Role of endoscopy in the staging of esophageal and gastric cancer

Gastric and Small Bowel Tumors

The incidence of gastric adenocarcinoma has decreased in the United States over the past 70 years although it continues to have a poor prognosis. While radical resection was initially the primary treatment for adenocarcinoma of the stomach, systemic chemotherapy and radiation have been shown to play a role in prolonging survival in most patient populations. This chapter explores the evidence that guides treatment for gastric cancer today. It also discusses the treatment for gastrointestinal stromal tumors (GIST), and small bowel tumors. In addition to systemic therapies, this chapter explores the surgical management of gastric and small bowel tumors including the extent of the gastric lymph node dissection.

EUS for the staging of gastric cancer: a meta-analysis

BACKGROUND

The role of EUS in the locoregional staging of gastric carcinoma is undefined.

OBJECTIVE

We aimed to comprehensively review and quantitatively summarize the available evidence on the staging performance of EUS.

DESIGN

We systematically searched the MEDLINE, Cochrane, CANCERLIT, and EMBASE databases for relevant studies published until July 2010.

SETTING

Formal meta-analysis of diagnostic accuracy parameters was performed by using a bivariate random-effects model.

PATIENTS

Fifty-four studies enrolling 5601 patients with gastric cancer undergoing disease staging with EUS were eligible for the meta-analysis.

MAIN OUTCOME MEASUREMENTS

EUS staging accuracy across eligible studies was measured by computing overall sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR).

RESULTS

EUS can differentiate T1-2 from T3-4 gastric cancer with high accuracy, with overall sensitivity, specificity, PLR, NLR, and DOR of 0.86 (95% CI, 0.81-0.90), 0.91 (95% CI, 0.89-0.93), 9.8 (95% CI, 7.5-12.8), 0.15 (95% CI, 0.11-0.21), and 65 (95% CI, 41-105), respectively. In contrast, the diagnostic performance of EUS for lymph node status is less reliable, with overall sensitivity, specificity, PLR, NLR, and DOR of 0.69 (95% CI, 0.63-0.74), 0.84 (95% CI, 0.81-0.88), 4.4 (95% CI, 3.6-5.4), 0.37 (95% CI, 0.32-0.44), and 12 (95% CI, 9-16), respectively. Results regarding single T categories (including T1 substages) and Bayesian nomograms to calculate posttest probabilities for any target condition prevalence are also provided.

LIMITATIONS

Statistical heterogeneity was generally high; unfortunately, subgroup analysis did not identify a consistent source of the heterogeneity.

CONCLUSIONS

Our results support the use of EUS for the locoregional staging of gastric cancer, which can affect the therapeutic management of these patients. However, clinicians must be aware of the performance limits of this staging tool.

Should direct mesocolon invasion be included in T4 for the staging of gastric cancer?

BACKGROUND AND OBJECTIVES

One of the sites most frequently invaded by gastric cancer is the mesocolon; however, the UICC does not mention this anatomical site as an adjacent structure involved in gastric cancer. The purpose of this study was to characterize and classify mesocolon invasion from gastric cancer.

METHODS

We examined 806 patients who underwent surgery for advanced gastric carcinoma from 1992 to 2007 at the Department of Surgery, Gangnam Severance Hospital, Korea. Among these, patients who showed macroscopically direct invasion into the mesocolon were compared to other patients with advanced gastric cancer.

RESULTS

The curability, number and extent of nodal metastasis, and the survival of the mesocolon invasion group were significantly worse than these factors in the T3 group. However, the survival of the mesocolon invasion group after curative resection was much better than that of patients who had incurable factors.

CONCLUSIONS

Mesocolon invasion should be included in T4 for the staging of gastric cancer.

Clinical staging of adenocarcinoma of the esophagogastric junction

Tumors of the esophagogastric junction are among the most frequent and cause lethal cancers. Patients often do not present until late in the disease when the tumor is sufficiently large to cause obstruction or invasion of the adjacent structures, and thus becomes symptomatic. Preoperative staging is critical to select those patients whose disease is still locally confined for curative surgery. Ideally, clinical staging should accurately predict tumor invasion, lymph node involvement, and distant metastases. Upper endoscopy establishes the tumor diagnosis by multiple biopsies and defines the tumor type (Siewert I-III), based on tumor localization in relation to the endoscopic cardia. Preoperative TNM staging has a strong impact on treatment strategy. Endoscopic Ultrasound (EUS) determines the T category, and to a lesser extent, the presence of lymph node metastases. Multislice Computed Tomography (CT) and 18Fluorode-ocx-glucose Positron Emission Computed Tomography (18FDG-PET-CT) provide further information, especially about systemic metastases. Diagnostic laparascopy is suggested in advanced (CT3/4) Siewert type II-III tumors to exclude peritoneal carcinomatosis. This chapter summarizes current staging modalities and their accuracy in clinical practice.

Imaging in local staging of gastric cancer: a systematic review

PURPOSE

Endoscopic ultrasound (EUS) has been established as the diagnostic modality of choice in local (T) staging of gastric cancer. Multidetector row computed tomography (MDCT) and magnetic resonance imaging (MRI) are promising alternatives. The aim of this study was to systematically review the literature regarding the performance of each of these imaging modalities.

METHODS

A systematic search for relevant studies was performed in the PubMed/MEDLINE and EMBASE databases. Two reviewers independently assessed the methodological quality of each study. Local staging performance of included studies was calculated.

RESULTS

Twenty-two EUS studies, five MDCT studies, one combined EUS and MDCT study, and three MRI studies met the inclusion criteria. The studies were of moderate methodological quality. Diagnostic accuracy of overall T staging for EUS, MDCT, and MRI varied between 65% to 92.1%, 77.1% to 88.9%, and 71.4% to 82.6%, respectively. Sensitivity for assessing serosal involvement for EUS, MDCT, and MRI varied between 77.8% to 100%, 82.8% to 100%, and 89.5% to 93.1%, respectively. Specificity for assessing serosal involvement for EUS, MDCT, and MRI varied between 67.9% to 100%, 80% to 96.8%, and 91.4% to 100%, respectively.

CONCLUSION

EUS, MDCT, and MRI achieve similar results in terms of diagnostic accuracy in T staging and in assessing serosal involvement. Most experience has been gained with EUS. Few MDCT studies and even fewer MRI studies are available. Thus, EUS remains the first-choice imaging modality in preoperative T staging of gastric cancer.

Evolving role of (18)F-fluorodeoxyglucose positron emission tomography in the management of esophageal carcinoma

Positron emission tomography (PTE) and PET/CT imaging with (18)F-fluorodeoxyglucose are metabolic imaging modalities that depict tissues based on their level of glucose uptake. PET provides useful information in the primary staging of disease. PET performance in detecting locoregional nodal metastases is limited; however, it is the most accurate single noninvasive modality for detecting distant metastases. It is the imaging modality of choice for whole-body scanning in high-risk patients or patients who have clinically suspected recurrence, and is particularly helpful in determining which patients are the best candidates for surgical cure.

Role of endoscopic ultrasonography in preoperative staging of gastric carcinoma

BACKGROUND

Preoperative staging of tumour extent in upper gastrointestinal malignancy greatly facilitates planning of therapy. The present study was undertaken to see whether preoperative endoscopic ultrasonography (EUS) accurately predicts the tumour stage in gastric carcinoma.

METHODS

Endoscopic ultrasonography was performed preoperatively on 112 patients with gastric cancer. All 112 patients underwent surgery. The results of EUS were compared with postoperative histological staging.

RESULTS

Endoscopic ultrasonography was correct in determining the primary tumour (T) and regional lymph node (N) staging in 83.0% and 64.2% of patients, respectively. EUS was correct in determining the absence of lymph node metastasis in 87.5% but was not reliable in determining metastasis in one to six regional lymph nodes (N1) and metastasis in seven to 15 regional lymph nodes (N2) stages; (61.5% and 33.3%, respectively). Of 26 patients with N1 stage, 10 had false negative results, whereas 11 patients in stage N2 were diagnosed endoscopically as stage N1. The sensitivity and specificity were 67.2% and 89%, respectively. The actual resection rate (75%) was almost identical to the rate predicted preoperatively by EUS (78%).

CONCLUSION

Endoscopic ultrasonography staging is the most accurate method for discriminating between potentially resectable (tumour invading lamina propria or submucosa (T1) to tumour that penetrates the serosa (visceral peritoneum) without invading adjacent structures (T3)) and potentially non-resectable (tumour invading adjacent structures (T4)) cases of upper gastrointestinal cancer.

Aggressive surgical treatment for T4 gastric cancer

Surgical treatment for locally advanced gastric cancer remains controversial, and many still question the benefits of extended resection. The aim of this study was to evaluate the effectiveness of combined resection of the involved organs with regard to survival in patients with gastric cancer. Between 1993 and 2000, among the 1638 patients with gastric cancer who underwent gastrectomy, 82 were found to have evidence of adjacent organ spread at laparotomy. A retrospective analysis of these patients was performed. Curative resections were carried out in 50 patients, whereas noncurative resections were performed in 32 patients. The 5-year survival rate in the group undergoing curative resection was 36.9%. The survival rate in the R0 group was significantly higher than the survival rate for patients undergoing noncurative resections. There was no significant difference in survival rates between patients with pT3 cancer and those with pT4 cancer. Seventy-one patients were pathologically proved to have lymph node metastasis, and the survival rate for patients with a lymph node ratio greater than 0.2 was lower than that in other groups. In multivariate analysis, peritoneal dissemination, lymph node ratio, and histologic findings were the predictors of survival. Patients with T4 gastric carcinoma, even with lymph node metastasis, might have benefited from aggressive surgery with curative intent.

N/A

N/A

Endoscopic treatment of early gastroesophageal malignancy

With the routine use of endoscopy, gastroesophageal cancers, which were often diagnosed in the symptomatic and incurable state, are now being diagnosed at earlier stages. Treatment of early-stage upper gastrointestinal cancers has evolved tremendously. Endoscopic therapy has been employed for early-stage lesions in an attempt to avoid the high morbidity and mortality associated with current curative procedures such as esophagectomy. These new endoscopic techniques include endoscopic mucosal resection, photodynamic therapy, electrocoagulation, and laser therapy. Exciting and novel endoscopic therapeutic options in diagnosing and treating early gastroesophageal cancers are the focus of this review.