Limitations of Early Rectal Cancer Nodal Staging may Explain Failure after Local Excision

Successful selection of patients with rectal cancer for local excision requires accurate preoperative lymph node staging. Although endorectal ultrasound is capable of detecting locally advanced disease, its ability to correctly identify nodal metastases in early rectal lesions is less well described. This study examines the accuracy of endorectal ultrasound in determining nodal stage based on depth of penetration of the primary lesion (T stage). Between 1998 and 2003, endorectal ultrasound was performed on 938 consecutive patients; 134 had biopsy-proven rectal cancers and were treated with radical resection, without neoadjuvant therapy. Lymph node metastases were measured pathologically and correlated with endorectal ultrasound and clinicopathologic features. Accuracy and specificity of endorectal ultrasound nodal staging was determined. The overall accuracy of endorectal ultrasound nodal staging for the study cohort was 70 percent, with a 16 percent false-positive rate and 14 percent false-negative rate. Endorectal ultrasound was more likely to overlook small metastatic lymph node deposits. The size of lymph node metastasis and accuracy of endorectal ultrasound nodal staging was related to T stage. The specificity of endorectal ultrasound nodal staging, or the ability to identify patients who were node-negative, was dependent on T stage. Early rectal lesions are more likely to have lymph node micrometastases not detected by endorectal ultrasound. The ability of endorectal ultrasound to correctly identify patients without lymph node metastasis is dependent on the T stage of the primary lesion. The limitations of endorectal ultrasound in accurately staging nodal disease in early rectal lesions may, in part, explain the relatively high recurrence rates seen after local excision. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, April 30 to May 5, 2005. Reprints are not available.     

Adenocarcinoma of the rectum treated by abdominoperineal excision: multivariate analysis of prognostic factors

The aims of this study were to describe the results of 100 consecutive abdominoperineal excisions, and to try to define homogeneous subgroups of survivors using the Cox regression analysis model. There was one postoperative death. No patient was lost to follow-up. Overall 5-year survival rate was 45%. Multivariate analysis selected 3 prognostic factors: lymph node involvement (p<0.001), local tumour extent (P=0.08), and extension to adjacent organs (p=0.03). Four subgroups of patients were defined. Best survival was observed in patients (n=43) with tumour invading into the subserosa (W1) or less and without lymph node metastasis (N0), with a 5-year survival of 82% (group 1). Patients in Group 2 (n=18) had a tumour invading into the muscularis propria or less with lymph node metastasis (W0 N+), or into the serosa or perirectal fat without lymph node invasion (W2 N0), with a 5-year survival of 51%. Patients in Group 3 (n=17) had a tumour invading into the subserosa with lymph node invasion (W1 N+) or extension to adjacent organ without lymph node invasion (W3 N0) with a 5-year survival of 24%. Patients in group 4 (n=22) had extension into the serosa or perirectal fat or more with lymph node invasion (W2 N+) with a 5-year survival of 2%. This scoring system is simple, practical and easy to apply. If it can be confirmed by other studies, its routine adoption could be justified.     

Transrectal ultrasound and computed tomography in preoperative staging of lower rectal adenocarcinoma

A comparison of transrectal ultrasound (TRUS) and computed tomography (CT) for staging of rectal carcinoma was performed. Thirty-two patients were examined by TRUS and 30 by CT. The results of these preoperative examinations were compared with postoperative histopathological findings. TRUS had an accuracy of 81% and it predicted perirectal tumor growth with a sensitivity of 90% and a specificity of 67%, whereas the corresponding figures for CT were 52%, 67%, and 27%. These findings indicate that TRUS is more efficient than CT in staging local tumor growth in rectal cancer. Neither technique, however, can reliably identify lymph node metastases, since no correlation was found between lymph node size as observed on CT and TRUS and tumor involvement as evaluated histopathologically.     

Can pathological complete response in the primary tumour following pre-operative pelvic chemoradiotherapy for T3–T4 rectal cancer predict for sterilisation of pelvic lymph nodes, a low risk of local recurrence and the appropriateness of local excision?

Introduction Local excision is considered inappropriate treatment for T3–T4 rectal adenocarcinomas, as it cannot provide prognostic information regarding lymph node involvement and has a high risk of pelvic recurrence. Preoperative chemoradiation (CRT) studies in rectal cancer suggest that a pathological complete response (pCR) in the primary tumour provides an excellent long-term outcome. If downstaging to stage pT0 predicts a tumour response within the perirectal and pelvic lymph nodes, this may allow local excision to be performed without increased risk of pelvic recurrence. This retrospective study aimed to determine the incidence of involved lymph nodes following pCR (ypT0) after preoperative CRT and total mesorectal excision.Method The outcome and treatment details of 211 patients undergoing preoperative CRT for clinically staged T3–T4 unresectable rectal adenocarcinomas between 1993 and 2003 at Mount Vernon Hospital were reviewed.Results Data were recorded from the 143 patients who completed treatment with a median follow-up of 25 months. Twenty-three patients (18%) were found to have had a pCR. Four out of 23 patients (17%) had involved lymph nodes. No pelvic recurrences developed after a ypCR. Overall survival was similar for patients with ypT0 or residual tumour.Conclusion Pathological complete response in the primary tumour failed to predict a response in the perirectal lymph nodes (p=0.08). The degree of response predicted a lymph node response (p=0.02). The detection of ypCR identified patients with a low rate of pelvic recurrence. This may in the future allow selection of patients for whom local excision can be performed without a higher risk of local relapse.On behalf of the Mount Vernon Colorectal Cancer Network     

Comparative efficacy of positron emission tomography with fluorodeoxyglucose in evaluation of small (<1 cm), intermediate (1 to 3 cm), and large (>3 cm) lymph node lesions

PURPOSE: Our objective was to determine if positron emission tomography (PET) with fluorodeoxyglucose (FDG; PET-FDG) imaging is equally efficacious in detection of metastases in small and large mediastinal lymph nodes as compared to CT scanning. MATERIALS AND METHODS: PET-FDG imaging, CT scanning, and histology results of sampled mediastinal lymph nodes were compared in 54 patients of total 118 patients studied. Efficacy of PET and CT was determined and compared in small (< 1 cm), intermediate (1 to 3 cm), and large (> 3 cm) mediastinal lesions. RESULTS: PET was accurate in 94% of patients in characterizing "N" disease as compared to 61% with CT. Overall, sensitivity, specificity, and accuracy of PET for staging mediastinal lymph nodes (n = 168 in 54 patients) was 96, 93, and 94%, as compared to 68, 65, and 66% with CT. Positive and negative predictive value of PET in detecting mediastinal adenopathy was 86% and 98%, as compared to 47% and 82% with CT, respectively. PET was also highly reliable and accurate for detecting lymph nodes < 1 cm, 1 to 3 cm, and > 3 cm in size with superior efficacy than CT. Sensitivity, specificity, and accuracy of PET for detecting malignancy in lymph node lesions < 1 cm in size was 97, 82, and 95%, respectively. CONCLUSION: PET-FDG imaging is equally reliable and accurate for detecting disease in small and large lymph node lesions in patients with suspected or proven lung cancer with better efficacy than CT.     

Computed tomography in staging of oesophageal carcinoma

The computed tomographic (CT) findings in 45 patients with histologically proved oesophageal carcinoma are reviewed. In 20 of these patients the CT findings were correlated with findings at surgery (19 patients) or autopsy (1 patient). Correlation analysis showed that the accuracy of CT in assessing both invasion of adjacent organs and mediastinal and abdominal lymph node involvement is limited. Twenty-five patients were considered inoperable; in 15 of these the conclusion was based on CT findings of distant metastases (14 patients) or definite local invasion (1 patient). Ten patients were inoperable for other reasons (general health condition). We found the value of CT to be in detecting distant metastases, thus avoiding unnecessary radical surgery; it is not a reliable way of defining the primary tumour.     

Three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer

PURPOSE: Preoperative staging of advanced carcinoma of the rectum by conventional endorectal ultrasonography is often impossible because of the presence of obstruction, which does not allow passage of the endoprobe. In a prospective Study, we investigated the value of three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer. This technique permits examination of obstructing rectal tumors because scan planes can be chosen deliberately within a scanned volume. METHODS: Overall obstructing tumors not accessible for conventional endoprobes were found in 26 of 94 patients who were subjected to endorectal ultrasonography for staging of rectal cancer. Three-dimensional volume scanning was performed using a three-dimensional frontfire transducer or a three-dimensional bifocal multiplane transducer (7.5/10 MHz). Data of the three-dimensional scans were stored on a hard disk for subsequent evaluation with a combison 530 processor. RESULTS: Three-dimensional transrectal endosonography enabled visualization of local tumor spread in all 26 patients. In 18 patients, obstruction was caused by advanced primary rectal carcinoma. Endosonography accurately determined the tumor infiltration depth in three T2 tumors, eight T3 tumors, and three T4 tumors. Overall accuracy for assessment of infiltration depth was 78 percent. Accuracy for assessment of perirectal lymph node involvement was 75 percent. In eight patients, the obstruction was attributable to extramural regrowth of rectal cancer after surgery. Diameter of the lesions ranged between 3 and 6 cm. Although all lesions were clearly depicted by three-dimensional endosonography, only five lesions (62 percent) were detected by computed tomography. CONCLUSIONS: Three-dimensional endorectal ultrasonography provides previously unattainable scan planes and enables accurate staging of obstructing rectal tumors. This technique may improve therapy planning in advanced rectal cancer by selecting patients who require preoperative adjuvant therapy.     

Prognostic profile in rectal cancer

PURPOSE: The purpose of this article was to review the prognostic factors of significance in rectal cancer. METHODS: This is a retrospective review of various reports and an examination of our data. RESULTS: Current imaging techniques with endorectal ultrasound, magnetic resonance imaging with a rectal probe, and possibly tagged monoclonal antibodies allow for presurgical assessment of the invasion of the rectal wall and detection of lymph node involvement. CONCLUSIONS: Tumor penetration of the rectal wall and lymph node metastases are the most important prognostic indicators in rectal cancer and predict local and distant recurrences. When lymph node metastases occur, they are more common in small lymph nodes (<5 mm). Patients with lymph node metastases always need to be considered for multimodality therapy. Tumors larger than or equal to T3 or with associated lymph node metastases should not be treated with sphincter-saving surgical procedures alone.     

Prognostic profile in rectal cancer

PURPOSE: The purpose of this article was to review the prognostic factors of significance in rectal cancer. METHODS: This is a retrospective review of various reports and an examination of our data. RESULTS: Current imaging techniques with endorectal ultrasound, magnetic resonance imaging with a rectal probe, and possibly tagged monoclonal antibodies allow for presurgical assessment of the invasion of the rectal wall and detection of lymph node involvement. CONCLUSIONS: Tumor penetration of the rectal wall and lymph node metastases are the most important prognostic indicators in rectal cancer and predict local and distant recurrences. When lymph node metastases occur, they are more common in small lymph nodes (<5 mm). Patients with lymph node metastases always need to be considered for multimodality therapy. Tumors larger than or equal to T3 or with associated lymph node metastases should not be treated with sphincter-saving surgical procedures alone.     

Endoscopic sonography of the anorectum in inflammatory rectal diseases]

213 patients, classified in 3 groups, were examined in a prospective trial using endorectal ultrasound. 80 patients (group A) had no anorectal disease, the endorectal ultrasound showed normal structures of the anorectum and the perirectal tissue. 80 patients (group B) suffered from Crohn's disease, 30 of them had no clinical signs, the rest of this group (50 patients) felt pain in the anal/perianal region. 83 patients (group C) had perianal abscesses or fistulas, Crohn's disease could be excluded. In all 64 perianal fistulas and 66 perianal abscesses were diagnosed. The results of the rectal-proctological examination were compared with endorectal ultrasound. 100% of the perianal abscesses could be recognized using endosonography. The digital-proctological examination revealed only 57% of perianal abscesses and 48% of perianal fistulas; the supralevatory abscesses couldn't be detected proctologically at all. By endorectal ultrasonography we obtained useful informations about localization and extension of the inflammatory process. From a therapeutic and prognostic view the endorectal ultrasound is a simple, practicable and useful method to investigate perianal and anorectal diseases.     

How accurate is endorectal ultrasound in the preoperative staging of rectal cancer?

In rectal cancer, depth of infiltration and metastatic involvement of lymph nodes are important prognostic factors. The correct choice of operative treatment depends on the extent of the disease. In a prospective study, the value of endorectal ultrasound in staging rectal cancer was evaluated, and factors affecting the method's accuracy are discussed. The overall accuracy in staging depth of infiltration was 89 percent. Overstaging occurred in 10.2 percent, understaging in 0.8 percent. Tumors of the lower rectum are incorrectly staged in 16.7 percent, whereas tumors of the middle and upper rectum had an incorrect staging in 6.3 percent (P <0.001). Compared with computed tomography, endorectal sonography is the more accurate staging method (74.7 vs.90.8 percent). In staging lymph nodes, the overall accuracy was 80.2 percent, sensitivity was 89.4 percent, specificity was 73.4 percent, positive predictive value (PPV) was 71.2 percent, and negative predictive value (NPV) was 90.4 percent. The staging accuracy depends on the size of the node. Endorectal ultrasound is a safe, inexpensive, and accurate staging method, in the assessment of both depth of infiltration and nodal status. The results are strongly related to the experience of the investigator.     

Lymphatics and colorectal liver metastases: the case for sentinel node mapping

Background: Hepatic resection remains the treatment of choice for patients with colorectal liver metastases (CLM). Indications for hepatic resection have been extended to include extrahepatic lymph node groups, resulting in increased survival benefits. The identification of specific lymph pathways and involved nodes is necessary to support the development of guidelines for a more focused approach to the management of this disease. The feasibility of sentinel node mapping should be investigated to define specific lymphatic groups involved in CLM.Methods: Scientific papers published from 1950 to 2012 were sought and extracted from the MEDLINE, PubMed and University of Melbourne databases.Results: Several studies have reported microscopic lymph node involvement in 10–15% of patients undergoing hepatic resection for CLM in which no macroscopic involvement was evident. In retrospect, over 80% of lymphadenectomies are proven unnecessary. Traditional imaging modalities have limited predictive value in detecting lymph node involvement. Sentinel node mapping has proved an extremely accurate tool in detecting lymph node involvement and can identify patients in whom lymphadenectomy may be beneficial.Conclusions: Current imaging techniques are inadequate to detect microscopic lymph node involvement in patients with resectable CLM. The use of sentinel node mapping is proposed to identify nodal groups involved and provide management strategies.     

Preoperative staging of rectal cancer

With the widespread introduction of preoperative radiotherapy for rectal cancer and the development of transanal endoscopic microsurgery for selected early lesions, preoperative radiological staging of these tumours has taken on increasing importance. This study is a systematic review to evaluate computed tomography (CT), endorectal sonography (ES) and magnetic resonance imaging (MRI) as preoperative staging modalities in rectal cancer. A Medline-based search identifying studies using CT, ES, or MRI in preoperative staging of rectal cancer between 1980 and 1998 was undertaken. The list of papers was supplemented by extensive cross-checking of citation lists. Studies were included if they met predetermined criteria. Data from the accepted studies were entered into pooled tables comparing radiological and pathological staging results for each modality both in determining bowel wall penetration and involvement of lymph nodes. Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were determined for the pooled results. Eighty-three studies from 78 papers including 4897 patients met the inclusion criteria. In determining the wall penetration of the tumour the values for sensitivity for CT, ES, MRI and MRI with endorectal coil were 78%, 93%, 86% and 89%; for specificity 63%, 78%, 77% and 79%; and for accuracy 73%, 87%, 82% and 84%, respectively. In determining the nodal involvement by tumour the sensitivity values for CT, ES, MRI and MRI with endorectal coil 52%, 71%, 65% and 82%; for specificity 78%, 76%, 80% and 83%; and for accuracy 66%, 74%, 74% and 82%, respectively. MRI with an endorectal coil is the single investigation that most accurately predicts pathological stage in rectal cancer. Accepted: 14 October 1999     

Endoluminal ultrasound diagnosis and operative management of rectal endometriosis

PURPOSE: Endorectal ultrasound was performed in patients with endometriosis to evaluate the role of this technique for rectal wall involvement and to evaluate the position of preoperative diagnosis in the operative management of rectal endometriosis. METHODS: Sixteen patients with suspected fixation of endometriomas to the rectal wall during bimanual examination were included in the study. Endorectal ultrasound was performed using a real time unit with a 7.5 MHz endorectal transducer. The probe was introduced via a rectoscope into the rectum up to the rectosigmoid. RESULTS: Endometriosis was confirmed histopathologically in all patients. In six patients rectal wall involvement was diagnosed, in two patients endometriomas were adjacent to the rectal wall, and in eight patients rectal wall involvement could be excluded. Preoperative diagnosis was confirmed in all patients during operation. Laparotomy was performed in those patients with preoperatively diagnosed rectal wall involvement, whereas the remaining patients were treated laparoscopically. Endometriomas with rectal wall involvement were treated in five of six patients with resection of the affected bowel predominantly by low anterior resection. CONCLUSIONS: Preoperative endorectal ultrasound is a reliable technique to visualize perirectal endometriomas and to assess rectal wall involvement. Based on preoperative endosonographic diagnosis, an operative management was established with laparotomy and resection of the affected bowel in cases of rectal wall involvement.     

The value of mediastinoscopy in preoperative evaluation of mediastinal involvement in non-small-cell lung cancer patients with clinical NO disease

BACKGROUND: The efficacy of mediastinal lymph node examination using cervical mediastinoscopy in operable non-small cell lung cancer patients without radiological nodal involvement on computerized tomography (CT) has been elusive. METHODS: The value of mediastinoscopy as a staging modality for assessing the mediastinal lymph node status was evaluated in 79 patients with presumed resectable non-small-cell lung cancer (NSCLC) with mediastinal nodes smaller than 1 cm (NO) form the CT scan. Sixty-one patients who did not have nodal involvement at mediastinoscopy and had complete medical records underwent complete resection. RESULTS: Negative predictive value (NPV) of the CT scan according to mediastinoscopy was 92.4 %. Histopathological examination of the surgical specimen showed the NPV of mediastinoscopy to be 93.4 %. Only 4 patients (3 patients with N2, 1 patient with N3 disease) were not correctly staged using CT scanning and mediastinoscopy. According to the pathological examination, the NPV of CT was found to be lower (76.5 %) in patients with adenocarcinoma, but the difference was not statistically significant (p > 0.128) CONCLUSION: Although the likelihood of surgical-pathological N2 is slightly higher in patients with adenocarcinoma, radiological examination of patients with cNO NSCLC disease can be as accurate as mediastinoscopy in appropriately staging mediastinal lymph node involvement.     

The prognostic significance of preoperative assessment of mediastinal lymph nodes in patients with lung cancer

In order to evaluate the prognostic significance of the preoperative assessment of mediastinal lymph nodes, 100 patients with potentially operable lung cancer underwent two-plane tomography, computed tomography (CT), transbronchial needle aspiration (TBNA; 47 patients), and cervical mediastinoscopy. Mediastinoscopy proved to be the most accurate staging procedure. Tomography was less specific, detecting only advanced mediastinal node involvement, and CT was as sensitive as mediastinoscopy but sensibly less specific. TBNA gave no false positive results but a false negative rate of 25.5 percent. Accurate preoperative staging of mediastinal nodes is mandatory to optimize the resectability rate of lung cancer. Where metastatic involvement of mediastinal nodes was preoperatively documented at more than one level, tumors were invariably unresectable. Mediastinoscopic demonstration of intracapsular metastases at only one level did not preclude complete resection. Before thoracotomy, confirmation of neoplastic spread to mediastinal nodes suggests very low survival rates, especially in patients with incomplete removal of tumors.     

New endoscopic ultrasound (EUS) applications in lung cancer: evaluation of patients with negative mediastinal CT and re-staging after neoadjuvant treatment

The main purpose of staging in non-small cell lung cancer (NSCLC) is to assess mediastinal lymph node involvement, with thoracic CT being the main non-invasive test for this. However, given that up to 15% of patients who show no mediastinal lymph node involvement in the CT have lymph node metastasis during surgery, other examinations are required. Endoscopic ultrasonography guided fine-needle aspiration (EUS-FNA) has shown to be able to detect advanced disease (metastatic mediastinal lymph nodes, adrenal metastasis, mediastinal invasion by the tumour) in approximately 25% of patients with a CT that suggested a non-advanced disease. Another situation in which CT has a very limited value is in the evaluation of the response to induction therapy, with its most limiting factor being its intrinsic inability to distinguish between a tumour and necrosis. In this context, EUS-FNA has shown to have a good performance, with a sensitivity, negative predictive value and precision of 75%, 67% and 83%, respectively. In conclusion, EUS-FNA may be considered a good alternative in the pre-operative staging of patients with NSCLC, with and without diseased mediastinal lymph nodes in CT, and could play an important role in the mediastinal re-staging of these patients by identifying a patient sub-group who might benefit from additional surgical treatment.     

Endoscopic ultrasound in non-small cell lung cancer and negative mediastinum on computed tomography

Despite technical advances in staging non-small cell lung cancer (NSCLC), accurate staging remains a challenge. Endoscopic ultrasound is useful in staging NSCLC when lymphadenopathy is present on a computed tomography (CT), but its role in the absence of lymphadenopathy on CT has not been well defined. Therefore, we sought to determine the clinical impact of endoscopic ultrasound (EUS) in staging NSCLC in absence of mediastinal lymphadenopathy on CT. Seventy-six patients with NSCLC with absence of mediastinal lymphadenopathy on CT were enrolled and followed prospectively. EUS-guided fine-needle aspiration was performed on sites that were suspicious for metastases. Surgical pathology after thoracotomy was used as the reference standard for assessing accuracy. Sixty-two (86%) patients underwent surgery, and 10 (13%) did not. EUS precluded surgery in 9 patients (12%) and influenced management in 18 (25%) of all patients in this study. EUS detected malignant mediastinal lymphadenopathy more frequently in patients with lower lobe and hilar cancers combined compared with upper lobe cancers (p = 0.004). EUS played a significant role in identifying patients with unresectable (N3) NSCLC when adenopathy was not present on CT imaging and appears to be more sensitive in detecting lymph node metastases in lower lobe and hilar NSCLC compared with upper lobe NSCLC.     

Occult nodal metastasis in patients with non‐small cell lung cancer at clinical stage IA by PET/CT

Background and objective: The introduction of ¹⁸F‐FDG PET/CT has enhanced the diagnostic accuracy of nodal staging for non‐small cell lung cancer (NSCLC). We analysed risk factors for occult nodal metastasis in patients with clinical stage IA NSCLC as determined by ¹⁸F‐FDG PET/CT. Methods: Data for 147 patients diagnosed as clinical stage IA NSCLC by PET/CT from 2005 to 2007 were retrospectively reviewed. All study patients underwent ¹⁸F‐FDG PET/CT for lung cancer staging. They also underwent cervical mediastinoscopy or systematic lymph node dissection. Results: Cervical mediastinoscopy was performed in 78 patients (53.1%), and N2 involvement was detected in 3.8% (3/78) of these patients. Thoracotomy with systematic lymph node dissection was done in 144 patients. Four patients (2.8%, 4/144) were diagnosed with N2 disease after systematic lymph node dissection. Total N2 involvement was 4.8% (7/147). As 9.5% (14/147) of study patients had N1 disease, 14.3% (21/147) of patients had occult nodal (N1 or N2) metastasis. In univariate analyses, larger tumour size and a higher primary tumour maximum standardized uptake value >7.3 (SUV_max) were associated with occult nodal metastasis. Multivariate analysis demonstrated that a primary tumour SUV_max >7.3 was an independent predictor of occult nodal metastasis (odds ratio: 7.574; P = 0.001). Conclusions: Preoperative PET/CT scans contribute to reduce the frequency of occult nodal metastasis compared with those reported in the pre‐PET/CT era. The higher SUV_max in primary tumour was an independent predictor of occult nodal metastasis in patients with clinical stage IA NSCLC by PET/CT.