Preoperative loco-regional imaging in rectal cancer

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.

Selection of patients with rectal cancer for neoadjuvant therapy using pre-therapeutic MRI - Results from OCUM trial

PURPOSE

No consensus is available on the appropriate criteria for neoadjuvant chemoradiotherapy selection of patients with rectal cancer. The purpose was to evaluate the accuracy of MRI staging and determine the risk of over- and undertreatment by comparing MRI findings and histopathology.

METHOD

In 609 patients of a multicenter study clinical T- and N categories, clinical stage and minimal distance between the tumor and mesorectal fascia (mrMRF) were determined using MRI and compared with the histopathological categories in resected specimen. Accuracy, sensitivity, specificity, positive predictive, and negative predictive value (NPV) were calculated. Overstaging was defined as the MRI category being higher than the histopathological category. mrMRF and circumferential resection margin (CRM) were judged as tumor free at a minimal distance > 1 mm. The chi-squared test or Fisher's exact test were used. P < 0.05 was considered significant.

RESULTS

The T category was correct in 63.5% (386/608) of patients; cT was overstaged in 22.9% (139/608) and understaged in 13.5% (82/608). MRI accuracy for lymph node involvement was 56.5% (344/609); 22.2% (28/126) of patients with clinical stage II and 28.1% (89/317) with clinical stage III disease were diagnosed by histopathology as stage I. The accuracy for tumor free CRM was 86.5% (527/609) and the NPV was 98.1% (514/524). In 1.7% (9/524) mrMRF was false negative.

CONCLUSION

MRI prediction of the tumor-free margin is more reliable than the prediction of tumor stage. MRF status as determined MRI should therefore be prioritized for decision making.

Transanal endoscopic microsurgery for rectal villous tumours: Can we rely solely on preoperative biopsies and the surgeon’s experience?

Background

Transanal endoscopic microsurgery has become the standard of treatment for rectal villous adenomas. However, the role of preoperative imaging for these lesions is not clear. The aim of this study was to compare the value of preoperative imaging and surgeon clinical staging in the preoperative evaluation of patients with rectal villous adenomas having transanal endoscopic microsurgery resection.

Methods

We conducted a single-centre comparative retrospective cohort study of patients who underwent transanal endoscopic microsurgery surgery for rectal villous adenomas from 2011 to 2013. The intervention was preoperative imaging versus surgeon clinical staging. The primary outcome was the accuracy of clinical staging by preoperative imaging and surgeon clinical staging according to the histopathologic staging.

Results

A total of 146 patients underwent transanal endoscopic microsurgery surgery for rectal villous adenomas. One hundred and twelve (76.7%) of those patients had no preoperative imaging while 34 patients (23.3%) had either endorectal ultrasound (22 patients) or magnetic resonance imaging (12 patients). Surgeon staging was accurate in 89.3% of cases whereas staging by endorectal ultrasound was accurate in 40.9% cases and magnetic resonance imaging was accurate in 0% of cases. In the imaging group, inaccurate staging would have led to unnecessary radical surgery in 44.0% of patients.

Conclusion

This study was subject to selection bias because of its retrospective nature and the limited number of patients with imaging. Patients with rectal villous tumours without invasive carcinoma on biopsies and without malignant characteristics on appearance in the judgment of an experienced colorectal surgeon might not benefit from preoperative imaging before undergoing transanal endoscopic microsurgery procedures.

The accuracy of trans rectal ultrasonography (TRUS) in early-stage rectal cancer or benign adenomas

Background: Screening for colorectal cancer in Denmark has resulted in more patients being diagnosed with benign adenomas and early-stage rectal cancer. In general, TRUS is accepted as a good modality for evaluating the above mentioned before deciding on surgery. Objective: To investigate the accuracy of TRUS in a clinical setting at the Region Hospital in Herning, Denmark. Study design: Retrospective cohort study from January 2016 to June 2018. Methods: Quantitative method. The cohort (117 patients) was recruited by searching for specific procedure codes. Data were collected by going through the electronic patient files. Results: TRUS predicted T0, T1, T2 and T3 with an accuracy of 91%, 35%, 43% and 20% respectively and an overall accuracy of 68%. A weighted Cohens kappa value of 0.30 (p  ≤  .05). TRUS differentiated between T0/T1 with a sensitivity of 70%, specificity of 85% and an accuracy of 85% and kappa value of 0.44 (p  ≤  .05). Conclusion: TRUS can with great precision establish whether the tumor is benign so correct local treatment can be instituted.

Endoscopic ultrasound in oncology: An update of clinical applications in the gastrointestinal tract

An accurate staging is necessary to select the best treatment and evaluate prognosis in oncology. Staging usually begins with noninvasive imaging such as computed tomography, magnetic resonance imaging or positron emission tomography. In the absence of distant metastases, endoscopic ultrasound plays an important role in the diagnosis and staging of gastrointestinal tumors, being the most accurate modality for local-regional staging. Its use for tumor and nodal involvement in pre-surgical evaluation has proven to reduce unnecessary surgeries. The aim of this article is to review the current role of endoscopic ultrasound in the diagnosis and staging of esophageal, gastric and colorectal cancer.

Learning curve for endorectal ultrasound in young and elderly: lights and shades

Aim of the study is to highlight difficulties faced by an inexperienced surgeon in approaching endorectal-ultrasound, trying to define when learning curve can be considered complete. A prospective analysis was conducted on endorectal-ultrasound performed for subperitoneal rectal adenocarcinoma staging in the period from January 2008 to July 2013, reported by a single surgeon of Department of Oncology, Section of General Surgery, "San Luigi Gonzaga" Teaching Hospital, Orbassano (Turin, Italy); the surgeon had no previous experience in endorectal-ultrasound. Fourty-six endorectal-ultrasounds were divided into two groups: early group (composed by 23 endorectal-ultrasounds, made from January 2008 to May 2009) and late group (composed by 23 endorectal-ultrasound, carried out from June 2009 to July 2013). In our experience, the importance of a learning curve is evident for T staging, but no statystical significance is reached for results deal with N stage. We can conclude that ultrasound evaluation of anorectal and perirectal tissues is technically challenging and requires a long learning curve. Our learning curve can not be closed down, at least for N parameter.

Systematic review and meta-analysis of the accuracy of MRI and endorectal ultrasound in the restaging and response assessment of rectal cancer following neoadjuvant therapy

AIM

Restaging imaging by MRI or endorectal ultrasound (ERUS) following neoadjuvant chemoradiotherapy is not routinely performed, but the assessment of response is becoming increasingly important to facilitate individualization of management.

METHOD

A search of the MEDLINE and Scopus databases was performed for studies that evaluated the accuracy of restaging of rectal cancer following neoadjuvant chemoradiotherapy with MRI or ERUS against the histopathological outcome. A systematic review of selected studies was performed. The methodological quality of studies that qualified for meta-analysis was critically assessed to identify studies suitable for inclusion in the meta-analysis.

RESULTS

Sixty-three articles were included in the systematic review. Twelve restaging MRI studies and 18 restaging ERUS studies were eligible for meta-analysis of T-stage restaging accuracy. Overall, ERUS T-stage restaging accuracy (mean [95% CI]: 65% [56-72%]) was nonsignificantly higher than MRI T-stage accuracy (52% [44-59%]). Restaging MRI is accurate at excluding circumferential resection margin involvement. Restaging MRI and ERUS were equivalent for prediction of nodal status: the accuracy of both investigations was 72% with over-staging and under-staging occurring in 10-15%.

CONCLUSION

The heterogeneity amongst restaging studies is high, limiting conclusive findings regarding their accuracies. The accuracy of restaging imaging is different for different pathological T stages and highest for T3 tumours. Morphological assessment of T- or N-stage by MRI or ERUS is currently not accurate or consistent enough for clinical application. Restaging MRI appears to have a role in excluding circumferential resection margin involvement.

Role of endoscopic ultrasonography in the loco-regional staging of patients with rectal cancer

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery.

Optimizing adjuvant treatment decisions for stage t2 rectal cancer based on mesorectal node size: a decision analysis

RATIONALE AND OBJECTIVES

The aim of this study was to optimize treatment decisions for patients with suspected stage T2 rectal cancer on the basis of mesorectal lymph node size at magnetic resonance imaging.

MATERIALS AND METHODS

A decision-analytic model was developed to predict outcomes for patients with stage T2 rectal cancer at magnetic resonance imaging. Node-positive patients were assumed to benefit from chemoradiation prior to surgery. Imperfect magnetic resonance imaging performance for primary cancer and mesorectal nodal staging was incorporated. Five triage strategies were considered for administering preoperative chemoradiation: treat all patients; treat for any mesorectal node >3, >5, and >7 mm in size; and treat no patients. If nodal metastases or unsuspected stage T3 disease went untreated preoperatively, postoperative chemoradiation was needed, resulting in poorer outcomes. For each strategy, rates of acute and long-term chemoradiation toxicity and of 5-year local recurrence were computed. Effects of input parameter uncertainty were evaluated in sensitivity analysis.

RESULTS

The optimal strategy depended on the outcome prioritized. Acute and long-term chemoradiation toxicity rates were minimized by triaging only patients with nodes >7 mm to preoperative chemoradiation (18.9% and 10.8%, respectively). A treat-all strategy minimized the 5-year local recurrence rate (5.6%). A 7-mm nodal triage threshold increased the 5-year local recurrence rate to 8.0%; when no patients were treated preoperatively, the local recurrence rate was 10.1%. With improved primary tumor staging, all outcomes could be further optimized.

CONCLUSIONS

Mesorectal nodal size thresholds for preoperative chemoradiation should depend on the outcome prioritized: higher size thresholds reduce chemoradiation toxicity but increase recurrence rates. Improvements in nodal staging will have greater impact if primary tumor staging can be improved.

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.

[Local diagnostics for rectal cancer. What is realistic?]

Accurate pretherapeutic staging of rectal cancer is crucial for further therapeutic management and important for prognosis. The most accurate diagnostic tools in the assessment of T and N categories of rectal cancer are endorectal ultrasound (EUS) and magnetic resonance imaging (MRI). Furthermore, MRI can accurately predict the distance of the tumor to the colorectal membrane (CRM) and computed tomography (CT) is more suitable for detecting distant metastases. In the routine care of rectal cancer EUS is the most frequently used diagnostic tool for local staging. The achieved accuracy for determining T category by EUS in routine clinical staging is lower than results reported in the literature. Furthermore, the accuracy of EUS depends on the experience of the examiner. Currently the frequency of using MRI for routine clinical staging of rectal cancer is low and in one out of five cases the local staging of rectal cancer is exclusively carried out by CT.

Current practice in preoperative therapy and surgical management of locally advanced rectal cancer: a bi-national survey

AIM

The Australasian colorectal surgeon's current approach to preoperative rectal cancer management was compared with international guidelines.

METHOD

Members of the Colorectal Surgical Society of Australia and New Zealand were surveyed in 2010, on the use of MRI and the management of locally advanced rectal cancer. Surgeons had to decide the appropriate management in five scenarios that were developed from national guidelines.

RESULTS

Of 174 invitations sent, 108 (62.1%) replies were received. Most surgeons (98.1%) had access to MRI. Ninety-three (86.1%) would use MRI routinely for staging. The majority selected a tumour-specific mesorectal resection for upper rectal cancer (58.2%) and a total mesorectal excision for distal cancer (100%). Almost all restorative operations included a covering ileostomy. One third of surgeons recommended that patients with a favourable cT3 mid-rectal tumour (N0, clear circumferential resection margins) should not have preoperative therapy and should proceed directly to surgery. When high-risk features, such as threatened resection margins or cN1 stage, were present, 5% and 15% of surgeons, respectively, would continue to treat by standard resection without preoperative therapy.

CONCLUSION

Evidence-based international guidelines for the management of rectal cancer have changed little in the last 10 years. Despite this, there is a clear gap between these and clinical practice. The main variance relates to the role of radiotherapy in locally advanced rectal cancer. Despite considerable evidence that radiotherapy reduces local recurrence for all stages of rectal cancer, current practice in Australasia is for its selective use.

High-throughput arrays identify distinct genetic profiles associated with lymph node involvement in rectal cancer

BACKGROUND

Preoperative clinical diagnosis of lymph node involvement guides treatment decisions for rectal cancer. Unfortunately, clinical staging still suffers from a lack of accuracy.

OBJECTIVE

The aim of this study was to evaluate objective genetic differences in primary rectal cancers with and without associated lymph node metastasis.

DESIGN

cDNA microarrays were generated from fresh-frozen tumors. Normalized data underwent global unsupervised hierarchical clustering analysis, and discriminating genes were mapped. Top discriminating genes were compared between stage II and III rectal cancers by use of an empirical Bayes 2 group t test with the Statistical Analysis of Microarrays and the Reproducibility-Optimized Test Statistic software separately to guide data reduction and deal with the difficulties of simultaneous statistical inference. Ingenuity Pathways Analysis software was used to analyze discriminating genes in terms of function and biological processes.

PATIENTS

Fifty-five patients with stage II and 22 patients with stage III rectal adenocarcinomas not treated with chemoradiation were included.

RESULTS

Two major unsupervised clusters emerged representing stage II and III cancers. In 1 cluster, 11 of 12 patients (92%) had stage III cancer; in the other cluster, 54 of 65 patients (83%) had stage II (p < 0.001). Five significantly differentially expressed genes characterized the stage III cluster: interleukin-8, 3-hydroxy-3-methylglutaryl coenzyme A synthase, carbonic anhydrase, ubiquitin, and cystatin (all p < 0.05). Of the 12 patients with differential expression of the 5 marker genes, only one had stage II cancer. Fifty-four of 55 stage II patients clustered with alternative expression patterns of the predictor genes. Differentially expressed genes are related to cancer-associated processes, pathways, and networks.

LIMITATIONS

The identified gene signatures have not yet been validated in independent patient populations.

CONCLUSIONS

Distinct gene expression signatures from primary rectal adenocarcinomas can help differentiate the presence or absence of lymph node metastases. These data are informative, and validation of this gene signature may provide a novel approach for more appropriate individualized treatment selection.

Surgical oncology issues in locally advanced rectal cancer

The management of locally advanced (T3/4) rectal cancer is evolving. Randomized trials have shaped the current adjuvant treatment options, but yet there remain many unanswered questions. These include how best to define which patients to treat and choosing between short-course radiotherapy and long-course chemoradiotherapy. With respect to surgery, the optimal timing, the surgical approach in abdominoperineal resections and the role of laparoscopic surgery remain active areas of research. The possibility of avoiding surgery in selected patients is also a topic of great interest. A multidisciplinary team approach in managing rectal cancer patients is popular where possible and recommended in some guidelines.

Current trends in staging rectal cancer

Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an important factor in deciding the need for neoadjuvant treatment and determines the prognosis. Those with threatened or involved margins are offered long course chemoradiation to enable R₀ surgical resection. Endoanal ultrasound (EUS) is useful for tumor (T) staging; hence EUS is a useful imaging modality for early rectal cancer. Magnetic resonance imaging (MRI) is useful for assessing the mesorectum and the mesorectal fascia which has useful prognostic significance and for early identification of local recurrence. Computerized tomography (CT) of the chest, abdomen and pelvis is used to rule out distant metastasis. Identification of the malignant nodes using EUS, CT and MRI is based on the size, morphology and internal characteristics but has drawbacks. Most of the common imaging techniques are suboptimal for imaging following chemoradiation as they struggle to differentiate fibrotic changes and tumor. In this situation, EUS and MRI may provide complementary information to decide further treatment. Functional imaging using positron emission tomography (PET) is useful, particularly PET/CT fusion scans to identify areas of the functionally hot spots. In the current state, imaging has enabled the multidisciplinary team of surgeons, oncologists, radiologists and pathologists to decide on the patient centered management of rectal cancer. In future, functional imaging may play an active role in identifying patients with lymph node metastasis and those with residual and recurrent disease following neoadjuvant chemoradiotherapy.

Clinicopathological staging of colorectal cancer: Evolution and consensus-an Australian perspective

In 1991 this journal published the report of an international working party to the World Congress of Gastroenterology regarding the clinicopathological staging of colorectal cancer. Since that time staging has continued to evolve as further prognostic factors in colorectal cancer have been elucidated in studies of increasingly large databases in several countries. This review summarizes several of the key issues that have arisen during this evolutionary process and raises matters which still remain controversial in staging at the present time.

The management of rectal cancer in Ireland in 2007--room for improvement?

INTRODUCTION

Effective management of rectal cancer relies on accurate pre-operative assessment, surgical technical excellence and integrated neoadjuvant and adjuvant chemo and/or radiotherapy. The aim of this study was to examine the management of rectal cancer in Ireland.

METHODS

This was a retrospective chart review. All cases of rectal cancer (15 cm or less from the anal verge) diagnosed in Ireland in the year 2007 were included in the audit.

RESULTS

In total data for 585 patients were included, under the care of 87 consultant surgeons operating in 48 hospitals. Only data recorded in medical charts were included. Pre-operative investigations were less utilised than recommended by current guidelines and consequently many cancers were inadequately staged. In total 52.5% of cases were discussed at a multi-disciplinary meeting. Overall, 88% of the patients had surgery, and the 30-day mortality rate was 1.7%. The quality of post-operative pathology reporting was variable, with adequacy of total mesorectal excision status unclear or unknown in 74% of cases. Cases were managed in a large number of centres, and in lower volume centres (<5 cases per annum) patients appeared to be less adequately investigated.

CONCLUSION

This study gives a snapshot of recent practice in the management of rectal cancer in Ireland but is of necessity limited as the audit was retrospective and long term outcomes have not been assessed. In 2007 rectal cancer was managed in a large number of centres and best practice was frequently not adhered to. The impending centralisation of cancer services is likely to impact on the management of rectal cancer in Ireland.

Anatomical landmarks for endosonography of the larynx

BACKGROUND

A precise knowledge of anatomy is necessary to allow a correct interpretation of sonographic images when investigating a particular region of the body. The objective of the present study was to establish anatomical landmarks for endosonography of the larynx.

METHODS

In an experimental study, a total of 32 normal human larynges were examined endosonographically, and the classical landmarks were correlated to horizontal whole-organ sections of the scanned specimens.

RESULTS

All laryngeal specimens showed a similar and reproducible sonoanatomy, which could be verified consistently on corresponding histological cross sections. Anatomical structures readily identified included the laryngeal framework, the vocal ligament, the vocal muscle, the ventricular fold, the preepiglottic and paraglottic space, and the epiglottis.

CONCLUSIONS

Due to a reproducible sonoanatomy of the larynx, endosonography might be an interesting complementary tool in the diagnostic investigation of laryngeal lesions such as medium-sized tumors, cysts, laryngoceles, and stenoses.

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.

Regional lymph node metastasis and locoregional recurrence of rectal carcinoma in the era of TME [corrected] surgery. Implications for treatment decisions

BACKGROUND AND AIMS

For rectal carcinoma treated according to the concept of total mesorectal excision (TME surgery), the independent influence of regional lymph node metastasis on the locoregional recurrence risk is still in discussion. A reliable assessment of this risk is important for an individualised selective indication for neoadjuvant radio-/radiochemotherapy.

METHODS

Analysis of literature, especially of the last 20 years, and consideration of pathological and oncological basic research. Multivariate analysis of data of the Erlangen Registry of Colorectal Carcinoma.

RESULTS

The clinical assessment of the pretherapeutic regional lymph node status by the present available imaging methods is still unreliable. The analysis of the association between pretherapeutic regional lymph node status and locoregional recurrence risk has to be based on follow-up data of patients treated by primary surgery and has to be distinguished between patients treated by conventional and optimised quality-assured TME surgery, respectively. Data from Erlangen show an increase of the local recurrence risk for patients with at least four involved regional lymph nodes.

CONCLUSIONS

For patients with at least four involved regional lymph nodes, a neoadjuvant radiochemotherapy may be indicated. However, today, the pretherapeutic diagnosis is uncertain and results in overtherapy in 40%. Thus, in case of positive lymph node findings by imaging methods, the benefits and risk of neoadjuvant therapy in such situations should always be discussed with the patient in the sense of informed consent and shared decision.

How useful is rectal endosonography in the staging of rectal cancer?

It is essential in treating rectal cancer to have adequate preoperative imaging, as accurate staging can influence the management strategy, type of resection, and candidacy for neoadjuvant therapy. In the last twenty years, endorectal ultrasound (ERUS) has become the primary method for locoregional staging of rectal cancer. ERUS is the most accurate modality for assessing local depth of invasion of rectal carcinoma into the rectal wall layers (T stage). Lower accuracy for T2 tumors is commonly reported, which could lead to sonographic overstaging of T3 tumors following preoperative therapy. Unfortunately, ERUS is not as good for predicting nodal metastases as it is for tumor depth, which could be related to the unclear definition of nodal metastases. The use of multiple criteria might improve accuracy. Failure to evaluate nodal status could lead to inadequate surgical resection. ERUS can accurately distinguish early cancers from advanced ones, with a high detection rate of residual carcinoma in the rectal wall. ERUS is also useful for detection of local recurrence at the anastomosis site, which might require fine-needle aspiration of the tissue. Overstaging is more frequent than understaging, mostly due to inflammatory changes. Limitations of ERUS are operator and experience dependency, limited tolerance of patients, and limited range of depth of the transducer. The ERUS technique requires a learning curve for orientation and identification of images and planes. With sufficient time and effort, quality and accuracy of the ERUS procedure could be improved.

The use of endoscopic ultrasonography and other imaging modalities in the preoperative staging of rectal villous tumours: a case of overstaging by magnetic resonance imaging

A case of a 60-year-old man with recurrent rectal villous adenoma is described. Preoperative staging with endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) revealed very discordant results. EUS showed a tumour present in the mucosa with no submucosal invasion, while MRI revealed invasion of the muscularis propria consistent with an invasive stage T2 carcinoma. Based on the MRI findings, the patient underwent a low anterior resection of the tumour. The surgical pathology specimen revealed a villous adenoma with lowgrade dysplasia but no carcinoma and no extension into the muscularis propria. The present case highlights the uncertainty that currently exists as to which imaging modality provides the greatest accuracy in the staging of rectal cancer and in guiding the type of surgical procedure performed. Two recent meta-analyses and a systematic review of the literature point to EUS as the imaging modality of choice for determining muscularis propria and perirectal tissue invasion, as well as nodal involvement.

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 simple scoring system based on clinical features to predict locally advanced rectal cancers

PURPOSE

The purpose of this study was to identify clinical risk factors and establish a prediction scoring system for locally advanced rectal cancer.

MATERIALS AND METHODS

Retrospective univariate and multivariate logistic analyses were conducted for 413 curable rectal cancer patients. Clinical factors found to be significantly related with tumor stages were incorporated into a scoring system to predict locally advanced stages, which was validated in an independent cohort of 279 rectal cancer patients.

RESULTS

In the training set, tumor size, differentiation, and serum carcinoembryonic antigen (CEA) level (P < 0.01) were significant predictors of locally advanced rectal cancer in both univariate and multivariate analyses, which were incorporated into a proposed scoring system to predict locally advanced stages. The area under the receiver operating characteristic curve (AUROC) of this scoring system was 0.751 and the prediction accuracy was 78.2%. Patients were categorized into three subsets according to the total score. The low-risk group (score 0) had a smaller chance (18.2%) to have locally advanced rectal cancer, compared to mean 49.2% for the intermediate-risk group (score 1) and mean 83.0% for the high-risk group (score of 2-4; P < 0.05). In the validation set, the AUROC of the scoring system was 0.756 and the prediction accuracy was 75.3%.

CONCLUSIONS

Tumor size more than 2 cm, poor differentiation, and elevated serum CEA level are high-risk factors of locally advanced rectal cancer. A simple scoring system based on these three factors may be valuable to predict locally advanced rectal cancer.

Lymph node harvest after proctectomy for invasive rectal adenocarcinoma following neoadjuvant therapy: does the same standard apply?

PURPOSE

Recent reports indicate that neoadjuvant therapy significantly reduces the lymph node harvest of rectal cancer. The aim of this study was to interpret the lymph node harvest in this setting based on the primary tumor response.

METHODS

All patients undergoing proctectomy were included. Three variables were used as indicators of primary tumor response: ypT stage, tumor size, and tumor regression grade.

RESULTS

From 1998 to 2007, 237 patients were identified: 157 in the neoadjuvant therapy group and 80 in the nonneoadjuvant therapy group. Neoadjuvant therapy significantly reduced the number of lymph nodes harvested (P = 0.011). Compared with the nonneoadjuvant group, there were significantly fewer lymph nodes in the neoadjuvant early T stage group (P = 0.001), small tumor size group (P = 0.003), and low tumor regression grade group (P < 0.001). However, there was no significant difference between the nonneoadjuvant group and the neoadjuvant advanced T stage (P = 0.664), large tumor (P = 0.815), and high tumor regression grade groups (P = 0.566).

CONCLUSION

The current standard of lymph node harvest should be applied to patients with poorly responding primary tumors after neoadjuvant therapy. However, a new standard may be necessary to define the adequate number of lymph nodes for tumors that respond well to neoadjuvant therapy.

Internal mammary nodes in breast cancer: diagnosis and implications for patient management -- a systematic review

The management of internal mammary nodes (IMNs) in breast cancer is controversial. Surgical series from the 1950s showed that one third of breast cancer patients had IMN involvement, with a higher risk in patients with medial tumors and/or positive axillary nodes. IMN metastasis has similar prognostic importance as axillary nodal involvement. However, after three randomized trials showed no survival benefit from extended mastectomy compared with radical or modified radical mastectomy, IMN dissection was largely abandoned. Recently, lymphoscintigraphy studies have renewed interest in IMN evaluation. Approximately one fifth of internal mammary sentinel nodes are pathologic, although most centers do not perform IMN biopsies because of concerns about morbidity and lack of established survival benefit. In addition, results from randomized trials testing the value of postmastectomy irradiation and a meta-analysis of 78 randomized trials have provided high levels of evidence that local-regional tumor control is associated with long-term survival improvements. This benefit was limited to trials that used systemic therapy, which was not routinely administered in the earlier surgical studies, although the contribution from IMN treatment is unclear. IMN irradiation has also been shown to cause increased cardiac morbidity. Before mature results from current randomized trials assessing the benefit of IMN irradiation become available, lymphoscintigraphy may be used to help guide decisions regarding systemic and local-regional treatment. However, even in patients with visualized primary IMN drainage, the potential benefit of treatment should be balanced against the risk of added morbidity.

Transrectal ultrasonography and magnetic resonance imaging in the staging of rectal cancer. Effect of experience

OBJECTIVE

To evaluate the effect of experience on preoperative staging of rectal cancer using magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS).

MATERIAL AND METHODS

From January 2002 to May 2006, 134 consecutive patients with biopsy-proven rectal cancer were examined with a 1.5-Tesla MRI unit and TRUS using a 6.5-MHz transducer. An experienced gastrointestinal radiologist (R1) or a general radiologist (R2) performed the evaluations. All patients (78 M, 56 F, mean age 69.1 years, range 38-89) were treated with surgery alone. The mean size of the tumour was 4.0 cm (range 1.1-7.5). A complete postoperative histopathological examination was used as the gold standard.

RESULTS

At pathology, 42 of 134 (31%) tumours were classified as T1-T2 and 92 (69%) were classified as T3-T4. The TRUS sensitivity in rectal tumour T-staging was 93% for R1 and 75% for R2 (p<0. 01); specificity was 83% for R1 and 46% for R2 (p<0.05). The MRI sensitivity in rectal tumour T-staging was 96% for R1 and 77% for R2 (p<0. 05); the specificity was 74% for R1 and 40% for R2 (p<0.05). There was no difference in the results of N-staging between R1 and R2 for either TRUS or MRI.

CONCLUSION

Reader experience had a statistically significant positive effect on the preoperative prediction of tumour involvement of the rectal wall. To obtain high-quality preoperative prediction of rectal cancer T-stage, it is suggested that preoperative TRUS and MRI staging should be supervised by an expert in the colorectal cancer team. In addition to this supervision, the person responsible for staging should be trained through a defined training programme.

Technique of high-frequency endolaryngeal ultrasound

Objective:

We describe in detail the technique of in vivo endolaryngeal ultrasound during microlaryngoscopy, offering a number of practical suggestions which may be of use, especially to the otolaryngologist.

Methods:

Endosonography is a non-invasive imaging technology usually applied for the assessment of local tumour growth and regional lymph node metastases in the digestive tract.

Conclusions:

Due to a penetrating depth of up to 25 mm and a high tissue resolution, endosonography also qualifies for use in the larynx. The technique may have a potentially important role in the intra- and post-operative investigation of laryngeal lesions bigger than 3 mm.

Prediction of rectal lymph node metastasis by pelvic computed tomography measurement

AIM

Rectal cancer staging represents a crucial step to select the best treatment for this tumour. Particularly after neo-adjuvant chemoradiotherapy (CRT), it may influence the surgical procedure (e.g. radical resection vs. local excision). The aim of this study was to determine the best lymph node size cut-off at computed tomography (CT) to predict nodal metastasis in rectal cancer patients with and without preoperative CRT.

METHODS

A consecutive series of patients operated on for primary mid-low rectal adenocarcinoma, all staged with pelvic CT scan, were subdivided as follows: those who underwent surgery alone treatment without CRT (Group A) and those who underwent preoperative CRT (Group B). All CT scans were re-viewed by a single radiologist and, based on the lymph node size, findings were compared with pathologic lymph node status (pN). At each lymph node size cut-off value, the following were calculated: accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The best cut-off value was defined as having an accuracy >or=70% with the highest NPV.

RESULTS

The study population consisted of 162 patients: Group A (n=52) and Group B (n=110). Patients classified as pN-positive (n=45) had a higher number of and larger sized lymph nodes by CT scan than patients classified as pN-negative (n=117). The cut-off values with an accuracy >or=70% ranged between 7 and 11 mm in Group A and between 9 and 14 mm in Group B. The cut-off with the best NPV was 7 mm for Group A and 10mm for Group B.

CONCLUSIONS

Acknowledging the limitations of the dimensional criterion, lymph node size cut-off values found in our study may be useful for planning rectal cancer treatment using CT scan.

The role of EUS and MRI in rectal cancer staging

Rectal cancer continues to be one of the most common tumors worldwide. Its prognosis mainly depends on early diagnosis and precise stage evaluation in order to choose the most effective treatment. In recent years, new and promising technologies have been proposed and are now available in daily practice. Each rectal cancer patient should be considered individually, choosing the diagnostic pretreatment exams that are appropriate for that single clinical case mainly related to the tumor and the available instruments. Clinicians must be informed about the efficacy of these technologies and be aware of any cause of mistake in tumor staging in order to reduce the risk of both improper use and inaccurate staging.

Optimal methods for staging rectal cancer

At present, several modalities exist for the preoperative staging of rectal lesions, including computed tomography (CT), body coil or endorectal coil magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) done by rigid or flexible probes, and positron emission tomography (PET). Staging accuracy for CT ranges from 53% to 94% for T-stage accuracy and from 54% to 70% for N-stage accuracy. Improved CT accuracy is observed at higher disease stages. Body coil MRI has shown T- and N-stage accuracy ranging from 59% to 95% and 39% to 95%, respectively. Endorectal coil MRI has shown improved T- and N-stage accuracy, with rates of 66% to 91% and 72% to 79%, respectively. The development of phased-array MRI, combining high spatial resolution with a larger field of view, offers promise to improve on these rates. EUS, considered the current gold standard, has shown T-stage accuracy ranging from 75% to 95%, with N-stage accuracy ranging from 65% to 80%. Flexible EUS probes have the advantage of being able to access and sample iliac nodes. Recent studies also suggest that three-dimensional EUS may provide greater accuracy than conventional two-dimensional EUS. Limited studies exist on the use of PET in primary tumor staging. PET may upstage disease in 8% to 24% of patients and has also been used in posttreatment restaging and surveillance. Postradiation edema, necrosis, and fibrosis seem to decrease restaging accuracy in all modalities. This article reviews the current literature about the staging accuracy of the various modalities and suggests a staging algorithm for rectal cancer.

Preoperative assessment of rectal cancer stage: state of the art

Rectal cancer is one of the most common tumors worldwide; it accounts for approximately 25-30% of cancers arising in the large bowel. Owing to greater distribution of screening programs and better attention from both patients and General Practitioners to this disease, in recent years we have observed an increasing number of cases diagnosed in the early stages, with a consequent better prognosis. The improved 5-year survival is also partially due to better, and more accurate, diagnostic techniques and to more curative treatments. In this review, the authors analyze and discuss the more recent diagnostic techniques for an accurate preoperative staging of rectal cancer, highlighting each method's advantages and limits for their routine use in clinical practice.

The advantages of volume rendering in three-dimensional endosonography of the anorectum

Anorectal diseases require imaging for proper case management. At present, endoanal ultrasonography and endorectal ultrasonography have become important parts of diagnostic workup of patients with fecal incontinence, perianal fistulas, and rectal cancer and provides sufficient information for clinical decision-making in many cases. However, with the currently available ultrasonographic equipment and techniques, a good deal of relevant information may remain hidden. The advent of high-resolution three-dimensional endoluminal ultrasound, constructed from a synthesis of standard two-dimensional cross-sectional images, and of "Volume Render Mode," a technique to analyze information inside a three-dimensional volume by digitally enhancing individual voxels, promises to revolutionize diagnosis of pelvic floor disorders. By use of the different postprocessing display parameters, the volume-rendered image provides better visualization performance when there are not large differences in the signal levels of pathologic structures compared with surrounding tissues. The anatomic structures in the pelvis, the axial and longitudinal extension of anal sphincter defects, the anatomy of the fistulous tract in complex perianal sepsis, and the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. This additional information will bring an improvement for both planning and conduct of surgical procedures.