Inclusion of Vasculature-Related Variables in the Dukes Staging System of Colon Cancer

Assessment of prognostic indicators and KRAS mutations in rectal cancer using a fractional-order calculus MR diffusion model: whole tumor histogram analysis

PURPOSE

This study aims to explore the relationship between apparent diffusion coefficient (ADC) and fractional-order calculus (FROC)-specific parameters with prognostic indicators and Kirsten rat sarcoma viral oncogene homologue (KRAS) mutation status in rectal cancer.

METHODS

One hundred fifty-eight patients with rectal cancer were retrospectively enrolled. Histogram measurements of ADC, diffusion coefficient (D), intravoxel diffusion heterogeneity (β), and a microstructural quantity (μ) were estimated for the whole-tumor volume. The relationships between histogram measurements and prognostic indicators were evaluated. The efficacy of histogram measurements, both conducted singly and in conjunction, for evaluating different KRAS mutation statuses was also assessed. The performance of mean and median histogram measurements in evaluating various KRAS mutation statuses was assessed using Receiver Operating Characteristic (ROC) curve analysis. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The histogram measurements of ADC, D, β, and μ differed significantly between well-moderately differentiated groups and poorly differentiated groups, T1-2 and T3-4 subgroups, lymph node metastasis (LNM)-negative and LNM-positive subgroups, extranodal extension (ENE)-negative and ENE-positive subgroups, tumor deposit (TD)-negative and TD-positive subgroups, and lymphovascular invasion (LVI)-negative and LVI-positive subgroups. The combination of Dmean, βmean, and μmean achieved the highest performance [The area under the ROC curve (AUC) = 0.904] in evaluating the KRAS mutation status.

CONCLUSION

When assessing parameters from the FROC model as potential biomarkers through histograms, they surpass traditional ADC values in distinguishing prognostic indicators and determining KRAS mutation status in rectal cancer.

The application of apparent diffusion coefficients derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer

OBJECTIVE

To investigate the diagnostic performance of the apparent diffusion coefficient (ADC) derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer.

MATERIALS AND METHODS

One hundred forty-six patients with rectal cancer who underwent preoperative MRI were prospectively enrolled. Two radiologists independently placed free-hand regions of interest (ROIs) in the largest tumor cross section and three small ROIs on the peritumoral zone adjacent to the tumor contour. Maximum values of tumor ADC (ADC_tmax), minimum values of tumor ADC (ADC_tmin), mean values of tumor ADC (ADC_tmean), mean values of peritumor ADC (ADC_pmean), and ADC_pmean/ADC_tmean (ADC ratio) were obtained on ADC maps and correlated with prognostic factors using uni- and multivariate logistic regression, and receiver operating characteristic curve (ROC) analysis.

RESULTS

Interobserver agreement was excellent for ADC_tmax and ADC_tmean (intraclass correlation coefficient [ICC], 0.915-0.958), and were good for ADC_tmin, ADC_pmean, and ADC ratio (ICC, 0.774-0.878). The ADC ratio was significantly higher in the poor differentiation, T3-4 stage, lymph node metastasis (LNM)-positive, extranodal extension (ENE)-positive, tumor deposit (TD)-positive, and lymphovascular invasion (LVI)-positive groups than that in the well-moderate differentiation, T1-2 stage, LNM-negative, ENE-negative, TD-negative, and LVI-negative groups (p = 0.008, < 0.001, < 0.001, 0.001, < 0.001, and < 0.001, respectively). The area under the ROC curve (AUC) of the ADC ratio was the highest for assessing poor differentiation (0.700), T3-4 stage (0.707), LNM-positive (0.776), TD-positive (0.848), and LVI-positive (0.778). Both the ADC ratio (AUC = 0.677) and ADC_pmean (AUC = 0.686) showed higher diagnostic performance for assessing ENE.

CONCLUSION

The ADC ratio could provide better predictive performance for assessing preoperative prognostic factors in resectable rectal cancer.

KEY POINTS

• Both the peritumor/tumor ADC ratio and ADC_pmean are correlated with important prognostic factors of resectable rectal cancer. • Both peritumor ADC and peritumor/tumor ADC ratio had higher diagnostic performance than tumor ADC for assessment of prognostic factors in resectable rectal cancer. • Peritumor/tumor ADC ratio showed the most capability for the assessment of prognostic factors in resectable rectal cancer.

Regulatory tumor-infiltrating lymphocytes prevail in endometrial tumors with low vascular survival ability

INTRODUCTION

Angiogenic activity and vascular survival ability are two distinct vasculature related tumor features that can be assessed in tumor tissues. We examined their correlation with anti-tumor immunity in a series of endometrial carcinomas.

MATERIAL AND METHODS

Thirty-three, stage I, endometrial carcinomas of endometrioid histology were analyzed with immunohistochemistry for the expression of CD31 pan-endothelial cell marker and CD25 and FOXP3 markers of regulatory T-cells. Angiogenic activity (AA) was assessed as the microvessel density in the invading tumor front (MVDt1). The vascular survival ability VSA was assessed by comparing the MVDt1 to the MVD in inner tumor areas (MVDt2 and MVDt3). The tumor-infiltrating lymphocyte TIL-density and the CD25+ and FOXP3+ TILD-density were assessed in the invading front and internal tumor areas.

RESULTS

The AA and VSA varied 4-fold and 10-fold among tumors, respectively. Highly angiogenic tumors were more frequently related with high histological grade (p = 0.01) and low VSA (p < 0.05). Although TIL-density was not associated with MVDt1, a statistically significant inverse association was noted with MVDt3 and VSA (p = 0.0005 and p = 0.002, respectively). Similarly, we observed a statistically significant association between the density of regulatory CD25+ and FOXP3+ TILs with low MVDt3 and low VSA (p = 0.03 and p = 0.04, respectively).

CONCLUSIONS

Low vascular survival ability relates to high accumulation of regulatory T-cells in inner tumor areas of endometrial carcinomas. The current data hypothesizes meaningful interactions between vascular survival, microenvironmental conditions, and immunosuppression in endometrial cancer.

Assessment of histologic prognostic factors of resectable rectal cancer: comparison of diagnostic performance using various apparent diffusion coefficient parameters

This study is to investigate optimum apparent diffusion coefficient (ADC) parameter for predicting lymphovascular invasion (LVI), lymph node metastasis (LNM) and histology type in resectable rectal cancer. 58 consecutive patients with resectable rectal cancer were retrospectively identified. The minimum, maximum, average ADC and ADC difference value were obtained on ADC maps. Maximum ADC and ADC difference value increased with the appearance of LVI (r = 0.501 and 0.495, P < 0.001, respectively) and development of N category (r = 0.615 and 0.695, P < 0.001, respectively). ADC difference value tended to rise with lower tumor differentiation (r = - 0.269, P = 0.041). ADC difference value was an independent risk factor for predicting LVI (odds ratio = 1.323; P = 0.005) and LNM (odds ratio = 1.526; P = 0.005). Maximum ADC and ADC difference value could distinguish N0 from N1 category, N0 from N1-N2, N0-N1 from N2 (all P < 0.001). Only ADC difference value could distinguish histology type (P = 0.041). ADC difference value had higher area under the receiver operating characteristic curve than maximum ADC in identifying LVI (0.828 vs 0.797), N0 from N1 category (0.947 vs 0.847), N0 from N1-N2 (0.935 vs 0.874), and N0-N1 from N2 (0.814 vs 0.770). ADC difference value may be superior to the other ADC value parameters to predict LVI, N category and histology type of resectable rectal cancer.

A Novel Multimodal Radiomics Model for Preoperative Prediction of Lymphovascular Invasion in Rectal Cancer

Objective: To explore a new predictive model of lymphatic vascular infiltration (LVI) in rectal cancer based on magnetic resonance (MR) and computed tomography (CT).

Methods: A retrospective study was conducted on 94 patients with histologically confirmed rectal cancer, they were randomly divided into training cohort (n = 65) and validation cohort (n = 29). All patients underwent MR and CT examination within 2 weeks before treatment. On each slice of the tumor, we delineated the volume of interest on T2-weighted imaging, diffusion weighted imaging, and enhanced CT images, respectively. A total of 1,188 radiological features were extracted from each patient. Then, we used the student t-test or Mann–Whitney U-test, Spearman's rank correlation and least absolute shrinkage and selection operator (LASSO) algorithm to select the strongest features to establish a single and multimodal logic model for predicting LVI. Receiver operating characteristic (ROC) curves and calibration curves were plotted to determine how well they explored LVI prediction performance in the training and validation cohorts.

Results: An optimal multi-mode radiology nomogram for LVI estimation was established, which had significant predictive power in training (AUC, 0.884; 95% CI, 0.803–0.964) and validation (AUC, 0.876; 95% CI, 0.721–1.000). Calibration curve and decision curve analysis showed that the multimodal radiomics model provides greater clinical benefits.

Conclusion: Multimodal (MR/CT) radiomics models can serve as an effective visual prognostic tool for predicting LVI in rectal cancer. It demonstrated great potential of preoperative prediction to improve treatment decisions.

DWI and T2-Weighted MRI Volumetry in Resectable Rectal Cancer: Correlation With Lymphovascular Invasion and Lymph Node Metastases

OBJECTIVE. The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. MATERIALS AND METHODS. This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses. RESULTS. Both gross tumor volume values showed correlations with lymphovascular invasion (r = 0.750 vs r = 0.710; p < 0.0001) and lymph node metastases (r = 0.780 vs r = 0.755; p < 0.0001). Both values were associated with lymphovascular invasion and lymph node metastases in univariate analysis (all p < 0.0001), whereas only the DWI-based value was an independent risk factor for lymphovascular invasion (odds ratio = 1.207; p = 0.005) and lymph node metastases (odds ratio = 1.420; p = 0.005) in multivariate analysis. Both values could distinguish between N0 and N1, N0 and N1-N2, and N0-N1 and N2 disease (all p < 0.0001) in the Mann-Whitney U test. The area under the ROC curve was higher for the DWI-based value in lymphovascular invasion (0.899 vs 0.877), N0 vs N1 (0.865 vs 0.827), N0 vs N1-N2 (0.934 vs 0.911), and N0-N1 vs N2 (0.932 vs 0.927). CONCLUSION. Tumor volumetry data correlated with both lymphovascular invasion and lymph node metastases in resectable rectal cancer. In particular, the DWI-based gross tumor volume showed the most potential for noninvasive preoperative evaluation of lymphovascular invasion and lymph node metastases.

The prognostic value of lymphovascular invasion in radical prostatectomy: a systematic review and meta-analysis

To systematically evaluate the prognostic value of lymphovascular invasion (LVI) in radical prostatectomy (RP) by a meta-analysis based on the published literature. To identify relevant studies, PubMed, Cochrane Library, and Web of Science database were searched from 1966 to May 2014. Finally, 25 studies (9503 patients) were included. LVI was found in 12.2% (1156/9503) of the RP specimens. LVI was found to be correlated with higher pathological tumor stages (greater than pT3 stage) (risk ratio [RR] 1.90, 95% confidence interval [CI] 1.73–2.08, P < 0.00001), higher Gleason scores (greater than GS = 7) (RR 1.30, 95% CI 1.23–1.38, P < 0.00001), positive pathological node (pN) status (RR 5.67, 95% CI 3.14–10.24, P < 0.00001), extracapsular extension (RR 1.72, 95% CI 1.46–2.02, P < 0.00001), and seminal vesicle involvement (RR 3.36, 95% CI 2.41–4.70, P < 0.00001). The pooled hazard ratio (HR) was statistically significant for Biochemical Recurrence-Free (BCR-free) probability (HR 2.05, 95% CI 1.64–2.56; Z = 6.30, P < 0.00001). Sensitivity analysis showed that the pooled HR and 95% CI were not significantly altered by the omission of any single study. Begg's Funnel plots showed no significant publication bias (P = 0.112). In conclusion, LVI exhibited a detrimental effect on the BCR-Free probability and clinicopathological features in RP specimens, and may prove to be an independent prognostic factor of BCR.

Prognostic Factors in Terms of the Number of Metastatic Nodules in Patients With Colorectal Cancer Liver Metastases

Purpose

The hepatic resection is the gold-standard treatment for patients with colorectal-cancer liver metastases (CLM). This study aimed to identify prognostic factors in patients with synchronous CLM who underwent a surgical curative (R0) resection with respect to the number of metastatic nodules.

Methods

Of 1,261 CLM patients treated between January 1991 and December 2010, 339 who underwent a R0 resection for synchronous CLM were included in this retrospective analysis. Patients were grouped according to the number of CLM nodules: 1–2 CLM nodules, n = 272 (group 1) and 3–8 CLM nodules, n = 67 (group 2).

Results

The 5-year progression-free survival (PFS) rate in group 1was better than that in group 2 (P = 0.020). The multivariate analysis identified lymph-node metastasis (N2), lymphovascular invasion (LVI), and three or more CLM nodules as independent poor prognostic factors for PFS in all patients and lymph-node metastasis (N2) and LVI as independent poor prognostic factors for patients in group 1. No independent prognostic factors were identified for patients in group 2. CLM treatment method and neoadjuvant chemotherapy were not associated with survival.

Conclusion

Three or more metastatic nodules, lymph-node metastasis (N2), and LVI were independent poor prognostic factors for PFS in patients with synchronous CLM who underwent a R0 resection. The latter 2 factors were also independent prognostic factors for PFS in patients with less than 3 CLM nodules; however, in patients with three or more CLM nodules, the prognosis for PFS may be related only to liver metastasis.

A two-gene blood test for methylated DNA sensitive for colorectal cancer

Background

Specific genes are methylated with high frequency in colorectal neoplasia, and may leak into blood. Detection of multiple methylated DNA biomarkers in blood may improve assay sensitivity for colorectal cancer (CRC) relative to a single marker. We undertook a case-control study evaluating the presence of two methylation DNA markers, BCAT1 and IKZF1, in circulation to determine if they were complementary for detection of CRC.

Methods

Methylation-specific PCR assays were developed to measure the level of methylated BCAT1 and IKZF1 in DNA extracted from plasma obtained from colonoscopy-confirmed 144 healthy controls and 74 CRC cases.

Results

DNA yields ranged from 2 to 730 ng/mL plasma (mean 18.6ng/mL; 95% CI 11-26 ng/mL) and did not correlate with gender, age or CRC status. Methylated BCAT1 and IKZF1 DNA were detected in respectively 48 (65%) and 50 (68%) of the 74 cancers. In contrast, only 5 (4%) and 7 (5%) controls were positive for BCAT1 and IKZF1 DNA methylation, respectively. A two-gene classifier model (“either or” rule) improved segregation of CRC from controls, with 57 of 74 cancers (77%) compared to only 11 of 144 (7.6%) controls being positive for BCAT1 and/or IKZF1 DNA methylation. Increasing levels of methylated DNA were observed as CRC stage progressed.

Conclusions

Detection of methylated BCAT1 and/or IKZF1 DNA in plasma may have clinical application as a novel blood test for CRC. Combining the results from the two methylation-specific PCR assays improved CRC detection with minimal change in specificity. Further validation of this two-gene blood test with a view to application in screening is now indicated.

Combination of letrozole, metronomic cyclophosphamide and sorafenib is well-tolerated and shows activity in patients with primary breast cancer

PURPOSE

To assess whether the combination of letrozole, metronomic cyclophosphamide and sorafenib (LCS) is well tolerated and shows activity in primary breast cancer (BC).

METHODS

Thirteen oestrogen receptor-positive, postmenopausal, T2-4, N0-1 BC patients received the LCS combination for 6 months. In these patients we examined the pharmacokinetics of sorafenib and cyclophosphamide, toxicity of the regimen, the clinical response to therapy and changes in the levels of biologically relevant biomarkers.

RESULTS

Adequate plasma concentrations of sorafenib were achieved in patients when it was dosed in combination with L+C. The mean plasma concentrations of C were consistently lower following administration of LCS, compared with administration of L+C only. The most common drug-related grade 3/4 adverse events were skin rash (69.3%), hand-foot skin reaction (69.3%) and diarrhoea (46.1%). According to RECIST Criteria, a clinical complete response was observed in 6 of 13 patients. A significant reduction in tumour size, evaluated with MRI, was also observed between baseline and 14 days of treatment in all 13 patients (P=0.005). A significant reduction in SUV uptake, measured by (18)FDG-PET/CT, was observed in all patients between baseline and 30 days of treatment (P=0.015) and between baseline and definitive surgery (P=0.0002). Using modified CT Criteria, a response was demonstrated in 8 out of 10 evaluable patients at 30 days and in 11 out of 13 evaluable patients at the definitive surgery. A significant reduction in Ki67 expression was observed in all patients at day 14 compared with baseline (P<0.00001) and in 9 out of 13 patients at the definitive surgery compared with baseline (P<0.03). There was also a significant suppression of CD31 and VEGF-A expression in response to treatment (P=0.01 and P=0.007, respectively).

CONCLUSIONS

The LCS combination is feasible and tolerable. The tumour response and target biomarker modulation indicate that the combination is clinically and biologically active.

Prognostic significance of lymphovascular or perineural invasion in patients with locally advanced colorectal cancer

BACKGROUND

This study was designed to evaluate the prognostic significance of the positivity of lymphovascular (LVI) and perineural invasion (PNI) in patients with locally advanced colorectal cancer.

METHODS

From January 1999 to December 2009, 1,437 consecutive patients who underwent curative surgery for stage II or III colorectal cancer were analyzed. Patients were then categorized into 4 groups: LVI-/PNI- (n = 850), LVI+ only (n = 178), PNI+ only (n = 271), and LVI+/PNI+ (n = 138).

RESULTS

With a median follow-up period of 56 months, the 5-year overall survival rates of patients with LVI-/PNI-, LVI+ only, PNI+ only, and LVI+/PNI+ were 82%, 73%, 71%, and 56%, respectively (P < .001), and the 5-year disease-free survival rates of patients with LVI-/PNI-, LVI+ only, PNI+ only, and LVI+/PNI+ were 80%, 70%, 65%, and 46%, respectively (P < .001). In multivariate analysis, LVI+/PNI+ was an independent prognostic factor for both overall survival (P < .001) and disease-free survival (P < .001).

CONCLUSIONS

Positivity of both LVI and PNI is a strong predictor of overall and disease-free survival in patients with stages II and III colorectal cancer.

The Factors Effecting Lymphovascular Invasion in Adenocarcinoma of the Colon and Rectum

Adenocarcinomas of the colon and rectum are the most common gastrointestinal malignancy, and lymph node metastases are established as a prognostic factor. Lymphovascular invasion has been recognized as an indication of lymph node metastases. This prompted us to investigate the features of primary tumor that may serve as a risk factor for lymphovascular invasion in colorectal carcinoma. Clinical and pathologic tissue data of colorectal carcinoma treated in our hospital were retrieved from the computer files at Haydarpasa Numune Education and Research Hospital, from June 1998 to December 2010, retrospectively. We excluded all patients who have two-thirds distal rectal carcinoma to rule out neoadjuvant treatment bias. Tissues from the specimens were stained with standard hematoxylin and eosin. Clinical data including age and sex of patient, location and diameter of tumor, perineural invasion, peritumoral lymphocytic infiltration, tumor grade, lymphovascular invasion, Pathologic T level (pT), and lymph node metastasis were recorded. Lymphovascular invasion was present only in 43 patients out of 108. Only pT and lymph node metastases were found to be statistically significant related to lymphovascular invasion (p = 0.04 and p < 0.001). Perineural invasion, pT, and peritumoral lymphocytic infiltration are the factors with p < 0.2 in the univariate analysis that were investigated with multivariate analysis, but no factor was found as an independent prognostic factor for lymphovascular invasion. Lymphovascular invasion is significantly related to lymph node metastases. Only pT is found as a factor that increases the lymphovascular invasion.

Vascular density analysis in colorectal cancer patients treated with vatalanib (PTK787/ZK222584) in the randomised CONFIRM trials

BACKGROUND

Pharmacological inhibitors of vascular endothelial growth factor (VEGF) receptors, like vatalanib, have been tested in randomised trials (CONFIRM (Colorectal Oral Novel therapy For the Inhibition of Angiogenesis and Retarding of Metastases) 1 and 2) in colorectal cancer showing activity in a subgroup of patients with high serum LDH expression. In the current study, we assessed the predictive role of vascular density (VD) in patients treated in the above trials.

METHODS

Paraffin-embedded materials from 141 patients were analysed with immunohistochemistry for the expression of the CD31 (pan-endothelial cell marker) and of phosphorylated pVEGFR2/KDR on endothelial cells. The VD was correlated with response to therapy and with progression-free (PFS) and overall survival (OS).

RESULTS

A significant association of pVEGFR2/KDR+ VD with poor response in the placebo group was noted (response rates (RRs) 15% (3/20) when high VD vs 52% (26/50) when low VD; P=0.006). The RR increased from 15 (3/20) to 50% (11/22) in tumours with high VD when vatalanib was added to chemotherapy (P=0.02). A significantly improved PFS was noted in patients with high pVEGFR2/KDR+ VD when treated with vatalanib (P=0.002). A similar effect was also noted in patients with high CD31+ VD (P=0.07). Overall survival was marginally improved (P=0.07).

CONCLUSION

Assessment of the activated vessel density may allow the stratification of patients recruited in randomised trials with VEGFR-targeting anti-angiogenic agents, unmasking their therapeutic potential and enabling their introduction in the clinical practice for the benefit of specific patient subgroups, at the same time reducing the cost of therapy.

Lymphovascular invasion is a significant prognosticator in rectal cancer patients who receive preoperative chemoradiotherapy followed by total mesorectal excision

PURPOSE

This study was designed to identify the significance of lymphovascular invasion as a prognosticator for tumor recurrence and survival in rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and total mesorectal excision (TME).

METHODS

Between January 2003 and October 2010, the study included 328 patients with primary rectal cancer who had received preoperative CRT followed by TME. We analyzed the clinicopathologic factors that may be associated with survival, such as age, gender, carcinoembryonic antigen (CEA) value, pathologic T and N stage, tumor response, histologic grade, lymphovascular invasion (LVI), and perineural invasion.

RESULTS

Higher pathologic T and N stage, poor tumor response, high-grade histology, and positive LVI were adverse prognostic factors for both disease-free survival (DFS) and overall survival (OS) on the multivariate analysis. Perineural invasion was a significant adverse prognostic factor affecting DFS (P=0.046) but not OS (P=0.08). Increased T and N stage and distant recurrence, but not local recurrence, were significant factors associated with LVI. The LVI-negative group had a higher DFS (71.4 vs. 56.2%, P=0.012) and OS rate (86.7 vs. 63.4%, P=0.020) at 5 years than the LVI-positive group did.

CONCLUSIONS

Positive LVI had a negative impact on survival in patients with rectal cancer who received preoperative CRT and TME and is significantly associated with an increased chance of distant recurrence. Based on this finding, more tailored adjuvant chemotherapy is warranted for advanced rectal cancer patients with LVI to reduce the distant dissemination of tumor.

Analysis of factors associated with prognosis after colorectal cancer resection in 174 Chinese elderly patients

PURPOSE

The purpose of the present study was to investigate risk factors associated with prognosis in elderly patients with colorectal cancer (CRC) and to determine treatment and follow-up strategies.

MATERIALS AND METHODS

CRC patients (age ≥70) who were treated with curative operation were studied. We compared 57 patients whose survival time was less than 2 years with 117 patients with survival time exceeding 5 years, based on the clinical, pathologic, and preoperative clinical laboratory analysis findings. A risk scoring system on basis of factors determined by multiple logistic regression analysis was explored and validated by both receiver operating characteristic and survival analysis.

RESULTS

Neuroticism, rural residence, deep layer invasion, lymphovascular invasion, and high serum CEA levels were found to be associated with adverse prognosis in the multivariate logistic regression model. Risk scoring system based on these factors showed that the patients with total score exceeding 2.5 had a significantly poorer prognosis (P < 0.05), which was validated by survival analysis.

CONCLUSIONS

Patients with neuroticism, rural residence, deep layer invasion, lymphovascular invasion, and high serum CEA level should be regarded as a high-risk group; a simple scoring system based on these factors could be used to evaluate the risk and facilitate treatment of CRC for elderly patients.

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.

Heterogeneous expression of cyclooxygenase-2 and inducible nitric oxide synthase within colorectal tumors: correlation with tumor angiogenesis

BACKGROUND

Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human cancers.

AIMS

To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis.

METHODS

Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE2 and NO at the same sites.

RESULTS

COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF.

CONCLUSION

Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.

Lymphovascular invasion in rectal cancer following neoadjuvant radiotherapy: A retrospective cohort study

AIM: To investigate the meaning of lymphovascular invasion (LVI) in rectal cancer after neoadjuvant radiotherapy.

METHODS: A total of 325 patients who underwent radical resection using total mesorectal excision (TME) from January 2000 to January 2005 in Beijing cancer hospital were included retrospectively, divided into a preoperative radiotherapy (PRT) group and a control group, according to whether or not they underwent preoperative radiation. Histological assessments of tumor specimens were made and the correlation of LVI and prognosis were evaluated by univariate and multivariate analysis.

RESULTS: The occurrence of LVI in the PRT and control groups was 21.4% and 26.1% respectively. In the control group, LVI was significantly associated with histological differentiation and pathologic TNM stage, whereas these associations were not observed in the PRT group. LVI was closely correlated to disease progression and 5-year overall survival (OS) in both groups. Among the patients with disease progression, LVI positive patients in the PRT group had a significantly longer median disease-free period (22.5 mo vs 11.5 mo, P = 0.023) and overall survival time (42.5 mo vs 26.5 mo, P = 0.035) compared to those in the control group, despite the fact that no significant difference in 5-year OS rate was observed (54.4% vs 48.3%, P = 0.137). Multivariate analysis showed the distance of tumor from the anal verge, pretreatment serum carcinoembryonic antigen level, pathologic TNM stage and LVI were the major factors affecting OS.

CONCLUSION: Neoadjuvant radiotherapy does not reduce LVI significantly; however, the prognostic meaning of LVI has changed. Patients with LVI may benefit from neoadjuvant radiotherapy.

Tumor deposits are encountered in advanced colorectal cancer and other adenocarcinomas: an expanded classification with implications for colorectal cancer staging system including a unifying concept of in-transit metastases

The seventh edition of the TNM Classification of Malignant Tumors is due to be published soon. In the current version dating back to 2002, tumor deposits, which are metastatic lesions commonly encountered in the routine histopathological examination of advanced colorectal cancer specimens, are classified according to their shape with different implications for staging. So distinguished, these lesions are considered either as metastatic lymph nodes (N category) or as vascular invasions (T category). We recently proposed a more comprehensive classification approach that also includes the M category. Relying on two of our independent recent studies, we aim here to provide suggestions for a novel classification of tumor deposits with diverse implications for TNM staging system of colorectal cancer. Furthermore, we show that tumor deposits are not limited to colorectal cancer, but they are common to different adenocarcinoma types.

Neoadjuvant treatment of colorectal cancer with bevacizumab: the perioperative angiogenic balance is sensitive to systemic thrombospondin-1 levels

PURPOSE

Colorectal cancer patients receiving neoadjuvant treatment with bevacizumab, a monoclonal antibody neutralizing vascular endothelial growth factor (VEGF), may suffer from wound healing complications after surgery as the antibody persists in patient blood. We characterized the systemic angiogenic balance in the perioperative period to evaluate its effect on physiologic angiogenesis.

EXPERIMENTAL DESIGN

Nineteen patients receiving combination chemotherapy and bevacizumab for six neoadjuvant cycles were compared with 14 patients receiving chemotherapy without bevacizumab. Plasma from perioperative days -1, +1, +7, and +21 was analyzed for VEGF, thrombospondin-1 (TSP-1), and PD-ECGF concentrations. The angiogenic capacity was further tested in an in vitro assay of endothelial cell proliferation and migration.

RESULTS

On day +1, the onset of wound healing was reflected in a change of balance, i.e., an increase of proangiogenic factors VEGF and platelet-derived endothelial cell growth factor compared with low TSP-1 inhibitor levels in both treatment groups. Patients with bevacizumab therapy showed significantly higher blood levels of total VEGF throughout the evaluation period. However, most VEGF molecules were inactive, i.e., complexed with antibody. Nevertheless, the capacity to stimulate endothelial growth was higher for these plasma samples and was reflected in low TSP-1 levels and an altered TSP-1 sensitivity. When purified TSP-1 protein was added, plasma samples of the bevacizumab but not the chemotherapy group showed reduced endothelial growth.

CONCLUSIONS

Feedback mechanisms of bevacizumab therapy are not restricted to VEGF expression but seem to involve additional factors, such as TSP-1, which influences the systemic angiogenic balance and permits endothelial growth.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer

BACKGROUND

Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors.

MATERIALS AND METHODS

In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha.

RESULTS

pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032).

CONCLUSIONS

pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

Pathological assessment of pericolonic tumor deposits in advanced colonic carcinoma: relevance to prognosis and tumor staging

The current TNM classification considers a tumor nodule in the pericolic/perirectal adipose tissue as venous invasion if the nodule has an irregular contour and as regional lymph node metastasis if the nodule has the form and smooth contour of a lymph node. However, detailed studies on the clinico-pathological implications of pericolonic tumor deposits and of extranodal extension are still lacking. We investigated the impact of these metastatic deposits in the pericolic fat in a series of 228 patients with advanced colon cancer. The pericolonic tumor deposits were characterized by their appearance, size, distance from the primary tumor and by their relation with the lymphatic tissue not organized in lymph nodes. These features were then compared with the clinico-pathological characteristics of the tumors and with the patients' survival. All these lesions were associated with reduced disease-free and overall survivals in a univariate analysis, but only pericolonic tumor deposits retained an independent prognostic role in the multivariate analysis. Our findings suggest that pericolonic tumor deposits are a destructive type of venous invasion different from other types of vessel involvement, and that these lesions may rather be included in the M category for staging purposes.

Predictive poor prognostic factors in colonic carcinoma

INTRODUCTION

Five-year survival in rectal cancer has been steadily improving since the introduction of neoadjuvant chemoradiation and total mesorectal excision surgery. In contrast, 5-year survival rates and management of colonic carcinoma remain relatively unchanged. This study aims to identify poor prognostic factors in colonic cancer patients that could potentially be predicted pre-operatively to identify a subset of patients amenable to neoadjuvant treatment strategies.

METHODS

Database compilation of all operable rectal and colonic cancer patients presenting to a single district general hospital over 5 years. Data were documented on presentation and site of tumour, TNM staging, differentiation and extramural venous invasion.

RESULTS

There was no significant difference in 4-year survival between rectal (57.5%) and right (57%) or left sided (52.5%) colonic cancers (p=0.4689). On multivariate analysis, N2-stage, T4-stage and emergency presentation were identified as independent prognostic factors. On univariate analysis, in addition to the above factors, presence of venous invasion (p=0.001) and poor differentiation (p=0.0003) of tumour also predicted for poor 5-year survival.

CONCLUSION

T4-stage and N2-stage and extramural venous invasion are poor prognostic factors that could be identified pre-operatively with suitably accurate imaging. Such patients could then be considered for a pre-operative treatment strategy.

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).

Angiogenesis in colorectal cancer: prognostic and therapeutic implications

Angiogenesis is important for tumor growth and metastasis. This account reviews the clinicopathological studies conducted in the field of angiogenesis in colorectal cancer, the methods of assessing vascular-related characteristics in tissue sections and provides a background for the usefulness of antiangiogenic policies along with chemotherapy and radiotherapy. Highly angiogenic colorectal tumors are associated with aggressive histopathological features and poor patients' survival. Similarly, factors stimulating angiogenesis, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), and others, are commonly related to increased vascular density (VD) and, therefore, to an unfavorable clinical course. Anti-VEGF agents have improved prognosis in patients with metastatic colorectal cancer, when added to standard chemotherapy. It is expected that, in addition to adjuvant chemotherapy and radiotherapy, agents blocking the stimulatory effect of VEGF on endothelial cells would prove beneficial to the patient.