Character of the invasive margin in colorectal cancer: does it improve prognostic information of Dukes staging?

The prognostic significance of growth pattern, tumor budding, poorly differentiated clusters, desmoplastic reaction pattern and tumor-stroma ratio in colorectal cancer and an evaluation of their relationship with KRAS, NRAS, BRAF mutations

Growth pattern (GP), tumor budding (TB), poorly differentiated clusters (PDC), desmoplastic reaction pattern (DRP) and tumor-stroma ratio (TSR) are prognostic histomorphological parameters in colorectal cancer (CRC). Correlations between these parameters, their individual prognostic values, and their relationship with KRAS/NRAS/BRAF mutations have not been comprehensively examined. We aimed to investigate these associations, which have not been previously explored in this combination. 126 CRC cases were included. GP, TB, PDC, DRP and TSR were evaluated by two experienced pathologists. KRAS/NRAS/BRAF mutation profile were determined using qPCR. Demographic, clinicopathological and survival data were recorded. Interrelations were investigated by statistical analysis. Infiltrative GP was more frequent in high-score TB, PDC-G3, and stroma-high tumors (p < 0.05). High-score TB was more common in PDC-G3 and stroma-high tumors (p < 0.05). Immature DRP was more frequent in stroma-high tumors (p = 0.014). Among histomorphological parameters, a significant relationship was found only between infiltrative GP and the presence of KRAS mutation (p = 0.023). Moreover, GP was significantly associated with pT, lymphatic invasion, perineural invasion (p < 0.05). Effects on survival were assessed using Kaplan-Meier method and Cox proportional hazards model. TB and PDC were identified as independent predictors of overall survival. Higher TB score (p = 0.008) and higher PDC grade (p = 0.013) lead to worse survival. Interestingly, GP, DRP, TSR or KRAS/NRAS/BRAF mutations were not associated with overall survival. Our results highlight the prognostic significance of TB and PDC. We suggest incorporating TB and PDC into routine CRC reports. The association of KRAS mutation with infiltrative GP supports its role in the acquisition of invasive behavior.

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.

Multiplexed 3D atlas of state transitions and immune interaction in colorectal cancer

Advanced solid cancers are complex assemblies of tumor, immune, and stromal cells characterized by high intratumoral variation. We use highly multiplexed tissue imaging, 3D reconstruction, spatial statistics, and machine learning to identify cell types and states underlying morphological features of known diagnostic and prognostic significance in colorectal cancer. Quantitation of these features in high-plex marker space reveals recurrent transitions from one tumor morphology to the next, some of which are coincident with long-range gradients in the expression of oncogenes and epigenetic regulators. At the tumor invasive margin, where tumor, normal, and immune cells compete, T cell suppression involves multiple cell types and 3D imaging shows that seemingly localized 2D features such as tertiary lymphoid structures are commonly interconnected and have graded molecular properties. Thus, while cancer genetics emphasizes the importance of discrete changes in tumor state, whole-specimen imaging reveals large-scale morphological and molecular gradients analogous to those in developing tissues.

Interpretable survival prediction for colorectal cancer using deep learning

Deriving interpretable prognostic features from deep-learning-based prognostic histopathology models remains a challenge. In this study, we developed a deep learning system (DLS) for predicting disease-specific survival for stage II and III colorectal cancer using 3652 cases (27,300 slides). When evaluated on two validation datasets containing 1239 cases (9340 slides) and 738 cases (7140 slides), respectively, the DLS achieved a 5-year disease-specific survival AUC of 0.70 (95% CI: 0.66–0.73) and 0.69 (95% CI: 0.64–0.72), and added significant predictive value to a set of nine clinicopathologic features. To interpret the DLS, we explored the ability of different human-interpretable features to explain the variance in DLS scores. We observed that clinicopathologic features such as T-category, N-category, and grade explained a small fraction of the variance in DLS scores (R² = 18% in both validation sets). Next, we generated human-interpretable histologic features by clustering embeddings from a deep-learning-based image-similarity model and showed that they explained the majority of the variance (R² of 73–80%). Furthermore, the clustering-derived feature most strongly associated with high DLS scores was also highly prognostic in isolation. With a distinct visual appearance (poorly differentiated tumor cell clusters adjacent to adipose tissue), this feature was identified by annotators with 87.0–95.5% accuracy. Our approach can be used to explain predictions from a prognostic deep learning model and uncover potentially-novel prognostic features that can be reliably identified by people for future validation studies.

Infiltrating Tumor Border Configuration is a Poor Prognostic Factor in Stage II and III Colon Adenocarcinoma

INTRODUCTION

Tumor border configuration (TBC) is a prognostic factor in colorectal adenocarcinoma; however, the significance of TBC is not well-documented in colon adenocarcinoma alone.

OBJECTIVE

Our aim was to study the effect of TBC on overall and disease-free survival in stage II and III colon adenocarcinoma.

METHODS

We included patients with stage II and III colon adenocarcinoma who were surgically treated at a tertiary medical center between 2004 and 2015, to ensure long-term follow-up. Patients were stratified into four groups based on stage and TBC. A Cox regression was used to model the relationship of groups while accounting for relevant confounders.

RESULTS

The cohort consisted of 700 patients (371 stage II and 329 stage III). Infiltrating TBC was statistically significantly associated with stage (p < 0.001) and extramural vascular invasion (p < 0.001), but not histologic grade (p = 0.7). Compared with pushing TBC, infiltrating TBC increased the hazard of death by a factor of 1.8 [95% confidence interval (CI) 1.4-2.4; p < 0.001] and 1.7 (95% CI 1.3-2.2; p < 0.001). The hazard of death in patients with stage II disease (infiltrating TBC) or stage III disease (pushing TBC) was not significantly different (adjusted hazard ratio 1.1, 95% CI 0.7-1.7; p = 0.8).

CONCLUSION

Infiltrating TBC is a high-risk feature in patients with stage II and III colon adenocarcinoma. Stage II disease patients with infiltrating TBC and who are node-negative should be considered for adjuvant chemotherapy.

Colonoscopy Surveillance After Colorectal Cancer: the Optimal Interval for Follow-Up

PURPOSE

Patients who have undergone curative surgery for colorectal cancer are at risk of developing a metachronous colorectal tumour or anastomotic recurrence. The aim of this study was to determine the incidence of recurrent colorectal cancer in a cohort of patients who participated in a colonoscopy surveillance programme.

METHODS

This single-centre retrospective observational cohort study included patients who underwent curative surgery for colorectal cancer between 2005 and 2015. All reports of postoperative colonoscopies were retrieved to calculate the incidence rates of recurrence and metachronous colorectal cancer.

RESULTS

Of 2420 patients, 1644 (67.9%) underwent at least one postoperative colonoscopy and 776 (32.1%) did not. In 1087 patients, colonoscopy was performed in the first 18 months after surgery, which detected 34 (3.1%) instances of metachronous colorectal tumours or anastomotic recurrence. Thirty-three additional patients were also diagnosed with recurrent colorectal cancer, but the tumours were detected by other diagnostic modalities or detected perioperatively, rather than by colonoscopy.

CONCLUSIONS

Patients with a history of colorectal cancer have an increased risk for a second colorectal tumour. Therefore, we recommend a colonoscopic surveillance programme with the first colonoscopy performed 1 year after curative surgery, which is in accordance with national guidelines.

TNMF versus TNM in staging of colorectal cancer

AIM

TNM staging and histological grading of rectal cancer has undergone no or minimal changes during the past 20 years despite their major impact on planning, reporting and outcome of the disease. The addition of category 'F' to the 'TNM' staging of colorectal cancer, which becomes TNMF will accommodate the expanding list of risk factors that may affect the management and thus avoid squeezing them into the TNM categories.

METHODS

Reporting of the following risk factors was traced in 730 (664 retrospective and 66 prospective) cases of colorectal cancer: age, Tumor location, preoperative CEA, intraoperative tumor perforation and blood transfusion, quality of TME, tumor grade, non nodal T.Ds, Lymphovascular invasion, lymph node ratio, circumferential tumor margins, apical lymph nodes, infiltrating or pushing and K-ras gene mutation.

RESULTS

The reporting of most risk factors was inadequate; also there is marked improvement in reporting in the prospective cases in preoperative CEA, intra operative blood transfusion and tumor perforation, quality of TME, tumor grade and non-nodal T.Ds (P-value <0.0001).

CONCLUSION

The addition of category 'F' to the TNM staging system to become TNMF may avoid ignoring already established risk factors due to our inability to accommodate them in the inhospitable TNM categories.

Incidence and risk factors of metachronous colorectal neoplasm after curative resection of colorectal cancer in Korean patients

OBJECTIVE

Early detection and endoscopic removal of metachronous neoplasms are important preventive strategies for patients with colorectal cancer (CRC) after curative tumor resection. We aimed to determine the incidence of and the risk factors for metachronous colorectal neoplasms after curative resection for CRC.

METHODS

We retrospectively reviewed clinical data of patients who underwent curative resection for CRC at the National Cancer Center, Korea, from July 2004 to July 2007 and were followed up for a mean duration of 40.7 months. The incidence of and the risk factors for developing metachronous neoplasms were analyzed.

RESULTS

A total of 1049 patients were included in this study. A follow-up colonoscopy showed that 454 (43.3%) patients developed metachronous neoplasms, including 46 (4.4%) with advanced adenoma or cancer. Univariate analyses revealed that age ≥ 60 years, male gender, diabetes mellitus, hypertension, synchronous adenoma, synchronous multiple adenoma and synchronous advanced adenoma were associated with the development of metachronous neoplasms. Baseline risk factors associated with metachronous advanced neoplasm were age ≥ 60 years, synchronous multiple adenoma and synchronous advanced adenoma. Multivariate analysis showed that age ≥ 60 years, synchronous adenoma and diabetes mellitus were risk factors for the development of metachronous neoplasms. The cumulative incidence of metachronous neoplasms was higher in patients with these risk factors than in those without.

CONCLUSIONS

Elder age, synchronous adenoma and diabetes mellitus are risk factors for developing metachronous neoplasia. Therefore, careful surveillance colonoscopy are necessary for these 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.

Micropapillary pattern at the invasive front and its association with unresectable colorectal carcinomas

Unresectable colorectal carcinomas (CRCs) as considered incurable even if the primary tumors and the metastatic ones can undergo resection are correlated with poor prognosis. We evaluated the association between micropapillary pattern at the invasive front and unresectable CRCs. Thirty-four out of 264 (12.9%) CRC patients with stages III and IV were unresectable cases. The patients with unresectable CRCs had significantly worse survival than those with resectable CRCs (P < 0.001). Micropapillary pattern was evident in 12 (4.5%) out of 264 cases. This pattern was observed in 6 of 34 (17.6%) unresectable CRCs and in 6 of 230 (2.6%) resectable cases (P = 0.002). Unresectable CRCs revealed more frequently deeper invasion (odds ratio (OR), 1.175; 95% confidence interval (CI), 1.113-1.241), lymph node metastasis (OR, 2.356; 95% CI, 1.132-4.905), and presence of micropapillary pattern at the invasive front (OR, 8.000; 95% CI, 2.415-26.504) as compared to resectable cases. By multivariable logistic regression analysis, only micropapillary pattern was shown to be an independent predictor of unresectable CRCs (OR, 9.451; 95% CI, 2.468-36.196; P < 0.001). In conclusion, micropapillary pattern at the invasive front is associated with unresectable CRCs, and detection of it could help identify unresectable CRC cases.

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.

The relationships between cellular components of the peritumoural inflammatory response, clinicopathological characteristics and survival in patients with primary operable colorectal cancer

Background:

The host inflammatory response is an important determinant of cancer outcome. We examined different methods of assessing the local inflammatory response in colorectal tumours and explored relationships with both clinicopathological characteristics and survival.

Methods:

Cohort study of patients (n=130) with primary operable colorectal cancer and mature follow-up. Local inflammatory response at the invasive margin was assessed with: (1) a semi-quantitative assessment of peritumoural inflammation using Klintrup–Makinen (K–M) grading and (2) an assessment of individual immune cell infiltration (lymphocytes, plasma cells, neutrophils, macrophages and eosinophils).

Results:

The peritumoural inflammatory response was K–M low grade in 48% and high grade in 52%. Inflammatory cells were primarily macrophages, lymphocytes and neutrophils with relatively few plasma cells or eosinophils. On univariate analysis, K–M grade, lymphocyte infiltration and plasma cell infiltration were associated with cancer-specific survival. On multivariate analysis, only systemic inflammatory response, TNM (tumour, node and metastases) stage, venous invasion, tumour necrosis and K–M grade were independently associated with cancer-specific survival. There was no relationship between local infiltration of inflammatory cells and a systemic inflammatory response. However, high K–M grade, lymphocyte infiltration and plasma cell infiltration were associated with a number of favourable pathological characteristics, including an absence of venous invasion.

Conclusion:

Infiltration of inflammatory cells in the invasive margin of colorectal tumours is beneficial to survival. The adaptive immune response appears to have a prominent role in the prevention of tumour progression in patients with colorectal cancer.

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.

The role of the in situ local inflammatory response in predicting recurrence and survival in patients with primary operable colorectal cancer

Colorectal cancer progression and survival is dependent on complex interactions between the tumour and the host. The pronounced local inflammatory response in and around the tumour is thought to represent the in situ host anti-tumour immune response. Since early reports, 40 years ago, there has been a continuing interest in establishing the cellular composition of immune cell infiltrates and their relationship with survival in colorectal cancer. In this review, we comprehensively examine the evidence for the local inflammatory cell reaction/in situ immune response in predicting outcome in primary operable colorectal cancer and make recommendations as to how such information may be incorporated into routine clinical assessment. Generally, an increasing number/density of immune cells in and around the tumour is associated with improved outcome in over 100 studies. Whilst the prognostic value of a generalized lymphocytic infiltrate or non-specific peritumoural inflammatory response is strongly related to survival based on 40 different studies, it is also apparent that most individual immune cell types relate to recurrence and cancer specific survival. The evidence is particularly robust for tumour infiltrating T lymphocytes and their subsets (CD3+, CD8+, CD45RO+, FOXP3+) in addition to tumour associated macrophages, dendritic cells and neutrophils. Taken together, the evidence suggests both adaptive and innate anti-tumour immune responses play key roles in determining cancer progression. In order to establish routine clinical utility there is a need to rationalise this prognostic information, published over a 40 years period, into a standardized assessment of tumour inflammatory cell infiltrate. Such standardization may also guide development of novel therapeutic interventions.

Expression of cyclin D2 is an independent predictor of the development of hepatic metastasis in colorectal cancer

INTRODUCTION

Cyclin D1 has been implicated in the progression of several cancers by virtue of its influence on progression of the G1/S phase of the cell cycle. However, little is known about the possible roles of cyclin D2 and D3 in colorectal cancers (CRCs).

METHOD

We investigated the expression levels of cyclin D2 and D3 in 84 CRC specimens. Antigen expression was determined by immunohistochemical analysis of cyclin D1, D2, D3, p16INK4A and Ki67 on tissue microarrays constructed using core samples from tumour centres and margins.

RESULTS

For the whole cohort, expression of cyclin D2 at the margin was associated with vascular invasion (P = 0.039), lymph node metastasis (P = 0.020) and liver metastasis (P < 0.001). In patients with stage I and II tumours (n = 84), elevated cyclin D2 and D3 were associated with vascular invasion (P = 0.014 and 0.028 respectively), liver metastasis (P = 0.001 and 0.007 respectively) and reduced disease specific survival (Cyclin D2, P < 0.022). No association was noted between the proliferative marker Ki-67 and the D-type cyclins.

CONCLUSION

These findings suggest that cyclin D2 expression at the invasive margin of CRCs is associated with liver metastasis and may serve as a useful prognostic marker and indicator of the need for adjuvant therapy.

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.

Association between histological type of tumour growth and patient survival in t2-t3 lymph node-negative rectal cancer treated with sphincter-preserving total mesorectal excision

For rectal cancer patients without nodal metastases the identification of unfavourable factors can be helpful for the better selection for adjuvant therapy and multimodality treatment. The aim of this study was to evaluate the impact of clinico-histological parameters on prognosis in node-negative rectal cancer patients. One hundred and thirty-nine consecutive node negative rectal cancer patients with complete five-year follow-up were studied prospectively. All of them underwent curative anterior resection with total mesorectal excision technique. Seventy-eight patients with tumour penetration beyond the bowel wall received neo-adjuvant short-course radiation (25 Gy) followed by surgery within 1 week and postoperative chemotherapy with 5-fluorouracil and folinic acid in six cycles or adjuvant radiochemotherapy: irradiation (50.4 Gy) combined with chemotherapy (as above). Cancer-specific survival was calculated according to the Kaplan-Meier method. Variables significant in univariate analysis by log-rank test (P < 0.05) entered the Cox proportional hazard model. Survival was decreased for males, older patients (>60 years) with extraperitoneal, poorly differentiated cancers, tumours with mucinous histology and with the absence of lymphocytic infiltration but with the lack of statistical importance. Prognosis was significantly improved for patients with T2 tumours versus T3 (P < 0.01) and with cancers with expanding growth comparing to diffusely infiltrating ones (P < 0.01). In multivariate analysis these parameters significantly and independently influenced survival (P < 0.01 and P < 0.05, respectively). Diffusely infiltrating growth of tumour can reflect the more aggressive cancer behaviour and unfavourable course of disease despite the optimised local control. Apart from the extent of tumour penetration the type of invasive margin can be an additional parameter helpful for the optimal treatment planning and better patient selection for postoperative chemotherapy.

Disturbed expression of E-cadherin, beta-catenin and tight junction proteins in colon carcinoma is unrelated to growth pattern and genetic polymorphisms

Adhesion proteins are responsible for the structural integrity of epithelial tissue and in tumors this integrity is often lost, resulting in a disorganization of the tissue. In the present study the complexity of the invasive front of colon carcinomas was correlated with cell adhesion protein expression and with polymorphisms in their genes. A complexity index was constructed from 32 colon carcinomas using computer-assisted morphometry estimating fractal dimension and tumor cell clusters followed by tree analysis. Immunohistochemical staining of beta-catenin, E-cadherin, occludin and claudin 2 was used for assessment of protein expression. Genetic screening of tissue from the tumor invasion front with laser microdissection was performed using SSCP and DNA sequencing. Adhesion protein distribution was significantly disturbed in most carcinomas. A single mutation in the gene of beta-catenin was found but there was no correlation between protein expression and genetic polymorphism. Nor was there any correlation between the complexity of the invasive border and protein distribution or genetic alterations. The results indicate that the complexity of colon carcinoma invasion is not dependent on genetic derangements in the genes of adhesion proteins or the protein distribution. Rather, aberrations in the function of other proteins related to the adhesive proteins could be responsible.

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

PURPOSE

There is an increasing need for accurate prognostic stratification of patients with Stage II colorectal cancer to identify a subgroup of high-risk patients who may benefit from adjuvant therapies. This study was designed to evaluate the prognostic impact of a wide spectrum of pathologic parameters in a consecutive series of homogenously treated and well-characterized patients with Stage IIA (T3N0M0) colorectal cancer.

METHODS

The study included 238 patients operated on by a single surgeon for Stage IIA colorectal tumors. The median postoperative follow-up was 110 (range, 96-120) months. At least 12 lymph nodes were harvested and examined in all the resection specimens. The prognostic value of 13 pathologic parameters, including lymph node occult disease (micrometastases) detected by immunohistochemistry, was investigated.

RESULTS

Multivariate analysis identified tumor growth pattern (expanding or infiltrating; P = 0.01) and extent of tumor spread beyond muscularis propria (< or =5 mm or >5 mm; P = 0.04) as the only factors having independent prognostic value. The combination of these two easily determined parameters allowed us to identify two groups of patients at low risk or high risk of tumor recurrence. The eight-year survival rates were 83.3 and 53.4 percent for the two groups, respectively. The high-risk group comprised those patients with infiltrating tumors and extramural tumor spread > 5 mm.

CONCLUSIONS

We propose a new and simple prognostic model to identify patients with high-risk Stage IIA colorectal cancer for whom adjuvant therapies may be justified and effective.

The influence of invasive growth pattern and microvessel density on prognosis in colorectal cancer and colorectal liver metastases

The nature of the invasive growth pattern and microvessel density (MVD) have been suggested to be predictors of prognosis in primary colorectal cancer (CRC) and colorectal liver metastases. The purpose of the present study was to determine whether these two histological features were interrelated and to assess their relative influence on disease recurrence and survival following surgical resection. Archival tissue was retrieved from 55 patients who had undergone surgical resection for primary CRC and matching liver metastases. The nature of the invasive margin was determined by haematoxylin and eosin (H&E) histochemistry. Microvessel density was visualised using immunohistochemical detection of CD31 antigen and quantified using image capture computer software. Clinical details and outcome data were retrieved by case note review and collated with invasive margin and MVD data in a statistical database. Primary CRCs with a pushing margin tended to form capsulated liver metastases (P<0.001) and had a significantly better disease-free survival than the infiltrative margin tumours (log rank P=0.01). Primary cancers with a high MVD tended to form high MVD liver metastases (P=0.007). Microvessel density was a significant predictor of disease recurrence in primary CRCs (P=0.006), but not liver metastases. These results suggest that primary CRCs and their liver metastases show common histological features. This may reflect common mechanisms underlying the tumour–host interaction.

Clinicopathological significance of stromal variables: angiogenesis, lymphangiogenesis, inflammatory infiltration, MMP and PINCH in colorectal carcinomas

Cancer research has mainly focused on alterations of genes and proteins in cancer cells themselves that result in either gain-of-function in oncogenes or loss-of-function in tumour-suppressor genes. However, stromal variables within or around tumours, including blood and lymph vessels, stromal cells and various proteins, have also important impacts on tumour development and progression. It has been shown that disruption of stromal-epithelial interactions influences cellular proliferation, differentiation, death, motility, genomic integrity, angiogenesis, and other phenotypes in various tissues. Moreover, stromal variables are also critical to therapy in cancer patients. In this review, we mainly focus on the clinicopathological significance of stromal variables including angiogenesis, lymphangiogenesis, inflammatory infiltration, matrix metalloproteinase (MMP), and the particularly interesting new cysteine-histidine rich protein (PINCH) in colorectal cancer (CRC).

Actual number of tumor budding as a new tool for the individualization of treatment of T1 colorectal carcinomas

BACKGROUND AND AIM

Treatment of T1 colorectal carcinomas, either local excision including endoscopic polypectomy or radical surgery, has always been problematic in everyday practice. Although previous studies have revealed that tumor budding at the invasive margin can be a marker for the malignant potential of T1 colorectal carcinomas, the evaluation of tumor budding has not been standardized as yet. In the present study, we attempted to apply the actual number of tumor budding units for the individualization of treatment in T1 colorectal carcinomas.

METHODS

In 76 T1 colorectal carcinomas, associations between lymph node metastasis and clinicopathological parameters were examined statistically. A mathematical formula for predicting the risk of lymph node metastasis was constructed and decision analysis was attempted to determine individually the indication for additional surgery after endoscopic mucosal resection of T1 colorectal carcinomas.

RESULTS

Of the clinicopathological parameters examined, multivariate analysis showed that the actual number of tumor budding units alone was significantly associated with lymph node metastasis. The probability of lymph node metastasis was calculated as Z = 0.07 x (budding counts) - 3.726, probability = 1/1 + e(-Z). The more the budding counts, the higher the probability of lymph node metastasis. This formula was able to accurately predict lymph node metastasis in successive cases. The actual number of tumor budding units can be applied to decision analysis in determining an indication for additional surgery after endoscopic mucosal resection of T1 colorectal carcinomas.

CONCLUSIONS

The actual number of tumor budding units may be useful in the decision making for patient-oriented treatment of T1 colorectal carcinomas.

Prognostic value of somatostatin receptor subtype 2 expression in colorectal cancer

The clinical relevance of the somatostatin receptor subtype 2 (sst2) is well defined in neuroendocrine tumors but it is still a matter of debate whether its expression may have a role also in other tumors not arising from the neuroectoderm. We investigated the prognostic value of the expression levels of sst2 mRNA in a consistent group of patients affected by colorectal cancer. Survival analysis of cancer-related death showed that patients with a high sst2 mRNA expression had an unfavourable outcome (p=0.037) and a significantly shorter disease-free survival (p=0.008). Surprisingly, our findings suggest that sst2 gene overexpression is a feature of colorectal tumors that have a negative outlook; in addition, it may allow additional insight into conventional therapeutic approaches for more aggressive tumors, whose prognosis needs to be improved.

Inflammation and prognosis in colorectal cancer

AIM OF THE STUDY

Previous work has indicated that quantification of inflammatory cell reaction is of prognostic value in colorectal cancer. We evaluated the prognostic significance of inflammatory cell reaction patterns in colorectal cancer and developed a grading method which could be used in the routine assessment of tumours.

METHODS

The intensity of overall inflammatory cell reaction, numbers of neutrophilic and eosinophilic granulocytes, lymphoid cells and macrophages in both the central region and the invasive margin were estimated in 386 colorectal cancer patients. Prognostic significance was analysed by uni- and multivariate analysis.

RESULTS

Our method for classification of inflammatory reaction was reliable. High-grade inflammation at the invasive margin in Dukes' stage A and B cancers (pT1-2N0 and pT3N0, respectively) was associated with better 5-year-survival (87.6%) than low-grade inflammation (47.0%).

CONCLUSIONS

Inflammatory cell response at the invasive border is a relevant prognostic indicator and could be easily incorporated into the routine evaluation of histopathological specimens.

[Prognostic value of the grade of cellular differentiation, of mucus presence and the growth pattern of the invasive margin in colorectal adenocarcinomas Dukes B]

BACKGROUND

The unfavorable evolution of approximately 1/3 of the patients with colorectal cancer, classified in the Dukes B stage, shows to be desirable the addition of another approaches morphologic prognostics. The reports of the literature about prognostic significance of cellular differentiation, mucus presence and the pattern of growth of the invasive margin in colorectal cancer were controversial.

AIMS

To evaluate the prognostic significance of tumor differentiation, mucus presence and the growth pattern of the invasive margin in patients with colorectal carcinomas classified in Dukes B stage.

MATERIALS AND METHOD

A retrospective study of 156 patients who had undergone curative resection for colorectal cancer was made at the Department of Gastroenterology Surgery of the "Hospital do Servidor Público Estadual", in São Paulo, SP, Brazil. Their mean age was 58 (range 28-83) years and consisted of 94 (60.26%) women and 62 (39.74%) men. The cellular differentiation was classified in two degrees: low and high malignancy degree, in agreement with the area of predominant differentiation of the tumor. Tumors with at least 60% of its volume in mucus were called mucinous carcinoma. The growth of the invasive margin was classified as expanding when the tumor showed a well-delineated and circumscribed border pushing the adjacent structures and infiltrating when the tumor advances by a process of seemingly effortless dissection between the normal structures of the bowel wall.

RESULTS

There were predominance of tumors of low malignancy (139 (89.10%)), non-mucinous (142 (91.03%)) and with margin of the infiltrating type (123 (78.85%)). Only the growth of the invasive margin influenced the survival of 5 years. Patients with tumor exhibiting margin of the expanding type, presented a favorable outcome than those with margin of the infiltrating type -- 81.82% x 60.98%.

CONCLUSION

The type of growth of the invasive tumor margin may help to identify the prognosis of low and high-risk subgroups of patients.

The influence of host response on colorectal cancer prognosis

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

Nuclear morphometric analysis of T2 lesions of the rectum--a simple, reproducible method for predicting malignancy potential

BACKGROUND

Using computerized nuclear morphometry, we searched for common, objective parameters for use in predicting potential malignancy of primary T2 tumors of the rectum.

METHODS

In 119 surgically resected T2 rectal cancers, the following parameters of the cancer cell nuclei were microscopically measured: mean nuclear area (NA), mean perimeter (PM), largest-to-smallest diameter ratios (LS), circularity factor (CF), and coefficient of variation of nuclear area (NACV). The calculated parameters were retrospectively analyzed and compared with patients' outcome.

RESULTS

NA, PM, and NACV correlated with recurrence. NA and NACV were significantly associated with disease-free survival. High NACV correlated with lymph node metastasis. In node-negative cases, high NACV correlated with recurrence and tended to be associated with poor prognosis.

CONCLUSIONS

These findings suggest that computerized morphometry is useful for predicting malignancy potential of T2 lesions of the rectum.

Human colorectal cancers with an intact p16/cyclin D1/pRb pathway have up-regulated p16 expression and decreased proliferation in small invasive tumor clusters

A systematic spatial heterogeneity with high proliferative activity at the luminal border and low activity at the invasive margin is an unexpected behavior that has been observed in colorectal cancer (CRC). To clarify this phenomenon and possible underlying regulatory mechanisms, we have by immunohistochemistry elucidated the proliferative activity and the expression of G1/S regulatory proteins in small and large tumor cell clusters at the invasive margin in 97 CRCs. By identifying small tumor clusters at the tumor front, actually invading cancer cells could be characterized and analyzed separately. These cells could then be compared with the main tumor mass represented by the larger tumor clusters. The proliferation was significantly lower in small tumor clusters compared with larger clusters (P < 0.001) and the decrease in proliferation was correlated with a p16 up-regulation (r(s) = -0.41, P < 0.001). Interestingly, CRCs lacking p16 expression (18%) or tumors with other aberrations in the p16/cyclin D1/pRb pathway had a less pronounced decrease in proliferation between large and small clusters (P < 0.001), further strengthening the association between p16 and ceased proliferation at the invasive margin. This contrasts to tumors with low p27 or abnormal p53 levels showing sustained proliferation in small tumor clusters. Our findings imply that invading CRC cells generally have low proliferative activity, and this phenomenon seems to be mediated through p16 and the p16/cyclin D1/pRb pathway.

Tumor invasion: role of growth factor-induced cell motility

Cancer progression to the invasive and metastatic stage represents the most formidable barrier to successful treatment. To develop rational therapies, we must determine the molecular bases of these transitions. Cell motility is one of the defining characteristics of invasive tumors, enabling tumors to migrate into adjacent tissues or transmigrate limiting basement membranes and extracellular matrices. Invasive tumor cells have been demonstrated to present dysregulated cell motility in response to extracellular signals from growth factors and cytokines. Recent findings suggest that this growth factor receptor-mediated motility is one of the most common aberrations in tumor cells leading to invasiveness and represents a cellular behavior distinct from-adhesion-related haptokinetic and haptotactic migration. This review focuses on the emerging understanding of the biochemical and biophysical foundations of growth factor-induced cell motility and tumor cell invasiveness, and the implications for development of targeted agents, with particular emphasis on signaling from the epidermal growth factor (EGF) and hepatocyte growth factor (HGF) receptors, as these have most often been associated with tumor invasion. The nascent models highlight the roles of various intracellular signaling pathways including phospholipase C-gamma (PLC gamma), phosphatidylinositol (PI)3'-kinase, mitogen-activated protein (MAP) kinase, and actin cytoskeleton-related events. Development of novel agents against tumor invasion will require not only a detailed appreciation of the biochemical regulatory elements of motility but also a paradigm shift in our approach to and assessment of cancer therapy.

Distribution of carcinoembryonic antigen and biologic behavior in colorectal carcinoma

PURPOSE

Carcinoembryonic antigen is assumed from the results of several experiments to be associated with invasion of colorectal carcinoma by adhesion or contact inhibition. The patterns and the intensity of carcinoembryonic antigen distribution in colorectal carcinoma were assessed to verify whether they were correlated with malignant potential from those biologic characteristics.

METHODS

Carcinoembryonic antigen distribution was tested in the archival samples of 149 colorectal carcinomas by immunohistochemistry, using three characterized anti-carcinoembryonic antigen monoclonal antibodies: T84.66, PR1A3, and PR3B10. The distribution patterns in neoplastic tissue were categorized into unstained, apicoluminal, and diffuse cytoplasmic patterns. Tumor, invasive tumor margin, and tissue surrounding the tumor were examined.

RESULTS

Although all three antibodies revealed a positive correlation, T84.66 showed better discrimination than the others. Although none of the negative staining of the tumor or invasive tumor margin showed recurrence, the apicoluminal pattern showed recurrence, and the diffuse pattern showed the most frequent recurrence (P < 0.01). Recurrence was also associated with staining intensity in the apicoluminal pattern in both the tumor and invasive tumor margin (P < 0.05). Infiltrative tumor growth and lymph node metastasis were more frequent in cases of positive staining in tissue surrounding the tumor. Patients with the apicoluminal pattern achieved longer survival than patients with the diffuse-cytoplasmic pattern in the invasive tumor margin (P = 0.024) by a multivariate analysis including tumor stage and histologic differentiation.

CONCLUSION

The distribution of carcinoembryonic antigen in tumors and surrounding tissue seems to be closely correlated with invasiveness and metastatic behavior in colorectal carcinoma. Carcinoembryonic antigen immune staining can be considered as an efficient tool to determine groups with risk of recurrence.