Importance of tumor pathology and morphology in patients with surgically resected colon cancer. Findings from the Gastrointestinal Tumor Study Group

Phenotypic screen of sixty-eight colorectal cancer cell lines identifies CEACAM6 and CEACAM5 as markers of acid resistance

Elevated cancer metabolism releases lactic acid and CO2 into the under-perfused tumor microenvironment, resulting in extracellular acidosis. The surviving cancer cells must adapt to this selection pressure; thus, targeting tumor acidosis is a rational therapeutic strategy to manage tumor growth. However, none of the major approved treatments are based explicitly on disrupting acid handling, signaling, or adaptations, possibly because the distinction between acid-sensitive and acid-resistant phenotypes is not clear. Here, we report pH-related phenotypes of sixty-eight colorectal cancer (CRC) cell lines by measuring i) extracellular acidification as a readout of acid production by fermentative metabolism and ii) growth of cell biomass over a range of extracellular pH (pHe) levels as a measure of the acid sensitivity of proliferation. Based on these measurements, CRC cell lines were grouped along two dimensions as "acid-sensitive"/"acid-resistant" versus "low metabolic acid production"/"high metabolic acid production." Strikingly, acid resistance was associated with the expression of CEACAM6 and CEACAM5 genes coding for two related cell-adhesion molecules, and among pH-regulating genes, of CA12. CEACAM5/6 protein levels were strongly induced by acidity, with a further induction under hypoxia in a subset of CRC lines. Lack of CEACAM6 (but not of CEACAM5) reduced cell growth and their ability to differentiate. Finally, CEACAM6 levels were strongly increased in human colorectal cancers from stage II and III patients, compared to matched samples from adjacent normal tissues. Thus, CEACAM6 is a marker of acid-resistant clones in colorectal cancer and a potential motif for targeting therapies to acidic regions within the tumors.

Evaluating the value of tumor length times width in colorectal adenocarcinoma with different tumor locations

The T classification, which reflects the vertical growth pattern of the tumor, is one of the most important prognostic factors in colorectal cancer. We aimed to investigate the prognostic value of tumor length and width in patients with colorectal cancer (CRC). A total of 259 patients with stage I-III CRC who underwent curative resection were reevaluated according to tumor location. One-way ANOVA analysis was conducted to investigate the relationship between the tumor length times width (TLTW) and clinical parameters. Univariate and multivariate analyses were conducted to analyze the potential prognostic factors affecting overall survival (OS) of patients with stage I-III CRC. In the entire cohort, the TLTW was analyzed as a continuous variable. The results suggested that TLTW (P = .003) and tumor location (P = .04) could be independent prognostic factors for patients with CRC. In addition, TLTW had an intimate relationship with tumor location (P < 0.001) and differentiation (P = .003). The mean TLTW of the right colon was significantly larger than mean TLTW of the left colon and rectal cancers. However, the mean TLTW of the left colon cancer was similar to that of the rectal cancer TLTW (P > 0.05, not shown). Subgroup analysis of TLTW according to tumor location suggested that TLTW was an independent prognostic factor for patients with right colon cancer (RCC) (P = .007) rather than left colon cancer (LCC) (P = .49) or rectal cancer (P = .16). Kaplan-Meier (K-M) analysis based on tumor location suggested that the survival rate of RCC patients had a distinctly higher trend rate than LCC patients and RECC patients in the long-term rather than in the short-term. TLTW is closely associated with tumor location in CRC. In addition, TLTW may be an independent prognostic factor for patients with RCC.

No significant relationship exists between tumor size and prognosis in distant metastatic hepatocellular carcinoma: a propensity score matching analysis based on SEER database

Background

Previous studies have shown that tumor size has an impact on the prognosis of hepatocellular carcinoma (HCC). Whether tumor size is related to the prognosis of distant metastatic HCC is unclear. The purpose of this study was to investigate the effect of tumor size on the prognosis of distant metastatic HCC.

Methods

Data on patients with HCC were collected from the (SEER) database of surveillance, epidemiology and final results. Propensity score matching (PSM) was used to reduce confounding factors and comprehensively evaluate the clinicopathological features and prognosis of distant metastatic HCC.

Results

There were 189 patients with distant metastatic HCC whose tumor size was ≤ 50 mm and 615 patients with a tumor size > 50 mm. The tumor sizes of distant metastatic HCC patients were associated with race, grade, surgical treatment, N and AFP. The Kaplan–Meier analysis showed that the mortality rate of patients with a tumor size > 50 mm was higher than that of patients with a tumor size ≤ 50 mm (p = 0.00062). However, there were no significant differences in mortality rates after adjusting for confounding variables by using propensity score matching (p = 0.23).

Conclusion

This propensity score matching study provides the best data in support of the following assertions: tumor size is not an independent prognostic factor for distant metastatic HCC.

The Critical Role of Tumor Size in Predicting Prognosis for T1 Colon Cancer

BACKGROUND

The role of horizontal growth index of tumor size in survival prediction is still underappreciated in colon cancer because of the identification of vertical infiltration index reflected by T stage. We sought to reveal the impact of T stage on the prognostic and predictive value of tumor size in colon cancer.

MATERIALS AND METHODS

Data of patients with stage I-III colon cancer were extracted from Surveillance, Epidemiology, and End Results Program (SEER) and Fudan University Shanghai Cancer Center (FUSCC) databases. Harrell's concordance index (c-index) and time-dependent receiver operating characteristic curve (ROC) were used to analyze the discriminative ability of prognostic factors.

RESULTS

Stratified analyses based on T stage found that the increase of T stage significantly and negatively repressed the effect of tumor size on death and recurrence risk. In addition, tumor size showed the greatest hazard ratio of cancer-specific death and relapse in T1 colon cancer. Even more importantly, the discriminatory ability of tumor size outperformed any other widely accepted prognostic clinical features in predicting cancer-specific survival (SEER: c-index 0.637, area under the ROC [AUC] 0.649; FUSCC: c-index 0.673, AUC 0.686) and disease-free survival (FUSCC: c-index 0.645, AUC 0.656) in T1 stage colon cancer.

CONCLUSION

Tumor size is a critical clinical factor with considerable prognostic and predictive value for T1 colon cancer, and it should be selectively incorporated into the current staging system to facilitate prediction of death and recurrence risk.

IMPLICATIONS FOR PRACTICE

To date, no consensus has been reached about the prognostic and predictive value of tumor size in colon cancer. Although tumor size is an independent prognostic factor for patients with colon cancer, the impact of tumor size on death or recurrence risk decreased notably with the increase of T stage. More importantly, the discriminative ability of tumor size outperformed any other clinical factors including N stage in patients with T1 colon cancer. Therefore, tumor size should be recommended to be incorporated into current staging systems to facilitate prognosis prediction for patients with T1 colon cancer.

Value of tumor size as a prognostic factor in metastatic colorectal cancer patients after chemotherapy: a population-based study

Aim: To evaluate the relationship between tumor size and survival in metastatic colorectal cancer (mCRC) patients who received chemotherapy. Materials & methods: SEER database was accessed for eligible patients. Multivariate Cox regression analysis was performed to compare the effect of tumor size on overall survival (OS) and CRC-specific survival (CCSS). Results: Tumor size ≥5 cm was an independent risk factor for OS and CCSS in mCRC patients treated with chemotherapy. Tumor size <5 cm did not show a survival advantage in patients whose primary tumor site was rectosigmoid junction, while tumor size ≥5 cm was associated with poor OS and CCSS in left-and right-sided colorectal cancer. Conclusion: Tumor size ≥5 cm was associated with poor prognosis after receiving chemotherapy treatment and a risk factor for survival of mCRC.

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.

Non-coding RNAs Enabling Prognostic Stratification and Prediction of Therapeutic Response in Colorectal Cancer Patients

Colorectal cancer (CRC) is a heterogeneous disease and current treatment options for patients are associated with a wide range of outcomes and tumor responses. Although the traditional TNM staging system continues to serve as a crucial tool for estimating CRC prognosis and for stratification of treatment choices and long-term survival, it remains limited as it relies on macroscopic features and cases of surgical resection, fails to incorporate new molecular data and information, and cannot perfectly predict the variety of outcomes and responses to treatment associated with tumors of the same stage. Although additional histopathologic features have recently been applied in order to better classify individual tumors, the future might incorporate the use of novel molecular and genetic markers in order to maximize therapeutic outcome and to provide accurate prognosis. Such novel biomarkers, in addition to individual patient tumor phenotyping and other validated genetic markers, could facilitate the prediction of risk of progression in CRC patients and help assess overall survival. Recent findings point to the emerging role of non-protein-coding regions of the genome in their contribution to the progression of cancer and tumor formation. Two major subclasses of non-coding RNAs (ncRNAs), microRNAs and long non-coding RNAs, are often dysregulated in CRC and have demonstrated their diagnostic and prognostic potential as biomarkers. These ncRNAs are promising molecular classifiers and could assist in the stratification of patients into appropriate risk groups to guide therapeutic decisions and their expression patterns could help determine prognosis and predict therapeutic options in CRC.

Unfavorable effect of small tumor size on cause-specific survival in stage IIA colon cancer, a SEER-based study

BACKGROUND

We sought to determine the prognostic role of tumor size on cause-specific survival (CSS) of patients with stage IIA colon cancer.

METHODS

Surveillance, Epidemiology and End Results (SEER) database was utilized to identify patients with stage IIA colorectal cancer (examined lymph nodes ≥12) diagnosed from 1988 to 2003. The prognostic effect of tumor size on CSS was evaluated by univariate and multivariate analyses.

RESULTS

A total of 8775 patients were enrolled in the analysis. The median follow-up time was 109 months. As determined by minimal P value method, tumor sizes of 2.5 and 6.0 cm were used as optimal cutoff value to divide the cohort. The 8-year CSS of colon cancer with tumor sizes ≤2.5, 2.6-6.0, and >6.0 cm was 81.6, 86.2, and 86.7% respectively (P = 0.003). In the multivariate analysis of colon cancer, using ≤2.5-cm tumors as reference, decreased hazard ratio (HR) of CSS was observed in 2.6-6.0 cm (HR, 0.736; 95% confidence interval (CI), 0.599-0.905; P = 0.004) and >6.0 cm (HR, 0.770; 95% CI, 0.619-0.958; P = 0.019) tumors.

CONCLUSIONS

In stage IIA colon cancer, small tumor size represented a subset with decreased CSS. Further studies are merited to validate the unfavorable prognostic role of small tumor size in stage IIA colon cancer.

Adjuvant therapy in colon cancer

Huge advances have been made in the treatment of colon cancer over the last decade. Success has been most noticeable in stage IV disease - where careful selection of patients with small-volume disease for treatment with surgical resection ± perioperative chemotherapy has resulted in an improvement in survival of approximately 5-50%; and stage III - disease where the advent of 5-fluorouracil/oxaliplatin, as adjuvant treatment has also resulted in a significant prolongation in survival. Progression-free survival is now an established surrogate for overall survival, and has resulted in more timely reporting of adjuvant studies and therefore faster integration of promising agents into the clinic. Targeted agents, which have shown promise in the metastatic setting, are currently being examined in the adjuvant setting, although results so far are disappointing. Patients with high-risk stage II cancer remain a challenging group. They have a poorer prognosis than those with stage IIIA disease, and national and international guidance recommend offering chemotherapy after careful discussion of the pros and cons. Despite the fact that we have identified many of the biological features that make stage II disease higher risk, we still struggle to achieve the same improvement in survival for this subgroup compared with others. It may be that these patients required treatment with alternative regimens and predictive biomarkers would be particularly helpful.

Clinicopathologic factors affecting recurrence after curative surgery for stage I colorectal cancer

PURPOSE

The objective of the current study was to identify the clinicopathological risk factors affecting recurrence after a curative resection for stage I colorectal cancer.

METHODS

We retrospectively studied 434 patients who underwent a curative resection for stage I colorectal cancer between January 1999 and December 2004. Postoperative oral chemotherapy was performed in 189 patients (45.3%). The following prognostic factors were correlated with recurrence: age, gender, preoperative carcinoembryonic antigen level, location of tumor, T stage, size of tumor, histologic differentiation, growth pattern, and lymphovascular invasion. The median follow-up duration was 65 months.

RESULTS

The overall recurrence rate was 4.6% (20/434). The median time to recurrence was 33 months. Two-thirds of the recurrence occurred more than two years after surgery. Risk factors associated with recurrence were rectal cancer (P = 0.009), T2 stage (P = 0.010), and infiltrative growth pattern (P = 0.020). A Cox proportional hazards regression analysis demonstrated that the infiltrative growth pattern was an independent predictor for recurrence. Tumor cell budding was observed in all pathologic reviews with recurrence.

CONCLUSION

Long-term follow-up is necessary for stage I colorectal patients with high risk factors like rectal cancer, T2 stage, and infiltrative growth pattern.

Value of tumor size as a prognostic variable in colorectal cancer: a critical reappraisal

OBJECTIVES

Vertical tumor growth, reflected by T classification, represents the most important prognostic variable in colorectal cancer. Our study aimed to investigate the impact of tumor size, particularly the maximum tumor diameter, on outcome of affected patients.

METHODS

A total of 381 colorectal cancer specimens were re-evaluated. Tumor size and location were extracted from the medical history and were known for 359 patients (94%). Receiver-operator characteristic analysis was applied to identify the optimal (maximum of sum of sensitivity and specificity) cut-off values with respect to prognostic impact.

RESULTS

Median tumor size was 4.5 cm (range, 0.6-15). Tumor size exceeding 4.5 cm was observed in 159 patients (44%) and was associated with high T and N classification, UICC stage, and tumor grade. At median follow-up of 45 months (range, 0-180), 141 patients (40%) showed tumor progression. Although 4.5 cm was identified as the optimal cut-off value within the whole group of patients, receiver-operator characteristic analysis restricted to different parts of the large bowel determined 5 cm, 5.3 cm, 3.9 cm, and 3.4 cm as cut-off values with the strongest discriminatory capacity in colon, right-sided colon, left-sided colon, and rectum cancers, respectively. Applying these cut-off values, tumor size was significantly associated with progression-free and cancer-specific survival in univariate and multivariate analyses in colon, yet not in rectum cancers.

CONCLUSIONS

Tumor size proved to be an independent prognostic parameter for patients with colorectal cancer. Optimal cut-off values vary among different parts of the large bowel. Whereas prognostic significance is strong within the colon, it appears to be of minor value within the rectum.

Colon cancer in Iceland--a nationwide comparative study on various pathology parameters with respect to right and left tumor location and patients age

Increasing evidence suggests genetic, biological and demographical difference between right and left colon cancer. Studies have also indicated age differences in the pathology of colon cancer. There is a scarcity of large-scale studies that closely examine the pathological differences regarding age and tumor location. The aim of our study was to do an extensive comparison of right- and left- sided colon cancers as well as comparing patients <50 years with older patients. A retrospective, population-based study was carried out on all patients with colon cancer in Iceland between 1955 and 2004. A total of 2293 cases were analyzed (1148 men, 1145 women). All histopathology material was re-evaluated. Differences in tumor characteristics between right and left location and younger (<50) and older (≥50) patients was evaluated in particular. Higher TNM-stage, larger tumors, vessel invasion, mucinous type, high grade and expanding tumor border occurred more frequently in right- versus left-sided lesions while annular and polypoid tumors were more common in left-sided tumors (p < 0.05). Young patients had more frequent lymph node metastases, vessel invasion, nonpolypoid lesions and infiltrating tumor border (p < 0.05). Right-sided lesions show more aggressive features, reflected in morphology and stage. Younger patients present more frequently with adverse features than do older patients. Frequency of right- and left-sided colon cancer differs by age with pronounced age-location differences in females. This supports the assumption of differences in etiology and carcinogenesis of right- and left-sided colon cancer, and between young and old patients.

Diagnostic and prognostic microRNAs in stage II colon cancer

MicroRNAs (miRNA) are a class of small noncoding RNAs with important posttranscriptional regulatory functions. Recent data suggest that miRNAs are aberrantly expressed in many human cancers and that they may play significant roles in carcinogenesis. Here, we used microarrays to profile the expression of 315 human miRNAs in 10 normal mucosa samples and 49 stage II colon cancers differing with regard to microsatellite status and recurrence of disease. Several miRNAs were differentially expressed between normal tissue and tumor microsatellite subtypes, with miR-145 showing the lowest expression in cancer relative to normal tissue. Microsatellite status for the majority of cancers could be correctly predicted based on miRNA expression profiles. Furthermore, a biomarker based on miRNA expression profiles could predict recurrence of disease with an overall performance accuracy of 81%, indicating a potential role of miRNAs in determining tumor aggressiveness. The expression levels of miR-320 and miR-498, both included in the predictive biomarker, correlated with the probability of recurrence-free survival by multivariate analysis. We successfully verified the expression of selected miRNAs using real-time reverse transcription-PCR assays for mature miRNAs, whereas in situ hybridization was used to detect the accumulation of miR-145 and miR-320 in normal epithelial cells and adenocarcinoma cells. Functional studies showed that miR-145 potently suppressed growth of three different colon carcinoma cell lines. In conclusion, our results suggest that perturbed expression of numerous miRNAs in colon cancer may have a functional effect on tumor cell behavior, and, furthermore, that some miRNAs with prognostic potential could be of clinical importance.

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.

CYP27A1 and CYP24 expression as a function of malignant transformation in the colon

Vitamin D deficiency is strongly associated with the risk of developing colorectal cancer (CRC). Because of the propensity of bioactive 1,25-dihydroxyvitamin D3 to cause toxic hypercalcemia, considerable effort has been directed to identifying safer drugs while retaining the efficacy of the parent compound. However, vitamin D precursors do not present toxicity concerns and may be sufficient for CRC chemoprevention or chemotherapy, providing the appropriate enzymes are present in colonic epithelia. We previously showed that CYP27B1 is present at equally high levels in the colon and CRC irrespective of differentiation but was not present in metastases. In this study we used quantitative immunohistochemistry to show that CYP27A1, converting D3 to 25-hydroxycholecalciferol, is present in increasing concentrations in the nuclei of normal colonic epithelia, aberrant crypt foci (ACF), and adenomatous polyps. Whereas total cellular CYP27A1 remains high in CRC and lymph node metastases, the amount of enzyme present in the nuclei decreases with tumor cell dedifferentiation while rising in the cytoplasm. Similarly, increasing amounts of the deactivating enzyme CYP24 are present in the nuclei of normal colonic epithelia, ACFs, and adenomatous polyps. Although the amount of total CYP24 decreases slightly in CRC as a function of tumor cell dedifferentiation and metastasis, location of this enzyme shifts almost entirely from the nuclear compartment to the cytoplasmic compartment. These data indicate that non-toxic vitamin D precursors should be sufficient for CRC chemoprevention, but that neither vitamin D nor its precursors may be sufficient for CRC chemotherapy.

Incidence and patterns of recurrence after resection for cure of colonic cancer in a well defined population

BACKGROUND

The aim of this study was to determine the incidence and patterns of failure following potentially curative surgery of colonic cancer.

METHODS

Data were obtained from the cancer registry of the Côte-d'Or (France). Data on 2657 patients who had resection for cure of colonic cancer between 1976 and 2000 were analysed. Local and distant failure rates were calculated using the actuarial method and multivariable analysis was performed using a Cox model.

RESULTS

The 5-year cumulative rate was 12.8 percent for local recurrence and 25.6 percent for distant metastases. Five-year cumulative local recurrence rates were 4.9 percent for stage I, 11.0 percent for stage II and 23.5 percent for stage III tumours (P<0.001). The corresponding rates for distant metastases were 6.4, 21.4 and 48.0 percent (P<0.001). The 5-year cumulative rates for distant metastases were 31.7 percent for the period 1976-1980 and 21.1 percent for 1996-2000, and the local recurrence rates were 17.6 and 9.0 percent respectively. The decreases in rates of local recurrence and distant metastases were significant in multivariable analysis. Cancer extension and presenting features were related to patterns of failure. Tumour location was significantly associated with risk of local recurrence, whereas age and gross features were associated with risk of distant metastasis.

CONCLUSION

Recurrence following resection of colonic cancer remains a substantial problem. Follow-up is of particular importance in the 3 years after surgery.

Epidemiology and management of liver metastases from colorectal cancer

OBJECTIVE/BACKGROUND

Little is known about the epidemiology and the management of liver metastases from colorectal cancer at a population level. The aim of this population-based study was to report on the incidence, treatment, and prognosis of synchronous and metachronous liver metastases.

METHODS

Data were obtained from the population-based cancer registry of Burgundy (France).

RESULTS

The proportion of patients with synchronous liver metastases was 14.5%. Age-standardized incidence rates were 7.6 per 100,000 in males, 3.7 per 100,000 in females. The 5-year cumulative metachronous liver metastasis rate was 14.5%. It was 3.7% for TNM stage I tumors, 13.3% for stage II, and 30.4% for stage III (P < 0.001). The risk of liver metastasis was also associated to gross features. Resection for cure was performed in 6.3% of synchronous liver metastases and 16.9% of metachronous liver metastases. Age, presence of another site of recurrence, and period of diagnosis were independent factors associated with the performance of a resection for cure. The 1- and 5-year survival rates were 34.8% and 3.3% for synchronous liver metastases. Their corresponding rates were, respectively, 37.6% and 6.1% for metachronous liver metastases.

CONCLUSION

Liver metastases from colorectal cancer remain a substantial problem. More effective treatments and mass screening represent promising approaches to decrease this problem.

Lymph nodes in colorectal carcinoma. The Poisson probability paradigm

This article introduces use of the Poisson probability density function and Bayes probability rule to understand and analyze lymph nodal metastases in colorectal carcinoma. We apply these models to 370 patients who underwent resection of their tumors. In 213 cases with negative lymph nodes, we found that the Bayes-estimated probability of missed metastases was related significantly to subsequent survival (P = .0006). In 157 cases with lymph nodal metastases, we found that the estimated value of the Poisson parameter a was associated more closely with subsequent survival than pN stage (P = 9 10(-6)). Consequently, we believe that the Poisson model provides insight and useful results in colorectal carcinoma.

Lymph nodes in colorectal carcinoma. The Poisson probability paradigm

This article introduces use of the Poisson probability density function and Bayes probability rule to understand and analyze lymph nodal metastases in colorectal carcinoma. We apply these models to 370 patients who underwent resection of their tumors. In 213 cases with negative lymph nodes, we found that the Bayes-estimated probability of missed metastases was related significantly to subsequent survival (P = .0006). In 157 cases with lymph nodal metastases, we found that the estimated value of the Poisson parameter a was associated more closely with subsequent survival than pN stage (P = 9 10(-6)). Consequently, we believe that the Poisson model provides insight and useful results in colorectal carcinoma.

Adjuvant treatment strategies for early colon cancer

Colon cancer remains a major cause of death; however, in the last 3 years a number of trials have been published that have led to changes in the treatment of patients with this disease. Initially, the adjuvant treatment of patients following curative resection was based on their Dukes staging; this is now being refined by consideration of other pathological factors, as well as the investigation of newer prognostic markers such as p53, Ki67 and a number of genes on chromosome 18. Tumours generally develop from the progressive accumulation of genetic events, although some develop through mutation or inactivation of DNA mismatch repair proteins leading to microsatellite instability; this is particularly important in Lynch's syndrome. The loss of gene expression can occur by deletion or mutation of genes or by aberrant methylation of CpG islands. In patients with Dukes C colon cancer the standard of care for adjuvant chemotherapy was previously based on bolus fluorouracil (5-fluorouracil) and folinic acid (leucovorin) administered 5 days per month or weekly for 6 months. Recent studies with a combination of infusional fluorouracil, folinic acid and oxaliplatin have been found to be superior. A further study replacing fluorouracil with oral capecitabine has also demonstrated equivalent disease-free survival. Although some debate remains regarding the benefit of adjuvant treatment for patients with Dukes B colon cancer, the emerging consensus is that, for those patients who are younger and have high-risk features, chemotherapy should be discussed. A number of large vaccine trials have also been conducted in the adjuvant setting and, overall, these have been disappointing. This is a rapidly advancing area of therapy and the results of new trials are awaited to determine whether additional benefits can be achieved with biological therapies such as anti-vascular endothelial growth factor and anti-epithelial growth factor receptor monoclonal antibodies, which have already been shown to be effective in setting of metastatic colon cancer.

Expression of Interleukin-11 and Interleukin-11 receptor α in human colorectal adenocarcinoma; Immunohistochemical analyses and correlation with clinicopathological factors

AIM: There is strong evidence that interleukin-11 (IL-11) is involved in the regulation of tumor progression, cellular growth and differentiation. Recently, interleukin-11 receptor (IL-11R) has been detected on some cancer cells. In this study, we investigated the expression of IL-11 and IL-11R in colorectal adenocarcinoma.

METHODS: To elucidate the involvement of IL-11 and IL-11Rα in human intestinal adenocarcinomas, we examined 115 cases of surgically resected human colonic adenocarcinoma and 11 cases of adenoma by immunohistochemistry and Western blotting.

RESULTS: Among 115 cases of adenocarcinoma, 100 cases (87.0%) showed positive staining in the cytoplasm of carcinoma cells for the IL-11, and 87 cases (75.6%) were positive for the IL-11Rα. Six cases (54.5%) and four cases (36.4%) of 11 adenomas were positive for IL-11 and IL-11Rα, respectively. The expression of IL-11Rα correlated with the histological differentiation (P = 0.033503), the depth of tumor invasion (P = 0.006395), Dukes’ classification (P = 0.015648) and lymphatic invasion (P = 0.003865). However, the expression of IL-11Rα was not correlated with the venous invasion and the presence of lymph node metastasis. The expression of IL-11 was not correlated with any clinicopathological factors. In Western blot analysis, two human colorectal carcinoma cell lines and four tissues of surgically resected human carcinoma expressed both IL-11 and IL-11Rα proteins.

CONCLUSION: IL-11 and IL-11Rα are highly expressed in human colorectal adenocarcinoma and the IL-11Rα expression is correlated with clinicopathological factors. These findings suggest that the expression of IL-11Rα is an important factor for the invasion of human colorectal adenocarcinoma.

Expression of vitamin D receptor and 25-hydroxyvitamin D3-1{alpha}-hydroxylase in normal and malignant human colon

Considerable evidence exists to support the use of vitamin D to prevent and/or treat colorectal cancer. However, the routine use of bioactive vitamin D, 1,25-dihydroxyvitamin D3, is limited by the side effect of toxic hypercalcemia. Recent studies, however, suggest that colonic epithelial cells express 25-hydroxyvitamin D3-1alpha-hydroxylase, an enzyme that converts nontoxic pro-vitamin D, 25-hydroxycholecalciferol [25(OH)D3], to its bioactive form. Yet, nothing is known as to the cellular expression of 1alpha-hydroxylase and the vitamin D receptor (VDR) in the earliest histopathologic structures associated with malignant transformation such as aberrant crypt foci (ACF) and polyps [addressing the possibility of using nontoxic 25(OH)D3 for chemoprevention], nor is anything known as to the expression of these proteins in colorectal cancer as a function of tumor cell differentiation or metastasis [relevant to using 25(OH)D3 for chemotherapy]. In this study, we show that 1alpha-hydroxylase is present at equal high levels in normal colonic epithelium as in ACFs, polyps, and colorectal cancer irrespective of tumor cell differentiation. In contrast, VDR levels were low in normal colonic epithelial cells; were increased in ACFs, polyps, and well-differentiated tumor cells; and then declined as a function of tumor cell de-differentiation. Both 1alpha-hydroxylase and VDR levels were negligible in tumor cells metastasizing to regional lymph nodes. Overall, these data support using 25(OH)D3 for colorectal cancer chemoprevention but suggest that pro-vitamin D is less likely to be useful for colorectal cancer chemotherapy.

Expression of p-STAT3 in human colorectal adenocarcinoma and adenoma; correlation with clinicopathological factors

BACKGROUND

The signal transducer and activator of transcription 3 (STAT3) is a key signalling molecule implicated in the regulation of growth and malignant transformation. Constitutive activation of STAT3 is seen in several tumour derived cell lines, and in a wide variety of human malignancies.

AIMS

To examine the relation between p-STAT3 (activated form of STAT3) expression and clinicopathological factors in human colorectal adenocarcinoma and adenoma.

METHODS

Immunohistochemical analyses were carried out on tissues from 44 colorectal adenomas and 95 colorectal adenocarcinomas, comprising 18 intramucosal carcinomas and 77 invasive carcinomas.

RESULTS

Seventy seven of these 139 samples (55.4%) showed immunoreactivity for p-STAT3. Positive staining for p-STAT3 was seen in 69 of the 95 carcinomas. Only eight of the 44 adenomas showed immunopositivity for p-STAT3, resulting in a significant difference between total adenocarcinomas and adenomas (p < 0.001). Among the 95 cases of colorectal adenocarcinoma, p-STAT3 immunoreactivity was significantly correlated with the depth of tumour invasion (p < 0.05), venous invasion (p < 0.05), lymph node metastasis (p < 0.05), and increasing stages of the Dukes' classification (p < 0.01). Expression of p-STAT3 was detected by Western blot analysis in two different cultured human colorectal carcinoma cell lines and six colon carcinoma tissue samples obtained at surgery.

CONCLUSION

This is the first study to report a significant correlation of p-STAT3 expression with the depth of tumour invasion. These findings suggest that p-STAT3 expression is an important factor related to carcinogenesis and/or tumour invasion of colorectal adenocarcinoma.

Expression and significance of Tie-1 and Tie-2 receptors, and angiopoietins-1, 2 and 4 in colorectal adenocarcinoma: Immunohistochemical analysis and correlation with clinicopathological factors

AIM: There is strong evidence that tyrosine kinases are involved in the regulation of tumor progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, among them Tie-1 and Tie-2 receptors constitute a major class. Angiopoietin (Ang)-1 is known as a ligand of Tie-2 tyrosine kinase receptor. The objective of this study was to establish a comprehensive Tie-1 and Tie-2 and Ang-1, 2 and 4 expression profile in human colorectal adenocarcinomas.

METHODS: We examined 96 cases of surgically resected human colorectal adenocarcinoma by immunohistochemistry and investigated the statistical correlation between the expressions of Ties and Angs and clinicopathological factors.

RESULTS: Among the 96 cases of adenocarcinoma, 87 (90.6%), 92 (95.8%), 83 (86.5%), 89 (92.7%), and 76 cases (79.2%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and Tie-2 and Ang-1, 2 and 4 proteins, respectively. Histologically, the expressions of Ties and Angs were variable. The expressions of Ties and Angs were correlated with several clinicopathological factors, but did not correlate with the presence of lymph node metastasis. Ties and Angs were highly expressed in human colorectal adenocarcinoma cells.

CONCLUSION: These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human colorectal adenocarcinoma.

Modeling recurrence in colorectal cancer

OBJECTIVE

To assess the role of recurrence in prognosis of colon cancer, we investigated several methodologic issues, including application of classic survival analysis and Markov model.

STUDY DESIGN AND SETTING

The data were recorded by the Registry of Digestive Tumors of Côte d'Or, France, for 874 patients who had been treated by surgery between 1976 and 1984 and followed for up to 11 years. Survival analyses included the Cox proportional hazards model and its two generalizations that allow recurrence to be taken into account as a time-dependent covariate or as a competing outcome. The Markov model was used to analyze simultaneously recurrence and death.

RESULTS

The competing risks approach is not appropriate because censoring is indisputably informative. The Markov model and the Cox model, with recurrence as a time-dependent covariate, provided similar results, demonstrating the impact of age and gender on recurrence and revealing a reduction in the effect of site and stage on mortality.

CONCLUSION

A Markov multistate model seems to give new insights about the course of digestive cancer progression and into the role of recurrence in this process.

Gene Expression Profiles and Molecular Markers To Predict Recurrence of Dukes' B Colon Cancer

Purpose

The 5-year survival rate of patients with Dukes' B colon cancer is approximately 75%. Identification of the patients at high risk of recurrence in this group would allow better staging and more informed use of adjuvant chemotherapy. In this study, we used DNA chip technology to systematically identify new prognostic markers for tumor relapse in Dukes' B patients.

Patients and Methods

Using Affymetrix U133a GeneChip containing approximately 22,000 transcripts (Affymetrix, Santa Clara, CA), RNA samples from 74 patients with Dukes' B colon cancer were analyzed. Thirty-one patients developed tumor relapse in less than 3 years, whereas 43 patients remained disease-free for more than 3 years after surgery. Two supervised class prediction approaches were used to identify gene markers that can best discriminate between patients who would experience relapse and patients who would remain disease-free. A multivariate Cox model was built to predict recurrence.

Results

Gene expression profiling identified a 23-gene signature that predicts recurrence in Dukes'B patients. This signature was validated in 36 independent patients. The overall performance accuracy was 78%. Thirteen of 18 relapse patients and 15 of 18 disease-free patients were predicted correctly, giving an odds ratio of 13 (95% CI, 2.6 to 65; P = .003). The log-rank test indicated a significant difference in disease-free time between the predicted relapse and disease-free patients (P = .0001).

Conclusion

The clinical value of these markers is that the patients at a high predicted risk of relapse (13-fold risk) could be upstaged to receive adjuvant therapy, similar to Dukes' C patients. Our data highlight the feasibility of a prognostic assay that could focus more intensive treatment for localized colon cancer.

Expression of GRP and its receptor in well-differentiated colon cancer cells correlates with the presence of focal adhesion kinase phosphorylated at tyrosines 397 and 407

Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are not normally expressed by epithelial cells lining the colon but are aberrantly expressed in cancer, where they act as morphogens and regulate tumor cell differentiation. Studies of colon cancer formation in mice genetically incapable of synthesizing GRP-R suggested that this receptor's morphogenic properties were mediated via focal adhesion kinase (FAK). We therefore set out to determine the presence of both total and phosphorylated forms of FAK in human colon cancer specimens as a function of tumor cell differentiation and GRP/GRP-R co-expression. Ten colon cancers containing 25 regions of distinct differentiation were randomly selected from our GI Cancer Tumor Bank. All specimens were immunohistochemically probed using antibodies recognizing GRP, GRP-R, total FAK, and FAK specifically phosphorylated at tyrosine (Y) 397, 407, 576, 577, 861, and 925. Antibody-specific chromogen was determined by quantitative immunohistochemistry (IHC) for each region of defined differentiation. Here we confirm that GRP/GRP-R co-expression is a function of differentiation, with highest levels observed in well-differentiated tumor cells. We also show that the amount of total FAK and of FAK phosphorylated at Y397 and Y407 tightly correlates with differentiation and with the amount of GRP/GRP-R co-expression. These findings are consistent with GRP/GRP-R acting as a morphogen by activating FAK, and suggest that this occurs via phosphorylation of this enzyme at two specific tyrosine residues.

Increased frequency of gastrin-releasing peptide receptor gene mutations during colon-adenocarcinoma progression

Epithelial cells lining the mature human colon do not normally express receptors for gastrin-releasing peptide (GRPR). In contrast, we have shown that when aberrantly expressed in functional form in colon cancer, this protein acted as a morphogen where it caused tumor cells to adopt a better-differentiated phenotype. Importantly, GRPR mRNA is ubiquitously mutated in human colon cancer cell lines, with inactivating mutations detected in all cell lines not expressing functional receptor. Since colon cancers are heterogeneously differentiated, we set out to determine if the GRPR gene was mutated as a function of tumor cell differentiation in archived human colon cancers. We used laser capture microscopy to dissect out 67 regions of defined differentiation from 20 human colon cancers randomly selected from the UIC GI Tumor Bank. Except for two polymorphisms, the GRPR gene was not mutated in nonmalignant epithelial cells. In contrast, 42 distinct mutations were identified in malignant cells. Overall mutation number inversely correlated with the degree of tumor cell differentiation. Within any cancer, all GRPR mutations found within better-differentiated cells were conserved in more poorly-differentiated cells; while all poorly-differentiated cells contained mutations resulting in GRPR pharmacological inactivation. These data suggest that accumulation of mutations within the GRPR gene ultimately resulting in the production of nonfunctional receptors may represent a previously unappreciated mechanism allowing for the dedifferentiation of tumor cells within any particular colon cancer; and that poorly-differentiated tumor cells within any individual cancer may arise clonally from their better-differentiated precursors.

Colon cancer during pregnancy

The medical community should become mobilized to diagnose colon cancer earlier in pregnancy to improve prognosis. The primary care physician or obstetrician should refer the pregnant patient with significant gastrointestinal complaints to the gastroenterologist for evaluation. Likewise, the gastroenterologist should be prepared to perform sigmoidoscopy, preferably without endoscopic medications, for significant lower gastrointestinal symptoms such as persistent rectal bleeding. Sigmoidoscopy is particularly sensitive in identifying colon cancer in pregnant patients because their cancers are usually distal and within reach of the sigmoidoscope.

Adjuvant chemotherapy in colon cancer: what is the evidence?

Over the last 12 years, numerous randomized trials have addressed the role of adjuvant chemotherapy in resected colon cancer. Together, these studies give conclusive evidence of the benefit of adjuvant 5-fluorouracil combined with folinic acid in stage III (node positive) disease and this is now considered the standard of care. The chemotherapy appears to be equally effective whether it is given daily for 5 days per month or on a weekly schedule. The overall effect is a relative reduction in tumour -recurrence of 25% or an absolute improvement in survival of 10%. However, doubt remains as to the role of adjuvant chemotherapy in stage II colon cancer. To date, most of the randomized trials have demonstrated a relative reduction in tumour recurrence but have not shown any significant impact on survival. It seems likely that this inability to demonstrate a survival benefit from adjuvant chemotherapy in stage II disease relates to the fact that the trials have been underpowered to do so. Nevertheless, the absolute survival advantage is only about 2% and clinicians need to weigh this against the costs and toxicities of the treatment when managing these patients.

Quantitative immunohistochemistry by measuring cumulative signal strength accurately measures receptor number

We previously demonstrated that quantitative immunohistochemistry (Q-IHC) performed by measuring the cumulative signal strength of the digital file encoding an image can be used to determine the absolute amount of chromogen present per pixel. We now show that Q-IHC so performed can be used to accurately determine the amount of peptide hormone receptor of interest in archived tissues. To do this we transfected Balb 3T3 fibroblasts with the cDNA encoding the human receptor for gastrin-releasing peptide (GRP), and selected six cell lines stably expressing between 10(2) and 10(6) receptors/cell. These cell lines were fixed in formalin, embedded in paraffin, and treated with antipeptide antibodies against the GRP receptor, followed by DAB chromogen to identify bound antibody. Images were acquired using a 4.9 million pixel digital scanning 24-bit RGB camera, saved in TIFF format, and used for subsequent analysis. Q-IHC was performed after digitally dissecting out the relevant portion of the image for analysis, and processing using a program written in C (available at http://www.uic.edu/com/dom/gastro/Freedownloads.html). Under the conditions defined here, chromogen quantity as determined by Q-IHC tightly correlated with GRP receptor number (r(2)=0.867) in these cell lines. Using the conversion factor identified as a result of these studies, we then determined GRP receptor number on eight randomly selected, archived human colon cancers. Overall GRP receptor expression in colon cancer depended on the degree to which cells within any particular tumor were differentiated, with well-differentiated cells expressing the greatest numbers of receptors (approximately 55,000 +/- 10,000 sites/cell). These studies indicate that Q-IHC can be used to determine receptor quantity in archived tissues and other samples of limited quantity.

Expression of e-cadherin and catenins in early gastric cancer

E-cadherin and its associated cytoplasmic proteins including alpha-, beta-, and gamma-catenin play a pivotal role in the maintenance of normal tissue architecture and the suppression of cancer invasion. The purpose of this study was to evaluate the expression of E-cadherin and alpha-, beta-, and gamma-catenin in a larger sample of early gastric cancer, and to examine the relation between these expressions and various clinicopathologic variables. The expression of E-cadherin and alpha-, beta-, and gamma-catenin was investigated using immunohistochemical technique with formalin-fixed, paraffin-embedded tissue specimens obtained from 108 patients who underwent surgery for early gastric cancer. In the gastric mucosa of noncancerous areas, epithelial cells showed equally strong membranous expression of E-cadherin and alpha-, beta-, and gamma-catenin proteins at the cell-cell boundaries. Reduced expression of E-cadherin and alpha-, beta-, and gamma-catenin was demonstrated in 43.5%, 39.8%, 42.6%, and 50% of cancer tissues, respectively. Whereas 34 tumors (31.5%) displayed preserved expression of all four E-cadherin-catenin complex components, 21 tumors (19.4%) displayed reduced expression of all components of this complex. Reduced expression of E-cadherin and alpha- and gamma-catenin occurred more frequently in diffuse than in intestinal types of cancer, and decreased expression of E-cadherin and alpha-, beta-, and gamma-catenin correlated with poor differentiation. The expression of E-cadherin and beta- and gamma-catenin did not correlate with the patient's age, gender, tumor size, location, macroscopic type, depth of invasion, or lymph node metastasis. Only reduced expression of alpha-catenin correlated with lymph node metastasis. Reduced expression of all four E-cadherin-catenin complex components correlated with poorly differentiated and diffuse-type cancers, but not with the patient's age, gender, tumor size, location, macroscopic type, depth of invasion, or lymph node metastasis. These results suggest that dysfunction of the E-cadherin-catenin complex occurs in an early stage of carcinogenesis, playing a crucial role in disruption of tissue architecture and loss of differentiation in early gastric cancer.

[Clinical and macroscopic variables that influence the prognosis of colorectal carcinoma]

BACKGROUND AND AIMS

The paradoxical evolution of approximately one third of patients with neoplasms cataloged in Dukes stages B and C demonstrates the desirability of utilizing other prognostic criteria that are capable of broadening the information provided by these two important variables. Only a small number of investigators have dedicated themselves to the study of the prognostic value of clinical and macroscopic parameters of colorectal neoplasms, and the results obtained have been shown to be controversial. The principal aim of this work was to evaluate the prognostic importance of these parameters.

PATIENTS AND METHODS

A study was made of 320 patients with colorectal cancer who underwent curative extirpation. They had a median age of 58 years, and there were 199 females (62.2%) and 121 males (37.8%). The patients were divided into three age groups: under 40 years old, between 40 and 60 years old and over 60 years old. The tumors were distributed in three intestinal segments: right colon, left colon and rectum. The neoplasms were classified as small (diameter less than or equal to 35 mm) and large (diameter greater than 35 mm). With regard to their form, they were classified as exophytic, when characterized by luminal growth, and endophytic, when there was intramural growth. The involvement of the intestinal circumference at the site of the neoplasm was considered as partial or total.

RESULTS

Of the 320 patients, 22 (6.9%) were aged under 40 years, 159 (49.7%) from 40 to 60 years and 139 (43.4%) presented an age of over 60 years. Seventy-three (22.8%) of the neoplasms were located in the right colon, 130 (40.6%) in the left colon and 117 (36.6%) in the rectum. Regarding the size, 280 (87.5%) were large and 40 (12.5%) small; exophytic lesions predominated over endophytic ones - 173 (54.1%) vs 147 (45.9%). A greater number of tumors presented total involvement of the intestinal circumference - 216 (67.5%) - while 104 (32.5%) presented partial involvement. The 5-year survival of the patients was not influenced by their age and sex, or by the location and size of the neoplasms. Exophytic lesions conferred greater survival on their sufferers (65.9%), in comparison with endophytic lesions (49.0%). The survival of patients with lesions partially involving the intestinal circumference was greater than for those with total involvement - 72.1% vs. 51.4%.

CONCLUSIONS

Clinical variables had no influence on the patients' prognosis. Among the macroscopic variables, the form of the neoplasia and its involvement in the intestinal circumference did influence the patients' prognosis. These last two variables are important data capable of contributing to the identification of patient subpopulations with greater or lesser prognostic risk.

Population-based study of factors influencing occurrence and prognosis of local recurrence after surgery for rectal cancer

BACKGROUND

Few data are available from population-based statistics on the risk of local recurrence after surgery for rectal cancer. The aims of this study were to determine factors influencing local control and to analyse treatment and prognosis of recurrences in a well defined population.

METHODS

Data were obtained from the cancer registry of the Côte d'Or (France). From 1976 to 1995, 682 patients resected for cure for a rectal carcinoma were included. Recurrence rates and survival rates were calculated using actuarial methods. A relative survival analysis and Cox multivariate analysis were performed.

RESULTS

During the study 135 local recurrences were registered. The 5-year cumulative local recurrence rate was 22.7 per cent. In multivariate analysis the two variables significantly associated with local recurrence risk were stage at diagnosis and the macroscopic type of growth. There was a non-significant decrease in local recurrence rate in patients treated by preoperative radiotherapy compared with that in patients treated by surgery alone. The proportion of patients re-resected for cure was 25.2 per cent, and increased from 13.0 per cent in 1976-1985 to 37.9 per cent in 1986-1995 (P = 0.001). The 5-year relative survival rate was 13.6 per cent overall and 40.6 per cent after resection for cure (P < 0.001).

CONCLUSION

Local recurrence of rectal cancer following resection remains a substantial problem. Improvement can be expected from better care and earlier diagnosis.

Expression of the ets-1 proto-oncogene in human colorectal carcinoma

The proto-oncogene, ets-1, is a transcription factor known to control the expression of a number of genes involved in extracellular matrix remodeling and has been postulated to play a role in cell migration and tumor invasion. To elucidate the involvement of ets-1 in human colorectal carcinomas, we examined 41 cases of colorectal adenoma and 122 cases of colorectal carcinoma by immunohistochemistry and compared the degree of Ets-1 expression with the depth of carcinoma invasion. In adenomas, 12 of 41 cases (29.3%) showed immuno-positivity for Ets-1. 12 of 27 cases (44.4%) of adenoma with high grade dysplasia showed immunopositivity for Ets-1. However, there was no positive case in low or moderate dysplasia of adenoma. In contrast, 103 of 122 cases (84.4%) of colorectal adenocarcinoma showed immunoreactivity for Ets-1 in the carcinoma cells themselves. We investigated the relationship between pathological features in colorectal carcinoma and Ets-1 immunoreactivity of the tumor cells. Among the 122 cases of invasive carcinomas, Ets-1 immunoreactivity was significantly correlated with the depth grading of tumor invasion (P < .0001), the presence of lymph node metastasis (P < .05), lymphatic invasion (P < .01) and venous invasion (P < .05). However, Ets-1 expression did not correlate with histological differentiation. In situ hybridization also confirmed the presence of ets-1 mRNA in colorectal carcinomas. Expression of ets-1 mRNA was also detected in two of three human colorectal carcinoma tissues and in four of six different kinds of carcinoma cell lines by the reverse transcription polymerase chain reaction method. These findings suggest that the expression of Ets-1 is one of the important factors related to carcinogenesis and/or tumor invasion of colorectal carcinoma.

A prospective study on radical and nerve-preserving surgery for rectal cancer in the Netherlands

INTRODUCTION

Preservation of the pelvic autonomic nerves is thought to lower bladder and sexual dysfunction after rectal cancer surgery. A prospective study was undertaken in a Dutch population to evaluate functional outcome, local recurrence and survival of a Japanese operative technique combining nerve preservation with radical tumour resection.

METHODS

Forty-seven patients were operated upon by a Japanese surgeon. Voiding and sexual function were prospectively analysed using questionnaires. Two-year follow-up on urinary function was complete in 73%, and 2-year follow-up of male sexual function was complete in 77%. Median follow-up for survival and recurrence was 42 months and was complete in all patients.

RESULTS

Five patients (19%) developed minor urinary incontinence in the period between 1 and 2 years of follow-up. Six patients (22%) had a persistently elevated frequency of voiding. There was no statistically significant correlation between the extent of nerve preservation and the reported minor voiding dysfunctions. None of the patients reported major incontinence of urine. Impotence was related to sacrifice of the inferior hypogastric plexus and ejaculatory dysfunction was related to sacrifice of the superior hypogastric plexus. Sexual function did not change during follow-up. Of 42 curatively-operated patients, three (7.1%) developed local recurrence. Sixty-seven per cent were overall free of recurrence. Disease-free survival was 57%.

CONCLUSIONS

Preservation of the pelvic autonomic nerves minimizes bladder dysfunction after rectal cancer surgery. The preservation of the total autonomic nerve system is essential for normal sexual function in male patients. Nerve preservation does not compromise radicality in mesorectal excision. Mesorectal excision should involve identification and preservation of the pelvic autonomic nerves.

Aberrant expression of gastrin-releasing peptide and its receptor by well-differentiated colon cancers in humans

Epithelial cells lining the adult human colon do not normally express gastrin-releasing peptide (GRP) or its receptor (GRPR). In contrast, approximately one-third of human colon cancers and cancer cell lines have been shown to express GRP-binding sites. Because GRPR activation causes the proliferation of many cancer cell lines, GRP has been presumed to act as a clinically significant growth factor. Yet GRP has not been shown to be expressed by colon cancers in humans nor has the effect of GRP and/or GRPR coexpression on tumor behavior been investigated. We therefore determined GRP and GRPR expression by immunohistochemistry in 50 randomly selected colon cancers resected between 1980 and 1997, all 37 associated lymph node and liver metastases, and 20 polyps. Tumor sections studied were those that contained the margin and adjacent nonmalignant epithelium. Overall, 84% of cancers aberrantly expressed GRP or GRPR, with 62% expressing both ligand and receptor, whereas expression was not observed in adjacent normal epithelium. Consistent with the previously established mitogenic capabilities of GRP, tissues coexpressing GRP and GRPR were more likely to express proliferating cell nuclear antigen than tissues not expressing both ligand and receptor. Yet GRP/GRPR coexpression was seen with equal frequency in stage A as in stage D cancers and was only detected in 1 in 37 metastases. Furthermore, Kaplan-Meier analysis did not reveal any difference in patient survival between those whose tumors did or did not express GRP/GRPR. In contrast, GRP/GRPR coexpression was found in all well-differentiated tumor regions, whereas poorly differentiated tissues never coexpressed GRP/GRPR. Overall, these data indicate that, although GRP is a mitogen, it is not a clinically significant growth factor in human colon cancers. Rather, the strong association of GRP/GRPR coexpression with tumor differentiation raises the possibility that these proteins primarily act in vivo as morphogens.

Accurate lymph-node detection in colorectal specimens resected for cancer is of prognostic significance

PURPOSE

Lymph-node involvement is the most important prognostic factor in colorectal cancers. Many staging systems adopted node status as a parameter of tumor classification. However, the number of identified and positive glands varies across articles, depending on specimen examination. There is a consistent risk of substaging tumors and undertreating patients. Aim of this study was to investigate the prognostic significance of different pathologic methods.

METHODS

Eight hundred one patients who underwent curative resection of colorectal cancer entered the study and were divided into two groups. In Group 1 the specimen was "en bloc" fixed, and nodes were identified by sight and palpation. In Group 2 the mesentery of the excised specimen was dissected away from the bowel, stretched, and pinned to cork board. The mesenteric segment surrounding the origin of principal vessels was divided from the segment surrounding the colic vessels. All specimen segments were fixed, node identification being performed by sight and palpation. Examined and positive nodes were recorded, and metastatic rate and incidence was calculated in the two groups. Patients were classified with use of different staging systems. Survival rates were calculated, related to tumor stage, and compared statistically. Pathologic procedures were included in a multivariate analysis.

RESULTS

A significantly higher number of detected and positive nodes and metastatic rate (37.5 vs. 30.2 percent; P < 0.05) were observed in Group 2; 45.2 percent of Group 2 and 25.3 percent of Group 1 cases had more than three positive nodes (P < 0.05). In Group 2 several patients shifted from earlier to more advanced stages compared with Group 1 cases. Five-year and ten-year survival rates were significantly higher (P = 0.04) in Group 2 (81.5 and 77.2 percent) than in Group 1 (76.7 and 61.5 percent), mostly in patients with TNM Stage N0. Survival analysis related to Astler and Coller's and Tang's classifications confirmed such features. Higher rates of local recurrences and distant metastases were found in Group 1, particularly if related to node status (P < 0.05). Multivariate analysis demonstrated the pathologic method is an independent prognostic factor.

CONCLUSIONS

This study demonstrates the prognostic impact of specimen examination. Inaccurate methods could down-stage the tumor and exclude the patient from adjuvant therapies, with detrimental effects on the outcome of the case.

Local recurrence in patients with rectal cancer diagnosed between 1988 and 1992: a population-based study in the west Netherlands

AIMS

We carried out a population-based study of local recurrence rates in curatively resected patients with rectal cancer, diagnosed between 1988 and 1992. The first objective was to make an inventory of the overall local recurrence rate after non-standardized conventional surgery, inter-institutional recurrence rate variability, and correlations between patient- and tumour-related factors and recurrence rate. A second objective was to investigate the compliance to guidelines for post-operative radiotherapy.

METHODS

Data were obtained from the Comprehensive Cancer Centre West. The study comprised 1105 patients from 12 hospitals. Of these patients, 437 were ineligible because of missing medical records, no carcinoma, incorrect registration, no laparotomy, non-curative resection, or loss to follow-up.

RESULTS

The overall local recurrence rate was 22.5% with a range of 9-36% between the hospitals. These differences were not significant. Dukes' Astler-Coller stage, tumour location, and residual tumour were significant independent prognostic factors for the risk of local recurrence. Indications for post-operative radiotherapy were Dukes' Astler-Coller B2 and C tumours, positive surgical margins, and tumour spill. Compliance to the guidelines for radiotherapy was only 50%. However, no significant difference in recurrence rate was found between patients treated according to the guidelines and those not treated according to the guidelines.

CONCLUSION

This study shows a large variability in local recurrence rate between the participating hospitals and confirms that the risk of recurrence in primary rectal cancer is dependent on Dukes' Astler-Coller stage, tumour location and residual tumour. Furthermore, this study contributes to the discussion about the feasibility of guidelines for post-operative radiotherapy.

Multidisciplinary management of recurrent colorectal cancer

Isolated pelvic recurrence of rectal carcinoma may occur in up to one third of patients following definitive resection of primary disease. The means by which recurrence is diagnosed, methods by which it may be treated, and reported outcomes are all evolving and improving. Current data indicate that a substantial proportion of patients treated by aggressive multi-modality salvage therapy may be provided with durable survival. This review highlights current concepts in the diagnosis and management of locally recurrent rectal carcinoma.

Colon cancer during pregnancy. The gastroenterologist's perspective

Colon cancer during pregnancy is uncommon but not rare, with an estimated incidence of several hundred cases per year in the United States. This type of cancer tends to have a poor prognosis that is attributable to delays in diagnosis and advanced disease at diagnosis. The diagnosis frequently is delayed because symptoms of colon cancer, such as rectal bleeding, nausea and vomiting, and constipation, often are attributed to normal pregnancy or minor complications of pregnancy. Pregnancy affects the diagnostic evaluation and therapy of colon cancer because of fetal risks of diagnostic tests and therapy. Appropriate medical evaluation of significant lower gastrointestinal complaints during pregnancy can lead to an earlier and improved diagnosis.

Expression of metastasis-related genes in surgical specimens of human gastric cancer can predict disease recurrence

It was determined whether the expression level of several genes that regulate different steps of metastasis in formalin-fixed paraffin-embedded archival specimens of human gastric cancers correlated with disease recurrence and metastasis. The steady-state mRNA expression level for epidermal growth factor receptor (EGF-R), basic fibroblast growth factor (bFGF), E-cadherin, type IV collagenase and multidrug resistance (MDR-1) were examined by a colorimetric in situ hybridisation (ISH) technique, concentrating on reactivity at the periphery of the lesions. All patients were operated on for cure. 15 cases were disease-free and 10 had disease recurrence by 4.5 years after resection of the primary tumours. The expression of EGF-R and bFGF type IV collagenase was higher and expression of E-cadherin was lower in the disease-recurrence cases than in the disease-free cases. The ratio between the expression level of collagenase type IV and E-cadherin at the periphery of the surgical specimens differed significantly between the disease-free cases and the recurrent-metastatic cases. These data show that multiparametric ISH analysis for several metastasis-related genes may allow prediction of disease recurrence of gastric cancer.

Estudo de fatores morfológicos prognósticos do câncer colo-retal extirpado

O valor prognóstico das variáveis morfológicas constituintes da Classificação de DUKES - nível de invasão parietal e comprometimento dos linfonodos - e o padrão de crescimento da margem invasiva da neoplasia foi estudado em 320 doentes com câncer colo-retal. O padrão de crescimento expansivo associou-se significantemente à presença de linfonodos livres (90,2%), ao estádio A de DUKES (70,4%) e a menor número de casos metastáticos (12,5%). O padrão infiltrativo associou-se a casos de neoplasias não confinadas à parede intestinal (85,7%) e a presença de metástases (87,5%). A sobrevivência de cinco anos foi de 83,5% para doentes com o padrão expansivo, significantemente maior que a de 49,8% para os com o padrão infiltrativo Na mesma classe de DUKES, a sobrevida mostrou-se sempre maior quando associada ao padrão expansivo de crescimento, caracterizando grupos de risco no mesmo estádio da doença.

Preoperative and postoperative imaging for colorectal cancer

Management and survival in colorectal cancer are dictated by the extent of the disease at the initial diagnosis. Technological advances over the past 25 years have improved the ability to accurately preoperatively stage these lesions and detect recurrence. This article reviews the focus on the utility of computerized tomography, magnetic resonance, endoscopic ultrasound, and newer imaging methods including PET scan and monoclonal antibodies in the management of colorectal carcinoma.

The integrin alpha 6 beta 4 and the biology of carcinoma

The integrin family of adhesion receptors plays a major role in epithelial organization and function. Moreover, the altered expression and function of specific integrins most likely contributes significantly to carcinoma progression. The integrin alpha 6 beta 4, the focus of this review, is a receptor for several members of the laminin family and is preferentially expressed at the basal surface of most epithelia, where it contributes to basement membrane interactions. Mounting evidence suggests that the alpha 6 beta 4 integrin plays a key role in carcinoma cell biology. Several histopathological studies have established a correlation between alpha 6 beta 4 integrin expression and tumor progression. The importance of alpha 6 beta 4 expression in tumors in underscored by the findings that invading fronts of several carcinomas are enriched in the expression of alpha 6 beta 4 integrin ligands, such as laminin-1 and laminin-5. The participation of the alpha 6 beta 4 integrin in invasion is supported further by in vitro functional studies using carcinoma cells that have been transfected with the beta 4 cDNA. The mechanisms by which alpha 6 beta 4 contributes to tumor progression are probably related to its mechanical and signaling properties and are currently under intense study.

Role of the E-cadherin/alpha-catenin complex in modulating cell-cell and cell-matrix adhesive properties of invasive colon carcinoma cells

BACKGROUND

The clinical behavior of colorectal cancer depends on its ability to invade and metastasize. Metastatic cells must dissociate from other cells and invade through basement membrane and stroma. Cell-cell adhesion in epithelial cells is mediated by the cell surface protein E-cadherin in association with alpha- and beta-catenin, which link E-cadherin to the cytoskeleton. Decreased cell-cell adhesion and increased motility on laminin have been correlated with more poorly differentiated and aggressive carcinomas.

METHODS

In this study, the RKO cell line, previously shown by us to lack E-cadherin expression, was transfected with the complementary DNA for E-cadherin. The transfectants were selected for high levels of surface expression by sequential FACS and examined in functional assays.

RESULTS

In comparison to control transfectants, the E-cadherin transfectants exhibited a more epithelial-like morphology, a 30% increase in Ca(2+)-dependent cell-cell aggregation, and a markedly reduced motility on the matrix proteins, collagen I and laminin.

CONCLUSIONS

These data demonstrate that correction of a defect in the cadherin/catenin cell-cell adhesion complex, often found in poorly differentiated and highly invasive tumors, facilitates increased cell-cell adhesion and retards tumor cell migration on basement membrane and stromal proteins.

From Dukes through Jass: pathological prognostic indicators in rectal cancer

In the recently described Jass staging system for resected adenocarcinoma of the rectum, peritumoral lymphocytic infiltration and tumor growth pattern are introduced as significant indicators of prognosis in conjunction with depth of tumor invasion and lymph node metastasis. The authors of this study have tested the applicability of the Jass system by reviewing 348 resected rectal cancers for 12 pathological variables, including two newly recognized features, namely the Crohn's-like lymphoid reaction and metastatic tumor nodules in pericolic fat. By univariate analysis improved 5-year survival rate was associated with tubular-type adenocarcinoma, low tumor grade, retention of tubule configuration and nuclear polarity, expanding tumor growth pattern, prominent peritumoral lymphocytic infiltration, absence of extramural vein invasion by tumor, all levels of intramural and extramural invasion short of widespread local tumor dissemination, a Crohn's-like lymphoid reaction pattern, and absence of both nodal metastasis and tumor nodules in perirectal fat. By Cox stepwise proportional hazards analysis, depth of tumor invasion, lymph node metastasis, Crohn's-like lymphoid reaction, and extramural venous invasion retained independent prognostic significance. Peritumoral lymphocytic infiltration and tumor growth pattern of the Jass staging system failed to compete successfully with other variables in the proportional hazards model, in part because of their correlation with the model's selected variables. Both intramural and extramural extent of tumor invasion coupled with lymph node metastasis form the cornerstones of rectal cancer staging. However, other factors do refine prognostication. From this study the Crohn's-like lymphoid reaction emerges as a significant new independent indicator of prognosis for survival from rectal cancer. Although the Crohn's-like lymphoid reaction and extramural vein invasion took precedence as staging variables in this study, a complex interrelationship with other parameters was observed.