EUS-FNA assessment of extramesenteric lymph node status in primary rectal cancer

A model based on endorectal ultrasonography predicts lateral lymph node metastasis in low and middle rectal cancer

PURPOSE

To investigate the risk factors for lymph node (LN) metastasis in low and middle rectal tumors, construct a predictive model and test the model's diagnostic efficacy.

METHODS

The clinical and pathological data of 172 patients with rectal cancer confirmed by surgery were retrospectively evaluated, among whom 61 patients were finally included in this study. Patients were divided into positive groups and negative groups based on LN metastasis, and risk factors that might affect LN metastasis were analyzed. Finally, a risk predictive model was constructed based on the weights of each risk factor.

RESULTS

Compared with pathology, the efficacy of diagnosing LN metastasis only according to conventional endorectal ultrasonography (ERUS) features of LN was not high, with sensitivity 67%, specificity 86%, positive predictive value 76%, negative predictive value 80%, and accuracy 79%. Univariate analysis showed that circumferential angle of the tumor, ultrasonic T- stage (UT stage), conventional ultrasound features diagnosis of LN metastasis, strain ratio (SR) of tumor were risk factors for LN metastasis, while vascular resistance index of rectal tumor was protective factor. Multivariate analysis showed that UT stage (OR = 7.188, p = 0.049), conventional ultrasound features diagnosis of LN metastasis (OR = 8.010, p = 0.025) and SR (OR = 5.022, p = 0.031) were independent risk factors for LN metastasis. These risk factors were included in logistic regression analysis and the model was established, Y = -7.3 + 1.9 X10 + 2.1 X11 + 1.6 X13 (Y = Logit[P], P: LN metastasis rate, X10: UT stage, X11: conventional ultrasound features diagnosis of LN metastasis, X13: SR). The receiver operating characteristic (ROC) curve was used to test the model's predictive efficacy, the area under the curve was 0.95, sensitivity: 95%, specificity: 87%. Hosmer-Lemeshow goodness of fit test showed X2 = 6.015, p = 0.65 (p > 0.05), indicating that the model had a high predictive value.

CONCLUSION

Evaluation of perirectal LN metastasis only based on conventional ERUS features of LN was not effective enough. UT stage of tumor, conventional ultrasound features diagnosis of LN metastasis and SR were independent risk factors for LN metastasis. The predictive model had good assessment efficacy and had certain clinical application value.

Impact of EUS-FNA for preoperative para-aortic lymph node staging in patients with pancreatobiliary cancer

BACKGROUND AND AIMS

In patients with pancreatobiliary cancer, para-aortic lymph node (PALN) metastasis is considered to be the involvement beyond the regional lymph nodes, namely, distant metastasis. Effective methods for preoperative PALN staging, however, are not established. This study aimed to compare the diagnostic capability for PALN metastasis between EUS-FNA and (18)F-fluorodeoxyglucose positron emission tomography with CT (PET/CT).

METHODS

We performed a prospective, nonrandomized, single-center trial. Between December 2010 and March 2014, 208 patients with pancreatobiliary cancer without apparent distant metastasis except for PALNs were assessed for study eligibility before surgery. Among them, 52 consecutive patients with PALN enlargement were enrolled in the study. (18)F-Fluorodeoxyglucose PET/CT and EUS-FNA were performed sequentially as a single combined procedure to evaluate PALN metastases. The primary outcome was to compare the diagnostic capability of EUS-FNA and PET/CT for PALN metastasis.

RESULTS

Of 71 enlarged PALNs in the 52 patients, 30 (42.3%) were finally diagnosed as metastases in 21 patients (40.4%). Of the 21 patients with PALN metastases, preoperative EUS-FNA or PET/CT made a correct diagnosis in 20 (95.2%) or 12 (57.1%), respectively. EUS-FNA had higher sensitivity and specificity for the diagnosis of PALN metastasis (sensitivity, 96.7% [29/30]; 95% confidence interval, 82.2%-99.9%; specificity, 100% [39/39]; 95% confidence interval, 91.0%-100%) than PET/CT.

CONCLUSIONS

EUS-FNA is superior to PET/CT for preoperative PALN staging in patients with pancreatobiliary cancer. Because of the clinical benefit of EUS-FNA to reduce unnecessary surgery, it should be part of the standard preoperative examination for patients with pancreatobiliary cancer. (UMIN clinical trials registry number: 000006408.).

Is it time to rethink the rule of total mesorectal excision? A prospective radiological and pathological study in 49 consecutive patients with mid-rectal cancer

AIM

Total mesorectal excision (TME) after neoadjuvant chemoradiotherapy is the standard treatment for T3-T4 and/or N+ mid-rectal tumours, regardless of the exact tumour level. This leads to optimal oncological results but possible impaired functional results. Reducing rectal excision could reduce the functional drawbacks. This study prospectively assessed the risk of N+ or other mesorectal tumour deposit (OTD) below the tumour level by magnetic resonance imaging (MRI) performed after chemoradiotherapy and pathological examination of the TME specimen.

METHOD

Consecutive patients with mid-rectal cancer who underwent TME after chemoradiotherapy were included. A prospective evaluation by postchemoradiotherapy MRI and pathological examination was performed to assess the location of N+ nodes and/or OTDs.

RESULTS

Of 49 consecutive patients, 27 (55%) presented with nodes on postchemoradiotherapy MRI. However, only 12 nodes (size 2-4 mm) in 9 patients (18%) were under the tumour level. On pathological examination, 717 total lymph nodes were found, with 37 N+ and 22 OTD. According to the tumour level: (i) above tumour level, 21/453 nodes were N+ and 6 OTD; (ii) at tumour level, 16/166 nodes were N+ and 15 OTD; (iii) below tumour level, 0/98 nodes (0%) was N+ and only 1 OTD (2%) was noted at 2 cm below tumour level.

CONCLUSION

After chemoradiotherapy, N+ and/or OTD located under the level of the rectal cancer seems to be a very rare event. A postchemoradiotherapy MRI could help detect such patients. For others patients, conservation of the lower rectum with only a subtotal mesorectal excision could possibly improve function.

Endoscopic Ultrasonography-Guided Biopsy for Differentiation of Benign and Malignant Pelvic Lesions: A Systematic Review and Meta-Analysis

BACKGROUND

Preoperative diagnosis of pelvic lesions remains challenging despite advances in imaging technologies. Endoscopic ultrasonography (EUS)-guided biopsy is an effective diagnostic modality for sampling the digestive tract and surrounding areas. However, a meta-analysis summarizing the diagnostic efficacy of EUS-guided biopsy for pelvic lesions has not been published.

AIMS

We aimed to evaluate the utility of EUS-guided biopsy in the diagnosis of pelvic lesions.

METHODS

Articles were identified via structured database search; only studies where pelvic lesions were confirmed by surgery or clinical follow-up were included. Data extracted were selected with strict criteria. A fixed-effects model was used to estimate the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). A summary receiver operating characteristic curve (SROC) was also constructed.

RESULTS

Ten studies containing a total of 246 patients were included. The pooled sensitivity of EUS-guided biopsy for differential diagnosis of pelvic masses was 0.89 (95% CI 0.83-0.94), and the specificity was 0.93 (95% CI 0.86-0.97). The area under the SROC was 0.9631. The combined PLR, NLR, and DOR were 11.75 (95% CI 5.90-23.43), 0.12 (95% CI 0.07-0.20), and 100.06 (95% CI 37.48-267.10) respectively. There is potential presence of publication bias in this meta-analysis.

CONCLUSIONS

Our meta-analysis shows that EUS-guided biopsy is a powerful tool for differentiating pelvic masses with a high sensitivity and specificity. Furthermore, it is a safe procedure with low rate of complication, although more high-quality prospective studies are required to be done.

The role of 3-D endorectal ultrasound in rectal cancer: our experience

In the last 20 years, endorectal ultrasound (ERUS) has been one of the main diagnostic methods for locoregional staging of rectal cancer. ERUS is accurate modality for evaluating local invasion of rectal carcinoma into the rectal wall layers (T category). Adding the three-dimensional modality (3-D) increases the capabilities of this diagnostic tool in rectal cancer patients. We review the literature and report our experience in preoperative 3-D ERUS in rectal cancer staging. In the group of 71 patients, the staging of preoperative 3-D endorectal ultrasonography was compared with the postoperative morphologic examination. Three-dimensional ERUS preoperative staging was confirmed with morphologic evaluation in 66 out of 71 cases (92.9%). The detection sensitivities of rectal cancer with 3-D ERUS were as follows: T1, 92.8%; T2, 93.1%; T3, 91.6%; and T4, 100.0%; with specificity values of T1, 98.2%; T2, 95.4%; T3, 97.8%; and T4, 98.5%. Three-dimensional ERUS correctly categorized patients with T1, 97.1%; T2, 94.3%; T3, 95.7%; and T4, 98.5%. The percentage of total overstaged cases was 2.75% and that of understaged cases was 6.87%. The metastatic status of the lymph nodes was determined with a sensitivity of 79.1% (19 of 24), specificity of 91.4% (43 of 47), and diagnostic accuracy of 87.3% (62 of 71). In our experience, 3-D ERUS has the potential to become the diagnostic modality of choice for the preoperative staging of rectal cancer.

Incidence and prognosis of lower rectal cancer with limited extramesorectal lymph node metastasis

PURPOSE

Patients with lower rectal cancer occasionally have limited extramesorectal lymph node metastasis. However, the incidence and prognosis of lower rectal cancer with limited extramesorectal lymph node metastasis remain unclear.

METHODS

A total of 714 patients with clinical stage II or III lower rectal cancer who underwent extramesorectal lymph node dissection at the National Cancer Center Hospital between 1985 and 2011 were reviewed.

RESULTS

Among the 714 patients with lower rectal cancer, 35 (4.9 %) had limited extramesorectal lymph node metastasis, of whom 28 (80.0 %) had one or two extramesorectal lymph node metastases. The 5-year overall survival rate was 74.5 %. The number of extramesorectal lymph node metastases was a significant prognostic factor. The 5-year overall survival rate of patients with three or more extramesorectal lymph node metastases was 28.6 %.

CONCLUSIONS

The incidence of limited extramesorectal lymph node metastasis in patients with lower rectal cancer was 4.9 %. Although the prognosis of patients with one or two extramesorectal lymph node metastases was favorable, that of patients with three or more such metastases was unfavorable.

Endoscopic ultrasound-guided fine needle aspiration as a diagnostic and staging tool for rectal and perirectal lesions-an institutional experience

The role of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in evaluating lesions adjacent to the upper gastrointestinal tract wall is well established. However, this tool is underused in evaluating rectal and perirectal lesions, possibly due to insufficient experience and underrecognized value of this procedure. In this study, we report our institutional experience with EUS-FNA as a diagnostic and staging tool for rectal and perirectal lesions. A retrospective chart review was performed and a cohort of 38 patients who underwent rectal EUS-FNA (41 specimens) at our institution between January 2002 and July 2012 was retrieved. The cytology diagnoses were compared with the concurrent or follow-up histologic and clinical diagnoses. Among the total 41 cases, rectal EUS-FNA was performed as a diagnostic procedure in 22 (54%) and a staging procedure in 19 (46%) cases. On cytology examination, 18 cases (44%) were diagnosed as malignant; 1 (2%), as atypical/suspicious for malignancy; 3 (7%), as benign neoplastic; 13 (32%), as nonneoplastic; and 6 (15%), as nondiagnostic cases. Concurrent or follow-up histologic diagnoses were available in 20 cases (48%), 19 of them had concordant cytological/histologic findings (10 benign, 9 malignant). One perirectal lymph node with negative cytology diagnosis was found to be positive on histologic examination, probably due to sampling error on cytology. The sensitivity and specificity of EUS-FNA for detecting malignant rectal/perirectal lesions in this study were 91% and 100%, respectively. Endoscopic ultrasound-guided fine needle aspiration is a useful diagnostic tool for rectal/perirectal lesions; it confirms or excludes malignancy for lesions with high or low clinical suspicions. It serves as a reliable staging method to identify patients for proper clinical management.

Diagnostic endoscopic ultrasonography: Assessment of safety and prevention of complications

Endoscopic ultrasonography (EUS) has gained wide acceptance as an important, minimally invasive diagnostic tool in gastroenterology, pulmonology, visceral surgery and oncology. This review focuses on data regarding risks and complications of non-interventional diagnostic EUS and EUS-guided fine-needle biopsy (EUS-FNB). Measures to improve the safety of EUS und EUS-FNB will be discussed. Due to the specific mechanical properties of echoendoscopes in EUS, there is a low but noteworthy risk of perforation. To minimize this risk, endoscopists should be familiar with the specific features of their equipment and their patients’ specific anatomical situations (e.g., tumor stenosis, diverticula). Most diagnostic EUS complications occur during EUS-FNB. Pain, acute pancreatitis, infection and bleeding are the primary adverse effects, occurring in 1% to 2% of patients. Only a few cases of needle tract seeding and peritoneal dissemination have been reported. The mortality associated with EUS and EUS-FNB is 0.02%. The risks associated with EUS-FNB are affected by endoscopist experience and target lesion. EUS-FNB of cystic lesions is associated with an increased risk of infection and hemorrhage. Peri-interventional antibiotics are recommended to prevent cyst infection. Adequate education and training, as well consideration of contraindications, are essential to minimize the risks of EUS and EUS-FNB. Restricting EUS-FNB only to patients in whom the cytopathological results may be expected to change the course of management is the best way of reducing the number of complications.

Endoscopic ultrasound-guided fine needle aspiration in hollow viscus cancer

Accurate cancer staging is essential in patients with hollow viscus malignancy to decide therapeutic modalities. Endoscopic ultrasound (EUS) is considered as the best modality for local staging of hollow viscus cancer. EUS-guided fine needle aspiration (FNA) is a minimally invasive and effective sampling method. EUS-FNA should be applied when positive diagnosis of malignancy can possibly change the choice of therapeutic options. EUS in conjunction with EUS-FNA can optimize stage-directed therapy which is helpful in selecting minimally invasive treatment option including endoscopic treatment and avoiding unnecessary surgery in advanced cases.