Presence Of Extramural Vascular Invasion Research Articles

Imaging and Metabolic Diagnostic Methods in the Stage Assessment of Rectal Cancer

Rectal cancer (RC) is a prevalent malignancy with significant morbidity and mortality rates. The accurate staging of RC is crucial for optimal treatment planning and patient outcomes. This review aims to summarize the current literature on imaging and metabolic diagnostic methods used in the stage assessment of RC. Various imaging modalities play a pivotal role in the initial evaluation and staging of RC. These include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI has emerged as the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and the presence of extramural vascular invasion. CT imaging provides valuable information about distant metastases and helps determine the feasibility of surgical resection. ERUS aids in assessing tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each diagnostic modality is essential for accurate staging and treatment decisions in RC. Furthermore, the integration of multiple imaging and metabolic methods, such as PET/CT or PET/MRI, can enhance diagnostic accuracy and provide valuable prognostic information. Thus, a literature review was conducted to investigate and assess the effectiveness and accuracy of diagnostic methods, both imaging and metabolic, in the stage assessment of RC.

Correlation between Lymphocyte-to-Monocyte Ratio (LMR), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR) and Extramural Vascular Invasion (EMVI) in Locally Advanced Rectal Cancer.

Rectal cancer constitutes around one-third of all colorectal cancers. New markers are required to optimize the treatment. Extramural vascular invasion (EMVI) is a magnetic resonance imaging (MRI)-based negative prognostic marker. Lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR) or platelet-to-lymphocyte ratio (PLR) are blood-based systemic inflammatory response markers with proven prognostic value in many cancers, including CRC. We hypothesized whether there is a relationship between LMR, NLR, PLR and the presence of EMVI on pre-treatment MRI in patients with locally advanced rectal cancer (LARC). We conducted a retrospective analysis of 371 patients with LARC treated in the Maria Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland between August 2016 and December 2021. One hundred eighty-four patients were found eligible for the study. A correlation between the extension of the tumour, nodal status, clinical stage of the disease and the presence of EMVI was found (p < 0.001). The pre-treatment level of neutrophils, platelets and carcinoembryonic antigen (CEA) was significantly higher in the EMVI-positive population (p = 0.041, p = 0.01, p = 0.027, respectively). There were no significant differences regarding the level of LMR, NLR and PLR between the EMVI-positive and EMVI-negative population. LMR, NLR and PLR do not differentiate patients in terms of EMVI; neither of these parameters is a good predictor of the status of EMVI in LARC.

Extramural vascular invasion as an independent prognostic marker in locally advanced rectal cancer: propensity score match pair analysis.

In rectal cancers, presence of extramural vascular invasion on MRI (mrEMVI) is associated with poor survival. The independent influence of mrEMVI in the presence of other prognostic factors has not been previously analyzed using match pair analysis. Consecutive 92 patients having mrEMVI at presentation treated between January 2016 and December 2018 were matched with 92 patients (1:1) without mrEMVI. Matching parameters were T stage, mesorectal fascia involvement, and tumor differentiation. The presence and absence of mrEMVI were correlated to outcomes. An event was defined as locoregional failure or distant metastasis or poor response to chemoradiation rendering the rectal tumor as inoperable. At 3years, in the mrEMVI-positive cohort, 59% had an event and in the mrEMVI-negative cohort, 45% had an event (p = 0.026). Local control was 90.2% (12recurrences in 122 who underwent surgery), two recurrences in the mrEMVI-positive cohort and ten patients in the mrEMVI-negative cohort, which missed statistical significance (p = 0.06). Distant metastasis-free survival was significantly worse in the mrEMVI-positive cohort versus the mrEMVI-negative cohort (58.2% vs. 69.4%) (p = 0.022). Similarly, Overall survival was significantly inferior in mrEMVI-positive cohort compared to the mrEMVI-negative cohort (57% vs. 72.4%) (p = 0.02). The multivariate regression analysis confirmed the independent predictive value of mrEMVI. CONCLUSION: Extramural vascular invasion detected through MRI is an independent risk factor for distant metastasis in the locally advanced carcinoma rectum. Aggressive treatment regimens like total neoadjuvant treatment should be considered in these cases pending randomized control studies.

Clinical and radiological predictors of organ preservation in patients with rectal cancer treated with total neoadjuvant therapy.

3619 Background: Baseline rectal MRI is routinely used for tumor staging, selecting the initial treatment and prognostication of patients with rectal adenocarcinoma. However, associations of baseline clinical and MRI variables with organ preservation (OP) in a prospective randomized trial have not been reported. Methods: Patients with MRI staged clinical stage II or III rectal adenocarcinoma treated in a prospective phase II clinical trial were randomized to either induction chemotherapy (FOLFOX or CAPEOX) followed by chemoradiation or chemoradiation followed by consolidation chemotherapy (FOLFOX or CAPEOX) and recommended total mesorectal excision (TME) or watch-and-wait (WW) based on clinical response. The primary outcome was OP, defined as the time from randomization to the clinical decision of TME or last follow-up, whichever occurred first. Clinical variables included: age, sex, race, tumor grade, radiation dose and treatment arm. Radiological variables (evaluated by baseline MRI prior to randomization) included: distance from the anal verge, tumor length, clinical T stage, clinical N stage, relationship to the mesorectal fascia, presence of extramural vascular invasion (EMVI) and mucinous radiographic findings (>50%). Associations of OP with clinical and radiological variables were assessed utilizing the Cox regression model in univariate and multivariate settings. The final multivariate model was chosen using backward selection. Results were analyzed by intention to treat. Results: Case report forms (CRFs) from baseline MRI were available for 289 of 324 randomized patients (89%). Patients with CRFs differed from those without CRFs in race, distance of the tumor from the anal verge and clinical T stage. Median follow-up was 3.4 years. A total of 156 of 324 patients were recommended TME during the study period. The 3-year OP rate was 47%. Independent predictors of OP in the multivariate analysis can be seen in the table. Conclusions: Although the patients included in this analysis may not be fully representative of the entire cohort, our data shows that several radiological variables associated with unfavorable tumor biology – tumor involvement of the mesorectal fascia, presence of EMVI and involved mesorectal nodes – were negatively associated with organ preservation. This information will be useful in selecting rectal cancer patients for WW and should be used for patient stratification in future clinical trials. Clinical trial information: NCT02008656. [Table: see text]

MRI features of signet ring rectal cancer.

Signet Ring Rectal Cancer (SRRC) of rectum is rare high-grade subtype with poor prognosis and characteristic histopathology. We evaluated its imaging appearance and correlated its outcomes. We conducted a retrospective review of the rectal MRIs of 97 patients with rectal SRRC, evaluating tumor morphology, T2 signal, length, location, pattern of tumor growth, nodal status and location, EMVI (extramural vascular invasion), site of metastases, and response to chemotherapy. The tumor signal on T2W images was categorized into intermediate, T2 hyperintense, and fluid/mucin bright. Imaging findings were correlated with risk of metastatic/ recurrent disease, disease-free survival, and overall survival. The median age of patients of SRRC in our study was 35years and more frequently found in male patients. The common imaging features of SRRC were T2-hyperintense signal (63%), infiltrative growth pattern (76%), positive MR CRM (Circumferential Resection Margin on MRI) (84%), presence of EMVI (51%), and advanced T and N stage (97% and 84%, respectively). Peritoneum and nodes were the most common sites of metastases. Raised serum CEA (Carcino-embryonic Antigen) levels, positive MR CRM status, extramesorectal adenopathy, and advanced N stage had statistically significant predictive value for recurrence or metastases. Elevated serum CEA levels (p = 0.019) and intermediate T2 signal (p = 0.012) demonstrated significant independent association with poor overall survival, while advanced N stage (p = 0.033) demonstrated significant independent association with worse disease-free survival in multivariate analysis. SRRC affected young patients and demonstrated T2-hyperintense signal and subepithelial spread in an infiltrative pattern. Elevated CEA levels and T2-intermediate signal intensity are independent predictors for worse overall survival and advanced nodal stage is independent prognostic factor of poor disease-free survival. MRI rectum can pinpoint the pathology given the distinct MRI morphology and age of presentation.

MRI Evaluation of Rectal Cancer Following Preoperative Chemoradiotherapy

ABSTRACT MR is the radiologic test of choice when evaluating rectal cancer both for staging and restaging following neoadjuvant chemoradiotherapy (nCRT) prior to surgery. Evaluation after treatment should include a description of interval change in the primary tumor location, extent and signal characteristics with particular attention to fibrosis and/or mucinous change. The circumferential resection margin, presence of extramural vascular invasion, and nodal involvement must also be addressed on restaging. Radiologists evaluating these examinations should be aware of pearls and pitfalls as their interpretation plays a key role in determining treatment options for affected patients.

Value of MRI in multimodal treatment of locally advanced rectal carcinoma

MRI is a basic tool in patient selection for preoperative neoadjuvant treatment of rectal carcinoma, with assessment of stage reduction. The aim of the paper was to evaluate chemoradiotherapy effects in advanced stage rectal carcinoma by comparison of MRI findings before and after chemoradiotherapy. Material and methods: Prospectively, MRI findings of 15 patients with rectal carcinoma confirmed at colonoscopy, were evaluated. In all patients preoperative neoadjuvant treatment was done and MRI restaging was performed after 6 to 8 weeks. MRI standard protocol was done on 1.5T machine, sagital T2WI, axial T1WI, T2WI and DWI. On MRI was assessed tumor and nodal stage, presence of extra-mural vascular invasion (EMVI), tumor localization within the rectum (low, medium, high rectum, recto-sigmoid junction). Computer tomography was performed in all patients for distant metastases assessment. Results: Out of 15 patients, 12 (66.7%) were male, and 3 (33.3 %) were female, with a mean age of 65 years (range 50 to 80years). Six cases had middle rectum localization, 6 cases in low rectum, and 3 patients had recto-sigmoid localization. At initial MRI, 7 cases (46.6%) had MR signs for T3 stage, and 8 cases (53.3%) had T4 stage. Comparison of MRI results before and after chemoradiotherapy showed stage decreasing in 5(33.3%), from T4 to T3 stage. In 11 patients (73.7%), EMVI after therapy became negative with a statistically significant difference before and after chemoradiotherapy. All patients before therapy had different numbers of metastatic lymph nodes in mesorectum, with number reduction in all cases after therapy and two patients were without metastatic lymph nodes. Conclusion: MRI has a significant value in pre- and post-neoadjuvant therapy assessment of resection margins involved by tumor, positive extramural vascular invasion, and metastatic lymph node around resection margins. This is important for operative planning in order to avoid extensive resection with surgery techniques that preserve the anal sphincter.

Diagnostic Accuracy of Rectal Tumor Staging MRI in Evaluating Extramural Vascular Invasion

Aim: To determine the diagnostic accuracy of baseline pre-operative MRI in detecting extramural vascular invasion in rectal tumors compared with histopathological reference standard. Materials and Methods: Patients presenting with rectal carcinoma at Salmaniya Medical Complex, Bahrain between 1 st January 2017 and 31 st December 2019 were retrospectively reviewed for the presence of extramural vascular invasion (EMVI) detected on pre-operative staging MRI and a 5-point EMVI score (0-4) was assigned. These findings were then correlated with histopathology reports that were labelled as either positive or negative for EMVI. Results: A total of 82 patients were included in this study. Out of these patients, 71 patients (86.5%) received pre-operative chemotherapy and radiotherapy. 11 patients (13.4%) did not receive any pre-operative chemotherapy or radiotherapy and proceeded directly to surgery. On MRI EMVI (mr-EMVI) was reported in 31 patients (37.8%) while on pathology it was seen in 26 patients (31.7%). Sensitivity, specificity and accuracy of mr-EMVI were 81.2%, 90% and 86.6%, respectively. It was noted that upon staging the tumor, the stage most frequently associated with EMVI was Stage T3c with 18 out of the 31 cases (58%) showing EMVI on MRI. The predominant location of the tumors showing mr-EMVI was in tumors located in mid rectum (90.3%; 28/31). Conclusion: Pre-operative baseline MRI for staging rectal tumors is a highly effective imaging modality to evaluate for the presence of EMVI which can have a significant effect on the management plan.

Rectal cancer MR staging: pearls and pitfalls at baseline examination.

In recent years, rectal MRI has become a central diagnostic tool in rectal cancer staging. Indeed, rectal MR has the ability to accurately evaluate a number of important findings that may impact patient management, including distance of the tumor to the mesorectal fascia, presence of extramural vascular invasion (EMVI), presence of lymph nodes, and involvement of the peritoneum/anterior peritoneal reflection. Many of these findings are difficult to assess in nonexpert hands. In this review, we present a practical approach for radiologists to provide high-quality interpretations at initial baseline exams, based on recent guidelines from the Society of Abdominal Radiology, Rectal and AnalCancer Disease Focused Panel. Practical pearls and pitfalls are discussed, focusing on optimization of technique including, patient preparation and protocol recommendations, interpretation, and essentials of reporting.

Роль МРТ в выявлении экстрамуральной сосудистой инвазии как индикатора наличия регионарных и отдаленных метастазов рака нижнеампулярного отдела прямой кишки

Rectal cancer occupies one of the leading places in the structure of mortality in both sexes, with the only radical method of treatment is surgery. For the planning of surgical treatment, it is important to assess the metastatic lesion of the locoregional lymph nodes, the presence of extramural lymphovascular invasion, which is an important predictor of recurrence of the disease, as well as an indicator of the early appearance of distant metastases. The effectiveness and reliability of preoperative staging of the low rectal cancer has increased significantly after the introduction into clinical practice of magnetic resonance imaging, as well as a comprehensive preoperative radiation examination of patients. The article is devoted to the problems of preoperative staging and determination of statistically significant relationships between the presence of extramural vascular invasion in cancer of the low rectal cancer and the presence of distant metastases, the identification of the correlation between T and N - stages of the tumor, their morphological types with diagnosed extramural vascular invasion.

MRI of Rectal Cancer: Tumor Staging, Imaging Techniques, and Management.

Rectal cancer is prone to local recurrence and systemic metastasis. However, owing to improvements in TNM staging and treatment, including a more widespread use of rectal MRI and increased radiologist awareness of the key rectal cancer TNM staging features, the mortality rate of rectal cancer has been declining over the past few decades in adults over 50 years of age. Currently, rectal MRI plays a key role in the pre- and posttreatment evaluation of rectal cancer, assisting the multidisciplinary team in tailoring the most appropriate treatment option. The benefits achieved with rectal MRI are strictly dependent on obtaining good-quality images, which is important for the characterization of the main anatomic structures and their relationship with the tumor. In primary staging, rectal MRI helps the radiologist (a) describe the tumor location and morphology, (b) provide its T and N categories, (c) detect the presence of extramural vascular invasion, and (d) identify its relationship with surrounding structures, including the sphincter complex and involvement of the mesorectal fascia. These features help diagnose locally advanced rectal tumors (categories T3c-d, T4, N1, and N2), for which neoadjuvant chemoradiotherapy (CRT) is indicated. In restaging after neoadjuvant CRT, in addition to reassessing the features noted during primary staging, rectal MRI can help in the assessment of treatment response, especially with the emergence of nonsurgical approaches such as "watch and wait." ©RSNA, 2019.

Prognostic utility of the presence of extramural vascular invasion in stage II and III colorectal cancer: Data from the FACS randomised controlled trial.

3575Background: Estimates of recurrence after resection of colorectal cancer (CRC) with curative intent form the basis of cancer staging and treatment planning. Adjuvant treatment is recommended in stage III and “high-risk” stage II patients. A key feature commonly used to define patients as “high-risk” is the presence of extramural vascular invasion (EMVI). There is a need to define the prognostic utility of EMVI in an accurately staged prospectively followed-up population managed in the modern era. Methods: Observational analysis of data from the FACS (follow-up after colorectal cancer surgery) trial after 5 years of follow-up. All participants had undergone treatment with curative intent for stage I-III primary CRC, with microscopically clear margins, no evidence of metastases on axial imaging and CEA < 10μg/l following completion of treatment. Data on EMVI were extracted from pathology reports and Cox proportional-hazards regression and Kaplan-Meier curves used to compare survival. Results: EMVI was i...

Local imaging of rectal cancer--update 2015: MRI as imaging biomarker

The significance of state of the art magnetic resonance imaging (MRI) for rectal cancer goes far beyond the detection and diagnostics of local dispersion and is increasingly focusing on patient prognosis. The identification of prognostic factors, such as tumor (T) and nodal (N) status, involvement of the circumferential resection margin, presence of extramural vascular invasion, tumor response prediction following neoadjuvant therapy, therapy-related changes in microcirculation, permeability and tissue cellularity and structured reporting are important elements of advanced rectal cancer imaging. In this context, multiparametric MRI is progressively evolving into a powerful imaging biomarker.

Prognostic value of lymph node ratio and extramural vascular invasion on survival for patients undergoing curative colon cancer resection.

Background:Increasing lymph node ratio (LNR) (ratio of metastatic lymph nodes to the total number of harvested lymph nodes) and extramural vascular invasion (EMVI) have been proposed as adverse prognostic indicators in colorectal cancer, although their use remains variable and controversial. The aim of the present study was to assess the prognostic value of LNR and EMVI in predicting survival for patients undergoing curative colon cancer resection.Methods:Between 2006 and 2012, 922 patients underwent curative colon cancer resection. Surgical technique and pathological assessment did not change during the study period. Clinical and pathological data were collected from a prospectively maintained database. The primary outcome measure was overall survival and disease-free survival. LNR was separated into five categories based on three previously calculated cutoff values: LNR 0 (no lymph nodes involved), LNR 1 (ratio 0.01<0.17), LNR 2 (ratio 0.18–0.41), LNR 3 (ratio 0.42–0.69), and LNR 4 (ratio >0.70).Results:Nine hundred and twenty-two patients underwent colon cancer resection. The median follow-up for survivors was 52.8 months (IQR 34.6–77.6). The median total number of lymph nodes harvested was 16 (IQR13-22). On multivariate analysis, both pN and LNR were strongly associated with overall and disease-free survival. Using the Akaike information criterion (AIC), LNR had greater prognostic value compared with pN. For overall survival, compared with patients in LNR category 0, hazard ratios (95% CI) for those in categories 1, 2, 3 and 4 were 1.37 (1.03,1.82), 2.37 (1.70,3.30), 2.40 (1.57,3.65) and 5.51 (3.16,9.58), respectively. For disease-free survival, patients had hazard ratios (95% CI) of 1.78 (1.25,2.52), 3.79 (2.56,5.61), 2.60 (1.50,4.48) and 4.76 (2.21,10.27), respectively. The presence of EMVI was a significant predictor of decreased overall and disease-free survival (P<0.001).Conclusions:This study demonstrated, in the presence of high surgical, oncology and pathological standards, EMVI and increasing LNR were independent predictors of decreased overall and disease-free survival for patients undergoing curative colon cancer resection. LNR was superior to pN stage in predicting overall and disease-free survival.

PWE-310 Extramural vascular invasion is a more powerful predictor of prognosis than tumour regression grade in rectal cancer

Introduction There are a number of pathological predictors of adverse outcome in rectal cancer which includes positive resection margin, extramural vascular invasion (EMVI) and tumour regression grade (TMG). The aim of this study is to elicit the prognostic significance of EMVI and TMG for primary rectal cancer. Method All patients undergoing surgery for primary rectal cancer were identified from a prospectively maintained database between 2004 and 2012. Tumours were graded using a quantitative 5-grade Mandard TRG classification and the presence of EMVI was histologically studied. Results A total of 342 patients were identified, of which 99 patients had a complete dataset for EMVI and TRG. The 5-year overall survival (OS) was 38% with a disease-free survival (DFS) of 72%. Poor TRG grades and EMVI positivity were found to prognostically significant for OS (p values 0.01 and 0.05, respectively) and DFS (p values 0.02 and 0.001, respectively) at univariate analysis. However, EMVI positivity remained statistically significant for OS (p = 0.05) and DFS (p = 0.01) at multivariate analysis over TRG (OS, p = 0.46 and DFS, p = 0.17). Conclusion The presence of EMVI is a more powerful prognostic factor than TRG in rectal cancer and should be taken into account during the risk stratification process when considering adjuvant chemotherapy. Disclosure of interest None Declared.

The role of epithelial mesenchymal transition and resistance to neoadjuvant therapy in locally advanced rectal cancer

Nonresponse to neoadjuvant therapy is a significant challenge for clinicians managing solid cancers. This study aimed to determine whether epithelial mesenchymal transition (EMT) was associated with nonresponse to neoadjuvant therapy in patients with locally advanced rectal cancer. Representative tissue specimens from the tumour-invasive front of consecutive patients undergoing resection of rectal cancer from 2009 to 2011 were used. Patients with marked regression to neoadjuvant therapy were classified as responders and the remainder were classified as nonresponders. Markers of EMT included reduced immunohistochemical expression of membranous E-cadherin, increased nuclear beta-catenin expression and tumour budding. In-situ hybridization was used to assess the expression of microRNA-200c (mir200c), an upstream master-regulator of EMT. Of 103 patients undergoing resection of rectal cancer, 69 received neoadjuvant chemoradiotherapy; 65% of these were nonresponders. Reduced expression of mir200c was significantly associated with a higher T grade. Reduced membranous E-cadherin, increased nuclear beta-catenin and tumour budding individually predicted the presence of extramural vascular invasion. Reduced E-cadherin, nucleic beta-catenin, reduced expression of mir200c and tumour budding were all significantly associated with nonresponse to neoadjuvant therapy (all P < 0.001). Reduced E-cadherin and expression of mir200c were both associated with reduced cancer-specific survival (log-rank P-values 0.036 and 0.009, respectively). Targeted biomarkers of EMT were associated with nonresponse to neoadjuvant therapy and reduced survival in advanced rectal cancer. EMT may provide a practical clinical biomarker and a novel therapeutic target to improve the proportion of patients who respond to neoadjuvant therapy.

OC-118 Extramural vascular invasion (EMVI) is a better prognostic indicator in PT4 colorectal cancer than pathological subtyping into PT4A and PT4B: clinicopathological analysis of 276 cases

IntroductionThe presence of extramural vascular invasion (EMVI) has been associated with reduced survival in colorectal cancer (CRC), and failure to consider it may account for discrepancies in outcome between similar...

Postgraduate Multidisciplinary Development Program: Impact on the Interpretation of Pelvic MRI in Patients With Rectal Cancer: A Clinical Audit in West Denmark

Pelvic MRI in patients with rectal cancer is an accepted tool for the identification of patients with poor prognostic tumors who may benefit from neoadjuvant therapy. In Denmark, this examination has been mandatory in the workup on rectal cancer since 2002. This study aimed to assess the impact of a multidisciplinary team course for doctors in West Denmark on the technical quality, reporting, and interpretation of pelvic MRI in rectal cancer. This study is interventional and observational. Two expert reviewers served as reference standard in the evaluation of consecutively performed pelvic MRI scans against which the evaluations from the participating centers were compared. Five imaging centers in West Denmark performed pelvic MRI in rectal cancer from March 1 to December 31, 2007. One hundred and eighty patients with newly diagnosed rectal cancer were enrolled. This study involved a multidisciplinary team course including on-site visits. The MR scans were evaluated concerning technical performance, reporting, interpretation, and the ability to correctly allocate patients to chemoirradiation based on imaging findings pre- and postcourse. Eighteen percent of the scans were of satisfying technical quality for staging rectal cancer before the course compared with 74% after (P < .001). After the course, the T-stage subclassification, the depth of extramural spread, the N stage, and the presence of extramural vascular invasion was reported significantly more frequently. Based on imaging findings, we observed no significant effect on the ability to perform correct treatment stratification according to Danish guidelines. The evaluation process itself may have improved the performance of the participating centers. Performance and reporting of pelvic MRI in patients with rectal cancer can be improved significantly through multidisciplinary development courses and on-site visits, whereas improvements in image interpretation with regard to treatment stratification may demand more intensive efforts.

Can depth of tumour invasion predict lymph node positivity in patients undergoing resection for early rectal cancer? A comparative study between T1 and T2 cancers

The present study investigated the risk of lymph node metastasis according to the depth of tumour invasion in patients undergoing resection for rectal cancer. The histology of patients undergoing oncological resection with regional lymphadenectomy for rectal cancer at St Marks Hospital from 1971 to 1996 was reviewed. Of the total number of 1549 patients, 303 patients with T(1) or T(2) rectal cancers were selected. The tumour type, grade, evidence of vascular invasion, depth of submucosal invasion (classed into 'sm1-3') were evaluated as potential predictors of lymph node positivity using univariate and multi-level logistic regression analysis. Tumour stage was classified as T(1) in 55 (18.2%) and T(2) in 248 (81.2%) patients. The incidence of lymph node metastasis in the T(1) group was 12.7% (7/55), compared to 19% (47/247) in the T(2) group. The node positive and negative groups were similar with regard to patient demographics, although the former contained a significantly higher number of poorly differentiated (P = 0.001) and extramural vascular invasion tumours (P = 0.002). There was no significant difference in the number of patients with sm1-3, or T(2) tumour depths within the lymph node positive and negative groups. On multivariate analysis the presence of extramural vascular invasion (odds ratio = 10.0) and tumour grade (odds ratio for poorly vs well-differentiated = 11.7) were independent predictors of lymph node metastasis. Whilst the degree of vascular invasion and poor differentiation of rectal tumours were significant risk factors for lymph node metastasis, depth of submucosal invasion was not. This has important implications for patients with superficial early rectal cancers in whom local excision is being considered.

Accuracy of CT prediction of poor prognostic features in colonic cancer

Whilst imaging of poor prognostic features in rectal cancers has assisted pre-operative treatment stratification, such features have yet to be evaluated in colonic cancers. This study aims to develop criteria for identifying poor prognostic features in colonic tumours and assess the accuracy of CT prediction against histopathology. Criteria were developed for predicting T-stage and N-stage, the presence of extramural vascular invasion and involvement of the retroperitoneal surgical margin (RSM). These criteria were tested on 33 patients with colonic cancer who underwent pre-operative high-resolution CT of their tumour. Two radiologists (Obs 1 and Obs 2) identified independently these poor prognostic features and the results were compared with the final histopathological results. Histological agreement and interobserver variation were calculated using the kappa test. Accuracy of CT prediction of tumour extension beyond muscularis propria was 82% (Obs 1) and 70% (Obs 2). Correct prediction of RSM involvement was 76% (95% confidence interval (CI): 57.8-88.9%) and 79% (95%CI: 61.1-91%) for Obs1 and Obs 2, respectively, with significant agreement between observers (kappa = 0.455, p = 0.050). Prognosis was correctly predicted using CT in 82% (95%CI: 61.5-81.2%) (Obs1) and 85% (95%CI: 68.1-94.9%) (Obs2) with moderate agreement (kappa = 0.459, kappa = 0.527, respectively) with histology. In conclusion, CT has potential as the imaging modality of choice in the pre-operative prediction of poor prognostic features in colonic cancers and could play a role in future treatment stratification.