Dukes' classification revisited. Findings from the National Surgical Adjuvant Breast and Bowel Projects (Protocol R-01)

Poorly differentiated cluster grade-a vital predictor for lymph node metastasis and oncological outcomes in patients with T1 colorectal cancer: a retrospective study

Background

T1 colorectal cancers have a low lymph node metastasis rate and good prognosis. Thus, endoscopic resection is an attractive choice. This study aimed to describe the value of poorly differentiated cluster grade in identifying endoscopically curable T1 colorectal cancers.

Methods

We included 183 T1 colorectal cancer patients who underwent curative resection. Univariate and multivariate logistic regressions were used to identify lymph node metastasis predictors. The Akaike information criterion was used to determine whether poorly differentiated cluster grade was the best predictor. Backward regression was used to screen the variables. Survival analyses were conducted to determine the prognostic predictive power of poorly differentiated cluster grade. Correlations among predictors and concordance between our pathologists were also investigated.

Results

Poorly differentiated cluster grade was an independent predictor for lymph node metastasis (adjusted odds ratio [OR]_{G 3} = 0.001; 95% confidence interval [95% CI]_{G 3} =  < 0.001, 0.139) in T1 colorectal cancer patients; moreover, it had the best predictive value (AIC = 61.626) among all indicators. It was also screened for inclusion in the predictive model. Accordingly, a high poorly differentiated cluster grade independently indicated shorter overall survival (hazard ratio [HR]_{G 2} = 4.315; 95% CI_{G 2} = 1.506, 12.568; HR_{G 3} = 5.049; 95% CI_{G 3} = 1.326, 19.222) and disease-free survival (HR_{G 3} = 6.621; 95% CI_{G 3} = 1.472, 29.786).

Conclusions

Poorly differentiated cluster grade is a vital reference to manage T1 colorectal cancer. It could serve as an indicator to screen endoscopically curable T1 colorectal cancers.

Nutritional status and its effect on complications in patients with colorectal cancer

BACKGROUND

Nutritional status is an important factor for predicting the risk of developing complications after a surgical procedure. Many nutritional assessments are used in clinical practice, but their role in predicting postoperative outcomes is unknown. Therefore, the aim of this study was to assess the utility of nutritional risk factors at the diagnosis of colorectal cancer (CRC) for predicting early postsurgical complications.

METHODS

This was a prospective observational study including 127 patients with CRC at diagnosis. Their preoperative nutritional status was analyzed by body mass index (BMI), triceps and subscapular skinfolds and two nutritional scales: the Patient-Generated Subjective Global Assessment (PG-SGA) and the Malnutrition Universal Screening Tool (MUST). The outcome variables, including postoperative complications, length of hospital stay and mortality, were analyzed.

RESULTS

Patients identified as malnourished by PG-SGA score had prolonged hospital stays (p = 0.01). The risk of infection was increased in older patients (hazard ratio, HR 1.12; 95% confidence interval, CI 1.04-1.21) but was not associated with nutritional status. Early wound dehiscence was increased in patients with higher BMI (HR 1.15; 95% CI 1.01-1.29), with higher subscapular skinfold thickness and increased age (HR 1.05; 95% CI 1.05-1.10). Postoperative mortality was not significantly associated with nutritional status.

CONCLUSION

Malnourished patients, as identified by the PG-SGA score, stayed longer in hospital than patients who were not malnourished, while increased BMI was recognized as a risk factor for wound dehiscence.

Budding, tumor-infiltrating lymphocytes, gland formation: scoring leads to new prognostic groups in World Health Organization low-grade colorectal cancer with impact on survival

Grading for colorectal carcinoma (CRC) is traditionally based on the percentage of gland formation. In recent years, high-grade CRC has become subject to more precise molecular grading strategies. Most, however, are low-grade cases according to the World Health Organization (WHO) with inhomogenous outcomes due to still insufficient characterization. On the other hand, budding and tumor-infiltrating lymphocytes have developed as interesting additive prognostic factors in CRC. Especially budding has been very well defined by the International Tumor Budding Consensus Conference recently. We analyzed a large collective of 576 WHO low-grade CRC cases, stages I to IV, diagnosed between 2005 and 2016 in terms of gland formation, budding, and tumor-infiltrating lymphocytes and developed a new, morphology-based risk score, taking into account each of the 3 parameters. For each parameter, 1 to 2 points were given, resulting in a sum score, dividing the CRC cases into a low-, an intermediate-, and a high-risk group. By our score, 179 (34.9%) of the cases were grouped as low risk, 241 (53.5) as intermediate risk, and 92 (35.5%) as high risk. The 3 groups differed significantly in pT, pN, and M as well as tumor stages, lymphatic vessel invasion, venous invasion, and overall survival (0.;P < .001 for low risk versus high risk, P = .038 for low versus intermediate risk, and P = .036 for intermediate versus high risk; log rank: median, 94.0 months [95% confidence interval {CI}, 74.9-113.1] for low risk; median, 63.0 months [95% CI, 44.0-82.0] for intermediate risk; and median, 40.0 months [95% CI, 23.4-56.7] for high risk) in Kaplan-Meier-analysis. Our proposed Bayreuth score enables separating the large group of WHO low-grade CRC cases into subgroups, which differ significantly in outcome.

Association between poorly differentiated clusters and efficacy of 5-fluorouracil-based adjuvant chemotherapy in stage III colorectal cancer

Objective

Although poorly differentiated cluster has been reported to be a useful grading system for predicting prognosis in colorectal cancer, its relationship to chemotherapy efficacy has not been demonstrated. We aimed to investigate the association between poorly differentiated cluster and the efficacy of 5-fluorouracil-based adjuvant chemotherapy in stage III colorectal cancer.

Methods

This retrospective study enrolled 131 patients with stage III colorectal cancer who underwent curative resection: 72 received 5-fluorouracil-based adjuvant chemotherapy (chemotherapy group) and 59 did not (surgery-alone group). Poorly differentiated cluster was defined as a cancer cluster of ≥5 cancer cells without gland-like structure, and was classified into poorly differentiated cluster G1, G2 and G3 according to the number of clusters. The benefit of 5-fluorouracil-based adjuvant chemotherapy was evaluated based on poorly differentiated cluster grade.

Results

Thirty-nine, 40 and 52 patients were classified as poorly differentiated cluster G1, G2 and G3, respectively. Significant differences in the 5-year cumulative recurrence rate and relapse-free survival were observed between poorly differentiated cluster G1/G2 and G3 (26.7% vs. 47.5%, P = 0.010; 66.0% vs. 43.9%, P = 0.004). A comparison of cumulative recurrence rate and relapse-free survival between the chemotherapy and surgery-alone groups showed a significant benefit of adjuvant chemotherapy in poorly differentiated cluster G1/G2 patients (cumulative recurrence rate: 17.4% vs. 37.3%, P = 0.035; relapse-free survival: 79.5% vs. 51.9%, P = 0.002), but not in poorly differentiated cluster G3 patients (cumulative recurrence rate: 48.6% vs. 44.8%, P = 0.885; relapse-free survival: 51.4% vs. 32.7%, P = 0.068).

Conclusions

In stage III colorectal cancer, poorly differentiated cluster G1/G2 predicts a significant benefit from 5-fluorouracil-based adjuvant chemotherapy, whereas poorly differentiated cluster G3 predicts a poor response to it.

High-risk features in potentially resectable colon cancer: a prospective MDCT-pathology agreement study

PURPOSE

Neoadjuvant chemotherapy in potentially resectable high-risk Stage II and Stage III colon cancer has demonstrated promising results in the PRODIGE 22-ECKINOXE Phase II trial. Identification of adverse morphologic features, namely T3 with >5 mm extramural extension/T4 stages and/or N2, is fundamental and requires accurate noninvasive imaging. Our aim was to assess the value of optimized preoperative MDCT to stratify potentially resectable colon cancer patients for neoadjuvant therapy.

METHODS

this is an observational prospective cross-sectional radiologic-pathologic agreement study. All patients with colon cancer referred to our Institution's Radiology department for preoperative MDCT staging between 01-10-2013 and 11-02-2015 underwent independent reading based on axial and multiplanar reconstruction images by 3 radiologists with 3, 6, and 20 years of experience in gastrointestinal radiology. T stage, extramural extension if T3 (≤5 mm or >5 mm), and N stage were recorded. Surgical specimens subsequently obtained underwent micro-pathologic analysis by a gastrointestinal pathologist with 9 years of experience in gastrointestinal pathology. Main outcome measures were sensitivity, specificity, PPV, NPV, AUROC, diagnostic accuracy, and interobserver agreement of optimized MDCT, and pathologic analysis of the surgical specimen considered the reference standard.

RESULTS

74 patients [43 males; median age 73 (45-89)] were eligible. MDCT sensitivity, specificity, PPV, NPV, AUROC, and diagnostic accuracy ranged between 42.9-76.2, 75.5-90.6, 55.2-76.2, 80.0-90.6, 0.67-0.83 and 0.76-0.86%, respectively, for the identification of T3 > 5 mm/T4 disease, with moderate interobserver agreement (0.49); and 8.3-33.3, 93.5-98.4, 20-66.7, 84.1-88.2, 0.51-0.65 and 0.80-0.86%, respectively, for the identification of N2 disease, with absent interobserver agreement (0.10).

CONCLUSIONS

Specificity of MDCT in the stratification of patients for neoadjuvant therapy may be high enough to prevent overtreatment. However, it may lead to undertreatment in a meaningful proportion of patients. Observer performance may benefit from targeted training programs, given the variability and observer dependence of the results. Limitations include 4-slice MDCT equipment, time to surgery and lack of long-term outcome information based on imaging parameters per se.

mRNA expression of IGF-1 and IGF-1R in patients with colorectal adenocarcinoma and type 2 diabetes

BACKGROUND AND AIMS

Increasing studies show that messenger RNA (mRNA) levels of local IGF-system are overexpressed in cancer tissue of patients with colorectal cancer (CRC). However, the influence of type 2 diabetes (T2DM) on the expression of insulin-like growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) mRNA in colorectal cancer tissue and adjacent non-cancerous tissue (ANCT) is unknown. The aim of this study was to assess mRNA expression of IGF-1 and IGF-1R in paired samples of cancer tissue and ANCT between colorectal adenocarcinoma (CA) patients with and without T2DM.

METHODS

To quantify the levels of IGF-1 and IGF-1R mRNA in CA, we analyzed the expression of IGF-1 and IGF-1R mRNA levels in paired samples of cancer tissue and ANCT in CA patients with and without T2DM using real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

mRNA levels of IGF-1 and IGF-1R were significantly higher in cancer tissue compared with its ANCT in CA patients with and without T2DM. Compared with the CA group, significantly higher levels of IGF-1 and IGF-1R mRNA were observed in cancer tissue in CA with T2DM group. No significant differences were observed in the role of cancer locations, Dukes stages and diabetes duration on mRNA expression of IGF-1. After adjusting for age, gender and Dukes stages, multivariate analysis indicated IGF-1 mRNA level was a risk factor for prognosis (p <0.05).

CONCLUSIONS

Our results support the hypothesis that IGF system plays an important role in CRC. Further larger studies are needed.

Histologic grading based on counting poorly differentiated clusters in preoperative biopsy predicts nodal involvement and pTNM stage in colorectal cancer patients

Histologic grading is commonly assessed in colorectal cancer preoperative biopsies. Nevertheless, its clinical impact is limited by low interobserver reproducibility and poor concordance with grading found in the final resection specimen. In the present study, we aimed to investigate the reproducibility, accuracy, and predictive value on lymph node status or pTNM stage of a novel grading system based on the number of poorly differentiated clusters in colorectal cancer preoperative endoscopic biopsies. Grading based on counting poorly differentiated clusters was assessed in 163 colorectal cancer endoscopic biopsies and corresponding surgical specimens. With this system, 152 biopsies could be graded with good interobserver agreement (κ = 0.735). In comparison with the surgical specimens, 75% of colorectal cancers were correctly graded in the biopsy, and 81% of poorly differentiated colorectal cancers were identified at initial biopsy. High poorly differentiated clusters grade in the biopsy was significantly associated with nodal metastasis, high pTNM stage (P < .0001), or histologic features suggestive of more aggressive behavior (tumor budding, perineural invasion, vascular invasion, and infiltrating tumor border) in the surgical specimen. Furthermore, this system identified colorectal cancer with nodal involvement or high pTNM stage with a 78% positive predictive value and 71% and 69% negative predictive values, respectively. Our findings suggest that a grading system based on the quantification of poorly differentiated clusters is feasible in most colorectal cancer endoscopic biopsies. In view of its good reproducibility, accuracy, and predictive value on the anatomical extent of the disease, it may be taken into account for decision-making in colorectal cancer treatment.

Colorectal carcinoma grading by quantifying poorly differentiated cell clusters is more reproducible and provides more robust prognostic information than conventional grading

The most widely used system to define the histological grade of colorectal carcinoma (CRC) is based on the degree of gland formation. This system suffers from significant interobserver variability which may limit its prognostic value and consequently better standardized criteria for the assessment of histological grading of CRC are needed. The present study aims to evaluate and to compare, in a cohort of postsurgical pTNM stage I CRC, conventional histological grading, and a novel grading system based on the number of poorly differentiated clusters of neoplastic cells, in terms of interobserver reproducibility, prognostic significance on progression-free survival, and association with other clinicopathological characteristics. Grading with both systems was performed by two pathologists independently and blinded to the clinicopathological data. Interobserver agreement was higher when grade was assessed by counting poorly differentiated clusters than by assessing the relative proportion of the glandular component. Contrary to conventional grading, the novel system provided significant prognostic information in terms of progression-free survival and was significantly associated with budding, invasive growth, lymphatic invasion, and occult nodal metastases of CRC. In conclusion, our findings suggest that a tumor grading system based on the number of poorly differentiated clusters is more reproducible and provides better prognostic stratification of pTNM stage I CRC patients than conventional grading.

New criteria for histologic grading of colorectal cancer

Conventional tumor grading systems based on the degree of tumor differentiation may not always be optimal because of difficulty in objective assessment and insufficient prognostic value for decision making in colorectal cancer (CRC) treatment. This study aimed to determine the importance of assessing the number of poorly differentiated clusters as the primary criterion for histologic grading of CRC. Five hundred consecutive patients with curatively resected stage II and III CRCs (2000 to 2005) were pathologically reviewed. Cancer clusters of ≥5 cancer cells and lacking a gland-like structure were counted under a ×20 objective lens in a field containing the highest number of clusters. Tumors with <5, 5 to 9, and ≥10 clusters were classified as grade (G)1, G2, and G3, respectively (n=156, 198, and 146 tumors, respectively). Five-year disease-free survival rates were 96%, 85%, and 59% for G1, G2, and G3, respectively (P<0.0001). Poorly differentiated clusters affected survival outcome independent of T and N stages and could help in more effective stratification of patients by survival outcome compared with tumor staging (Akaike information criterion, 1086.7 vs. 1117.0; Harrell concordance index, 0.73 vs. 0.67). The poorly differentiated cluster-based grading system showed a higher weighted κ coefficient for interobserver variability (5 observers) compared with conventional grading systems (mean, 0.66 vs. 0.52; range, 0.55 to 0.73 vs. 0.39 to 0.68). Our novel histologic grading system is expected to be less subjective and more informative for prognostic prediction compared with conventional tumor grading systems and TNM staging. It could be valuable in determining individualized postoperative CRC treatment.

Accuracy of multidetector computed tomography in identifying poor prognostic factors in colonic cancer

BACKGROUND

Recent neoadjuvant strategies for high-risk colonic tumours have renewed interest in accurate preoperative staging. The aim of this study was to validate prospectively the accuracy of multidetector computed tomography (MDCT) in stratifying patients into good and poor prognostic groups in a multicentre setting.

METHODS

Staging MDCT scans of 84 patients with colonic cancer were reviewed by two independent radiologists and stratified into low-risk (T1/T2 and T3 with extramural tumour depth (EMD) of less than 5 mm) and high-risk (T3 with EMD of at least 5 mm and T4) tumours. Nodal status and extramural venous invasion (EMVI) were also assessed.

RESULTS

The accuracy, sensitivity, specificity and positive predictive value of stratification by CT compared with histological examination was 74 (95 per cent confidence interval 64 to 82), 78 (65 to 87), 67 (49 to 81) and 81 (68 to 89) per cent respectively. Accuracy for detecting malignant lymph nodes and EMVI was 58 and 70 per cent respectively. The agreement for predicting prognostic stratification was moderate (kappa = 0.54).

CONCLUSION

As the ability of CT to identify node status is poor, the depth of tumour invasion beyond the muscularis propria is the most accurate way to identify patients with a poor prognosis who may be suitable for neoadjuvant treatment.

Pathophysiology, clinical presentation, and management of colon cancer

Colon cancer is believed to arise from two types of precursor polyps via two distinct pathways: conventional adenomas by the conventional adenoma-to-carcinoma sequence and serrated adenomas according to the serrated adenoma-to-carcinoma theory. Conventional adenomas arise from mutation of the APC gene; progression to colon cancer is a multistep process. The fundamental genetic defect in serrated adenomas is unknown. Environmental factors can increase the risk for colon cancer. Advanced colon cancer often presents with symptoms, but early colon cancer and premalignant adenomatous polyps commonly are asymptomatic, rendering them difficult to detect and providing the rationale for mass screening of adults over age 50.

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.

Risk factors for occult lymph node metastasis of colorectal cancer invading the submucosa and indications for endoscopic mucosal resection

PURPOSE

Although risk factors for histologically overt lymph node metastasis in patients with early-stage colorectal cancer have been clarified, the risk factors for occult lymph node metastasis are not clear. This study was designed to clarify risk factors for lymph node metastasis, including occult metastasis, in patients with colorectal cancer invading the submucosa and to determine the criteria for endoscopic resection of early colorectal cancer.

METHODS

The risk factors for lymph node metastasis, including occult metastasis, were analyzed in 86 cases of surgically resected colorectal cancer invading the submucosa. The lymph nodes were assessed by immunohistochemistry with cytokeratin antibody CAM5.2.

RESULTS

The frequencies of overt and occult metastasis to the lymph nodes were 13 percent (11/86) and 13 percent (10/75), respectively. Multivariate analysis showed vascular invasion (P = 0.001) and tumor budding (P = 0.003) to be independent risk factors for lymph node metastasis, including occult metastasis. For tumors with submucosal invasion < or =1,000 microm, no lymph node metastasis was found. The frequencies of lymph node metastasis for tumors with submucosal invasion of 1,000 to 2,000 microm and >2,000 microm were 21 and 37 percent, respectively. In considering combinations of risk factors, there was no lymph node metastasis in tumors having neither vascular invasion nor tumor budding and submucosal invasion of < or =3,000 microm.

CONCLUSIONS

Vascular invasion, tumor budding, and the degree of submucosal invasion were significant risk factors for lymph node metastasis, including occult metastasis. These three factors can be used in combination to identify patients requiring additional surgery after endoscopic resection.

Tumor invasion of lymph node capsules in patients with Dukes C colorectal adenocarcinoma

PURPOSE

The objective of this study was to investigate the correlation between the microscopic findings of positive lymph nodes, especially focusing on capsular invasion, and the outcome after curative surgical resection of colorectal cancer.

METHODS

We analyzed 480 positive lymph nodes from 155 consecutive patients with Stage III colorectal cancer to determine the frequency and significance of lymph node capsular invasion. Recurrence-free and cancer-specific survival rates were assessed in the patients with and without lymph node capsular invasion.

RESULTS

Between April 1995 and December 2000, 406 consecutive patients with primary colorectal cancer underwent curative resection. Regional lymph node metastases were present in 155 cases (38.2 percent). During the median follow-up period of 4.8 years, 41 patients (26.5 percent) developed recurrent disease and 28 patients died of cancer. Lymph node capsular invasion was detected in one or more lymph nodes from 75 cases (48.3 percent). The five-year recurrence-free rate was 56.1 percent in this group, whereas in the 80 patients without lymph node capsular invasion the rate was 88 percent (P<0.01). Features that were associated with recurrent disease were greater number of positive lymph nodes, venous invasion in primary tumor, infiltrative growth pattern of intranodal tumor, and presence of lymph node capsular invasion. Multivariate analysis identified lymph node capsular invasion as the only significant prognostic factor for recurrence. In multivariate analysis with regard to survival, lymph node capsular invasion, venous invasion, and number of positive nodes remained as significant prognostic factors.

CONCLUSIONS

Lymph node capsular invasion, determined by routine hematoxylin-eosin staining, is a potent prognostic factor in Stage III colorectal cancer.

Value of carcinoembryonic antigen and cytokeratins for the detection of recurrent disease following curative resection of colorectal cancer

AIM: To evaluate the efficacy of postoperative serial assay of carcinoembryonic antigen (CEA) and cytokeratins for the detection of recurrent disease in patients with colorectal adenocarcinoma after radical surgery.

METHODS: Between 1993 and 2000, 120 patients with colorectal adenocarcinoma underwent radical surgery in the Department of Surgical Gastroenterology, Federal University of São Paulo-Escola Paulista de Medicina, São Paulo, Brazil. Periodic postoperative evaluation was performed by assaying markers in peripheral serum, colonoscopy and imaging examination. Presence of CEA was detected using the Delfia^® method with 5 μg/L threshold, and cytokeratins using the LIA-mat^® TPA-M Prolifigen^® method with 72 U/L threshold.

RESULTS: In the first postoperative year, patients without recurrent disease had normal levels of CEA (1.5 ± 0.9 μg/L) and monoclonal tissue polypeptide antigen-M (TPA-M, 64.4 ± 47.8 U/L), while patients with recurrences had high levels of CEA (6.9 ± 9.8 μg/L, P < 0.01) and TPA-M (192.2 ± 328.8 U/L, P < 0.05). During the second postoperative year, patients without tumor recurrence had normal levels of CEA (2.0 ± 1.8 μg/L) and TPA-M (50.8 ± 38.4 U/L), while patients with recurrence had high levels of CEA (66.3 ± 130.8 μg/L, P < 0.01) and TPA-M (442.7 ± 652.8 U/L, P < 0.05). The mean follow-up time was 22.3 mo. There was recurrence in 23 cases. Five reoperations were performed without achieving radical excision. Rises in tumor marker levels preceded identification of recurrences: CEA in seven (30%) and TPA-M in eleven individuals (48%).

CONCLUSION: Intensive follow-up by serial assay of CEA and cytokeratins allows early detection of colorectal neoplasm recurrence.

Gastrointestinal, Pancreatic, and Hepatic Cancer During Pregnancy

Pregnancy affects the clinical presentation, evaluation, treatment, and prognosis of patients with gastrointestinal cancer. Pregnant patients may present with advanced gastrointestinal cancer as a result of delayed diagnosis, in part because of difficulty differentiating signs and symptoms of cancer from signs and symptoms of normal pregnancy. The approach to cancer surgery and chemotherapy must be modified in pregnant patients to minimize fetal and maternal risks. Because of these factors, women who develop gastrointestinal cancers during pregnancy seem to have a poor prognosis. This article focuses on cancers of the colon, stomach, pancreas, and liver that occur during pregnancy.

Staging of colorectal cancer: past, present, and future

Since the inception of staging for colorectal cancer (CRC), anatomic extent of disease has provided a solid foundation for predicting prognosis and guiding treatment in patients with CRC. However, the rapid advances in biologic and genetic technology have provided many new possibilities for enhancing the predictive power of the staging system. In this article, we will briefly discuss the history of CRC staging, identify the current parameters for American Joint Committee on Cancer staging including recent changes, and offer guidelines for future staging modifications. Although anatomic parameters have served us well for many years, their continued use as sole contributors to CRC staging is questionable. Staging in the future is likely to be a complicated combination of anatomic and biologic markers used together in mathematic modeling to group patients into prognostic risk groups, which can be used to guide tailored therapy.

From Colonic Polyps to Colon Cancer: Pathophysiology, Clinical Presentation, and Diagnosis

Epidemiologists, basic researchers, clinicians, and public health administrators unite! Develop and implement a simple, safe, and effective preventive and screening test for colon cancer. The public will willingly and enthusiastically accept such a test. Many thousands of lives are at stake every year.

The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps

A review of the pathophysiology, clinical presentation, and diagnosis of colon cancer and colonic polyps is important and timely. This field is rapidly changing because of breakthroughs in the molecular basis of carcinogenesis and in the technology for colon cancer detection and treatment. This article reviews colon cancer and colonic polyps, with a focus on recent dramatic advances, to help the pri-mary care physician and internist appropriately refer patients for screening colonoscopy and intelligently evaluate colonoscopic findings to reduce the mortality from this cancer.

Ki-ras gene mutations, LOH of the APC and DCC genes, and microsatellite instability in primary colorectal carcinoma are not associated with micrometastases in pericolonic lymph nodes or with patients' survival

AIMS

The primary aim of this study was to look for possible correlations between molecular genetic changes in primary colorectal cancer and the presence or absence of micrometastases in the accompanying pericolonic lymph nodes. The secondary aim was to correlate the data on these molecular genetic changes and micrometastases with survival.

METHODS

One hundred and twenty five Dukes's stage B colorectal cancers from 1989 to 1992 were analysed. The primary tumours were evaluated for Ki-ras mutation, adenomatous polyposis coli (APC) loss of heterozygosity (LOH), deleted in colon cancer (DCC) LOH, and microsatellite instability using standard molecular techniques. All available lymph nodes were immunohistochemically stained for micrometastases.

RESULTS

Micrometastases were present in 41% of patients. There were significantly more lymph nodes removed in the patients with micrometastases. Micrometastases were not associated with Ki-ras mutation, APC LOH, DCC LOH, or microsatellite instability, even when controlling for the number of lymph nodes removed. None of the molecular variables considered had a significant impact on either overall survival or on death with disease.

CONCLUSIONS

There are insufficient data to justify using molecular genetic changes in primary colorectal carcinomas as prognostic markers. Micrometastases do not provide prognostic information on survival. There is value in increasing the numbers of lymph nodes removed and analysed along with the primary tumour.

Expression of proliferating cell nuclear antigen and CD44 variant exon 6 in primary tumors and corresponding lymph node metastases of colorectal carcinoma with Dukes' stage C or D

AIM: To study changes in characteristics of colorectal carcinoma during the metastatic process and to investigate the correlation between cell proliferation activity and metastatic ability of patients with Dukes’ stage C or D.

METHODS: Formalin fixed and paraffin embedded materials of primary tumors and corresponding lymph node metastases resected from 56 patients with Dukes' stage C or D of colorectal carcinoma were stained immunohistochemically with proliferating cell nuclear antigen (PCNA) and CD44 variant exon 6 (CD44v6).

RESULTS: Thirty-one of 56 patients (55.4%) expressed PCNA in the primary sites and 36 of 56 patients (64.3%) expressed PCNA in the metastatic lymph nodes. A significant relation in PCNA expression was observed between the primary site and the metastatic lymph node (0.010 < P < 0.025). Forty-one of 56 patients (73.2%) expressed CD44v6 in the primary site and 39 of 56 patients (69.6%) expressed CD44v6 in the metastatic lymph node. There was also an significant relationship of CD44v6 between the primary site and the metastatic lymph node (0.005 < P < 0.010). No difference was observed between expression of CD44v6 and PCNA in the primary site (0.250 < P < 0.500).

CONCLUSION: This study partially demonstrates that tumor cells in metastatic lymph node of colorectal carcinoma still possess cell proliferation activity and metastatic ability of tumor cells in primary site. There may be no association between cell proliferation activity and metastatic ability in colorectal carcinoma.

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.

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.

Impact of the number of negative nodes on disease-free survival in colorectal cancer patients

PURPOSE

Between 1995 and 1999, we observed an increasing number of nodes being recovered from colorectal specimens. Patients with colorectal cancer were studied to determine whether increasing the number of negative nodes recovered would better stage the patient and more accurately predict disease-free survival.

METHODS

All patients undergoing colorectal resection with curative intent between 1995 and 1999 at a tertiary referral hospital were retrospectively reviewed. Tumor stage, grade, number of nodes recovered, and the association of these factors with disease-free survival was analyzed.

RESULTS

Three hundred forty-five patients with M0 disease undergoing surgical resection of carcinoma of the colon or rectum were studied. There was no statistically significant difference in tumor stage or grade during the study period. A statistically significant increase in the mean number of nodes recovered was observed during the study period. Node-positive patients did substantially worse than node-negative individuals. When compared with a national cancer registry (OncoPool), we observed a significantly greater number of nodes sampled in our study population and a statistically significant improved disease-free survival between our node-negative patients and that of the national cancer registry population.

CONCLUSION

The extent of the pathologic assessment of the nodal status of colorectal cancer patients as determined by the number of nodes examined affects disease-free survival. The need for quality control for uniform pathologic assessments is critical.

Pattern of lymph node micrometastasis and prognosis of patients with colorectal cancer

BACKGROUND

Studies of lymph node micrometastases in patients with colorectal cancer have ignored the prognostic significance of the number and level of lymph node micrometastases. The aim of this study was to clarify the prognostic significance of the status of lymph node micrometastases in histologically node-negative colorectal cancer.

METHODS

We used immunohistochemistry with anti-cytokeratin antibody CAM5.2 to examine 1013 lymph nodes in 42 patients (12 recurrent and 30 nonrecurrent) with histologically determined Dukes' B colorectal cancer. Five serial 6-microm sections were used for immunohistochemical staining. The frequency, tumor cell pattern, and number and level of lymph node micrometastases were compared between the recurrent and nonrecurrent groups.

RESULTS

Micrometastasis was confirmed in 16% (59/373) of lymph nodes in the recurrent group and 12% (77/640) of lymph nodes in the nonrecurrent group, and the frequency of lymph node micrometastases was 92% (11/12) in the recurrent group and 70% (21/30) in the nonrecurrent group. The tumor cell pattern in the metastatic lymph nodes was similar in the recurrent and nonrecurrent groups. Micrometastasis in four or more lymph nodes occurred more frequently in the recurrent group than in the nonrecurrent group (58% vs. 20%, P < .05), and micrometastasis to N2 or higher nodes occurred more frequently in the recurrent group than in the nonrecurrent group (92% vs. 47%, P < .01).

CONCLUSIONS

The number and level of positive micrometastatic lymph nodes was significantly correlated with postoperative recurrence of histologically determined Dukes' B colorectal cancer. This parameter is a useful prognostic indicator in histologically node-negative colorectal cancer and is helpful in planning adjuvant chemotherapy.

Appropriate lymph node dissection for early gastric cancer based on lymph node metastases

BACKGROUND

Lymph node dissection in patients with early gastric cancer is controversial because lymph node metastases are much less common than in advanced cancer. Therefore, routine extensive lymph node dissection with wide resection of the stomach may be excessive, and an appropriate lymph node dissection procedure in patients with early gastric cancer should be established.

METHODS

Retrospectively, 588 consecutive patients with early gastric cancer were analyzed by univariate and multivariate analysis to predict lymph node metastases with clinicopathologic variables. The sites and rates of lymph node metastases for each tumor location were mapped.

RESULTS

In early gastric cancer, depth of invasion was an independent predictive factor of lymph node metastases. In cancer confined to the mucosa, however, tumor diameter was the only predictive factor. In contrast, tumor diameter, macroscopic appearance, and histologic type were not predictive factors in early gastric cancers invading the submucosa. In mucosal cancer, metastasis to lymph nodes was confined to the paragastric lymph nodes on the same side of the stomach as the tumor. In submucosal cancer, the incidence of lymph node metastasis was 2% to 17% in group 1 and 1% to 3% in group 2 lymph nodes.

CONCLUSIONS

In mucosal cancer, lymph node dissection is unnecessary for tumors measuring less than 30 mm, and limited lymph node dissection with local gastrectomy is appropriate when tumor diameters are 30 mm or greater. In submucosal cancer, gastrectomy with dissection of group 1 and some group 2 lymph nodes should be sufficient to remove all nodal metastases.

Biologic and clinical significance of lymphadenectomy

Interest in the lymphatic system and its relationship to metastases has developed owing to renewed interest in sentinel node biopsy. This article summarizes the anatomy, physiology, and biology of the lymphatic system and lymph node metastases, and reviews studies of lymph node metastases and surgical resection of cancers in different anatomic sites. On the basis of these studies, the authors conclude that lymph node metastasis functions as an indicator of prognosis, not the controlling or determining factor of prognosis. Thus, varying degrees of treatment of regional lymph nodes and metastases do not seem to be controlling factors in the outcome of cancer.

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance.

MATERIALS AND METHODS

The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care.

RESULTS AND CONCLUSIONS

Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

American Joint Committee on Cancer Prognostic Factors Consensus Conference: Colorectal Working Group

BACKGROUND

The American Joint Committee on Cancer (AJCC), which regularly reviews TNM staging systems, established a working party to develop recommendations for colorectal carcinoma.

METHODS

A multidisciplinary consensus conference using published literature developed an arbitrary classification system of prognostic marker value (Category I, IIA, IIB, III, and IV), which forms the framework for this report.

RESULTS

The working party concluded that several T categories should be subdivided: pTis into intraepithelial carcinoma (pTie) and intramucosal carcinoma (pTim); pT1 into pT1a and pT1b corresponding to the absence or presence of blood or lymphatic vessel invasion, respectively; and pT4 into pT4a and pT4b according to the absence or presence of tumor involving the surface of the specimen, respectively. The working party also recommended that TNM groups be stratified based on the presence or absence of elevated serum levels of carcinoembryonic antigen (CEA) (>/= 5 ng/mL) on preoperative clinical examination. In addition, the working party also concluded that carcinoma of the appendix should be excluded from the colorectal carcinoma staging system because of fundamental differences in natural history.

CONCLUSIONS

The TNM categories and stage groupings for colorectal carcinoma published in the current AJCC manual have clinical and academic value. However, a few categories require subdivision to provide increasing discrimination for individual patients. The serum marker CEA should be added to the staging system, whereas multiple other factors should be recorded as part of good clinical practice. Although many molecular and oncogenic markers show promise to supplement or modify the current staging systems eventually, to the authors' knowledge none have yet been evaluated sufficiently to recommend their inclusion in the TNM system.

Evidence of in vivo peroxynitrite formation in patients with colorectal carcinoma, higher plasma nitrate/nitrite levels, and lower protection against oxygen free radicals

Endogenously formed nitrogen and oxygen free radicals are believed to be involved in human cancer etiology. Plasma nitrate/nitrite originates from endogenous nitric oxide production in fasting humans, decrease in superoxide scavenger activity (SSA), and free sulfhydryl groups (SH) reflects the amount of superoxide anion generated, and nitrotyrosine is believed to be formed by the interaction of tyrosine and peroxynitrite in vivo. The aim of the current study was to measure plasma nitrate/ nitrite, SSA, and SH in 69 patients (mean age +/- standard deviation, 66 +/- 11 years) with colorectal carcinoma. Nitrotyrosine was measured from both the plasma and tumor tissues in 32 patients. All patients had adenocarcinoma of the colon or rectum. Twenty-five patients were classified as stage B according to Dukes classification as modified by Astler-Coller, 13 were classified as stage C, and 31 patients were classified as stage D. To determine whether the changes are specific for colorectal cancer, 20 patients with active inflammatory bowel disease (IBD; mean age, 52 +/- 18 years) and 30 healthy volunteers, who served as control subjects (mean age, 48 +/- 11 years), were studied. Plasma nitrate/nitrite was measured by the modified Griess method, SSA was measured by an electron/spin resonance spin trapping method, free SH was measured by Ellman's method, and the presence of nitrotyrosine in the plasma and tumor tissue was detected by high performance liquid chromatography (HPLC) using C- 18-derivatized silica (5 microm) column (C18S, Crestpaque, New York, NY, USA) and at a wavelength of 274 nm. Patients with colorectal carcinoma and with active IBD had a significantly higher plasma nitrate/ nitrite level (51.2 +/- 26.2 microm and 56.0 +/- 14.6 microm versus. 29.6 +/- 6.3 microm; p < 0.01), and a lower SSA level (39 +/- 11.5 U/g protein and 52.0 +/- 18.9 U/g protein versus. 88 +/- 25.1 U/g protein; p < 0.05) and SH level (7.7 +/- 3.89 microm protein and 6.4

Histopathologic criteria for local excision of colorectal cancer: multivariate analysis

BACKGROUND

Local treatment of colorectal cancer, including endoscopic removal of colonic polyps and transanal resection of rectal tumors, has become widely accepted. However, risk factors predicting the presence of lymph node metastasis have not been fully investigated. To determine the criteria for local excision of colorectal cancer, histopathologic factors independently predicting the lymph node metastasis were investigated.

METHODS

We performed a retrospective histopathologic study on 335 patients who underwent resection of colorectal cancer and dissection of regional lymph nodes between 1982 and 1996. Features of node-positive tumors (n = 150) were compared with those of node-negative tumors (n = 185), with special reference to the histopathologic findings of the resected tumor. Multivariate analysis was done using the stepwise logistic regression test.

RESULTS

Node-positive tumors, when compared with node-negative tumors, were characterized by tumor larger than 6 cm (42% vs. 22%), serosal invasion (88% vs. 56%), lymphatic invasion (32% vs. 5%), venous invasion (9% vs. 2%), and histology other than well-differentiated (66% vs. 29%). Multivariate analysis showed that factors independently associated with lymph node metastasis were serosal invasion, lymphatic invasion, and histologic type. When these three risk factors were negative, lymph node metastasis was rare (5%). When one, two, or three factors were positive, the frequency of lymph node metastasis was 38%, 66%, and 85%, respectively.

CONCLUSIONS

In colorectal cancer, factors independently associated with lymph node metastasis are serosal invasion, lymphatic invasion, and histologic type. When these three parameters are favorable, local treatment of colorectal cancer does not require additional lymph node dissection.

Do the level of nodal disease according to the TNM classification and the number of involved cervical nodes reflect prognosis in patients with differentiated carcinoma of the thyroid gland?

BACKGROUND AND OBJECTIVES

The importance of nodal involvement as a prognostic factor in differentiated carcinoma of the thyroid gland remains controversial. We therefore attempted to confirm the prognostic factors in differentiated thyroid carcinoma, with special reference to nodal status.

PATIENTS AND METHODS

A total of 139 patients with differentiated thyroid cancer followed for 2-27 years, with a median follow-up of 7 years were studied. All patients underwent surgical resection, either subtotal, total, or lobectomy, with modified radical neck dissection. Survival was calculated using the Kaplan-Meier method.

RESULTS

Ten (7%) patients have died from thyroid cancer. Adverse prognostic factors included age >45 years (P=0.0120), the presence of distant metastases (P=0.0006), and TNM stage (P=0.0002). The number of lymph nodes dissected ranged from 6 to 92, with an average of 26. Lymph node metastases were found in 102 (73%) patients. There was no difference in survival according to the level of nodal disease by the TNM classification. Furthermore, the number of cervical lymph nodes involved had no effect on the survival.

CONCLUSION

Our results suggest that the presence of histologically confirmed lymph node metastases is not an important prognostic factor in patients with differentiated thyroid carcinoma.

Assessing the effectiveness of mesorectal excision in rectal cancer: prognostic value of the number of lymph nodes found in resected specimens

PURPOSE

The aim of this study was to determine whether the number of involved or uninvolved lymph nodes in resected specimens can be used to predict the effectiveness of surgical resection for rectal cancer.

METHODS

Local recurrence and survival rates for 118 patients undergoing curative resection for rectal carcinoma, without adjuvant therapy, were retrospectively studied.

RESULTS

Mean follow-up was 62+/-37 months. Mean number of involved or uninvolved lymph nodes per resected specimen was 12+/-7. Overall local recurrence rate was 15.2 percent. In patients without involved lymph nodes (N0 patients) and with T1 or T2 tumors, the local recurrence rate ranged from 0 to 8 percent (not significant), depending on the number of lymph nodes on the specimen. In patients without involved lymph nodes and those with T3 tumors, the actuarial survival rate at ten years was significantly lower (P < 0.05), and the local recurrence rate was higher (P < 0.02) in patients with fewer than ten lymph nodes than in those with more than ten nodes. In patients with involved lymph nodes, the mean number of nodes on the resected specimen correlated closely with the mean number involved by the tumor.

CONCLUSION

The assessment of the effectiveness of rectal excision for cancer is in part helped by the number of involved or uninvolved lymph nodes found on the resected specimen. This is of particular interest in patients without involved lymph nodes and those having infiltrating T3 tumors, for whom the long-term survival and local recurrence rates were significantly better when more than ten lymph nodes were present. On the other hand, when fewer than ten nodes were found, whatever the cause, adjuvant radiotherapy had to be considered, because of the high risk of local failure rate.

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.

Use of guanylyl cyclase C for detecting micrometastases in lymph nodes of patients with colon cancer

INTRODUCTION

Guanylyl cyclase C appears to be expressed only in colorectal cancer cells in extraintestinal tissues. Thus, guanylyl cyclase C may be useful as a marker to detect colorectal cancer micrometastases not detectable by histopathology in lymph nodes of patients.

METHODS

Twelve patients with colon adenocarcinoma, Dukes Stages A through C2, and one patient with a tubulovillous adenoma were included in this study. Forty-two lymph nodes were collected from fresh surgical specimens, and each was examined by histopathology and reverse transcription followed by polymerase chain reaction using guanylyl cyclase C-specific primers. Histopathology identified colon cancer cells in 6 of 16 lymph nodes from five Dukes Stage C patients but not in lymph nodes from the patient with a tubulovillous adenoma, the Dukes Stage A patient, or six Dukes Stage B patients. Reverse transcription followed by polymerase chain reaction using guanylyl cyclase C-specific primers was performed on all 42 lymph nodes.

RESULTS

Guanylyl cyclase C messenger RNA was not detected by reverse transcription followed by polymerase chain reaction in lymph nodes from the patient with the tubulovillous adenoma or the patient with Dukes Stage A colon carcinoma. Seven lymph nodes from Dukes Stage C patients revealed guanylyl cyclase C messenger RNA including six lymph nodes containing histopathologically confirmed metastases. Of significance, guanylyl cyclase C messenger RNA was detected in 6 of 21 lymph nodes from Dukes Stage B patients. Indeed, clinical staging of two patients could be upgraded from B to C using reverse transcription followed by polymerase chain reaction and guanylyl cyclase C-specific primers.

CONCLUSION

Reverse transcription followed by polymerase chain reaction using guanylyl cyclase C-specific primers might be useful to more accurately assess micrometastases in lymph nodes of colorectal cancer patients undergoing disease staging.

Artificial neural networks applied to outcome prediction for colorectal cancer patients in separate institutions

BACKGROUND

Artificial neural networks are computer programs that can be used to discover complex relations within data sets. They permit the recognition of patterns in complex biological data sets that cannot be detected with conventional linear statistical analysis. One such complex problem is the prediction of outcome for individual patients treated for colorectal cancer. Predictions of outcome in such patients have traditionally been based on population statistics. However, these predictions have little meaning for the individual patient. We report the training of neural networks to predict outcome for individual patients from one institution and their predictive performance on data from a different institution in another region.

METHODS

5-year follow-up data from 334 patients treated for colorectal cancer were used to train and validate six neural networks designed for the prediction of death within 9, 12, 15, 18, 21, and 24 months. The previously trained 12-month neural network was then applied to 2-year follow-up data from patients from a second institution; outcome was concealed. No further training of the neural network was undertaken. The network's predictions were compared with those of two consultant colorectal surgeons supplied with the same data.

FINDINGS

All six neural networks were able to achieve overall accuracy greater than 80% for the prediction of death for individual patients at institution 1 within 9, 12, 15, 18, 21, and 24 months. The mean sensitivity and specificity were 60% and 88%. When the neural network trained to predict death within 12 months was applied to data from the second institution, overall accuracy of 90% (95% CI 84-96) was achieved, compared with the overall accuracy of the colorectal surgeons of 79% (71-87) and 75% (66-84).

INTERPRETATION

The neural networks were able to predict outcome for individual patients with colorectal cancer much more accurately than the currently available clinicopathological methods. Once trained on data from one institution, the neural networks were able to predict outcome for patients from an unrelated institution.

von Hippel-Lindau disease gene deletion detected in microdissected sporadic human colon carcinoma specimens

The progression of human malignancies is thought to involve the inactivation or loss of tumor suppressor genes. Previous studies have suggested that inactivation of tumor suppressor genes on chromosomes 5q, 17p, 18q, and 8p play a role in the development of colorectal carcinoma. However, chromosome 3p at the von Hippel-Lindau disease (VHL) gene locus (3p25-26) has not been previously implicated in the development or progression of sporadic colorectal carcinoma. The authors have analyzed VHL gene alterations on chromosome 3p in sporadic human colon carcinomas and adenomas using modified microdissection techniques. These techniques allow for procurement and analysis of selected subpopulations of cells from both paraffin-embedded and frozen human tumor specimens. VHL disease gene deletion was detected by polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) analysis in microdissected colon carcinoma specimens. Allelic loss of VHL gene was detected in 7 of 11 (64%) informative patients who underwent colectomy for primary sporadic colon carcinoma. However, no allelic loss of VHL gene was shown in colonic adenomas of eight informative patients. These results indicate that VHL disease gene deletion frequently occurs in sporadic colon carcinoma. Because this deletion was not present in adenomas, VHL gene may play a role in colonic carcinogenesis and represent a relatively late event in colonic neoplasia progression. Additionally, microdissection of tissue sections may be especially useful in detecting allelic loss in PCR-based studies of infiltrating tumors, particularly when the tumor cells represent a relatively small percentage of the total cell population.

Lymphocyte subset infiltration patterns and HLA antigen status in colorectal carcinomas and adenomas

Fifty eight large bowel adenocarcinomas and 20 adenomas were studied immunohistochemically, using fresh frozen tissue sections, with regard to lymphocyte subpopulations (CD3, CD4, CD8, CD19, and CD20) in the inflammatory infiltrate and to expression of human leucocyte antigens (HLA-ABC, HLA-A2, and HLA-DR). The findings were related to differentiation and Duke's stage of carcinoma. The inflammatory infiltrate was found to have a phenotype that remained constant irrespective of the intensity of the inflammation. CD4 and CD3 positive cells predominated with fewer CD8 positive cells and a scanty diffuse CD19/20 positive cell population. CD19/20 follicular aggregates were common at the advancing margin of the carcinomas. There was no significant association with Duke's stage, differentiation or HLA status. HLA changes (ABC loss, A2 loss, and DR gain) were associated with differentiation, being more common and more extensive in poorly differentiated carcinomas. HLA-A2 loss was also associated with stage of progression of carcinoma. Inflammation associated with adenomas was found to have a similar phenotype to that associated with carcinomas. HLA changes in adenomas were uncommon, being seen in only one of our 20 cases.

Relation between stage, grade, proliferation, and expression of p53 and CD44 in adenomas and carcinomas of the colorectum

AIMS

To investigate the changes in and relations among p53, CD44 and MIB-1 expression in adenocarcinomas of the colorectum and to determine whether these changes are progressive across the adenoma-carcinoma sequence.

METHODS

Expression of p53 protein, CD44 adhesion molecule and MIB-1 proliferation antigen was detected using immunohistochemistry in 68 colorectal carcinomas and 32 colorectal adenoma. The staining characteristics were compared with degree of dysplasia in adenomas, and differentiation and Dukes' stage in carcinomas. Results were analysed and assessed using Spearman's rank correlation and independent t tests.

RESULTS

p53 staining was present in som adenomas and correlated with the degree of dysplasia. There was significantly more staining in carcinomas than adenomas and significant correlation between staining and Dukes' stage. CD44 staining was maximal in adenomas, diminished in carcinomas and was minimal in metastasising carcinomas. There was inverse correlation between p53 and CD44 expression across the adenoma-carcinoma-metastasising carcinoma sequence. MIB-1 expression was highest in carcinomas but did not correlate with either p53 or CD44 expression.

CONCLUSIONS

There are progressive changes in p53, CD44 and MIB-1 expression in adenomas and carcinomas. A combination of these tests may prove useful in assessing which patients with adenomas are at greatest risk of progressing to carcinoma.

Impact of the Crohn's-like lymphoid reaction on staging of right-sided colon cancer: results of multivariate analysis

The presence of lymphoid aggregates within the muscularis propria or pericolic fibroadipose tissue apposing invasive colorectal carcinoma, termed the Crohn's-like lymphoid reaction, has been related to improved patient length of survival according to univariate statistical analysis. We tested the Crohn's-like lymphoid reaction as an indicator of prognosis in a multivariate statistical analysis of 344 resected right-sided colonic cancers. Improved 5-year survival in univariate analysis was associated with low tumor grade, regular tubule configuration, expanding tumor growth pattern, prominent peritumoral lymphocytic infiltration, absence of tumoral invasion of extramural veins, all levels of intramural and extramural invasion short of widespread local tumor permeation, conspicuous Crohn's-like lymphoid reaction, and absence of both nodal metastasis and nodal-independent tumor nodules in pericolic fat. By the Cox proportional hazard model using the stepwise method, depth of tumor invasion, lymph node metastasis, Crohn's-like lymphoid reaction, and metastatic tumor nodules in pericolic fat retained independent prognostic significance. Combining the four variables to formulate pathological prognostic categories yielded a highly favorable prognostic group-92% 5-year survival and 95% confidence limits (88% to 96%)--encompassing 53% of the study population. It included all Dukes' stage A carcinomas, 66% of Dukes' stage B adenocarcinomas, and 11% of Dukes' stage C cancers. Lymph node metastases coupled with intramural and extramural extent of tumor invasion are the cornerstones of colorectal cancer staging. Addition of other variables improves prognostication for the cecum and ascending colon. From this study the Crohn's-like lymphoid reaction and metastatic tumor nodules in pericolic fat emerge as significant independent indicators of prognosis for right-sided colon cancer. Complex correlations of both indicators with nonselected variables were observed.

Relationship of P-glycoprotein and carcinoembryonic antigen expression in human colon carcinoma to local invasion, DNA ploidy, and disease relapse

BACKGROUND

The clinical significance of expression of the MDR1 gene product P-glycoprotein (P-gp) in relation to the intrinsic drug resistance and progression of human colon cancer is largely unknown. To elucidate the role of P-gp in these cancers further, the frequency and intensity of P-gp and carcinoembryonic antigen (CEA) immunostaining were measured at the single-cell level and correlated with known prognostic indices (i.e., DNA ploidy, vessel/lymphatic microinvasion, histologic grade, and disease relapse).

METHODS

Fifty-two untreated Dukes' Stage B2 colon cancers were immunostained with the anti-P-gp monoclonal antibodies JSB-1 and HYB-241, and anti-CEA. DNA content and cell proliferation were measured by flow cytometry.

RESULTS

JSB-1 and HYB-241 detected P-gp in 44 and 42 of 52 carcinomas, respectively, and CEA was found in 50 of the 52 tumors. The level of P-gp expression was not associated with DNA ploidy, indices of local invasiveness, or histologic grade. In a multivariate analysis, however, a high level of P-gp expression (as assessed by JSB-1), DNA aneuploidy, microinvasion, and single carcinoma cell invasion individually predicted disease relapse (P < 0.05).

CONCLUSIONS

The results indicate that diffuse P-gp immunostaining is present in the majority of Stage B2 human colon cancers and therefore may be an important contributor to their intrinsic drug resistance. The association between a high level of P-gp expression and disease relapse suggests that P-gp can be of prognostic value in Stage B2 colon cancers.

Dukes's classification: a valid prognostic indicator for gastric cancer

Dukes's classification for colorectal cancer is simple, and correlates well with survival. This study assessed whether the principles of Dukes's classification applied to gastric cancer resulted in the separation of prognostically useful groups. The cumulative survival curves determined by Dukes's, Astler-Coller's (another classification for colorectal cancer), and the Japanese classification for gastric cancer were evaluated using 476 curatively treated patients with gastric cancer. Of the three staging systems, both Dukes's and the Japanese classifications showed a step-wise relationship between the stage of the tumour and the survival of patients. The prognostic value of Dukes's classification was reinforced when Dukes's C cases were subdivided according to the number of positive nodes (1-6 v > or = 7) or the level of positive nodes (n1 v n2,n3) but not when the subdivision was made according to the depth of wall invasion. A modified Dukes's classification in which Dukes's cases are subdivided according to the number of metastatic nodes (Dukes's Ca = 1-6 nodes, Dukes's Cb > 6 nodes) could be both simply and accurately applied to gastric cancer.

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.

Evaluation of the secretory component as a prognostic variable in colorectal carcinoma

Expression of the secretory component (SC) of IgA was investigated in normal colonic mucosa, in adenomas and in 188 colon carcinomas. Of the carcinoma patients, 149 underwent potentially curative surgical treatment. In particular, it was of interest to determine whether pathohistological or clinical parameters showed any association with the mode of SC expression in carcinomas. Irrespective of anatomical site, normal colon mucosa was generally SC-positive. Normal epithelium, however, displayed microheterogeneity in SC content, which was related to columnar and goblet-cell type and microtopographical site, implying a subtle regulatory mechanism. In contrast to adenomas, which were evenly SC-positive and showed focally weak SC expression in only 2 out of 20 cases, carcinomas were rather heterogeneous in their SC-expression pattern. In all, 48 carcinomas were entirely positive, 48 were completely negative and the remaining 92 showed various patterns of heterogeneous SC expression. The mode of SC expression was correlated with tumor staging, i.e., complete absence of SC was more often found in Dukes' C and D groups. In addition, the presence of SC in carcinomas was statistically correlated with the mucinous type. The mode of SC expression was not correlated with tumor grading and tumor location. The rate of disease-free survival and the risk of tumor-related death revealed a significant correlation with the mode of SC expression when patients who had received potentially curative or non-curative treatment were included in the log-rank test. Absence or low levels of SC expression were more frequent in the group that suffered a tumor relapse than in the recurrence-free cohort. Tumor-related death was more frequent when primaries were characterized by absence or low levels of SC expression. We conclude that absence or low levels of SC expression are an unfavorable prognostic variable in colorectal carcinoma.

Prognostic significance of the number of positive lymph nodes in gastric carcinoma

A total of 195 patients with node-positive gastric carcinoma who were treated by curative gastrectomy and lymphadenectomy were studied to evaluate the prognostic significance of the number of metastatic lymph nodes. Univariate analysis showed that the number and level of positive nodes, tumour size and depth of invasion, and type of gastrectomy were significantly related to patient survival. Multivariate analysis indicated that the number of positive nodes (up to six versus seven or more; relative risk 2.91), depth of invasion (three levels; relative risk 1.83) and histological type (well versus poorly differentiated; relative risk 0.63) were independently correlated with survival. The results indicate that the total number of positive nodes is the most significant prognostic factor in patients with node-positive gastric carcinoma.

A selective approach to adjunctive therapy for cancer of the rectum

PURPOSE

To present results of a selective approach to adjunctive therapy and surgery based on a new model of clinical staging for rectal cancer.

METHODS AND MATERIALS

Three hundred and sixty-two patients with rectal cancer treated with adjunctive radiation therapy and surgery have been analyzed to define patient selection criteria based on clinical assessment of disease. Clinical prognostic features of tumor mobility and level of lesion in the rectum with reference to the anorectal junction were used. Mobile, early fixed (partial), advanced fixed (total) and frozen pelvis are defined as clinical Stages I, II, III, and IV. Tumors above 6 cm (middle valve), 3-6 cm (inferior to middle valve), 0-3 cm (anorectum to inferior valve), and into the anal canal are defined as levels a, b, c, d, respectively. Based on this model, patients with mobile tumors of the proximal rectum (CS Ia, b) are treated with 500 cGy preoperative radiation and selective postoperative radiation (4500 cGy) for Stages B2 and C cancer. All other patients are treated with escalating doses of preoperative radiation. Follow-up in these patients ranges from 1 year to 14 years with a median of 5 years.

RESULTS

Overall 5-year survival of the total group of patients is 69%. Survival by pathological stage is 82% for O, A, B1, 67% for B2, 74% for C1, and 51% for C2. Survival by clinical stages is 77% for CS I, 67% for CS II, 57% for CS III, and 21% for CS IV. Overall local recurrence is 43/362 (12%). L.R. by pathological stages is 5% for O, A, B1, 18% for B2, 10% for C1, and 17% for C2. L.R. by clinical stages is 9% for CS I, 14% for CS II, 17% for CS III, and 50% for CS IV.

CONCLUSION

An integrated adjunctive therapy and selective surgical approach based on careful clinical staging of rectal cancer results in a global improvement in overall local control and survival of patients.