis, the progressive aging of the population will constitute, in the future, an issue increasingly more important for public health. The present study is the first effort to present and analyze survival rates in Italian elderly cancer patients in order to provide a starting point for the development of better clinical strategies addressed to the aged.

Materials and methods

The presented data come from a large data set consisting of survival data relating to 25,798 men and 20,479 women, aged 65–84 years at diagnosis, collected by Italian cancer registries participating in the ITACARE project. Relative survival rates of patients have been calculated by sex, quinquennial age classes and the considered entire age class for overall malignant neoplasms and the 10 most frequent cancer sites in the elderly.

Results

When all Italian data for all cancers in the 65–84 year age group were pooled, survival rates at 5 years from the diagnosis was 27% and 39% in men and women, respectively. As regards specific sites, survival rates below 50% were observed for lung, stomach and ovary cancer at 1 year from diagnosis. At 5 years from diagnosis, the rates were less than 50% for colon, prostate, cervix, multiple myeloma, non-Hodgkin's lymphoma and melanoma (only in men). The best survival at 5 years from diagnosis (above 50%) was in women for melanoma and corpus uteri and breast cancer. For all cancers, the prognosis for women was better in each considered age group even though a dramatic decrease in survival with age was observed in both sexes. In general, a similar decline in survival with increasing age characterized all considered specific sites. However, at closer observation, the patterns of a decrease revealed some differences. The ratio between the survival rates of 55–64 vs 65–84 year age class indicated that the sites with the greatest advantage of survival for younger patients (ratio >1.5) were ovary, lung and melanoma (only in men), whereas the least advantage was observed for colon, corpus uteri, breast and prostate. By calendar periods, excluding non-Hodgkin's lymphoma for women, an increase in survival was observed for all considered sites, improving an encouraging successful trend in diagnostic and therapeutic progresses.

The Availability of Histologic Grading among 5,923 Italian Cancer Patients and Its Relationship with Survival: A Population-Based Study

Aim

The specific goal of the study was to evaluate the availability of the histologic grading of cancer and its effect on survival in an Italian population-based cancer series.

Methods

Data were drawn from the Tuscany Cancer Registry, active in central Italy since 1985. Among the cases incident during the period 1985 to 1989, bladder, prostate, colon, corpus uteri, rectum and stomach cancers, for which the proportion of graded cases exceeded 50%, were analyzed. Overall, 5,923 cancer cases were included. Ten-year relative survival rates by grade were computed.

Results

Overall, data on histologic grading was available only for 38% of cases. The sites most frequently graded were urinary bladder (80%), prostate (73%), colon (71%), corpus uteri (69%), rectum (65%) and stomach (56%). For all the cancer sites analyzed, the 10-year relative survival rates increased as the histologic grading improved. The grade distribution resulted related also to the disease extension, more limited the extension higher the proportion of well differentiated cases.

Conclusions

Due to the evidenced importance of histologic grading as a valuable prognostic factor, it should be requested by clinicians and reported by pathologists more frequently than has been done in the area.

Comparison of Basic and Ensemble Data Mining Methods in Predicting 5-Year Survival of Colorectal Cancer Patients

INTRODUCTION

Colorectal cancer (CRC) is one of the most common malignancies and cause of cancer mortality worldwide. Given the importance of predicting the survival of CRC patients and the growing use of data mining methods, this study aims to compare the performance of models for predicting 5-year survival of CRC patients using variety of basic and ensemble data mining methods.

METHODS

The CRC dataset from The Shahid Beheshti University of Medical Sciences Research Center for Gastroenterology and Liver Diseases were used for prediction and comparative study of the base and ensemble data mining techniques. Feature selection methods were used to select predictor attributes for classification. The WEKA toolkit and MedCalc software were respectively utilized for creating and comparing the models.

RESULTS

The obtained results showed that the predictive performance of developed models was altogether high (all greater than 90%). Overall, the performance of ensemble models was higher than that of basic classifiers and the best result achieved by ensemble voting model in terms of area under the ROC curve (AUC= 0.96).

CONCLUSION

AUC Comparison of models showed that the ensemble voting method significantly outperformed all models except for two methods of Random Forest (RF) and Bayesian Network (BN) considered the overlapping 95% confidence intervals. This result may indicate high predictive power of these two methods along with ensemble voting for predicting 5-year survival of CRC patients.

Comparison of oncological outcomes of right-sided colon cancer versus left-sided colon cancer after curative resection: Which side is better outcome?

PROPOSE

There are embryological origins, anatomical, histological, genetic, and immunological differences between right-sided colon cancer (RCC) and left-sided colon cancer (LCC). Many studies have sought to determine the survival and prognosis according to tumor location. This study aimed to analyze outcomes between RCC and LCC.

MATERIAL AND METHOD

Between January 2000 and December 2012, data on 414 patients who underwent curative resection for RCC and LCC were retrieved from a retrospective database. Propensity score matching (1:1) was performed and RCC was identified in 207 and LCC in 207 patients.

RESULTS

On average, RCC exhibited a more advanced N stage, increased tumor size, more frequently poorly differentiated tumors, more harvested lymph nodes, and more positivity of lymphovascular invasion than LCC. With a median follow-up of 66.7 months, the 5-year overall survival (OS) rates for RCC and LCC were 82.1% and 88.7%, respectively, (P < .05). The 5-year disease-free survival (DFS) rates were 81.4% (RCC) and 88.3% (LCC; P < .05). In stage III cancers, the DFS rates were 61.1% (RCC) and 81.9% (LCC; P < .05), while the OS rates were 65.6% (RCC) and 78.6% (LCC; P = .056).

CONCLUSION

On the basis of present data, LCC exhibited better survival outcomes than RCC after curative resection. Especially in stage III, LCC showed better oncologic outcomes. Proper specialized treatment related to the location of colon cancer is needed.

Prognostic Impact of Primary Tumor Location on Clinical Outcomes of Metastatic Colorectal Cancer Treated With Cetuximab Plus Oxaliplatin-Based Chemotherapy: A Subgroup Analysis of the JACCRO CC-05/06 Trials

INTRODUCTION

Primary tumor location is a critical prognostic factor in metastatic colorectal cancer (mCRC); however, it remains unclear whether tumor location is a predictor of the response to cetuximab treatment. It is also uncertain if BRAF mutation contributes to the impact of tumor location on survival. We assessed the prognostic impact of tumor location on clinical outcomes in mCRC patients treated with first-line cetuximab chemotherapy.

PATIENTS AND METHODS

The associations of tumor location with overall survival and progression-free survival were evaluated in mCRC patients with KRAS exon 2 wild-type tumors who were enrolled onto 2 clinical trials: JACCRO CC-05 of cetuximab plus FOLFOX (n = 57, UMIN000004197) and CC-06 of cetuximab plus SOX (n = 61, UMIN000007022). Tumors proximal or from splenic flexure to rectum were defined as right-sided or left-sided, respectively. In addition, exploratory RAS and BRAF mutation analyses were performed.

RESULTS

A total of 110 patients were assessable for tumor location; 90 had left-sided tumors. Left-sided tumors were significantly associated with longer overall survival (36.2 vs. 12.6 months, hazard ratio = 0.28, P < .0001) and progression-free survival (11.1 vs. 5.6 months, hazard ratio = 0.47, P = .0041) than right-sided tumors; similar results were obtained in multivariate analysis. A subanalysis showed that the association was evident in the FOLFOX group and that tumor location was an independent prognostic factor irrespective of BRAF status in RAS wild-type patients.

CONCLUSION

Primary tumor location might be a predictor of survival independent of BRAF status in mCRC patients who receive first-line cetuximab combined with oxaliplatin-based chemotherapy.

The association of HMGB1 expression with clinicopathological significance and prognosis in Asian patients with colorectal carcinoma: a meta-analysis and literature review

Background

The association of high mobility group box 1 (HMGB1) expression with clinicopathological significance and prognosis in Asian patients with colorectal carcinoma (CRC) remains controversial. The purpose of this study was to conduct a meta-analysis and literature review to identify the role of HMGB1 in the development and prognosis of CRC in Asians.

Methods

All eligible studies regarding the association between HMGB1 expression in tissue with clinicopathological significance and prognosis in Asian patients with CRC published up to January 2015 were identified by searching PubMed, Web of Science, Chinese National Knowledge Infrastructure, and WanFang database. Analysis of pooled data was performed, while odds ratio (OR) or hazard radio with 95% confidence interval (CI) was calculated and summarized to evaluate the strength of this association in fixed- or random-effects model.

Results

The expression level of HMGB1 in CRC tissues was much higher than normal colorectal tissues (OR =27.35, 95% CI 9.32–80.26, P<0.0001) and para-tumor colorectal tissues (OR =10.06, 95% CI 4.61–21.95, P<0.0001). There was no relation between the HMGB1 expression and sex, age, clinical T stage, tumor size, and location (colon or rectum cancer). However, a significant relation was detected between the HMGB1 expression and clinical stage (American Joint Committee on Cancer 7), lymph node metastasis, distant metastasis, tumor invasion depth, and differentiation rate (P=0.002, P≤0.0001, P<0.0001, P<0.0001, and P=0.007, respectively). Patients with higher HMGB1 expression had shorter overall survival time, whereas patients with lower level of HMGB1 had better survival (hazard ratio =1.40, 95% CI 0.98–1.82, P<0.0001).

Conclusion

In this meta-analysis, our results illustrated the significant relationship of HMGB1 protein overexpression in tissues with clinicopathological characteristics and prognosis of CRC. Thus, HMGB1 may be a promising marker in predicting the clinical outcome of patients with CRC. However, more well-designed studies of large sample size are warranted to validate the findings of current study.

The Worse Prognosis of Right-Sided Compared with Left-Sided Colon Cancers: a Systematic Review and Meta-analysis

BACKGROUND

Right-sided colon cancers (RCC) and left-sided colon cancers (LCC) are of different embryological origins, and various differences exist between them. However, the survival difference has not been assessed. The aim of this meta-analysis was to quantify the prognostic differences between RCC and LCC.

METHODS

Fifteen studies that compared the prognosis of colon cancer according to tumor location were identified. The effects of tumor location on survival outcome were assessed.

RESULTS

Patients with RCC had a significantly worse prognosis than did those with LCC in overall survival (OS) (hazard ratio (HR) = 1.14, 95 % confidence interval (CI) 1.06-1.22, p < 0.01). Our subgroup analyses demonstrated significant prognostic differences in Western countries (HR = 1.15, 95 % CI 1.08-1.23, p < 0.01), a nationwide database (HR = 1.15, 95 % CI 1.05-1.27, p = 0.01), and a stage-adjusted analysis (HR = 1.14, 95 % CI 1.05-1.24, p < 0.01).

CONCLUSIONS

These findings demonstrate that tumor location is associated with prognosis in colorectal cancer patients, and those with RCC have a significantly worse prognosis than those with LCC in terms of OS. RCC should be treated distinctively from LCC, and the establishment of standardized management for colon cancer by tumor location is needed.

A prognostic analysis of 895 cases of stage III colon cancer in different colon subsites

PURPOSE

Stage III colon cancer is currently treated as an entity with a unified therapeutic principle. The aim of the retrospective study is to explore the clinicopathological characteristics and outcomes of site-specific stage III colon cancers and the influences of tumor location on prognosis.

METHODS

Eight hundred ninety-five patients with stage III colon cancer treated with radical operation and subsequent adjuvant chemotherapy (5-fluorouracil/oxaliplatin) were divided into seven groups according to colon segment (cecum, ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, and sigmoid colon). Expression of excision repair cross-complementing group 1 (ERCC1) and thymidylate synthase (TS) was examined by immunohistochemistry. We assessed if differences exist in patient characteristics and clinic outcomes between the seven groups.

RESULTS

There were significant differences in tumor differentiation (P < 0.001), T stage (P < 0.001), N stage (P < 0.001), American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) stage (P < 0.001), metachronous liver metastasis (P < 0.001), metachronous lung metastasis (P < 0.001), and ERCCI expression (P < 0.001) between the seven groups. Both 5-year recurrence-free survival (RFS) and 5-year overall survival (OS) exhibited significant differences (both P < 0.001) with survival gradually decreasing from cecum to sigmoid colon. Cox regression analyses identified that tumor location was an independent prognostic factor for RFS and OS.

CONCLUSIONS

Stage III colon cancer located proximally carried a poorer survival than that located distally. Different efficacies of FOLFOX adjuvant chemotherapy may be an important factor affecting survival of site-specific stage III colon cancers.

Impact of diabetes on overall and cancer-specific mortality in colorectal cancer patients

PURPOSE

Diabetes is associated with increased risk of developing colorectal cancer (CRC), but its effect on overall and cancer-specific mortality in CRC patients has been little investigated. The aim of this study was to assess the influence of diabetes on overall and cancer-specific mortality in Italian CRC patients.

METHODS

Cases of adult (≥15 years) CRC, diagnosed in 2003-2005, most followed-up to the end of 2008, were randomly selected from the Italian Cancer Registries database. Diabetic status, sex, age, tumor stage, subsite, treatment, morphology, and grade were obtained by consultation of patient clinical records. Poisson multivariable regression models, adjusted for potential confounding variables, were used to estimate hazard ratios (HRs) for all-cause and CRC-specific mortality, according to diabetic status.

RESULTS

A total of 1,039 CRC cases with known fasting glucose or diabetic status, archived in 7 cancer registries, was analyzed. Compared to non-diabetics, diabetics (specific diagnosis or glucose ≥126 mg/dl) were older and less likely to receive adjuvant therapy. Diabetics were at higher risk of all-cause death [HR 1.41; 95 % confidence interval (CI) 1.18-1.70] and CRC death (HR 1.36; 95 % CI 1.11-1.67), with no differences by sex or subsite.

CONCLUSIONS

Diabetes was significantly associated with increased overall and CRC-specific mortality. Our findings indicate that diabetes is a negative prognostic factor for CRC and suggest that in patients with CRC, diabetes prevention and treatments that stabilize the condition and control its complications might reduce mortality. Further studies are required to ascertain the mechanisms linking diabetes to greater mortality in CRC patients.

Tumor budding is an independent predictor of outcome in AJCC/UICC stage II colorectal cancer

BACKGROUND

In colorectal cancer, the morphology of the invasive tumor margin may reflect aggressiveness of tumor growth, thus providing important prognostic information. The tumor growth pattern according to Jass and the extent of tumor budding were analyzed in patients with American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) stage II disease.

METHODS

Tumors of 120 randomly selected patients with AJCC/UICC stage II disease were retrospectively reviewed for tumor growth pattern (expanding vs. infiltrating) and the extent of tumor budding, with high-grade budding reflecting presence of 10 or more budding foci scattered at the invasive tumor margin. Progression-free and cancer-specific survivals were determined by the Kaplan-Meier method. For multivariable analysis, Cox's proportional hazards regression models were performed.

RESULTS

The infiltrating growth pattern was significantly associated with histological subtype and lymphovascular invasion, while high-grade budding was significantly associated with tumor grade and lymphovascular invasion. High-grade budding, but not the infiltrating growth pattern, was significantly associated with outcome in univariable analysis. Cox's proportional hazards regression models proved tumor budding to be an independent predictor of disease progression (hazard ratio 3.91, 95 % confidence interval 1.3-11.77; P = 0.02) and cancer-related death (hazard ratio 5.90, 95 % confidence interval 1.62-21.51; P = 0.007). The combination of infiltrating growth pattern and high-grade budding did not have a stronger prognostic significance than tumor budding alone.

CONCLUSIONS

Tumor budding independently predicted patient outcome in patients with AJCC/UICC stage II colorectal cancer and may therefore be used for accurate prognostication, patient counseling, and design of clinical trials by using integrated multimodal therapy.

Cost-effectiveness analysis of postoperative surveillance protocols following radical surgery for colorectal cancer

INTRODUCTION

Up to 30-50% of patients who undergo radical surgery for colorectal cancer (CRC) develop tumor relapse. The aim of this study was to assess various surveillance protocols utilized in a tertiary referral hospital in Northern Italy.

METHODS

Data concerning 373 consecutive patients who underwent radical surgery for CRC between 1990 and 2006 and whose data had been entered into a prospective database were considered eligible for this study. The overall costs and the percentages of recurrence following the various surveillance protocols were calculated.

RESULTS

One hundred two (27.35%) of the patients suffered a recurrence after a mean of 17.6 (95% CI 13.9-21.1) months. The combination of physical examination, colonoscopy, thorax-abdominal computed tomography (CT) scan, and serum carcinoembryonic antigen (CEA) dosage was found to be the most cost/effective one to monitor stages I and II colon cancer; while physical examination, rigid sigmoidoscopy, thorax-abdominal CT scan, and serum CEA dosage were found to be the most cost/effective surveillance to monitor stages III and IV of colon cancer and rectal cancer.

CONCLUSIONS

Adherence to follow-up guidelines and early detection are vital factors affecting the curability of relapsed cancer in CRC patients who undergo surgery. The first five years after surgery was found to be the most risky period for recurrence. Cost/effectiveness analysis indicate that follow-up protocols should be tailored to the risk of recurrence with the aim of identifying relapse when the disease is at an asymptomatic, presumably more curable stage.

Prognostic significance and molecular associations of tumor growth pattern in colorectal cancer

BACKGROUND

Infiltrative growth pattern at the tumor margin has been associated with shorter patient survival. However, little is known about the prognostic significance of tumor growth pattern, independent of tumoral molecular alterations and other histologic features.

METHODS

Utilizing a database of 1139 colon and rectal cancer patients in two prospective cohort studies, histologic features including tumor growth pattern, tumor differentiation, lymphocytic reaction, mucinous component, and signet ring cell component were recorded by a single pathologist. Cox proportional hazard model was used to compute mortality hazard ratio, adjusting for clinical, pathologic, and tumor molecular features, including microsatellite instability, the CpG island methylator phenotype, long interspersed nucleotide element 1 (LINE-1) methylation, and KRAS, BRAF, and PIK3CA mutations.

RESULTS

Among 1139 colorectal cancers, we observed expansile growth pattern in 372 tumors (33%), intermediate growth pattern in 610 tumors (54%), and infiltrative growth pattern in 157 tumors (14%). Compared to patients with expansile growth pattern, those with infiltrative growth pattern experienced shorter cancer-specific survival (log rank P < 0.0001; multivariate hazard ratio 1.74; 95% confidence interval 1.22-2.47) and overall survival (log rank P < 0.0001; multivariate hazard ratio 1.78; 95% confidence interval 1.33-2.39). The prognostic association of infiltrative growth pattern was confined to patients with stage I-III disease (P (interaction) with stage = 0.0001).

CONCLUSIONS

Infiltrative growth pattern was associated with worse prognosis among stage I-III colorectal cancer patients, independent of other clinical, pathologic, and molecular characteristics.

[Efficacy of CT colonography versus colonoscopy in screening for colorectal cancer]

OBJECTIVE

To determine the efficacy and effectiveness of CT colonography in comparison with those of colonoscopy in screening for colorectal cancer.

MATERIAL AND METHODS

We systematically reviewed all the studies in the scientific literature that assessed the efficacy of CT colonography in screening for colorectal cancer. We excluded articles that assessed the efficacy of other screening techniques for colorectal cancer and those that used CT colonography in the diagnostic workup of suspected lesions or symptomatic patients. After a critical reading of the 213 references obtained, we selected nine studies.

RESULTS

The specificity of CT colonography in screening for colorectal cancer was high, although it decreased with the diameter of the polyp to be detected. The sensitivity of CT colonography in the detection of polyps less than or equal to 6mm in diameter was very low and heterogeneous, although it was higher for polyps greater than 9mm in diameter.

CONCLUSION

CT colonography has high specificity but very heterogeneous sensitivity, although in most cases it was not as sensitive or specific as conventional colonoscopy.

Early discontinuation but not the timing of adjuvant therapy affects survival of patients with high-risk colorectal cancer: a population-based study

BACKGROUND

Adjuvant therapy results in significant improvement in survival of patients with high-risk colorectal cancer. Little is known about the significance of timing and early discontinuation of adjuvant treatment in such patients. Our study aims to determine the prognostic impact of timing and completion of adjuvant therapy in patients with high-risk colorectal cancer.

METHODS

Medical records of patients with stage III colon and stage II/III rectal cancer diagnosed between 1993 and 2000 in the province of Saskatchewan were reviewed. Cox proportional hazards models were used to analyze the impact of timing and completion of adjuvant therapy on survival.

RESULTS

Six hundred sixty-three eligible patients with a median age of 66 years were identified. Sixty-five percent patients received adjuvant <56 days after surgery and 79% patients completed planned treatment. Median follow-up was 54.6 months. Five-year disease-free survival and overall survival of patients who received adjuvant therapy <56 days after surgery was 54.6% and 59.5%, respectively, compared with 51.9% and 57.1%, respectively, of patients who received therapy ≥56 days after surgery (P = NS). The five-year disease disease-free survival and overall survival of patients who completed planned treatment was 56.7% and 62.3%, respectively, compared with 42.1% and 45%, respectively, of patients who required early treatment discontinuation (P < .0001). On multivariate analysis, age ≥65 years, T4 tumor, grade 3 cancer, node-positive disease, rectal tumor, and early treatment discontinuation were identified as poor prognostic factors.

CONCLUSIONS

Although time to adjuvant therapy following surgical resection did not impact the outcomes, failure to complete planned therapy was associated with adverse prognosis.

Carcinoma obstruction of the proximal colon cancer and long-term prognosis--obstruction is a predictor of worse outcome in TNM stage II tumor

PURPOSE

Colon obstruction is suggested to be a predictor of poor outcome in colon cancer. However, the effect of obstruction on outcome in patients with different tumor-nodes-metastases (TNM) stage cancer has not been fully addressed. The aim of this study is to determine whether colon obstruction predicts surgical and long-term oncologic outcomes in patients with proximal colon cancer.

METHODS

A total of 1,492 consecutive patients underwent open resection of primary adenocarcinoma of right colon in a single institution between January 1995 and December 2005. Clinical and follow-up data were extracted from a prospective colorectal cancer database. Univariate and multivariate analyses were performed to identify colon obstruction and other predictors of surgical and oncologic outcomes.

RESULTS

Among 1,492 patients, 306 (20.5%) patients presented with colon obstruction. The rates of surgical morbidity and mortality were greater in patients with an obstruction as compared to patients without an obstruction (22.2% and 3.9% vs. 14.1% and 1.9%; p = 0.0005 and 0.041, respectively). Obstruction predicted a worse long-term disease-free survival (DFS) among patients with stage II-III disease (log-rank test, p = 0.0003). The data were stratified by TNM stage. Obstruction predicted a worse DFS among patients with TNM stage II cancer (598 patients; log-rank test, p = 0.001; Cox regression, p = 0.012), but it was not a predictor in TNM stage III cancer patients (424 patients; p = 0.116; p = 0.108).

CONCLUSIONS

Colon obstruction was an independent predictor of long-term outcome only in TNM stage II but not in stage III proximal colon cancer. Patients with TNM stage II obstructive colon cancer could be included in future trials of adjuvant therapies.

The proportion of tumour cells is an independent predictor for survival in colorectal cancer patients

Background:

The proportion of epithelial and stromal cells in tumours is thought to have an important role in the progression of epithelial malignancy. We aimed to determine whether the relative proportion of tumour (PoT) was related to survival in colorectal cancer.

Methods:

The PoT at the luminal surface was measured by point counting using virtual tissue sections in a series of 145 colorectal cancer cases. The relationship of PoT to clinicopathological parameters including cancer-specific survival was analysed. Modified receiver operating characteristic curves were used to determine the optimum cut off points to dichotomise the data for survival analyses.

Results:

Tumours with PoT-low (⩽47%) were associated with significantly lower cancer-specific survival when compared to PoT-high (hazard ratio (HR)=2.087, 95% CI=1.088–4.003, P=0.024). On sub-analysis, the prognostic effect remained significant in colonic tumours (HR=2.474, 95% CI=1.132–5.408, P=0.019) and tumour, node, metastasis stage III disease (HR=3.480, 95% CI=0.325–9.136, P=0.007). Multivariate Cox regression analysis demonstrated that PoT was an independent prognostic marker when adjusted for age, T stage, N stage and extramural vascular invasion (P=0.017).

Conclusion:

This study suggests that a low proportion of tumour cells in colorectal cancer is related to poor cancer-specific survival. A relatively quick, inexpensive and well-established method such as point counting on diagnostic tissue sections could be used to identify a subset of patients who may benefit from adjuvant therapy.

Merging Claims Databases with a Tumor Registry to Evaluate Variations in Cancer Mortality: Results from a Pilot Study of 698 Colorectal Cancer Patients Treated at One Hospital in the 1990s

BACKGROUND

Prognostic models are essential for evaluating variations in cancer mortality statistics. While cancer stage is the most widely accepted and commonly used predictor of survival for cancer, electronic claims databases contain large amounts of information on cancer patients. Previous studies have used Medicare databases and tumor registry information from the Surveillance Epidemiology and End Results data sets to evaluate variations in outcomes for older cancer patients. We evaluated if similar analytic efforts could be carried out with readily available data sets for colorectal cancer patients of all ages who received care at a single hospital during the 1990s.

METHODS

Hospital tumor registry and discharge claims data for patients at one mid-western hospital with surgically treated stage I-III colorectal cancer from 1990-1998 were used to model survival. Kaplan-Meier logrank tests and Cox proportional hazards models tested the statistical significance of demographic, operative, and clinicopathological factors as predictors of survival. Survival probabilities also were compared to U.S. population life table data to determine if survival deficits were larger for younger cancer patients.

RESULTS

Of the 698 colorectal cancer patients, overall five-year survival probability was 65%, with a median follow-up of 44.7 months. Factors associated with higher relative risks of death included sociodemographic characteristics [female gender (1.5, 95% CI: 1.1-1.9), ages 70-79 years (1.7, 95% CI: 1.2-2.3), and > or = 80 years (3.3, 95% CI: 2.4-4.7) as compared to younger patients], clinical characteristics [moderate (1.5, 95% CI: 1.1-2.1) or severe (2.1, 95%: 1.4-3.2) comorbid illness, as compared to mild or no comorbid illnesses and emergency admission (2.1, 95% CI: 1.5-2.9)], pathological characteristics [positive surgical margins (3.5, 95% CI: 2.3-5.3): and higher cancer stage (stage II RR = 1.5, 95% CI = 1.1-2.2; stage III RR = 2.2, 95% CI = 1.5-3.2), as compared to stage I]. A comparison to the age- and gender-matched survival probabilities of the general population demonstrated similar deficits in survival for older patients (> or = 70 years) and younger patients (< 70 years).

CONCLUSIONS

While cancer stage is a reliable predictor of survival, other sociodemographic and clinical data elements can improve the evaluation of expected survival rates for patients with surgically resectable colorectal cancers. To facilitate comparative interpretations of mortality data, consideration should be given to merging hospital discharge claims data sets with tumor registry information in a manner analogous to that which has been done for older cancer patients who are covered by the Medicare program.

Tumor subsite location within the colon is prognostic for survival after colon cancer diagnosis

PURPOSE

Proximal colon cancers are more likely to present with advanced stage than distal cancers; however, previous reports conflict regarding the independent prognostic significance of tumor location on survival. We examined survival by colon cancer subsite location by use of data from the California Cancer Registry.

METHODS

An analysis of colon cancer cases from 1994 to 2004 was conducted, with follow-up through 2006. Colon subsite location was defined as proximal colon (cecum, ascending colon, hepatic flexure), transverse colon, descending colon (splenic flexure, descending colon), and sigmoid colon. Subsite-specific survival analyses were conducted with use of the Kaplan-Meier method and Cox proportional hazards ratios.

RESULTS

A total of 82,926 colon cancer cases were identified, including 40,078 proximal (48%), 8,023 transverse (10%), 8,657 descending (10%), and 26,168 sigmoid cancers (32%). A larger proportion of sigmoid cancers (30.5%) presented as Stage I compared with proximal (18.5%), transverse (16.8%), or descending colon cancers (20.1%). Proximal cancers had the greater proportion with high tumor grade (27%), and had a greater mean number of lymph nodes examined. There were no differences in treatment rendered when each colon subsite was stratified by stage. After adjustment for stage, grade, treatment, lymph node examination, and other relevant clinical variables, sigmoid cancers had decreased colorectal cancer-specific mortality compared with proximal tumors (hazards ratio = 0.88; 95% confidence interval, 0.85-0.92).

CONCLUSIONS

In this analysis, sigmoid colon cancers were observed to have earlier stage, lower tumor grade, and independently decreased colorectal cancer-specific mortality compared with proximal tumors.

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.

Comparison of colorectal and gastric cancer: survival and prognostic factors

BACKGROUND/AIMS

Gastric and colorectal cancers are the most common gastrointestinal malignancies in Iran. We aim to compare the survival rates and prognostic factors between these two cancers.

METHODS

We studied 1873 patients with either gastric or colorectal cancer who were registered in one referral cancer registry center in Tehran, Iran. All patients were followed from their time of diagnosis until December 2006 (as failure time). Survival curves were calculated according to the Kaplan-Meier Method and compared by the Log-rank test. Multivariate analysis of prognostic factors was carried out using the Cox proportional hazard model.

RESULTS

Of 1873 patients, there were 746 with gastric cancer and 1138 with colorectal cancer. According to the Kaplan-Meier method 1, 3, 5, and 7-year survival rates were 71.2, 37.8, 25.3, and 19.5%, respectively, in gastric cancer patients and 91.1, 73.1, 61, and 54.9%, respectively, in patients with colorectal cancer. Also, univariate analysis showed that age at diagnosis, sex, grade of tumor, and distant metastasis were of prognostic significance in both cancers (P < 0.0001). However, in multivariate analysis, only distant metastasis in colorectal cancer and age at diagnosis, grade of tumor, and distant metastasis in colorectal cancer were identified as independent prognostic factors influencing survival.

CONCLUSIONS

According to our findings, survival is significantly related to histological differentiation of tumor and distant metastasis in colorectal cancer patients and only to distant metastasis in gastric cancer patients.

Prognostic factors in 1,138 Iranian colorectal cancer patients

BACKGROUND AND AIM

The incidence of colorectal cancer is increased in Iran in recent years and colorectal cancer is the fourth most common cancer in both sexes. The aim of this study is to define the prognostic factors in Iranian colorectal cancer patients using univariate and multivariate methods.

MATERIALS AND METHODS

All patients with colorectal cancer diagnosis according to the pathology report that registered in our cancer registry center in the period between Jan 2002 until Jan 2007 were eligible for this study. These patients were followed up by telephone contact. The probability curves for survival were calculated according to the Kaplan-Meier method and compared by the Log-rank test. Multivariate analysis was carried out using the Cox proportional hazard model.

RESULTS

Of 1,138 cases, a survival information was available on 1,127 patients, 690 males (61.2%) and 437 females (38.8%). Mean survival time was 105.1 (CI: 95.1-115.1) months. The Kaplan-Meier method indicated that the 1, 3, 5, 7, 10, and 15 years of survival rates are 91.1%, 73.1%, 61.0%, 54.9%, 47.9%, and 25.9%, respectively. According to the univariate analysis, the factors influencing overall survival rate were the following: type of first treatment, body mass index, marital status, tumor grade, extent of wall penetration, distant metastasis, regional lymph nodes metastasis, and pathologic stage of tumor. The following five variables were independent prognostic factors for survival as determined by multivariate analysis: tumor size, metastasis of tumor, body mass index, marital status, and grade of tumor.

CONCLUSION

Our results showed that stage of tumor, distant metastasis, grade of tumor, and tumor size should be considered as the most important prognostic factors in colorectal cancer patients.

Lack of association between diagnostic and therapeutic delay and stage of colorectal cancer

BACKGROUND

A recent review suggests that there is no association between diagnostic and therapeutic delays and survival in colorectal cancer patients. However, the effect of tumour stage on the relationship between delay and survival in CRC should be clarified. We review here the evidence on the relationship between diagnostic and therapeutic delays and stage in colorectal cancer.

METHODS

We conducted a systematic review of Medline, Embase, Cancerlit and the Cochrane Database of Systematic Reviews to identify publications published between 1965 and 2006 dealing with delay, stage and colorectal cancer. A meta-analysis was performed based on the estimation of the odds ratios (OR) and on a random effects model.

RESULTS

We identified 50 studies, representing 18,649 patients. Thirty studies were excluded due to excessively restricted samples (e.g. exclusion of patients with intestinal obstruction or who died 1-3 months after surgery) or because they studied only a portion of the delay. Of the 37 remaining studies, great variability was noted in connection with the type of classification used for disease stage and the type of measurement used for the delay. Meta-analysis was performed based on 17 studies that included 5209 patients. The combined OR was 0.98 (95% confidence interval (CI): 0.76-1.25), suggesting a lack of association between delay and disease stage. In four studies, cancers of the colon and rectum were dealt with separately, and a meta-analysis was performed using the data for colon cancer (1001 patients) and for rectal cancer (799 patients). In both cases, the combined ORs overlapped 1.0, and showed opposite associations when studied separately: 0.86 (95% CI: 0.63-1.19) for the colon (i.e. more delay is associated with the earlier stage at diagnosis) and 1.93 (95% CI: 0.89-4.219) for the rectum (i.e. less delay is associated with the earlier stage).

CONCLUSIONS

When colorectal cancers are taken as a whole, there appears to be no association between diagnostic delay and disease stage when diagnosis is made. However, when cancers of the colon and the rectum are studied separately, there may be an opposite association. More studies about this issue are needed with larger and unrestricted samples.

Hazard regression model and cure rate model in colon cancer relative survival trends: are they telling the same story?

Hazard regression models and cure rate models can be advantageously used in cancer relative survival analysis. We explored the advantages and limits of these two models in colon cancer and focused on the prognostic impact of the year of diagnosis on survival according to the TNM stage at diagnosis. The analysis concerned 9,998 patients from three French registries. In the hazard regression model, the baseline excess death hazard and the time-dependent effects of covariates were modelled using regression splines. The cure rate model estimated the proportion of 'cured' patients and the excess death hazard in 'non-cured' patients. The effects of year of diagnosis on these parameters were estimated for each TNM cancer stage. With the hazard regression model, the excess death hazard decreased significantly with more recent years of diagnoses (hazard ratio, HR 0.97 in stage III and 0.98 in stage IV, P < 0.001). In these advanced stages, this favourable effect was limited to the first years of follow-up. With the cure rate model, recent years of diagnoses were significantly associated with longer survivals in 'non-cured' patients with advanced stages (HR 0.95 in stage III and 0.97 in stage IV, P < 0.001) but had no significant effect on cure (odds ratio, OR 0.99 in stages III and IV, P > 0.5). The two models were complementary and concordant in estimating colon cancer survival and the effects of covariates. They provided two different points of view of the same phenomenon: recent years of diagnosis had a favourable effect on survival, but not on cure.

Optimal pathologic staging: defining stage II disease

Tumor stage remains the most important determinant of prognosis in colorectal cancer and is the basis of all authoritative patient management guidelines. The pathologic assessment of stage II disease is especially critical because it may help to identify patients at additional risk for whom surgery alone may not be curative. Accurate analysis of regional lymph nodes, extent of tumor penetration, and circumferential resection margins constitute the most crucial issues. For assignment of pN0, adequacy of the surgical resection and thoroughness of the lymph node harvest from the resection specimen are both essential. The minimum number of lymph nodes has been variably determined to be between 12 and 18 for assignment of pN0, but the confidence level increases with increasing numbers of nodes examined. The ability of exhaustive analysis of sentinel lymph nodes using special techniques to substitute for an exhaustive lymph node harvest and standard node examination has not been definitively shown. Although special techniques may facilitate the identification of minute amounts of tumor (i.e., isolated tumor cells) in regional lymph nodes, the prognostic significance of such findings remains unclear. Additional stage-independent pathologic features that have been validated as adverse prognostic factors include involvement by tumor of mural lymphovascular channels, venous vessels, or the surgical resection margin of the operative specimen and high tumor grade. The presence of these features may help to identify patients for whom surgery alone will not be curative and adjuvant therapies may be appropriate.

Relationship of diagnostic and therapeutic delay with survival in colorectal cancer: a review

BACKGROUND

Early diagnosis of colorectal cancer before the onset of symptoms improves survival. Once symptoms have occurred, however, the effect of delay on survival is unclear. We review here evidence on the relationship of diagnostic and therapeutic delay with survival in colorectal cancer.

METHODS

We conducted a systematic of Medline, Embase, Cancerlit and the Cochrane Database of Systematic Reviews to identify publications published between 1962 and 2006 dealing with delay, survival and colon cancer. A meta-analysis was performed based on the calculation of the relative risk (RR) and on a model of random effects.

RESULTS

We identified 40 studies, representing 20,440 patients. Fourteen studies were excluded due to excessively restricted samples (e.g. exclusion of patients with intestinal obstruction, with tumours at stage C or D at the time of diagnosis, or who died 1-3 months after surgery); or because they studied only a portion of the delay. Of the 26 remaining studies, 20 showed no association between delay and survival. In contrast, four studies showed that delay was a factor contributing to better prognosis, and two showed that it contributed to poorer prognosis. There was no association between delay and survival when the colon and rectum were considered separately, when a multivariate analysis was performed, and when the effects of tumour stage and degree of differentiation were taken into account. To perform a meta-analysis, 18 additional studies were excluded, since the published articles did not specify the absolute numbers. In the remaining eight studies, the combined relative risk (RR) of delay was 0.92 (confidence interval (CI) 95%: 0.87-0.97).

CONCLUSIONS

The results of the review suggest that there is no association between diagnostic and therapeutic delay and survival in colorectal cancer patients. Colon and rectum should be assessed separately, and it is necessary to adjust for other relevant variables such as tumour stage.

The influence of host response on colorectal cancer prognosis

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide. Several tumor characteristics have been shown to be of prognostic significance, although stage at diagnosis continues to be the most important predictor of survival. Emerging new data suggest that the presence of a host response to CRC may also influence survival and other outcomes in CRC. This review summarizes recent evidence regarding the prognostic significance of the host response to CRC. In retrospective analyses, tumor-associated macrophages and tumor-infiltrating lymphocytes appear to be the elements most significantly associated with improved outcomes in CRC. The presence of other cells, including dendritic cells, natural killer cells, eosinophils, and mast cells, also appears to be associated with increased survival. The influence of the host response to CRC needs confirmation in prospective studies, but in the meantime should be part of risk stratification. Novel approaches to further augmenting this response merit study.

Long-term prognosis of patients with obstructing carcinoma of the right colon

BACKGROUND

The long-term prognosis of patients with colon cancer is dependent on many factors. The aim of this retrospective study was to assess the long-term prognosis of patients with obstructing carcinoma of the right colon.

METHODS

From 1981 to 1988, 256 patients at the Veterans General Hospital-Taipei who were status postcurative resection of right colon adenocarcinoma were classified as obstruction group (n = 35) or nonobstruction group (n = 221) as appropriate.

RESULTS

Analysis revealed no differences in age, sex, tumor location, or stage (P >0.05) between the two groups. However, the overall and distant recurrence rates were significant higher in obstructed patients than in nonobstructed patients. Further, long-term crude and cancer-specific survival rates were significantly lower in obstructed patients when examining either overall patient outcome or stage-matched outcomes. Multivariate analysis demonstrated that obstruction and tumor stage were both independent prognostic factors.

CONCLUSIONS

Obstruction status was an independent prognostic factor for patients with right colon carcinoma. The long-term prognosis of patients with obstructing carcinoma of the right colon was poor.

The clinicopathological significance of inferior mesenteric lymph node metastasis in colorectal cancer

AIMS

There are few studies reporting survival or recurrence patterns in colorectal cancer patients with inferior mesenteric lymph node metastasis (IMLN+). The present study evaluated the prognostic significance of patients being IMLN+ or IMLN- in colorectal cancer.

METHODS

Survival, recurrence pattern and treatment protocols were compared between 63 IMLN+ patients and 108 IMLN- patients with stage III and IV rectal and sigmoid cancer undergoing curative surgery. Lymph node sampling was routinely performed prior to inferior mesenteric artery ligation and excision flush with aorta. Limited principal node dissection including IMLN was performed in cases of identified node metastasis.

RESULTS

The 5-year disease-free survival rates were 50% in IMLN- and 31% in IMLN+ patients (P=0.004). The 5-year disease-free survival rate was greater in the N1 group than the N2 group (P=0.038). Cox regression analysis showed IMLN+, lymphovascular tumour invasion, T4, M1, and pre-operative serum CEA level over 6 ng/ml were independently associated with unfavorable disease-free survival. The prognostic significance of M category was greater when the IMLN+ was included in the M1 as opposed to the N category. In patients undergoing absolute curative surgery, post-operative recurrence rates were 34% for IMLN- and 57% for IMLN+ patients (P=0.009; OR, 2.611; 95% CI, 1.313-5.194). For IMLN+ patients, post-operative adjuvant treatment independently correlated with disease-free survival (P=0.029).

CONCLUSIONS

IMLN+ is an independent survival factor enhancing the prognostic significance of the M category in the AJCC staging. Curative radical surgery and post-operative chemoradiotherapy appears to be warranted for IMLN+ colorectal cancer patients as it resulted in 5-year disease-free survival rates of up to 31% compared to 50% in IMLN- patients.

Colorectal cancer survival trends in Norway 1958–1997

The purpose of this study was to examine the pattern of survival for colorectal adenocarcinoma (CRC), and to investigate the prognostic factors for the disease. In the analysis, 50993 cases of CRC aged 40-84 years, diagnosed between 1958 and 1997 in Norway, were included. Esteve's relative survival method was used, together with a time trend analysis, conducted by least-squares linear regression. Cox proportional hazards regression analysis was used to examine cause-specific mortality. Five-year relative CRC survival has increased by an estimated 3% per 5-year diagnostic period. In 1958-1962, relative survival was about 40% for both males and females, and increased to 56 and 60%, respectively, in 1993-1997. Rectal cancer had a higher cause-specific mortality (RR 1.26, 95% CI 1.22-1.30) than proximal colon (reference) and distal colon (RR 0.97, 95% CI 0.93-1.00 cancers), while females had a lower cause-specific mortality than males (RR 0.88, 95% CI 0.86-0.90). The increase in the relative survival rate in Norway is probably due to improved treatments and advanced diagnostics. Norway has a higher CRC survival rate than the EUROCARE average.

Rectal cancer in Luxembourg : a national population-based data report, 1988-1998

BACKGROUND

Morphologic criteria which might help to support the need for a preventive strategy for early detection of rectal cancer were analysed. Population-based data on rectal adenomas with high-grade dysplastic changes (n = 199) and invasive adenocarcinomas (n = 912) registered by the national Morphologic Tumour Registry (MTR) and diagnosed in a central department of pathology in Luxembourg between 1988 and 1998 were considered.

METHODS

The analysis concerned time trends in frequency, crude incidence, tumour-stage, the rectal "high-grade" adenoma/invasive adenocarcinoma-ratio and the survival rates. Histopathological tumour-stage parameters (UICC/AJCC, 1997) in a consecutive series of 641 resected rectal cancers and their relationship with the observed patient survival are investigated.

RESULTS

The majority of invasive adenocarcinomas are diagnosed at a late stage (i.e. Stage II and III) into contrast with the highly significant increase (355 %) in frequency of rectal high-grade adenomas (Stage 0). During the two-time periods 1988-1992 and 1994-1998 Stage I and Stage IV-cases decreased by 11 % and 47 % respectively. Tumour-stage correlates with prognosis. The rectal high-grade adenoma / invasive adenocarcinoma-ratio improved significantly over the last five years.

CONCLUSION

Over the study period, there has been a highly significant rise in the incidence of resected rectal adenomas with high-grade intraepithelial neoplasia. The ratio of early tumours to invasive cancers has risen while the numbers of colonoscopies and rectoscopies remained unchanged respectively decreased. As the number of advanced tumour-stages remained stable, mass-screening procedures focusing on the fifty to sixty age group should be reinforced.

Prognostic factors in 165 elderly colorectal cancer patients

AIM: To analyse the prognostic factors in 165 colorectal patients aged ≥ 70.

METHODS: One hundred and sixty-five elderly patients with colorectal cancer diagnosed by histology were entered into the retrospective study between 1994 and 2001. Patients were given optimal operation alone, chemotherapy after operation, or chemotherapy alone according to tumor stage, histology, physical strength, and co-morbid problems. Survival rate was calculated by Kaplan-Meier method, and compared with meaningful variances by Log-rank method. Prognostic factors were analyzed by Cox regression.

RESULTS: The 1, 2, 3, 4, 5 year survival rate (all-cause mortality) was 87.76%, 65.96%, 52.05%, 42.77%, 40.51%, respectively. The mean survival time was 41.89 ± 2.33 months (95%CI: 37.33-46.45 months), and the median survival time was 37 months. Univariate analysis showed that factors such as age, nodal metastasis, treatment method, Duke’s stage, gross findings, kind of histology, and degree of differentiation had influences on the survival rate. Multivariate analysis showed that factors such as treatment method, Duke’s stage, kind of histology and degree of differentiation were independent prognostic factors.

CONCLUSION: This study suggests that the prognosis of elderly colorectal cancer patients is influenced by several factors. Most of elderly patients can endure surgery and/or chemotherapy, and have a long-time survival and good quality of life.

Retrospective measurement of different size parameters of non-radiated rectal cancer on MR images and pathology slides and their comparison

There are no non-invasive methods to assess the real tumor size in rectal cancer prior to surgery, especially following radio/chemotherapy. Magnetic resonance imaging is gaining increasing acceptance as the primary modality at many centers for evaluation of pelvic malignancies including rectal cancers. The aim of this study was to evaluate if the tumor size as assessed by stereological or metric means on MRI correlates to the corresponding pathologic findings. To our knowledge, no such previous work has been reported in the literature. From the Cancer Register Center, 18 patients in the age range of 39-90 years with rectal cancer who had complete preoperative MR with subsequent giant section pathological examinations of the resected bowel were included. The tumor size was measured on MR and histopathologic specimen using both a stereologic and a metric mode. The measured parameters included the maximum transverse area occupied by the tumor, thickness, width, and the length of tumor and the volume of the tumor measured in two different fashions by the product of area and length (al) or the product of thickness, width, and length (twl). The depth of tumor infiltration (T) and presence of local lymph node metastases (N) were also separately evaluated on the histopathologic specimen. There were 1, 4, 12, and 1 patients with tumor stages T1, T2, T3, and T4, respectively. The mean thickness, width, length, area, and volumes, al and twl, were 1.62, 2.8, and 4.78 cm, and 4.72 cm2, 26.29 cm3, and 20.07 cm3, respectively. Regression curves were drawn for above-mentioned parameters. They showed some correlation with square correlation coefficient measuring between 0.38 and 0.82. The best correlation was seen for area (0.75) and volume measured by the product of area and length of the tumor (0.82). With the formula proposed from this material, we assume that rectal tumors can be measured on MR images using a metric model, especially area and the volume (the product of area and length), and then extrapolated to what we would expect from pathology, hence providing us with a tool where we could measure tumor response after neoadjuvant therapy.

Immunology and immunotherapy of colorectal cancer

This review critically discusses data on immunology of colorectal cancer, starting from pathology and molecular biology, and then considering the molecular characterisation of colon cancer antigens and the clinical trials of immunotherapy. A careful evaluation of histopathological studies on intra-epithelial infiltration by T cells in primary tumours, together with the analysis of HLA expression by colorectal cancer cells, suggest that anti-tumour T cell immune responses may take place in vivo in those patients, influencing prognosis and shaping the tumour immunological profile. Moreover, the molecular characterisation of tumour antigens expressed by colorectal carcinomas, together with improved understanding of mechanisms of the immune response and more sensitive methods for the in vivo detection of T cell responses, are now allowing researchers to design new and more effective vaccination protocols, with encouraging preliminary results. By drawing together the experimental evidence from different research fields, this review provides support for the concept that colorectal carcinoma is immunogenic and may reasonably be considered as a target for immunotherapy, and attempts to address critical issues and envisage future developments in this challenging research field.

[Clinical, pathological and molecular prognostic factors in colorectal carcinomas]

Various aspects of the progression and prognosis of colorectal carcinoma have been investigated in numerous publications during recent years. An exact macroscopic and microscopic examination is still of basic importance but different factors of the molecular pathogenesis of colorectal carcinoma could be described by immunohistochemistry and molecular biology. Furthermore, they have been evaluated regarding their importance for the course of disease and prognosis and in particular, the different pathways of carcinogenesis and microsatellite instability were included. The detection of micrometastasis was investigated applying mostly molecular genetic methods. Numerous oncogenes, tumor suppressor genes and regulators of the cell cycle, markers of proliferation and apoptosis, cell adhesion antigens and angiogenetic factors were characterized with regard to their prognostic potential. In the future, so-called response predictors will presumably gain a certain relevance in the context of neoadjuvant (radiotherapy) chemotherapy. The present review summarizes these results and discusses the future clinical relevance.

Pathologic prognostic factors in the recurrence of rectal cancer

For rectal cancer, local recurrence following surgical treatment is a grave complication that occurs in as many as 25% of cases. Pathological examination of the surgical resection specimen plays a primary role in assessing both the surgery- and tumor-related factors that contribute to the risk of recurrence. Among the tumor-related factors, stage has long been considered the single most accurate indicator of survival. However, recent evidence strongly suggests that the most powerful predictor of both local recurrence and overall outcome in the absence of distant metastatic disease is the macroscopic quality of the mesorectum in the resection specimen and the proximity of the tumor to the circumferential (radial) resection margin. Additional pathologic features have been shown to have stage-independent prognostic significance in colorectal cancer and may help to further define risk of adverse outcome. Such features include: tumor grade; histologic type; extent of extramural penetration by tumor; neural, venous, and/or lymphatic invasion; tumor border configuration; tumor budding; and host lymphoid response. The predictive value of tumor-specific molecular features is currently under investigation and may help to further improve prognostication and refine individual patient management in rectal cancer.

Population-based survival analysis of colorectal cancer patients in Singapore, 1968-1992

Since the 1980s, colorectal cancer incidence in Singapore has ranked second to lung in males and females. We describe a population-based analysis of survival of colorectal cancer patients diagnosed from 1968 to 1992 in Singapore. Data of colorectal cancer patients diagnosed during 1968-1992 were retrieved from the Singapore Cancer Registry. Patients were passively followed up for death to the end of 1997. The final dataset consisted of 10,114 subjects. Observed and relative survival rates were calculated by stage (localized, regional metastases and distant metastases), age, ethnicity and calendar period for both genders. Over the study period, a significant progress in survival of colorectal cancer patients was observed. For localized cancer of the colon, the 5-year age-standardized relative survival (ASRS) increased from 36% in 1968-1972 to 66% in 1988-1992 for males and from 32 to 71% for females. For localized rectal cancer, the 5-year ASRS improved from 25 to 66% for males and from 23 to 66% in females. Similarly, improvement was observed in colorectal cancer patients with regional metastases, but not in those with distant metastases. Calendar year period and clinical stage of disease were identified as major significant prognostic factors of survival for colorectal cancer. The substantially improved colorectal cancer survival rates reflected the interplay of cancer control activities in various areas, such as health promotion, early diagnosis and treatment. Our study shows a unique changing pattern of survival experience for colorectal patients from a country undergoing rapid economic development.

Efficacy and toxicity of adjuvant chemotherapy in elderly patients with colon carcinoma: a 10-year experience of the Geisinger Medical Center

BACKGROUND

Although the benefit from adjuvant chemotherapy has been established clearly in patients with Stage III colon carcinoma, the degree to which elderly patients with colon carcinoma can tolerate such therapy generally has remained unknown.

METHODS

The authors reviewed all patients in their Tumor Registry with Stage II and Stage III adenocarcinoma of the colon who underwent potentially curative resection for their disease at the Geisinger Medical Center between January 1990 and September 2000. One hundred twenty patients underwent complete resection of their colon carcinoma and received 5-fluorouracil-based (5-FU) adjuvant chemotherapy.

RESULTS

The 5-year disease free survival rate for patients age > or =65 years (Group A) was 70% compared with 56% for patients age < 65 years (Group B) (P = 0.085). The 5-year overall survival rate for patients in Group B was 77% compared with 62% for the patients in Group A (P = 0.143). In a Cox regression model, age was not a predictor of disease free survival (P = 0.633) or overall survival (P = 0.900) when it was analyzed as a continuous variable. Only 19 patients were age > 75 years, and the disease free and overall survival rates for this group were similar but were underpowered compared with the rates for the patients ages between 65-75 years. When gender and disease stage were included in the model, age remained a nonsignificant variable (P = 0.400 for disease free survival; P = 0.615 for overall survival). Nine of 56 patients in Group A (16%) experienced Grade 3-4 toxicity compared with 14 of 64 patients in Group B (22%) (P = 0.420). The lack of a correlation between toxicity and age was maintained after controlling for disease stage and patient gender (P = 0.343). There were no correlations between preoperative carcinoembryonic antigen level, tumor grade, or lymph node involvement and patient age (P = 0.258, P = 0.256, and P = 0.519, respectively).

CONCLUSIONS

Elderly patients with Stage II and Stage III colon carcinoma benefit from 5-FU-based adjuvant therapy without a significant increase in toxicity compared with their younger counterparts. Adjuvant chemotherapy should be presented to elderly patients with high-risk, resected colon carcinoma. The data regarding age cannot be generalized to patients age > 75 years.

Comparative expression of the mitotic regulators SAK and PLK in colorectal cancer

BACKGROUND

Disruption of normal mechanisms for cell cycle regulation is important in carcinogenesis. SAK and PLK are members of the polo family of serine threonine kinases, which in lower organisms have been shown to be required for the precise regulation of mitosis. Studies of human polo family members have focused on PLK, which has been found to be overexpressed in several tumor types, with the degree of overexpression correlating with adverse clinical outcome. However, PLK expression had not previously been analyzed in colorectal cancer. SAK, a polo family member with unique properties, had not been systematically studied in any tumor type.

METHODS

In this study, SAK expression was evaluated in a series of sporadic human colorectal cancer specimens (n = 74) and compared with that of PLK. Expression was assessed by reverse transcription-polymerase chain reaction.

RESULTS

In the majority of cases, both SAK and PLK were more highly expressed in tumor tissue than in adjacent normal intestinal mucosa. Levels of SAK and PLK expression in tumor relative to paired normal mucosa correlated directly with patient age and with each other but did not correlate with tumor stage. These results suggest a mechanism for augmented disruption of mitotic regulation in older patients.

CONCLUSIONS

The polo family mitotic regulators SAK and PLK are both aberrantly expressed in colorectal cancer. The potential prognostic significance of SAK and PLK expression in colorectal cancer will be evaluated in the future.