Section III: Endoscopic and other staging techniques

Endobronchial ultrasonography added to endoscopic ultrasonography improves staging in esophageal cancer

BACKGROUND

The gold standard for staging the local extension (T stage) and lymph node (LN) status (N stage) of esophageal cancer is endoscopic ultrasonography (EUS). When biopsy of the peritumoral LNs is performed using EUS, there is a risk of specimen contamination secondary to piercing the primary tumor; this shortcoming can be circumvented with endobronchial ultrasonography (EBUS). Moreover, EBUS allows for biopsy of LN stations not accessible with EUS.

METHODS

The study consisted of a prospective clinical trial. Fifty-two consecutive patients with potentially resectable esophageal cancer referred for endoscopic staging were prospectively enrolled. Radial and convex EUS followed by convex EBUS were performed during a single staging procedure. The LNs not accessible by EUS were biopsied using EBUS. Results of the EBUS procedure were compared to those of EUS in terms of the addition of staging information, upstaging, and confirmation of stage.

RESULTS

The combined EBUS-EUS procedure was performed in 42 patients. Ten patients were excluded. In all, 54 LNs were biopsied under EUS guidance and 48 LNs were biopsied under EBUS guidance. The EUS results were positive for metastatic esophageal cancer in 29 LNs (54%), and EBUS was positive in 10 LNs (21%). The addition of EBUS to EUS in the staging of esophageal cancer led to nodal and patient upstaging in 5 patients (12%) and confirmed the EUS stage with additional negative or positive LN sampling in 29 patients (69%). Positive EBUS that led to upstaging (5 patients) changed the treatment plan from potentially resectable to palliative. There was no morbidity related to EBUS.

CONCLUSIONS

A combined EBUS-EUS staging procedure improves precision in staging, leads to upstaging, and can change the treatment plan in patients with esophageal cancer.

An expert opinion on esophageal cancer therapy

INTRODUCTION

Worldwide, esophageal cancer (EC) is the seventh leading cause of cancer-related death, with its incidence increasing in the US, where a change in its epidemiology has been noted. Most patients present with regional or distant disease and, therefore, have a very poor prognosis.

AREAS COVERED

Progress made over the last 20 years in the diagnosis, staging and management of EC is focused on in this review, with the emphasis on locally-advanced disease treated with curative intent. Evidence is reviewed from prospective randomized trials and meta-analyses and data are presented regarding new therapy with targeted agents. Although surgery has been the mainstay of treatment for EC, survival with this approach alone remains disappointing. As a result, combined modality treatment (CMT) including chemotherapy and radiation has been incorporated into the treatment paradigm for both operable and inoperable disease. The evidence supporting CMT for EC, the role of surgery at different stages, and how treatment strategies differ based on histology are outlined.

EXPERT OPINION

Trends in 5-year overall survival rates over the last 30 years have increased (from 5 to 17%), suggesting that small, yet significant, improvements in diagnosis, staging, treatment and supportive care are being made. Clearly, the choice of treatment should be guided by disease stage, histology and patient co-morbidities.

Staging accuracy of endoscopic ultrasound based on pathologic analysis after minimally invasive esophagectomy

Endoscopic ultrasonography (EUS) is a common staging modality used in patients with esophageal cancer. The objective of this analysis was to evaluate the accuracy and sensitivity of EUS in determining the depth of penetration (T stage) and nodal status (N stage) in patients with esophageal cancer who underwent minimally invasive esophagectomy (MIE). A retrospective analysis of all patients at a university hospital who underwent preoperative EUS followed by MIE for cancer was performed. We compared the results of preoperative EUS to final pathologic analyses of the esophageal specimen, examining the accuracy of EUS staging. Ninety-five patients with esophageal cancer who underwent MIE had preoperative EUS. Twenty-four of the 95 patients were excluded for lack of a repeat EUS after neoadjuvant therapy before resection. Hence, 71 patients were evaluated for the accuracy of EUS staging. The accuracy of EUS for T0 disease was 80 per cent; T1 disease was 75 per cent; T2 disease was 39 per cent; and T3 disease was 88 per cent. The overall EUS accuracy for T stage was 72 per cent with overstaging occurring mostly for pathologic T1 tumors in 18 per cent and understaging occurring mostly for pathologic T3 tumors in 11 per cent. The sensitivity and specificity for detection of nodal involvement were 79 per cent and 74 per cent, respectively. However the accuracy for T and N staging by EUS after neoadjuvant therapy decreased to 63 per cent and 38 per cent, respectively. Endoscopic ultrasound in the absence of neoadjuvant therapy is a relatively accurate and sensitive modality for determining the depth of tumor penetration and the presence of nodal disease in patients with esophageal carcinoma. The accuracy for T and N staging is less reliable after neoadjuvant therapy.

Review of endoscopic ultrasound-guided fine-needle aspiration cytology

This review, based on the Hennepin County Medical Center experience and review of the literature, vastly covers the up-to-date role of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (FNA) in evaluating tumorous lesions of the gastrointestinal tract and adjacent organs. Emphasis is given to the tumoral and nodal staging of esophageal, pulmonary, and pancreatic cancer. This review also discusses technical, pathological, and gastroenterologic aspects and the role of the pathologist and endosonographer in the evaluation of these lesions, as well as the corresponding FNA cytology and differential diagnosis.

Comparison of positron emission tomography, computed tomography, and endoscopic ultrasound in the initial staging of patients with esophageal cancer

INTRODUCTION

Improvement in esophageal cancer staging is needed. Positron emission tomography (PET), computed tomography (CT), and endoscopic ultrasound (EUS) in the staging of esophageal carcinoma were compared.

METHODS

PET, CT, and EUS were performed and interpreted prospectively in 75 patients with newly diagnosed esophageal cancer. Either tissue confirmation or fine needle aspiration (FNA) was used as the gold standard of disease. Sensitivity and specificity for tumor, nodal, and metastatic (TNM) disease for each test were determined. TNM categorizations from each test were used to assign patients to subgroups corresponding to the three treatment plans that patients could theoretically receive, and these were then compared.

RESULTS

Local tumor staging (T) was done correctly by CT and PET in 42% and by EUS in 71% of patients (P value > 0.14). The sensitivity and specificity for nodal involvement (N) by modality were 84% and 67% for CT, 86% and 67% for EUS, and 82% and 60% for PET (P value > 0.38). The sensitivity and specificity for distant metastasis were 81% and 82% for CT, 73% and 86% for EUS, and 81% and 91% for PET (P value > 0.25). Treatment assignment was done correctly by CT in 65%, by EUS in 75%, and by PET in 70% of patients (P value > 0.34).

CONCLUSIONS

EUS had superior T staging ability over PET and CT in our study group. The tests showed similar performance in nodal staging and there was a trend toward improved distant disease staging with CT or PET over EUS. Assignment to treatment groups in relation to TNM staging tended to be better by EUS. Each test contributed unique patient staging information on an individual basis.

Virally-directed fluorescent imaging (VFI) can facilitate endoscopic staging

BACKGROUND

Replication-competent, tumor specific herpes simplex virus NV1066 expresses green fluorescent protein (GFP) in infected cancer cells. We sought to determine the feasibility of GFP-guided imaging technology in the intraoperative detection of small tumor nodules.

METHODS

Human cancer cell lines were infected with NV1066 at multiplicities of infection of 0.01, 0.1 and 1. Cancer cell specific infectivity, vector spread and GFP signal intensity were measured by flow cytometry and time-lapse digital imaging (in vitro); and by use of a stereomicroscope and endoscope equipped with a fluorescent filter (in vivo).

RESULTS

NV1066 infected all cancer cell lines and expressed GFP at all MOIs. GFP signal was significantly higher than the autofluorescence of normal cells. One single dose of NV1066 spread within and across body cavities and selectively infected tumor nodules sparing normal tissue. Tumor nodules undetectable by conventional thoracoscopy and laparoscopy were identified by GFP fluorescence.

CONCLUSION

Virally-directed fluorescent imaging (VFI) is a real-time novel molecular imaging technology that has the potential to enhance the intraoperative detection of endoluminal or endocavitary tumor nodules.