Assessment of publication bias in the reporting of EUS performance in staging rectal cancer

Surgeon assessment of significant rectal polyps using white light endoscopy alone and in comparison to fluorescence-augmented AI lesion classification

PURPOSE

Perioperative decision making for large (> 2 cm) rectal polyps with ambiguous features is complex. The most common intraprocedural assessment is clinician judgement alone while radiological and endoscopic biopsy can provide periprocedural detail. Fluorescence-augmented machine learning (FA-ML) methods may optimise local treatment strategy.

METHODS

Surgeons of varying grades, all performing colonoscopies independently, were asked to visually judge endoscopic videos of large benign and early-stage malignant (potentially suitable for local excision) rectal lesions on an interactive video platform (Mindstamp) with results compared with and between final pathology, radiology and a novel FA-ML classifier. Statistical analyses of data used Fleiss Multi-rater Kappa scoring, Spearman Coefficient and Frequency tables.

RESULTS

Thirty-two surgeons judged 14 ambiguous polyp videos (7 benign, 7 malignant). In all cancers, initial endoscopic biopsy had yielded false-negative results. Five of each lesion type had had a pre-excision MRI with a 60% false-positive malignancy prediction in benign lesions and a 60% over-staging and 40% equivocal rate in cancers. Average clinical visual cancer judgement accuracy was 49% (with only 'fair' inter-rater agreement), many reporting uncertainty and higher reported decision confidence did not correspond to higher accuracy. This compared to 86% ML accuracy. Size was misjudged visually by a mean of 20% with polyp size underestimated in 4/6 and overestimated in 2/6. Subjective narratives regarding decision-making requested for 7/14 lesions revealed wide rationale variation between participants.

CONCLUSION

Current available clinical means of ambiguous rectal lesion assessment is suboptimal with wide inter-observer variation. Fluorescence based AI augmentation may advance this field via objective, explainable ML methods.

Value of biplane transrectal ultrasonography plus micro-flow imaging in preoperative T staging and rectal cancer diagnosis in combination with CEA/CA199 and MRI

BACKGROUND

Rectal cancer is one of the most common malignant tumors and has a high incidence rate and fatality rate. Accurate preoperative T staging of rectal cancer is critical for the selection of appropriate rectal cancer treatment. Various pre-operative imaging methods are available, and the identification of the most accurate method for clinical use is essential for patient care. We investigated the value of biplane transrectal ultrasonography (TRUS) combined with MFI in preoperative staging of rectal cancer and explored the value of combining TRUS plus MFI with CEA/CA199 and MRI.

METHODS

A total of 87 patients from Daping Hospital with rectal cancer who underwent TRUS examination plus MFI were included. Grades of MFI were determined by Alder classification. Among the total patients, 64 underwent MRI and serum CEA/CA199 tests additionally within one week of TRUS. Pathological results were used as the gold standard for cancer staging. Concordance rates between TRUS, MRI, and CEA/CA199 for tumors at different stages were compared.

RESULTS

There were no significant differences between the Alder classification and pathological T staging. The concordance rate of TRUS and MFI for rectal cancer T staging was 72.4% (K = 0.615, p < 0.001). Serum CEA and CA199 levels were significantly different in tumors at different stages and increased progressively by pathological stage (p < 0.001); the accuracy rate was 71.88% (K = 0.599, p < 0.001), while that of MRI was 51.56% (K = 0.303, p < 0.001), indicating that TRUS had higher consistency in the preoperative T staging of rectal cancer. The combination of TRUS, MRI, and CEA/CA199 yielded an accuracy rate of 90.6%, which was higher than that of any method alone.

CONCLUSIONS

Preoperative T staging of rectal cancer from biplane TRUS plus MFI was highly consistent with postoperative pathological T staging. TRUS combined with MRI and serum CEA/CA199 had a greater value in the diagnosis of rectal cancer and a higher diagnostic rate than any examination alone.

[Rational staging and follow-up of colorectal cancer : Do guidelines provide further help?]

CLINICAL/METHODICAL ISSUE

Colorectal cancer is one of the most common malignant tumors. Preoperative imaging is crucial in rectal cancer as patients can only receive optimal treatment when accurate staging is performed. The N‑staging is often difficult with the available options and must be called into question as a staging parameter.

STANDARD RADIOLOGICAL METHODS

Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) are particularly suitable for local staging. Multiparametric MRI with diffusion imaging is indispensable for tumor follow-up.

METHODICAL INNOVATIONS

The assessment of infiltration of the mesorectal fascia is best accomplished using high-resolution MRI. In addition, extramural vascular infiltration (EMVI) has become established as another important prognostic factor. After neoadjuvant therapy and restaging of locally advanced rectal cancer, the identification and validation of prognostically relevant image parameters are prioritized. Multiparametric MRI of the rectum including diffusion imaging as well as the application of radiological and pathological scores (MR-TRG) are becoming increasingly more important in this context.

ASSESSMENT

For the radiologist it is important to become familiar with indicators of the resectability of rectal cancer and to be able to reliably read prognostically relevant imaging parameters in the tumor follow-up.

PRACTICAL RECOMMENDATIONS

For the practical application, the establishment of a fixed MRI protocol is essential. In addition to a guideline-compliant TNM classification, the radiologist must provide the clinician with information on infiltration of the mesorectal fascia and extramural vascular infiltration. The MR-TRGs are becoming increasingly more important in tumor follow-up.

EUS versus magnetic resonance imaging in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis

BACKGROUND AND AIMS

EUS and magnetic resonance imaging (MRI) are both used for locoregional staging of rectal cancer, which determines treatment options. There is a lack of consensus on the best modality for locoregional staging, with studies supporting both EUS and MRI. In this study, we performed the first diagnostic test accuracy meta-analysis to compare the diagnostic accuracy, sensitivity, and specificity of EUS and MRI in the staging of rectal cancer.

METHODS

A comprehensive electronic literature search up to June 2018 was performed to identify prospective cohort studies directly comparing the accuracy of EUS with MRI in staging nonmetastatic rectal cancer with surgical pathology as the reference standard. Quality of the included studies was measured by using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. A bivariate hierarchical model was used to perform the meta-analysis of diagnostic test accuracy according to the Cochrane approved methodology. Summary receiver operating characteristics were developed, and the area under the curve was calculated for overall and individual T and N staging, for EUS, MRI, and head-to-head comparison.

RESULTS

Six of 2475 studies including 234 patients were eligible. Pooled sensitivity and specificity in T staging were .79 (95% confidence interval [CI], .72-.85) and .89 (95% CI, .84-.93) for EUS and .79 (95% CI, .72-.85) and .85 (95% CI, .79-.90) for MRI, respectively. Pooled sensitivity and specificity in N staging were .81 (95% CI, .71-.89) and .88 (95% CI, .80-.94) for EUS and .83 (95% CI, .73-.90), and .90 (95% CI, .82-.95) for MRI, respectively. In area under the curve head-to-head analysis, EUS was superior to MRI in overall T staging (P < .05). EUS outperformed MRI in overall T, overall N, T1, and T3 staging (P < .01), after excluding studies using an endorectal coil for MRI. MRI was superior to EUS in T2 staging (P = .01) in both analyses.

CONCLUSIONS

EUS and MRI both provide reasonable diagnostic accuracy in the staging of nonmetastatic rectal cancer. EUS was superior to MRI in overall T staging and overall T and N staging after adjusting for MRI technology. Practitioners should be aware of advantages and disadvantages of both modalities and choose appropriate methods while considering diagnostic accuracy of each test and institutional practices and limitations.

Optimal Imaging Strategies for Rectal Cancer Staging and Ongoing Management

Imaging determines the optimal treatment for rectal cancer patients. High-resolution magnetic resonance imaging (MRI) overcomes many of the known limitations of previous methods. When performed in accordance with the recommended standards, MRI enables accurate staging of both early and advanced rectal cancer, accurate response assessment, the delineation of recurrent disease and planning surgical treatment in a safe and effective manner. Tumour-related high-risk features with known adverse outcomes can be preoperatively identified and treated with neoadjuvant chemoradiotherapy. Further, MRI post-treatment tumour response assessment using TRG grading system also predicts the likely survival outcomes and in the future will be used to modify treatment further by stratification into good and poor responders. There is a paucity of literature with validated outcome data concerning use of diffusion-weighted imaging and positron emission tomography (PET)/computed tomography (CT), and in the absence of any validated methods and outcome data, their use in the initial assessment and restaging after treatment is limited to research protocols. Combination MRI and CT is essential for distant spread assessment and recurrent disease, and currently PET-CT is sometimes used in the workup of patients with recurrent and metastatic disease.

Efficacy of 3-Dimensional Endorectal Ultrasound for Staging Early Extraperitoneal Rectal Neoplasms

BACKGROUND

Adequate oncologic staging of rectal neoplasia is important for treatment and prognostic evaluation of the disease. Diagnostic methods such as endorectal ultrasound can assess rectal wall invasion and lymph node involvement.

OBJECTIVE

The purpose of this study was to correlate findings of 3-dimensional endorectal ultrasound and pathologic diagnosis of extraperitoneal rectal tumors with regard to depth of rectal wall invasion, lymph node involvement, percentage of rectal circumference involvement, and tumor extension.

DESIGN

Consecutive patients with extraperitoneal rectal tumors were prospectively assessed by 3-dimensional endorectal ultrasound blind to other staging methods and pathologic diagnosis.

PATIENTS

Patients who underwent endorectal ultrasound followed by surgery were included in the study.

SETTINGS

The study was conducted at a single academic institution.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values, area under curve, and κ coefficient between 3-dimensional endorectal ultrasound and pathologic diagnosis were determined. Intraclass correlation coefficient was calculated for tumor extension and percentage of rectal wall involvement.

RESULTS

Forty-four patients (27 women; mean age = 63.5 years) were evaluated between September 2010 and June 2014. Most lesions were malignant (72.7%). For depth of submucosal invasion, 3-dimensional endorectal ultrasound showed sensitivity of 77.3%, specificity of 86.4%, positive predictive value of 85.0%, a negative predictive value of 79.2%, and an area under curve of 0.82. The weighted κ coefficient for depth of rectal wall invasion staging was 0.67, and there was no agreement between 3-dimensional endorectal ultrasound and pathologic diagnosis for lymph node involvement (κ = -0.164). Intraclass correlation coefficient for lesion extension and percentage of rectal circumference involvement were 0.45 and 0.66. A better correlation between 3-dimensional endorectal ultrasound and pathologic diagnosis was observed in tumors <5 cm and with <50% of rectal wall involvement.

LIMITATIONS

The relatively small sample size of patients with early rectal lesions referred directly for surgery could represent a potential selection bias.

CONCLUSIONS

Three-dimensional endorectal ultrasound was effective for determining rectal wall invasion and lesion extension in tumors <5 cm and with <50% of rectal wall invasion but was limited for detecting lymph node involvement in early rectal lesions.

Imaging in rectal cancer with emphasis on local staging with MRI

Imaging in rectal cancer has a vital role in staging disease, and in selecting and optimizing treatment planning. High-resolution MRI (HR-MRI) is the recommended method of first choice for local staging of rectal cancer for both primary staging and for restaging after preoperative chemoradiation (CT-RT). HR-MRI helps decide between upfront surgery and preoperative CT-RT. It provides high accuracy for prediction of circumferential resection margin at surgery, T category, and nodal status in that order. MRI also helps assess resectability after preoperative CT-RT and decide between sphincter saving or more radical surgery. Accurate technique is crucial for obtaining high-resolution images in the appropriate planes for correct staging. The phased array external coil has replaced the endorectal coil that is no longer recommended. Non-fat suppressed 2D T2-weighted (T2W) sequences in orthogonal planes to the tumor are sufficient for primary staging. Contrast-enhanced MRI is considered inappropriate for both primary staging and restaging. Diffusion-weighted sequence may be of value in restaging. Multidetector CT cannot replace MRI in local staging, but has an important role for evaluating distant metastases. Positron emission tomography-computed tomography (PET/CT) has a limited role in the initial staging of rectal cancer and is reserved for cases with resectable metastatic disease before contemplating surgery. This article briefly reviews the comprehensive role of imaging in rectal cancer, describes the role of MRI in local staging in detail, discusses the optimal MRI technique, and provides a synoptic report for both primary staging and restaging after CT-RT in routine practice.

Limits of endorectal ultrasound in tailoring treatment of patients with rectal cancer

BACKGROUND

Endorectal ultrasound (ERUS) is considered reliable in staging rectal cancer, but recently some critics have questioned its accuracy. The aim of this study was to evaluate how often an ERUS-based decision leads to an appropriate treatment.

METHODS

Two hundred and twenty patients with rectal cancer staged with ERUS who underwent a surgical resection or a local excision without neoadjuvant therapy from 1997 to 2012 were included. According to ERUS, patients were divided into three groups of indication: (a) local excision (Tis-1 N0), (b) direct surgery (T2 N0), (c) preoperative chemoradiation (T3-4 or N+). Accuracy was explored by the correlation established with the final pathology.

RESULTS

Accuracy for T and N staging was 65 and 64%, respectively. Indication to local excision and to chemoradiation was correct in 97 and 88% of patients staged by ERUS. Accuracy of indication to direct surgery was poor (37%), and 21% of patients were overtreated in this group.

CONCLUSIONS

ERUS seems not able to fulfill all the needs of ideal tailored therapeutic strategies. T2 diagnosis needs to be confirmed by an excisional biopsy before a final decision is made because overstaging of early tumors may occur in a not-so-negligible proportion of patients.

Multidisciplinary treatment of rectal cancer in 2014: Where are we going?

In the present review we discuss the recent developments and future directions in the multimodal treatment of locally advanced rectal cancer, with respect to staging and re-staging modalities, to the current role of neoadjuvant chemo-radiation and to the conservative and more limited surgical approaches based on tumour response after neoadjuvant combined therapy. When initial tumor staging is considered a high accuracy has been reported for T pre-treatment staging, while preoperative lymph node mapping is still suboptimal. With respect to tumour re-staging, all the current available modalities still present a limited accuracy, in particular in defining a complete response. The role of short vs long-course radiotherapy regimens as well as the optimal time of surgery are still unclear and under investigation by means of ongoing randomized trials. Observational management or local excision following tumour complete response are promising alternatives to total mesorectal excision, but need further evaluation, and their use outside of a clinical trial is not recommended. The preoperative selection of patients who will benefit from neoadjuvant radiotherapy or not, as well as the proper identification of a clinical complete tumour response after combined treatment modalities,will influence the future directions in the treatment of locally advanced rectal cancer.

MR imaging for rectal cancer: the role in staging the primary and response to neoadjuvant therapy

Pre-operative staging is an essential aspect of modern rectal cancer management and radiological assessment is central to this process. An ideal radiological assessment should provide sufficient information to reliably guide pre-operative decision-making. Technical advances allow high-resolution imaging to not only provide prognostic information but to define the anatomy, helping the surgeon to anticipate potential pitfalls during the operation. The main imaging modality for local staging of rectal cancer is Magnetic Resonance Imaging (MRI), as it defines the tumour and relevant anatomy providing the most detail on the important prognostic factors that influence treatment choice. In addition, there is an emerging role for MRI in the assessment of the response to neoadjuvant therapy. This article is an evidence-based review of rectal cancer staging focusing on post-treatment assessment of response using MRI. The discussion extends into the implications for reliably assessing response and how this may influence future rectal cancer management.

Use of endoscopic ultrasound in the preoperative staging of gastric cancer: a multi-institutional study of the US gastric cancer collaborative

BACKGROUND

Endoscopic ultrasound (EUS) can be used to guide the therapeutic plan for patients with gastric adenocarcinoma (GAC), but data on its use and accuracy remain poorly defined. We sought to define the use of EUS, as well as characterize the diagnostic accuracy of EUS among patients with GAC.

STUDY DESIGN

We identified 960 patients who underwent resection of GAC between 2000 and 2012 from 7 major academic institutions participating in the US Gastric Cancer Collaborative. Clinicopathologic and EUS data were collected and analyzed using chi and kappa statistics.

RESULTS

Of 960 patients, 223 (23.2%) underwent evaluation with preoperative EUS. Among patients who underwent EUS, 74 (33.2%) received neoadjuvant chemotherapy; 149 (66.8%) proceeded directly to resection. Among patients who did not receive neoadjuvant therapy and received curative intent gastric resection, the EUS T classifications were T1 (33.3%), T2 (35.6%), T3 (18.9%), T4 (12.1%) and the N classifications were N0 (68.1%) and N ≥ 1 (31.9%). In contrast, when tumor stage was based on the final surgical specimen, there was a higher proportion of cases with more advanced T stage (T1, 36.4%; T2, 14.4%; T3, 23.5%; T4, 25.7%) and N stage (N0, 51.3%; N ≥ 1, 48.7%). The agreement of preoperative EUS compared with surgical staging for T (kappa = 0.28, p < 0.001) and N (kappa = 0.33, p < 0.001) classification was only fair.

CONCLUSIONS

Less than one-quarter of patients with GAC underwent preoperative EUS staging. In patients who did not receive preoperative chemotherapy, tumor stage on EUS often did not correlate with T stage and N stage on final pathologic analysis. Endoscopic ultrasound should be combined with other staging modalities to optimize staging of patients with GAC.

Imaging in rectal cancer: magnetic resonance imaging versus endorectal ultrasonography

Over the past several decades there have been tremendous improvements in the outcomes of patients with rectal cancer. Imaging modalities such as endorectal ultrasonography (ERUS), magnetic resonance imaging (MRI), and computed tomography scanning play a pivotal role in evaluating rectal cancer preoperatively, planning surgical procedures, and selecting patients for neoadjuvant therapy. This article provides an overview of rectal anatomy and pelvic structures relevant to preoperative assessment and surgical treatment. The technical aspects, applications, and limitations of the imaging tools currently in use are examined, focusing on MRI and ERUS.

MR evaluation of rectal cancer: current concepts

Magnetic resonance imaging has become more frequently utilized for staging, preoperative planning, and post-neoadjuvant evaluation of rectal cancer. It offers detailed resolution of the layers of the rectal wall, visualization of the mesorectal fascia, and identification of locoregional nodal involvement. Many advances have been made since the original protocols and include the use of phased-array coils, orthogonally obtained images and 3-dimensional sequences, the use of diffusion-weighted and perfusion protocols to better evaluate the tumor before and after neoadjuvant therapy, and the development of techniques to better evaluate metastatic nodes. Magnetic resonance imaging shows similar accuracy to endorectal ultrasound when staging and offers a less invasive technique that is not limited by patient discomfort or decreased luminal size. This article is meant to provide an update on the recent advances in rectal cancer imaging while addressing the controversial issues that exist in staging, technique, and imaging protocol.

Stage and size using magnetic resonance imaging and endosonography in neoadjuvantly-treated rectal cancer

AIM: To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS).

METHODS: In this study, patients were recruited in a phase I/II trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stage I and stage II or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour.

RESULTS: The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording.

CONCLUSION: MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.

The accuracy of multi-detector row computerized tomography in staging rectal cancer compared to endoscopic ultrasound

BACKGROUND/AIM

Our aim was to evaluate the diagnostic accuracy of multi-detector row computerized tomography (MDCT) in staging of rectal cancer by comparing it to rectal endoscopic ultrasound (EUS).

MATERIALS AND METHODS

We prospectively included all patients with rectal cancer referred to our gastroenterology unit for staging of rectal cancer from December 2007 until February 2011, 53 patients whose biopsy had proven rectal cancer underwent both MDCT scan of the pelvis and rectal EUS. Both imaging modalities were compared and the agreement between T- and N-staging of the disease was assessed.

RESULTS

We staged 62 patients with rectal cancer during the study period. Of these, 53 patients met the inclusion criteria and were evaluated (25 women and 28 men). The mean age was 57.79 ± 14.99 years (range 21-87). MDCT had poor accuracy compared with EUS in T-staging with a low degree of agreement (kappa = 0.26), while for N-staging MDCT had a better accuracy and a moderate degree of agreement with EUS (kappa = 0.45).

CONCLUSIONS

MDCT has a poor accuracy for predicting tumor invasion compared to EUS for T-staging while it has moderate accuracy for N-staging.

Prognostic relevance of gastric cancer staging by endoscopic ultrasound

BACKGROUND

Recent trials and guidelines have established the use of neoadjuvant chemotherapy for resectable UICC stage II to IV gastric cancers. In this setting, preoperative staging is pivotal for correct patient selection. This cohort study was designed to assess the accuracy of endoscopic ultrasound (EUS) and the ability to select correctly patients for neoadjuvant chemotherapy on the basis of survival outcome.

METHODS

Eighty-two consecutive Caucasian patients (46 male; median age 72 years) with gastric cancer underwent EUS staging and subsequent surgery without perioperative chemotherapy or radiotherapy. Patients were followed for a median of 800 days postoperatively. Pathology and EUS UICC and T stages were compared and evaluated as predictors of survival using Kaplan-Meier and Cox regression analysis.

RESULTS

The overall accuracy of EUS for UICC classification compared with pathology was 62 %, and the accuracy for delineation of UICC I was 89 %. For the therapeutically relevant differentiation of early gastric cancer (UICC stage I), EUS (mean survival, 2,298 days, R2 = 0.23) and pathology (2,461 days, R2 = 0.24) predicted survival equally well. Similar results were obtained for T staging by EUS (mean survival, 2,065 days for uT1/2, R2 = 0.24) or pathology (2,185 days, R2 = 0.22).

CONCLUSIONS

EUS identifies the low risk subgroup (uUICC stage I or uT1/2) with similar performance as pUICC stage I or stage pT1/2 in gastric cancer and very similar survival characteristics. EUS thus may be the noninvasive method of choice for preoperative selection of patients for immediate resection versus neoadjuvant chemotherapy.

Laparoscopic proctectomy: oncologic considerations

The role of laparoscopic proctectomy in rectal cancer has not clearly been defined. Publications on long-term outcomes after laparoscopic proctectomy is lacking and there is a wide variation of practice patterns of rectal cancer management. Current data supports the feasibility of laparoscopic proctectomy for rectal cancer but due to surgeon, patient and tumor related factors open technique may be favored. Current series suggest that laparoscopic proctectomy can be performed with similar oncologic adequacy with regards to, circumferential resection margin, distal margin, local recurrence and quality of life. Ongoing trials will provide evidence clarifying the role of laparoscopic proctectomy in rectal cancer. Until then, high-level laparoscopic skills and meticulous preoperative evaluation of both patient and tumor can identify appropriate candidates.

Preoperative radiation therapy for upper rectal cancer T3,T4/Nx: selectivity essential

This review explores the current available literature regarding the role of neoadjuvant therapy for upper locally advanced rectal cancers (≥10 cm-15 cm). Although there is a paucity of data evaluating the outcomes of preoperative chemoradiation for upper rectal cancers the authors suggest that T3N0 tumors will not likely benefit from radiation and that treatment of T4N0 should be individualized.

Pretherapy imaging of rectal cancers: ERUS or MRI?

ERUS and MRI should be seen more as complementary rather than competitive techniques. Each has its own strengths and weaknesses. ERUS is better in showing the tumor extent in small superficial tumors, whereas MRI is superior in imaging the more advanced tumors. The choice of imaging technique depends also on the amount of information that is required for choosing certain treatment strategies, like the distance to the mesorectal fascia for a short course of preoperative radiotherapy. For lymph node imaging, both techniques are at present only moderately accurate, although this could change with advances in new MR techniques.

Endorectal ultrasound: its role in the diagnosis and treatment of rectal cancer

With development over the past 25 years of new surgical techniques and neoadjuvant therapy regimens for rectal cancer, physicians now have a range of treatment options that minimize morbidity and maximize the potential for cure. Accurate pretreatment staging is critical, ensuring adequate therapy and preventing overtreatment. Many options exist for staging primary rectal cancer. However, endorectal ultrasound (ERUS) remains the most attractive modality. It is an extension of the physical examination, and can be performed easily in the office. It is cost effective and is generally well tolerated by the patient, without need for general anesthesia. The authors discuss the data currently available on ERUS, including its accuracy and limitations, as well as the technical aspects of performing ERUS and interpreting the results. They also discuss new ultrasound technologies, which may improve rectal cancer staging in the future.

Rectal cancer staging

Rectal cancer staging provides critical information concerning the extent of the disease. The information gained from staging is used to determine prognosis, to guide management, and to assess response to therapy. Accurate staging is essential for directing the multidisciplinary approach to therapy. This article focuses on the evolution of staging systems, the rational for staging, and current methods used to stage rectal cancer.

Endosonographic staging of lower intestinal malignancy

The use of EUS in the assessment of rectal pathology is well established. The accurate staging of lower intestinal tumours predicts prognosis and guides the planning of individual patient treatment. Increased experience and the development of high resolution three-dimensional EUS has lead to the greater accuracy of rectal staging with EUS of rectal tumours now considered the gold standard showing T stage accuracy that ranges from 75% to 95%, with N stage accuracy ranging from 65% to 80%. The use of EUS in the staging of colonic pathology, however, is not so well established though advances in miniprobe EUS has improved the assessment of colonic tumours. EUS is also of benefit in the assessment of anal pathology though here, accurate correlation with histology has not been firmly established.

A new rectal ultrasonographic method for the staging of rectal cancer

PURPOSE

Radial transrectal ultrasound is the most frequently used method for preoperative staging of rectal cancer. Accuracy rates of transrectal ultrasound have fallen significantly to 64% and 70% for tumor and node staging, respectively. The use of a frontal probe may overcome the drawbacks of radial transrectal ultrasound. This study was designed to compare the accuracy of frontal transrectal ultrasound performed with a frontal probe with the classic procedure, which uses a radial probe, in the preoperative T and N staging of rectal cancer.

METHODS

Seventy-four patients with rectal adenocarcinoma underwent both techniques. Thirty patients had a neoadjuvant treatment. The staging accuracy of both methods was determined by comparing the results of each with the findings of surgical histopathologic evaluation.

RESULTS

Forty-six men and 28 women were recruited. Frontal transrectal ultrasound was performed in all patients. Staging was amenable in only 58 patients with the radial transrectal ultrasound because the tumors were either stenotic or too proximal. Frontal transrectal ultrasound was accurate in the T staging of 89% of the tumors, whereas radial transrectal ultrasound was accurate in only 69% (P = 0.004). The difference was even more significant when we compared accuracy among the 58 patients in whom both examinations were completed (P = 0.002). Both methods had similar accuracy for lymph node staging. Neoadjuvant treatment had no influence on accuracy. No overstaging of the tumor occurred with the frontal transrectal ultrasound. Understaging was more frequently encountered with radial transrectal ultrasound than with frontal transrectal ultrasound (26% vs. 11%, respectively; P = 0.036).

CONCLUSION

Compared with radial transrectal ultrasound, frontal transrectal ultrasound has a better accuracy for T staging of rectal cancer. Its advantage in overcoming the drawbacks of radial transrectal ultrasound may make this procedure the method of choice for rectal cancer staging.

Optimum lymph node dissection in clinical T1 and clinical T2 colorectal cancer

PURPOSE

On the basis of a retrospective review, we aimed to clarify the optimum extent of lymph node dissection in patients with cT1 and cT2 colorectal cancer.

METHODS

We reviewed medical records of 487 patients with cT1 and 351 patients with cT2 colorectal tumors, who had undergone curative surgery.

RESULTS

In patients with cT1 tumors, results of pathologic examination showed either no lymph node metastasis or metastasis within the paracolic or pararectal region in 284 (98.3 percent) of 289 patients with colon tumors and 195 (98.5 percent) of 198 with rectal tumors. Of 459 patients without clinically evident metastasis, only one patient with a poorly differentiated adenocarcinoma had metastasis beyond the paracolic area. In 28 patients with cT1 tumors and clinically diagnosed node metastasis, pathologic examination showed that node involvement did not extend beyond the named vessel in 26. Among patients with cT2tumors, 97.5 percent of patients with colon tumors and 95.9 percent with rectal tumors had no or limited metastasis. Of 276 without clinically evident metastasis, none had node metastasis at the roots of the named vessels; of 75 with clinically evident metastasis, none had pathologic extension beyond the roots of the named vessels.

CONCLUSIONS

In cT1 patients with cN-negative colorectal cancers, paracolorectal lymph node dissection may be optimal; in those with cN positivity, the regional nodes along the named vessels should be dissected. In cT2 patients who are cN-negative, dissection of the regional nodes may be optimal. For those with cN positivity, dissection at the roots of the named vessels should be considered.

[Current imaging for rectal cancer]

Rectal cancer is one of the most common causes of death from cancer. Accurate staging is necessary for optimal treatment. The tumor node metastasis (TNM) system is used to describe numerically the anatomical extent of cancer. Various diagnostic methods provide accurate staging. Endorectal ultrasound (EUS) and magnetic resonance tomography (MR) are most adequate for determining tumor stage. Moreover, MR is highly accurate in predicting the circumferential resection margin. Accurate node staging remains however difficult with both EUS and MR. Modern multidetector row CT is predestined for detecting distant metastases as it is a widespread, fast, and reproducible method.

[I Brazilian consensus of endoscopic ultrasonography]

BACKGROUND

In the last 20 years, several papers have focused on demonstrating the impact of endoscopic ultrasonography findings on the management of different clinical scenarios in digestive disease. This fact is an indirect evidence of the difficulty of popularization of the method. On other hand, the limited availability of endoscopic ultrasonography in Brazil is a direct evidence of this limitation. This was the rationale for the organization of a consensus meeting on endoscopic ultrasonography. It was aimed to identify the best evidence that support the use of endoscopic ultrasonography in gastroenterology.

METHODS

A panel of experts on endoscopic ultrasonography was selected based on the files of the Gastroenterology and Endoscopy Societies and on the registries of endoscope manufacturers. Two members of the meeting selected the relevant topics that were transformed into questions. The topics and the questions were debated among the experts five months before the consensus meeting. The experts were asked to perform systematic reviews in order to answer the questions so it could be possible to grade the answers based on the strength of the evidence. During the two days of the meeting the answers were presented, debated and voted. Consensus was reached when a minimum of 70% of the voters were in agreement. The final consensus report was submitted to the experts' evaluation and approval.

RESULTS

Seventy nine questions were debated by the experts at the pre-Consensus meeting. As the result of this debate 85 questions came out and were assigned to the members of the panel. During the Consensus meeting 22 experts debated and voted 85 answers. Consensus was reached for several clinical scenarios for which the impact of endoscopic ultrasonography findings were supported by level 1 evidences: differential diagnosis of subepithelial lesions and thickening of gastric folds, staging and diagnosis of unresectable esophageal cancer, indirect signs of peritoneal involvement of gastric cancer, MALT gastric lymphoma and rectal cancer staging, diagnosis of common bile duct and gallbladder stones, diagnosis of chronic pancreatitis and differential diagnosis of a solid mass in chronic pancreatitis, differential diagnosis of the pancreatic cyst, prediction of the results of the endoscopic treatment of esophageal varices and diagnosis and staging of non-small cell lung cancer.

CONCLUSIONS

There are the highest levels of evidences that support the indication of endoscopic ultrasonography for several digestive diseases and even for non-small cell lung cancer.

Local management of rectal neoplasia

The treatment of rectal neoplasia, whether benign or malignant, challenges the surgeon. The challenge in treating rectal cancer is selecting the proper approach for the appropriate patient. In a small number of rectal cancer patients local excision may be the best approach. In an attempt to achieve two goals-cure of disease with a low rate of local failure and maintenance of function and quality of life-multiple approaches can be utilized. The key to obtaining a good outcome for any one patient is balancing the competing factors that impact on these goals. Any effective treatment aimed at controlling rectal cancer in the pelvis must take into account the disease in the bowel wall itself and the disease, or potential disease, in the mesorectum. The major downside of local excision techniques is the potential of leaving untreated disease in the mesorectum. Local management techniques avoid the potential morbidity, mortality, and functional consequences of a major abdominal radical resection and are thus quite effective in achieving the maintenance of function and quality of life goal. The issue for the transanal techniques is how they fare in achieving the first goal-cure of the cancer while keeping local recurrence rates to an absolute minimum. Without removing both the rectum and the mesorectum there is no completely accurate way to determine whether a rectal cancer has moved outside the bowel wall, so any decision on local management of a rectal neoplasm is a calculated risk. For benign neoplasia, the challenge is removing the lesion without having to resort to a major abdominal procedure.

[Progress in diagnostics of anorectal disorders. Part I: anatomic background and clinical and neurologic procedures]

Diagnostics and therapy of anorectal disorders are still questions of surgery. Exact knowledge of functional anatomy and precise clinical examination constitute the basis for the resulting therapeutic strategies. Three-dimensional endosonography and technical advances in flexible endoscopy using high-resolution chromoendoscopy and narrow-band imaging enable exact staging and diagnosis, even of malignancies in earliest stages. Furthermore new in-vivo staining methods combined with high-resolution imaging facilitate the discrimination of inflammatory and neoplastic lesions, which often lead to diagnostic difficulties in chronic inflammatory bowel disease. Developments in neurologic testing, including surface electromyography and sacral nerve stimulation, complement the diagnostic armamentarium.

Circulating lymphangiogenic growth factors in gastrointestinal solid tumors, could they be of any clinical significance?

Metastasis is the principal cause of cancer mortality, with the lymphatic system being the first route of tumor dissemination. The glycoproteins VEGF-C and VEGF-D are members of the vascular endothelial growth factor (VEGF) family, whose role has been recently recognized as lymphatic system regulators during embryogenesis and in pathological processes such as inflammation, lymphatic system disorders and malignant tumor metastasis. They are ligands for the VEGFR-3 receptor on the membrane of the lymphatic endothelial cell, resulting in dilatation of existing lymphatic vessels as well as in vegetation of new ones (lymphangiogenesis). Their determination is feasible in the circulating blood by immunoabsorption and in the tissue specimen by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Experimental and clinicopathological studies have linked the VEGF-C, VEGF-D/VEGFR3 axis to lymphatic spread as well as to the clinical outcome in several human solid tumors. The majority of these data are derived from surgical specimens and malignant cell series, rendering their clinical application questionable, due to subjectivity factors and post-treatment quantification. In an effort to overcome these drawbacks, an alternative method of immunodetection of the circulating levels of these molecules has been used in studies on gastric, esophageal and colorectal cancer. Their results denote that quantification of VEGF-C and VEGF-D in blood samples could serve as lymph node metastasis predictive biomarkers and contribute to preoperative staging of gastrointestinal malignancies.

[Progress in diagnostics of anorectal disorders. Part II: radiology]

Diagnostics and therapy of anorectal disorders remain a surgical question. In close cooperation between different departments (radiology and gastroenterology, urology and gynecology, dermatology and psychology), the role of radiologic imaging is of growing importance. Exact knowledge of functional anatomy and precise clinical examination constitute the basis of the according therapeutic strategies. In this context radiology has contributed decisively. Developments in imaging techniques, e.g. dynamic MRI, highly contributed to better understanding of complex functional pelvic floor disorders. The combination of nanotechnology and high-resolution imaging allows precise staging, especially in rectal cancer. Furthermore, advances in virtual colonoscopy could lead to widely acceptable and patient-friendly screening for colorectal malignancies.

Pathophysiology, clinical presentation, and management of colon cancer

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

Endoscopic ultrasound in the diagnosis, staging and management of colorectal tumors

Endoscopic ultrasound (EUS) has evolved as a useful technique for imaging and intervention in the colon and rectum. This article reviews the clinical applications of EUS for imaging and intervention in colorectal cancer, with an emphasis on the most recent clinical studies.

Early rectal cancer: local excision or radical surgery?

BACKGROUND

Sphincter preservation, disease control, and long-term survival are the main goals in the treatment of rectal cancer. Although transanal local excision is attractive because it is a sphincter sparing procedure, some contradictory data exist in the literature about its ability to locally control disease and provide overall survival comparable with radical procedures, even for patients with early stage tumor.

PURPOSE

To compare transanal local excision and radical surgery treatment results based on the appropriate data in literature.

METHODS

We reviewed the literature to identify the current recurrence and survival rates of both techniques as well as the salvage surgery success. A PubMed search of the last 10 years was performed, and a total of 10 nonrandomized studies were identified; only 1 study was prospective, 5 were comparative, and 5 were case reports.

RESULTS

Five-year overall survival rate varied from 69% to 83% in the local excision group versus 82% to 90% for the radical excision group. Local recurrence rates ranged from 9% to 20% for local excision and from 2% to 9% for radical surgery. Systemic recurrence rates ranged from 6% to 21% for local excision and from 2% to 9% for radical surgery.

CONCLUSION

Radical surgery is the more definitive cancer treatment; however, it does not eliminate local excision as a reasonable choice for many patients, who will have lesser procedure-related morbidity and will accept an increased risk of tumor recurrence, a prolonged period of postoperative cancer surveillance, and a decreased success rate by salvage surgery.

Recent developments in the role of endoscopic ultrasonography in diseases of the colon and rectum

PURPOSE OF REVIEW

Endoscopic ultrasound has evolved as a useful technique for imaging and intervention in a variety of gastrointestinal and extraintestinal diseases including diseases of the colon and rectum. This paper will review recent developments in endoscopic ultrasound for colorectal diseases.

RECENT FINDINGS

Recent studies have shown significant clinical impact of endoscopic ultrasound in rectal cancer staging. Iliac lymph node evaluation by endoscopic ultrasound-guided fine needle aspiration may further expand the role of endoscopic ultrasound in rectal cancer. Three-dimensional endoscopic ultrasound may help decrease some of the errors of staging with two-dimensional endoscopic ultrasound and may further improve staging accuracy. Recent studies have confirmed continued problems with re-staging rectal cancer after chemoradiation. Endoscopic ultrasound-fine needle aspiration can be helpful in detecting local recurrence of rectal cancer and has been shown to be useful in evaluation of subepithelial masses of the colon and rectum and evaluation of rectosigmoid endometriosis.

SUMMARY

Endoscopic ultrasound continues to be useful for a variety of conditions of the colon and rectum with recent studies confirming its clinical impact as well as expanding its role into newer indications. Assessment for residual cancer after chemoradiation is still problematic and hopefully technological developments in ultrasound in the future may help in improving the accuracy of endoscopic ultrasound in this situation.

Endoanal ultrasound evaluation of anorectal diseases and disorders: technique, indications, results and limitations

Imaging of the rectum, anorectal junction and surrounding tissues is both difficult and technically challenging. CT and conventional barium studies offer limited information in local staging of rectal and perirectal neoplasms, anal carcinomas and extension perianal fistulas in patients with inflamamatory bowel disease, or in evaluating patients with fecal incontinence. During past decade, sonography and MR imaging have resulted in significant improvement in the imaging of rectal and perirectal and anal and perianal disease. The aim of this article is to review possibility of the EAUS in the evaluation both normal anal anatomy and anorectal disease and disorders (anal carcinoma, sphincter defects, anal fistulas, perianal abscesses and other pathological conditions).

Preoperative loco-regional imaging in rectal cancer

Preoperative staging of rectal cancer can influence the choice of surgery and the use of neoadjuvant therapy. This review evaluates the use of endorectal ultrasound (ERUS) and magnetic resonance imaging (MRI) in the local staging of rectal cancer. Staging for distant metastases is beyond the scope of this review. A MEDLINE search for published work in English between 1984-2004 was carried out by entering the key words of ERUS, MRI and preoperative imaging and rectal cancer. Initially, 867 articles were retrieved. Abstracts were reviewed and papers selected according to the inclusion criteria of a minimum of 50 patients and papers published in English. Papers focusing on preoperative chemoradiotherapy and distal metastases were excluded. Thirty-one papers were included in the systematic review. The examination techniques and images obtained are discussed and the respective accuracy is reviewed. ERUS and MRI have complementary roles in the assessment of tumour depth. Ultrasound has an overall accuracy of 82% (T1, 2, 40-100%; T3, 4, 25-100%) and is particularly useful for early localized rectal cancers. MRI has an accuracy of 76% (T1, 2, 29-80%; T3, 4, 0-100%) and is useful in more advanced disease by providing clearer definition of the mesorectum and mesorectal fascia. Both methods have similar accuracy in the assessment of nodal metastases. Ultrasound is more operator dependent and accuracies improve with experience, but it is more portable and accessible than MRI. Improvements in technology and increased operator experience have led to more accurate preoperative staging. ERUS and MRI are complementary and are most accurate for early localized cancers and more advanced cancers, respectively.

Efficacy of 3-dimensional endorectal ultrasonography compared with conventional ultrasonography and computed tomography in preoperative rectal cancer staging

BACKGROUND

This study was performed to verify reports of the decreased accuracy of endorectal ultrasonography (EUS) in preoperative staging of rectal cancer, and to compare the efficacy of 3-dimensional (3D) EUS with that of 2-dimensional (2D) EUS and computed tomography (CT).

METHODS

Eighty-six consecutive rectal cancer patients undergoing curative surgery were evaluated by 2D EUS, 3D EUS, and CT scan.

RESULTS

The accuracy in T-staging was 78% for 3D EUS, 69% for 2D EUS, and 57% for CT (P < .001-.002), whereas the accuracy in evaluating lymph node metastases was 65%, 56%, and 53%, respectively (P < .001-.006). Examiner errors were the most frequent cause of misinterpretation, occurring in 47% of 2D EUS examinations and in 65% of 3D EUS examinations. By eliminating examiner errors, the accuracy rates in T-staging and lymph node evaluation could be improved to 88% and 76%, respectively, for 2D EUS, and to 91% and 90%, respectively, for 3D EUS. Conical protrusions along the deep tumor border on 3D images were correlated closely with infiltration grade, advanced T-stage, and lymph node metastasis.

CONCLUSIONS

We found that 3D EUS showed greater accuracy than 2D EUS or CT in rectal cancer staging and lymph node metastases. Concrete 3D images based on tumor biology appear to provide more accurate information on tumor progression.

Staging of esophageal carcinoma in a low-volume EUS center compared with reported results from high-volume centers

BACKGROUND

It is well known that a learning curve exists for performing EUS.

OBJECTIVE

To determine whether the number of EUS investigations performed in a center affects the results of esophageal cancer staging.

DESIGN

We compared EUS in the evaluation of T stage and the presence of regional and celiac lymph nodes in a low-volume center where <50 EUS/endoscopist/y were performed with reported results from 7 high-volume EUS centers.

SETTING

A reference center for esophageal cancer (>90 cases/y) but a low-volume center for EUS when it comes to individual endoscopists.

PATIENTS

From 1994 to 2003, 244 patients underwent EUS, without specific measures to pass a stenotic tumor or FNA and with postoperative TNM stage as the criterion standard in the low-volume EUS center. In the high-volume centers, 670 EUS investigations for esophageal cancer were performed, if needed, with dilation, and with postoperative TNM stage and/or FNA as the criterion standard.

INTERVENTIONS

Retrospective analysis.

MAIN OUTCOME MEASUREMENTS

Sensitivity and specificity of EUS for esophageal cancer staging.

RESULTS

In the low-volume center, results of EUS for T3 staging in patients in whom passage of the EUS probe was possible were almost comparable for sensitivity (85% vs 88%-94%) but were lower for specificity (57% vs 75%-90%), whereas both sensitivity (58% vs 75%-90%) and specificity (87% vs 94%-97%) for T1 or T2 stages were lower than those reported in the high-volume centers. In the low-volume center, sensitivities of EUS for regional (45% vs 63%-89%) and celiac (19% vs 72%-83%) lymph nodes were lower, whereas specificities (75% vs 63%-82% and 99% vs 85%-100%, respectively) were comparable with those from high-volume centers. Results in the low-volume EUS center were worse if the EUS probe could not pass the stricture, which occurred in almost 30% of patients.

LIMITATIONS

Both FNA and dilation before EUS for stenotic tumors were not performed in the low-volume EUS center.

CONCLUSIONS

The results of EUS performed in a low-volume EUS center compared unfavorably with those reported from high-volume EUS centers. The results of this study suggest that preoperative staging by EUS should be performed by experienced and dedicated EUS endoscopists to optimize staging of esophageal cancer.

Modern management of rectal cancer: A 2006 update

The goal of this review is to outline some of the important surgical issues surrounding the management of patients with early (T1/T2 and N0), as well as locally advanced (T3/T4 and/or N1) rectal cancer. Surgery for rectal cancer continues to develop towards the ultimate goals of improved local control and overall survival, maintaining quality of life, and preserving sphincter, genitourinary, and sexual function. Information concerning the depth of tumor penetration through the rectal wall, lymph node involvement, and presence of distant metastatic disease is of crucial importance when planning a curative rectal cancer resection. Preoperative staging is used to determine the indication for neoadjuvant therapy as well as the indication for local excision versus radical cancer resection. Local excision is likely to be curative in most patients with a primary tumor which is limited to the submucosa (T1N0M0), without high-risk features and in the absence of metastatic disease. In appropriate patients, minimally invasive procedures, such as local excision, TEM, and laparoscopic resection allow for improved patient comfort, shorter hospital stays, and earlier return to preoperative activity level. Once the tumor invades the muscularis propria (T2), radical rectal resection in acceptable operative candidates is recommended. In patients with transmural and/or node positive disease (T3/T4 and/or N1) with no distant metastases, preoperative chemoradiation followed by radical resection according to the principles of TME has become widely accepted. During the planning and conduct of a radical operation for a locally advanced rectal cancer, a number of surgical management issues are considered, including: (1) total mesorectal excision (TME); (2) autonomic nerve preservation (ANP); (3) circumferential resection margin (CRM); (4) distal resection margin; (5) sphincter preservation and options for restoration of bowel continuity; (6) laparoscopic approaches; and (7) postoperative quality of life.

© 2006 The WJG Press. All rights reserved.

Feasibility and accuracy of TRUS in the pre-treatment staging for rectal carcinoma in general practice

AIMS

Transrectal ultrasonography (TRUS) is the diagnostic tool of choice for local staging of rectal carcinoma. The accuracy in determining of tumour infiltration depth has been reported to reach 95% (on average, 85%). The aim of the study was to analyse the diagnostic accuracy of the TRUS in the clinical routine.

PATIENTS AND METHODS

From 01/01/2000 to 12/31/2003, all patients with rectal carcinoma were enrolled in a prospective multicenter observational study. In case of complete findings of pre-operative TRUS and post-operative histological investigation of the surgical specimen on the tumour infiltration depth, overall accuracy of TRUS was determined.

RESULTS

Overall, 13,610 patients with rectal carcinoma were enrolled in the study. Five thousand and fifty-six subjects (37%) underwent TRUS. In 3,501 patients, TRUS finding (uT-stage) could be compared with the result of the definitive histologic investigation (pT-stage). The accuracy of TRUS in all T-stages was 65.8%. The highest sensitivity was achieved in the T3-stage (74.9%), while in T2, T1, and T4, it was 59.6, 59.0 and 31.1%, respectively. In discriminating tumour growth limited to the rectal wall vs that through the rectal wall into the neighboring tissue, TRUS-associated accuracy was 76.5%. There were no differences between various tumour locations above the anocutaneous line.

CONCLUSIONS

Diagnostic accuracy of TRUS in determining depth of tumour infiltration within or through the rectum wall in the routinuous diagnostic of rectal carcinoma does not reach the excellent published study results. A considerable improvement of the qualitative outcome in using this specific diagnostic tool appears to be recommendable to utilize its advantages such as high accuracy, efficacy, and practicability in the diagnostic process and deriving consequences for a possible neoadjuvant treatment as well as optimal planning of the surgical approach.