Pathologic determinants of survival after resection of T3N0 (Stage IIA) colorectal cancer: proposal for a new prognostic model

Evaluation of prognostic models to improve prediction of metastasis in patients following potentially curative treatment for primary colorectal cancer: the PROSPECT trial

Background

Despite apparently curative treatment, many patients with colorectal cancer develop subsequent metastatic disease. Current prognostic models are criticised because they are based on standard staging and omit novel biomarkers. Improved prognostication is an unmet need.

Objectives

To improve prognostication for colorectal cancer by developing a baseline multivariable model of standard clinicopathological predictors, and to then improve prediction via addition of promising novel imaging, genetic and immunohistochemical biomarkers.

Design

Prospective multicentre cohort.

Setting

Thirteen National Health Service hospitals.

Participants

Consecutive adult patients with colorectal cancer.

Interventions

Collection of prespecified standard clinicopathological variables and more novel imaging, genetic and immunohistochemical biomarkers, followed by 3-year follow-up to identify postoperative metastasis.

Main outcome

Best multivariable prognostic model including perfusion computed tomography compared with tumour/node staging. Secondary outcomes: Additive benefit of perfusion computed tomography and other biomarkers to best baseline model comprising standard clinicopathological predictors; measurement variability between local and central review; biological relationships between perfusion computed tomography and pathology variables.

Results

Between 2011 and 2016, 448 participants were recruited; 122 (27%) were withdrawn, leaving 326 (226 male, 100 female; mean ± standard deviation 66 ± 10.7 years); 183 (56%) had rectal cancer. Most cancers were locally advanced [≥ T3 stage, 227 (70%)]; 151 (46%) were node-positive (≥ N1 stage); 306 (94%) had surgery; 79 (24%) had neoadjuvant therapy. The resection margin was positive in 15 (5%); 93 (28%) had venous invasion; 125 (38%) had postoperative adjuvant chemotherapy; 81 (25%, 57 male) developed recurrent disease. Prediction of recurrent disease by the baseline clinicopathological time-to-event Weibull multivariable model (age, sex, tumour/node stage, tumour size and location, treatment, venous invasion) was superior to tumour/node staging: sensitivity: 0.57 (95% confidence interval 0.45 to 0.68), specificity 0.74 (95% confidence interval 0.68 to 0.79) versus sensitivity 0.56 (95% confidence interval 0.44 to 0.67), specificity 0.58 (95% confidence interval 0.51 to 0.64), respectively. Addition of perfusion computed tomography variables did not improve prediction significantly: c-statistic: 0.77 (95% confidence interval 0.71 to 0.83) versus 0.76 (95% confidence interval 0.70 to 0.82). Perfusion computed tomography parameters did not differ significantly between patients with and without recurrence (e.g. mean ± standard deviation blood flow of 60.3 ± 24.2 vs. 61.7 ± 34.2 ml/minute/100 ml). Furthermore, baseline model prediction was not improved significantly by the addition of any novel genetic or immunohistochemical biomarkers. We observed variation between local and central computed tomography measurements but neither improved model prediction significantly. We found no clear association between perfusion computed tomography variables and any immunohistochemical measurement or genetic expression.

Limitations

The number of patients developing metastasis was lower than expected from historical data. Our findings should not be overinterpreted. While the baseline model was superior to tumour/node staging, any clinical utility needs definition in daily practice.

Conclusions

A prognostic model of standard clinicopathological variables outperformed tumour/node staging, but novel biomarkers did not improve prediction significantly. Biomarkers that appear promising in small single-centre studies may contribute nothing substantial to prognostication when evaluated rigorously.

Future work

It would be desirable for other researchers to externally evaluate the baseline model.

Trial registration

This trial is registered as ISRCTN95037515.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 09/22/49) and is published in full in Health Technology Assessment; Vol. 29, No. 8. See the NIHR Funding and Awards website for further award information.

[Prognostic factors: Degree of subserosal invasion, tumor-serosal distance and subserosal elastic boundary invasion in colonic adenocarcinoma]

The aim was to study the prognostic impact of tumor infiltration of the subserosa in colonic adenocarcinoma, by evaluating the degree of tumor infiltration in the subserosa (DISS), tumor-serosa distance (DTS), and invasion of the elastic boundary of the subserosa (ILE) after elastic fiber staining.

MATERIAL AND METHODS

All patients operated on for colonic adenocarcinoma classified as pT3 without lymph node or visceral metastasis operated on at the CHU d'Amiens between 2004 and 2017 were included. All slides were reviewed by 2 pathologists. Bivariate and subgroup analyses were performed according to the presence of a DISS≤5mm or>5mm, a DTS≤1mm or>1mm and the presence or absence of an ILE. These statistical analyses were then correlated with the 5-year survival.

RESULTS

One hundred and one patients were included in the study. We performed elastic fiber staining on an average of 2 tumor blocks per case and 39.6% of patients had invasion of the elastic boundary. However, bivariate and subgroup analyses showed no statistically significant association between DISS, DTS or ILE and 5-year survival.

CONCLUSION

None of these three histopathological criteria proved to have prognostic value in our series, contrary to some results in the literature. However, as these data are subject to a number of confounding factors, we do not recommend that pathologists specify these different criteria in their reports.

Development and validation of a scoring system incorporating tumor growth pattern and perineural invasion for risk stratification in colorectal cancer

Tumor growth pattern (TGP) and perineural invasion (PNI) at the invasive margin have been recognized as indicators of tumor invasiveness and prognostic events in colorectal cancer (CRC). This study aims to develop a scoring system incorporating TGP and PNI, and further investigate its prognostic significance for CRC risk stratification. A scoring system, termed tumor-invasion score, was established by summing TGP and PNI scores. The discovery cohort (N = 444) and the validation cohort (N = 339) were used to explore the prognostic significance of the tumor-invasion score. The endpoints of the event were disease-free survival (DFS) and overall survival (OS) which were analyzed by the Cox proportional hazard model. In the discovery cohort, Cox regression analysis showed that DFS and OS were inferior for score 4 group compared with score 1 group (DFS, hazard ratio (HR) 4.44, 95% confidence interval (CI) 2.49-7.92, p < 0.001; OS, 4.41, 2.37-8.19,p < 0.001). The validation cohort showed similar results (DFS, 4.73, 2.39-9.37, p < 0.001; OS, 5.52, 2.55-12.0, p < 0.001). The model combining tumor-invasion score and clinicopathologic information showed good discrimination performance than single predictors. TGP and PNI were associated with tumor invasiveness and survival in CRC. The tumor-invasion score generated by TGP and PNI scores served as an independent prognostic parameter of DFS and OS for CRC patients.

Preoperative prognostic nutritional index predicts risk of recurrence after curative resection for stage IIA colon cancer

BACKGROUND

Preoperative nutritional and inflammatory indices have been reported to be associated with the prognosis of patients with malignancy. We evaluated clinicopathological factors, including nutritional and inflammatory indices, and recurrence prognosis in patients with stage IIA colon cancer (CC) who underwent curative surgery.

METHODS

This retrospective study included 197 patients with stage IIA CC who had undergone curative resection. We evaluated the association between prognostic nutritional index (PNI), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) with clinicopathological factors and prognosis for recurrence. For the recurrence-free survival (RFS) analysis, receiver operating characteristic (ROC) curves were used to determine appropriate cutoff values for PNI, NLR, and PLR.

RESULTS

Univariate analyses showed that PNI<44.8 (P = 0.028) was significantly associated with worse RFS in patients with stage IIA CC patients. In the multivariate analyses, PNI<44.8 (hazard ratio [HR] 2.082; 95% confidence interval [CI] 1.005-4.317; P = 0.049) independently and significantly predicted RFS.

CONCLUSION

PNI is a useful marker for predicting recurrence prognosis in post-resection patients with stage IIA CC.

Assessment of peritoneal elastic laminal invasion improves survival stratification of pT3 and pT4a colorectal cancer: a meta-analysis

Evaluating peritoneal elastic laminal invasion (ELI) has been proposed as an additional assessment for pT3 colorectal cancers (CRC). Its clinical significance has not yet been established. We performed a meta-analysis to investigate the prognostic impact of ELI assessment for subcategorisation of pT3 CRC. We performed a search in three electronic databases. HR and its 95% CI for overall survival (OS) and disease-free survival (DFS) were calculated using the random effects model weighted by the inverse variance method. We identified six studies that met inclusion criteria out of an original 703 studies found with our database search terms. Our meta-analysis included 1925 patients with pT3 and pT4a CRCs. The presence of ELI in pT3 CRC was associated with shortened OS compared with ELI negative pT3 CRC (HR=1.76; 95% CI 1.21 to 2.55); whereas the DFS was not statistically significant (HR=1.79; 95% CI 0.91 to 3.52). Furthermore, pT4a patients’ OS (HR=1.84; 95% CI 1.41 to 2.40) and DFS (HR=1.88; 95% CI 1.17 to 3.04) were even worse than the OS and DFS of pT3 ELI (+) patients. ELI is a useful marker for stratifying patients with pT3 or pT4a CRCs into three prognostically distinct groups. We recommend the subcategorisation of pT3 CRC by ELI for better prognostic assessment and treatment strategy of patients with CRC.

How Should Imaging Direct/Orient Management of Rectal Cancer?

Modern rectal cancer management is dependent on preoperative staging, and radiological assessment is a crucial part of this process. Imaging must provide sufficient information to guide preoperative decision-making that is reliable and reproducible. Different methods have been used for local staging; however, magnetic resonance imaging (MRI) has shown to be the most reliable tool for this purpose. MRI offers prognostic information about the patients and guides the decision between neoadjuvant treatment and total mesorectal excision alone. Also, not only the initial staging but also restaging by MRI can provide significant information regarding tumor response that is essential when considering alternative approaches.

Personalizing prognosis in colorectal cancer: A systematic review of the quality and nature of clinical prognostic tools for survival outcomes

Integrating diverse types of prognostic information into accurate, individualized estimates of outcome in colorectal cancer is challenging. Significant heterogeneity in colorectal cancer prognostication tool quality exists. Methodology is incompletely or inadequately reported. Evaluations of the internal or external validity of the prognostic model are rarely performed. Prognostication tools are important devices for patient management, but tool reliability is compromised by poor quality. Guidance for future development of prognostication tools in colorectal cancer is needed.

Complete Pathological Response After Neoadjuvant Long-Course Chemoradiotherapy for Rectal Cancer and Its Relationship to the Degree of T3 Mesorectal Invasion

BACKGROUND

Many studies have shown significantly improved outcomes (reduced local recurrence and improved overall survival) for patients achieving a complete pathological response from neoadjuvant chemoradiotherapy.

OBJECTIVE

This study aimed to document the complete pathological response rate and outcomes in patients receiving preoperative long-course chemoradiotherapy stratified for the extent of T3 mesorectal invasion measured on preoperative imaging.

DESIGN

This is a retrospective study of prospectively collected data, of patients with rectal cancer in the Cabrini Monash University Department of Surgery colorectal neoplasia database, incorporating data from Cabrini Hospital and The Alfred Hospital, identifying patients entered between January 2010 and June 2014.

PATIENTS AND SETTINGS

One hundred eighteen patients with T3 rectal cancer met the selection criteria for the study; 26 achieved complete pathological response (22%).

MAIN OUTCOME MEASURES

Outcomes in terms of complete pathological response and oncological outcomes such as disease-free and overall survival were analyzed.

RESULTS

Patients with complete pathological response had significantly less preoperative invasion than those with no complete pathological response (p < 0.001). Depth of invasion was the only variable associated with complete pathological response (p < 0.002), and the likelihood of complete pathological response decreased by 35% for every millimeter of invasion. Complete pathological response was associated with increased disease-free survival (p = 0.018) and a lower risk of cancer progression (p = 0.046). Depth of invasion was associated with an increased risk of death after surgery; HR increased by 1.07 (95% CI, 1.00-1.15) for each 1-mm increase in invasion.

LIMITATIONS

This was a retrospective study with the usual limitations, although these were minimized through the use of a clinician-driven prospective database.

CONCLUSIONS

The smaller the degree of T3 invasion, the higher the chance of achieving complete pathological response (up to 35%), which is associated with improved disease-free and overall survival. A higher complete pathological response rate is observed in early T3 disease in comparison with more extensive T3 invasion.

Loss of CDH1 (E-cadherin) expression is associated with infiltrative tumour growth and lymph node metastasis

Background:

Loss of CDH1 (E-cadherin) expression in cancer cells may promote cell migration and invasion. Therefore, we hypothesised that loss of CDH1 expression in colorectal carcinoma might be associated with aggressive features and clinical outcome.

Methods:

Utilising molecular pathological epidemiology database of 689 rectal and colon cancer cases in the Nurses' Health Study and the Health Professionals Follow-up Study, we assessed tumour CDH1 expression by immunohistochemistry. Multivariate logistic regression analysis was conducted to assess association of CDH1 loss with tumour growth pattern (expansile-intermediate vs infiltrative) and lymph node metastasis and distant metastasis, controlling for potential confounders including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, and PIK3CA, BRAF and KRAS mutations. Mortality according to CDH1 status was assessed using Cox proportional hazards model.

Results:

Loss of tumour CDH1 expression was observed in 356 cases (52%), and associated with infiltrative tumour growth pattern (odds ratio (OR), 2.02; 95% confidence interval (CI), 1.23–3.34; P=0.006) and higher pN stage (OR, 1.73; 95% CI, 1.23–2.43; P=0.001). Tumour CDH1 expression was not significantly associated with distant metastasis or prognosis.

Conclusions:

Loss of CDH1 expression in colorectal cancer is associated with infiltrative tumour growth pattern and lymph node metastasis.

A clinical model for predicting lymph node metastasis in submucosal invasive (T1) colorectal cancer

BACKGROUND

No single histopathological feature of submucosal invasive colorectal cancer (T1-CRC) can reliably predict the risk for lymph node metastasis (LNM).

AIM

The purpose of the study was to develop a prediction model of LNM in T1-CRC.

METHODS

Ninety-seven surgically resected T1-CRC at our institution were retrospectively evaluated. Morphology, localization, grading, mode of growth, presence of background adenoma, lymphoid infiltration, angiolymphatic invasion, budding, and depth of invasion were assessed. Mortality and morbidity related to surgery were also evaluated. Benefit-risk balance was assessed according to the presence of severe complications and to the presence of LNM.

RESULTS

Fourteen cases had LNM (14%). Eight patients (8%) presented severe surgical complications and there were two deaths (2 %). Infiltrative growth pattern (OR 31.91, 95% CI 2.37-428.36; p = 0.009) and the absence of lymphoid infiltrate (OR 28.75; 95% CI 2.13-388.37; p = 0.011) were the only variables independently associated with LNM in the multivariate analysis. Both variables were included in the prediction model together with sessile morphology (OR 4.88; 95% CI 0.81-29.3; p = 0.083) and poorly differentiated carcinoma (OR 11.77; 95% CI 0.77-179.83; p = 0.076). A 0-100 score was developed (infiltrative growth pattern: no = 0, yes = 33; lymphoid infiltrate: no = 29, yes = 0; sessile morphology: no = 0, yes = 15; poorly differentiated: no = 0, yes = 23). Cutoff point to indicate additional surgery was set in 35 points (i.e., 10% risk LNM). Discrimination of the prediction model was excellent (AUC 0.90; 95% CI 0.81-0.99).

CONCLUSION

Combined evaluation of infiltrative growth pattern, lymphoid infiltration, poorly differentiated carcinoma, and sessile appearance showed good performance for discriminating T1-CRC patients with LNM. The benefit-risk balance was in favor of surgery when at least two of these criteria were present.

Clinical impact of elastic laminal invasion in colon cancer: elastic laminal invasion-positive stage II colon cancer is a high-risk equivalent to stage III

BACKGROUND

Elastic laminal invasion is defined as tumor invasion beyond the peritoneal elastic lamina. It is one of the factors affecting the prognosis of patients with colon cancer.

OBJECTIVE

This study aimed to investigate the clinical impact of elastic laminal invasion in colon cancer and the magnitude of the worse prognosis of elastic laminal invasion-positive, node-negative patients.

DESIGN

This was a retrospective cohort study.

SETTINGS

This study reviewed data from a tertiary care cancer center in Japan.

PATIENTS

The records of 436 patients with pT3 or pT4a colon cancer who underwent curative resection between January 1996 and December 2006 were reviewed.

MAIN OUTCOME MEASURES

The primary outcome measure was recurrence-free survival. Cox regression analyses established the factors associated with recurrence-free survival. Six groups formed by combining the factors were compared.

RESULTS

Of the patients with pT3 disease, those who were positive for elastic laminal invasion had a 5-year recurrence-free survival rate of 73.8% compared with a rate of 85.0% in those who were negative for elastic laminal invasion and 53.5% in patients with pT4 disease. Three unfavorable prognostic factors were identified, including lymph node metastasis, positive elastic laminal invasion, and a lack of adjuvant chemotherapy. Log-rank analysis revealed statistically significant differences in recurrence-free survival between group 1 (node negative, elastic laminal invasion negative, and no adjuvant chemotherapy) and group 3 (node negative, elastic laminal invasion positive, and no adjuvant chemotherapy). The HR for group 1 compared with group 3 was 0.49 (95% CI, 0.27-0.90). Furthermore, the HRs for group 2 (node positive, elastic laminal invasion negative, and received adjuvant chemotherapy) and group 4 (node positive, elastic laminal invasion positive, and received adjuvant chemotherapy) vs group 3 were 0.77 (95% CI, 0.35-1.69) and 1.36 (95% CI, 0.62-2.98).

LIMITATIONS

Our study has limited prediction accuracy of our prognostic stratification, and an analysis of small subgroups may not have been capable of detecting significant differences. In addition, a wide range of hematoxylin and eosin- and elastica-stained slides were examined per case.

CONCLUSIONS

Elastic laminal invasion adversely influences prognosis in pT3 and pT4a colon cancer. Although elastic laminal invasion positivity does not affect prognosis in node-positive patients receiving adjuvant chemotherapy, node-negative patients with elastic laminal invasion have a similar risk of recurrence as node-positive patients.

The tumor border configuration of colorectal cancer as a histomorphological prognostic indicator

Histomorphological features of colorectal cancers (CRC) represent valuable prognostic indicators for clinical decision making. The invasive margin is a central feature for prognostication shaped by the complex processes governing tumor-host interaction. Assessment of the tumor border can be performed on standard paraffin sections and shows promise for integration into the diagnostic routine of gastrointestinal pathology. In aggressive CRC, an extensive dissection of host tissue is seen with loss of a clear tumor-host interface. This pattern, termed "infiltrative tumor border configuration" has been consistently associated with poor survival outcome and early disease recurrence of CRC-patients. In addition, infiltrative tumor growth is frequently associated with presence of adverse clinicopathological features and molecular alterations related to aggressive tumor behavior including BRAFV600 mutation. In contrast, a well-demarcated "pushing" tumor border is seen frequently in CRC-cases with low risk for nodal and distant metastasis. A pushing border is a feature frequently associated with mismatch-repair deficiency and can be used to identify patients for molecular testing. Consequently, assessment of the tumor border configuration as an additional prognostic factor is recommended by the AJCC/UICC to aid the TNM-classification. To promote the assessment of the tumor border configuration in standard practice, consensus criteria on the defining features and method of assessment need to be developed further and tested for inter-observer reproducibility. The development of a standardized quantitative scoring system may lay the basis for verification of the prognostic associations of the tumor growth pattern in multivariate analyses and clinical trials. This article provides a comprehensive review of the diagnostic features, clinicopathological associations, and molecular alterations associated with the tumor border configuration in early stage and advanced CRC.

Prognostic subdivision of ypT3 rectal tumours according to extension beyond the muscularis propria

Background

The subdivision of T3 in rectal carcinoma according to the depth of invasion into perirectal fat has been recommended in the TNM Supplement since 1993. This study assessed the prognostic impact of this pathological staging in tumours removed after neoadjuvant chemoradiotherapy (ypT3).

Methods

Data from patients with ypT3 rectal carcinoma (less than 12 cm from the anal verge) treated with neoadjuvant chemoradiation and total mesorectal excision were analysed. Tumour category ypT3 was subdivided into ypT3a (5 mm or less) and ypT3b (more than 5 mm), based on histological measurements of maximal tumour invasion beyond the outer border of the muscularis propria.

Results

Important differences between ypT3a (81 patients) and ypT3b (43) were found in 5-year rates of locoregional recurrence (7 versus 18 per cent; P = 0·049), distant metastasis (20 versus 41 per cent; P = 0·002), disease-free survival (73 versus 47 per cent; P = 0·001), overall survival (79 versus 74 per cent; P = 0·036) and cancer-related survival (81 versus 74 per cent; P = 0·007). In Cox regression analyses, the ypT3 subclassification was identified as an independent prognostic factor for disease-free (ypT3b: hazard ratio (HR) 2·13, 95 per cent confidence interval 1·16 to 3·89; P = 0·014), observed (ypT3b: HR 2·02, 1·05 to 3·87; P = 0·035) and cancer-related (ypT3b: HR 2·46, 1·20 to 5·04; P = 0·014) survival. Extramural venous invasion was found to be an additional prognostic factor, but the pathological node category after chemoradiotherapy (ypN) did not influence survival.

Conclusion

In ypT3 rectal carcinomas, the proposed subclassification is superior to ypN in predicting prognosis.

The detection and role of lymphatic and blood vessel invasion in predicting survival in patients with node negative operable primary colorectal cancer

Although vascular invasion in colorectal cancer has been recognised since 1938, detection methods and results remain inconsistent. Vascular invasion is currently an independent prognostic factor in colorectal cancer influencing disease progression and survival. The vascular system consists of three components, arterial, venous and lymphatic vessels, all of which can be invaded but accurate distinction between the components remains difficult with routine staining techniques. Even though higher detection rates with elastica staining, for large vessel invasion, and recent techniques for immunohistochemistry for small vessel invasion, have been reported, a standardised method of detection has not been agreed upon which is reflected in the variability of published results. As a result of the Bowel Cancer Screening Programme in the UK it will be necessary to attempt to identify and stratify patients better, to be able to handle the stage migration to early node negative colorectal cancer. At present up to a third of patients, with node-negative colorectal cancer on conventional histopathological analysis, ultimately die of recurrent disease. It is therefore important to develop and standardised methods to identify lymphatic and blood vessel invasion which will influence ultimate survival. The present review summarises the current status of detection methods for these components of vascular invasion.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lymph node micrometastases and isolated tumor cells influence survival in stage I and II colon cancer

PURPOSE

Lymph-node status is considered the most important prognostic factor in colorectal cancer. The aim of the present prospective study was to evaluate the influence of micrometastases and isolated tumor cells on recurrence and disease-free survival in colon cancer.

METHODS

A total of 193 patients with colon cancer, operated on between 2000 and 2005, were enrolled in the study. All lymph nodes were examined by routine microscopy in hematoxylin and eosin-stained sections. If no metastases were identified in any node, all nodes were examined immunohistochemically with monoclonal antibody CAM 5.2.

RESULTS

Ordinary metastases were found in 67 patients, leaving 126 patients in stage I/II. Immunohistochemistry showed that 5% (6/126) of these had micrometastases and 26% (33/126) had isolated tumor cells. A median of 5 years of follow-up revealed local or distant recurrence in 23% (9/39) of stage I/II patients with micrometastases or isolated tumor cells, compared with 7% (6/87) without micrometastases or isolated tumor cells (P = .010). Five-year disease-free survival for patients with and without micrometastases or isolated tumor cells was 75% and 93%, respectively (P = .012). When analyzed separately, patients with isolated tumor cells (excluding micrometastases) had also lower survival than node-negative patients (P = .012).

CONCLUSION

The presence of micrometastases and isolated tumor cells was found to be a prognostic factor for recurrence and disease-free survival. This may have implications for future treatment of stage I/II colon cancer.

Elevated preoperative neutrophil to lymphocyte ratio predicts risk of recurrence following curative resection for stage IIA colon cancer

BACKGROUND AND OBJECTIVES

Adjuvant chemotherapy for stage II colon cancer remains controversial but may be considered for patients with high-risk features. Recent studies have shown that elevated neutrophil to lymphocyte ratio (NLR) is a worse prognostic factor and a predictor of response to chemotherapy in patients with advanced colorectal cancer. The purpose of this study was to evaluate whether NLR predicts risk of recurrence in patients with stage IIA colon cancer undergoing curative resection without adjuvant chemotherapy.

METHODS

We retrospectively reviewed 141 consecutive patients with stage IIA colon cancer treated with curative surgery alone from 2002 to 2006. NLR, as well as demographics, clinical, histopathologic, and laboratory data were analyzed. Univariate and multivariate analyses were conducted to identify prognostic factors associated with recurrent-free survival (RFS).

RESULTS

Cox's regression analysis demonstrated that elevated NLR (>4) (hazard ratio, 4.88; P < 0.01) and less lymph node sampling (<15 lymph nodes; hazard ratio, 3.80; P < 0.05) were adverse prognostic factors for RFS. The 5-year RFS was 91.4% (95% CI, 88.6-94.2%) for patients with normal NLR and 63.8% (51.1-76.3%) for patients with elevated NLR. The 5-year RFS for patients with 0, 1, and 2 of the identified risk factors was 95.1%, 87.4%, and 33.3%, respectively (P < 0.001).

CONCLUSIONS

Elevated preoperative NLR is an independent predictor of worse RFS for patients with stage IIA colon cancer and a potential biomarker to identify candidates for adjuvant chemotherapy.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.

Clinical significance of pT sub-classification in surgical pathology of colorectal cancer

PURPOSE

Tumour stage is the strongest prognostic parameter in colorectal cancer. The study aimed to evaluate the prognostic impact of pT2, pT3, and pT4 sub-classification.

METHODS

Three hundred eighty-one surgical colorectal cancer specimens were retrospectively re-evaluated. pT2 tumours were sub-classified according to infiltration of the inner circumferential (pT2a) or outer longitudinal (pT2b) layer of the muscularis propria. pT3 tumours were sub-classified by measuring the maximal tumour invasion beyond the outer border of the muscularis propria (pT3a <or= 1 mm, pT3b > 1-5 mm, pT3c > 5-15 mm, and pT3d > 15 mm). pT4 tumours were sub-classified according to invasion of other organs or structures (pT4a) or perforation of the visceral peritoneum (pT4b). Data were correlated with other pathological parameters and patient outcome.

RESULTS

Seventy pT2 tumours were re-classified as 37 pT2a and 33 pT2b tumours. There was no significant association with tumour grade, angioinvasion, or lymph node involvement and no significant impact on prognosis. Two hundred eighteen pT3 tumours were re-classified as 49 pT3a, 83 pT3b, 53 pT3c, and 33 pT3d tumours. pT3 sub-classification was significantly associated with tumour grade, angioinvasion, and lymph node involvement and proved to be an independent prognostic variable with respect to progression-free and cancer-specific survival. A cut-off level of 5 mm is recommended. Sixty-five pT4 tumours were re-classified as 15 pT4a and 50 pT4b tumours. There was no significant association with tumour grade, angioinvasion, or lymph node involvement and no significant impact on prognosis.

CONCLUSIONS

pT3 sub-classification was significantly associated with patient outcome. In contrast, pT2 and pT4 sub-classification did not show clinical significance.

Correlação de fatores anatomopatológicos com a sobrevida de pacientes operados por adenocarcinoma colorretal

OBJETIVO: Avaliar a influência de fatores anatomopatológicos como prognóstico na sobrevida de pacientes operados de adenocarcinoma colorretal. MÉTODOS: Estudo tipo coorte histórica aberta, baseado na análise de 119 pacientes operados de adenocarcinoma colorretal com intenção curativa no Hospital Universitário Júlio Muller, no período de 1984 a 2002. Os dados foram obtidos dos prontuários médicos e de exames anatomopatológicos revisados, sendo submetidos à análise estatística de sobrevida em cinco anos pelo método de Kaplan & Méier. O reto foi o segmento mais acometido em 44,5% dos casos. O aspecto macroscópico tumoral predominante foi o ulcerado ou infiltrante (50,4%), com tamanhos entre 2 e 17 cm, sendo que a maioria dos tumores (64,7%) infiltrava até a camada serosa. O número médio de linfonodos analisados foi de 11,8(±7,3) por peça cirúrgica, indentificando-se nestes, 42,8% de metástases. A maioria dos tumores (85,4%) era bem ou moderadamente diferenciada. Foram observadas embolização angiolinfática e perineural em respectivamente 51,2% e 23,5%. RESULTADOS: Não houve significância estatística quanto a morfologia (p=0,87), tamanho do tumor (p=0,56) e grau de diferenciação celular (p=0,83). Os fatores que se correlacionaram com a sobrevida foram o sítio do tumor primário (p=0,04), a invasão angiolinfática intra-tumoral (p=0,02), invasão perineural (p<0,01), a infiltração das camadas (p=0,02), e o comprometimento linfonodal (p<0,01). CONCLUSÃO: A análise dos fatores anatomopatológicos mostrou correlação significativa da sobrevida com o sítio primário, a camada acometida, invasão perineural, invasão angiolinfática e comprometimento dos linfonodos.