A cost analysis of endoscopic ultrasound in the evaluation of pancreatic head adenocarcinoma

OBJECTIVE: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) biopsy of nonperitumoral (NPT) lymph nodes (LN) can be helpful in preoperative staging of pancreatic head adenocarcinoma. The economic impact of this staging strategy has not yet been described. The aim of this study was to apply a decision analysis model to compare the costs of three approaches to the management of nonmetastatic pancreatic head adenocarcinoma: EUS FNA versus CT-guided FNA versus surgery. A cost minimization approach was employed, as viewed from the perspective of the payer. METHODS: A decision analysis model was designed using DATA Version 3.5, taking the entry criteria as "resectable" pancreatic head adenocarcinoma as determined by helical CT. Detection of metastatic NPT LN on FNA signified unresectability and obviated the need for surgery. Baseline probabilities were varied through plausible ranges using sensitivity analysis. Cost inputs were based on Medicare professional plus facility fees. The endpoint was cost of management per patient. RESULTS: EUS FNA was the least costly strategy ($15,938) compared with CT FNA ($16,378) and surgery ($18,723). Sensitivity analysis revealed that EUS FNA remained the least costly option provided the frequency of NPT LN involvement was >4%; below this value, surgery became the least costly. CONCLUSIONS: EUS FNA is the least costly staging strategy in the workup of patients with nonmetastatic pancreatic head adenocarcinoma primarily because of confirmation of NPT LN involvement avoiding unnecessary surgery. These results support performing EUS in patients whose tumors are thought to be resectable on helical CT to enhance NPT LN assessment.     

Role of endoscopic ultrasound in superficial esophageal cancer

The recent increase in the incidence of superficial esophageal cancer and promising developments in potentially curative endoscopic therapies have placed endoscopic ultrasound in a central position with regard to decision making. This is a review of the literature to determine the role of endoscopic ultrasound and high frequency probe ultrasonography in the assessment of superficial esophageal carcinomas.     

Assessment of clinical impact of endoscopic ultrasound on esophageal cancer

BACKGROUND AND AIM: Endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is the most accurate imaging modality for locoregional staging of esophageal cancer. It remains unclear whether this technology impacts on the outcome of patients with this malignancy. The aim of the present study was to assess the impact of EUS FNA by comparing the clinical outcomes of patients with esophageal cancer before and after the introduction of this staging modality in our institution. METHODS: Outcomes of patients with de novo non-metastatic esophageal cancer seen in 1998 without EUS FNA evaluation (non-EUS control group) were compared to patients evaluated in 2000 with EUS FNA (EUS group). RESULTS: Outcomes of 60 (non-EUS control group) and 107 (EUS group) patients with non-metastatic esophageal cancer were compared. Preoperative neoadjuvant therapy was administered to 35 patients in the EUS group, all of whom had advanced disease. Cox proportional hazards demonstrated EUS FNA to be associated with reduced recurrence risk (hazard ratio [HR]: 0.63; 95% confidence interval [CI]: 0.43-0.87), P = 0.004, and reduced mortality (HR: 0.66; 95% CI: 0.47-0.90), P = 0.008. CONCLUSIONS: The EUS staging of esophageal cancer leads to appropriate use of preoperative neoadjuvant therapy in patients with advanced disease. Use of EUS is associated with a recurrence-free survival advantage and overall survival advantage in patients, thus supporting its routine use in esophageal cancer staging.     

Preoperative evaluation of gastric cancer by endoscopic ultrasound.

The preoperative use of endoscopic ultrasound was evaluated in 74 patients with confirmed gastric cancer. It was used in diagnosing the depth of invasion in the gastric wall, the infiltration to the adjacent organs, and the involvement of the perigastric lymph nodes. Results were compared with histological findings in resected specimens. Accuracy in staging gastric cancer using the T grade of the 1987 TNM system was 81.1% (60 of 74 patients). Endoscopic ultrasound provided excellent results compared with computed tomography and conventional ultrasound, particularly in evaluating perigastric lymph node metastasis and direct infiltration to the adjacent organs. The success rate in detecting lymph node metastasis was 50% (11 of 22 patients); the accuracy in diagnosing direct infiltration to the adjacent organs was 60% (three of five patients). This technique is useful in diagnosing malignant invasion and lymph node metastasis of gastric carcinomas but requires further refinement for use in diagnosing the disease itself. Its preoperative use is recommended for establishing surgical and other treatment plans, as well as in predicting the prognosis of gastric cancer.     

Prognostic significance of the endoscopic ultrasound defined lymph node metastasis count in esophageal cancer

The key prognostic factor which predicts outcome after esophagectomy for cancer is the number of malignant lymph node metastases, but data regarding the accuracy of endoscopic ultrasound (EUS) in determining and predicting the metastatic lymph node count preoperatively are limited. The aim of this study was to assess the prognostic significance of EUS defined lymph node metastasis count (eLNMC) in patients diagnosed with esophageal cancer. Two hundred and sixty‐seven consecutive patients (median age 63 years, 187 months) underwent specialist EUS followed by stage directed multidisciplinary treatment (183 esophagectomy [64 neoadjuvant chemotherapy, 19 neoadjuvant chemoradiotherapy], 79 definitive chemoradiotherapy, and 5 palliative therapy). The eLNMC was subdivided into four groups (0, 1, 2 to 4, >4) and the primary measure of outcome was survival. Survival was related to EUS tumor (T) stage (P < 0.0001), EUS node (N) stage (P < 0.0001), EUS tumor length (p < 0.0001), and eLNMC (P < 0.0001). Multivariable analysis revealed EUS tumor length (hazard ratio [HR] 1.071, 95% CI 1.008–1.138, P= 0.027) and eLNMC (HR 1.302, 95% CI 1.133–1.496, P= 0.0001) to be significantly and independently associated with survival. Median and 2‐year survival for patients with 0, 1, 2–4, and >4 lymph node metastases were: 44 months and 71%, 36 months and 59%, 24 months and 50%, and 17 months and 32%, respectively. The total number of EUS defined lymph node metastases was an important and significant prognostic indicator.     

The role of endoscopic ultrasound for the evaluation and treatment of esophageal motility disorders

Esophageal motor disorders constitute a heterogeneous group of diseases that result in symptoms of dysphagia and chest pain. The primary diagnostic tool in the evaluation of patients with esophageal motor disorders is high resolution esophageal manometry. While manometric findings provide the sine qua non for the diagnosis of achalasia, they are limited in that they cannot provide meaningful anatomic correlates. Endoscopic ultrasound (EUS) has a key role in the evaluation of patients with esophageal motor disorders. Both probe-based ultrasound systems and echoendoscopes can provide high resolution imaging of the esophageal wall and surrounding structures. Due to a variety of factors, EUS has demonstrated clear variability in esophageal and muscle thickness. This may also reflect further anatomic heterogeneity among esophageal motor disorders. The benefit of EUS in the evaluation of alternative causes for outflow obstruction and pseudoachalasia is clear and should be considered in patients with atypical presentations. Novel indications for EUS include advanced imaging techniques and EUS directed treatments to the lower esophageal sphincter. EUS alone is not a replacement for standard diagnostic tests, it remains a helpful tool in the overall management of patients with esophageal motor disorders.     

Risk of esophageal variceal bleeding based on endoscopic ultrasound evaluation of the sum of esophageal variceal cross-sectional surface area

OBJECTIVE: The aim of this study was to evaluate the risk of future variceal bleeding, based on the endoscopic ultrasound measurement of the sum of the cross-sectional surface area (CSA) of all of the esophageal varices in the distal esophagus. METHODS: Twenty-eight patients with portal hypertension and esophageal varices, but no prior history of variceal bleeding, were evaluated using endoscopic ultrasound (20-MHz ultrasound probe, Microvasive, Boston, MA; Olympus, Tokyo, Japan). The entire esophagus was imaged, and an image was selected at a point where the varices appeared the largest. This image was digitized, and the sum of the CSA of all of the varices was measured (Image Pro Plus, Silver Springs, MD) by an investigator blinded to the patients' clinical status. The follow-up time for each patient was calculated (time to first bleed, time to liver transplantation, time to death, or time to the end of study). The Cox Proportional Hazards Model was used to determine if there was a significant difference between the sums of the CSA in the patients who bled compared with those who did not bleed. An OR was calculated to determine the risk of future variceal bleeding based on the sum of the CSA as measured in cm(2)/month. Positive and negative predictive values were calculated for future variceal bleeding. RESULTS: Six of 28 patients (21%) experienced esophageal variceal bleeding on follow-up. The mean CSA +/- SEM of the sum of the esophageal varices in these patients was 0.77 cm(2) +/- 0.31 cm(2) (range 0.07-2.09 cm(2)). The mean time to bleeding was 15.5 months +/- 4.95 months (range 1-29 months). Twenty-two of 28 patients (79%) did not experience variceal bleeding. The mean CSA +/- SEM of the sum of the varices in these patients was 0.36 cm(2) +/- 0.08 cm(2) (range 0.02-1.19 cm(2)). The mean time to follow-up was 35.7 months +/- 6.69 months (range 1.2-103.2 months). The sum of the CSA between the patients who bleed and those who did not bleed was significantly different at the p < 0.018 level. The OR for the risk of variceal bleeding for each one cm(2) difference in the sum of the CSA per month was 6.34. Using a cutoff of 0.45 cm(2), the sensitivity and specificity for future variceal bleeding was 83% and 75%, respectively. CONCLUSIONS: There is a significant difference (p < 0.018) in the sum of the esophageal variceal CSA between those patients who will experience future variceal bleeding and those who will not. There is a 76-fold increase per year in the risk of future variceal bleeding for each one cm(2) increase in variceal CSA. Using a cutoff value for the CSA of 0.45 cm(2), the sensitivity and specificity for future variceal bleeding above and below this point is 83% and 75%, respectively.     

Assessment for diagnosis of lymph node metastasis in esophageal cancer using endoscopic ultrasound elastography

Background

We performed endoscopic ultrasound real-time tissue elastography to more accurately diagnose lymph node metastasis of esophageal cancer. The aim of this study was to evaluate the ability of EUS elastography to distinguish benign from malignant lymph nodes in esophageal cancer patients.

Methods

The present study had two steps. As the first step (study 1), we developed diagnostic criteria for metastatic lymph nodes using elastography and verified the validity of the criteria. Three hundred and twenty-two lymph nodes from 35 patients treated by surgical resection were included in the study. As the second step (study 2), we preoperatively examined the lymph nodes of esophageal cancer patients with EUS elastography and compared its diagnostic performance with that of the conventional B-mode EUS images. A total of 115 lymph nodes from 31 patients were included.

Results

In study 1, lymph nodes were considered malignant if 50 % or more of the node appeared blue, or if the peripheral part of the lesion was blue and the central part was red/yellow/green. The sensitivity and specificity of the elastography were 79.7 and 97.6 % with an accuracy of 93.8 %, which was significantly higher than the values for conventional B-mode imaging. In study 2, the sensitivity and specificity of the EUS elastography were 91.2 and 94.5 % with an accuracy of 93.9 %, which was also significantly higher than the values for conventional B-mode EUS imaging.

Conclusions

The present study demonstrated that EUS elastography is useful for diagnosing lymph node metastasis of esophageal cancer.

     

Clinical implications of the extent of invasion of T3 esophageal cancer by endoscopic ultrasound

BACKGROUND: Endoscopic ultrasound (EUS) is an accurate imaging modality for local staging of esophageal cancer. We aimed to determine if depth of tumor invasion beyond muscularis propria (MP), as determined by preoperative EUS, is predictive of tumor recurrence or survival (a positive change in mortality) in patients with T3 esophageal cancer. METHODS: Records and images of all patients with T3 N1 M0 esophageal cancer staged with EUS at our institution between January 1999 and October 2003 were reviewed. EUS images were independently reviewed by five blinded endosonographers and tumors were classified as minimally invasive (invasion < 3 mm beyond MP) or advanced (invasion > or = 3 mm beyond MP) T3 disease. RESULTS: One hundred and sixty-five patients with esophageal cancer underwent EUS for staging and 39 patients with T3 N1 esophageal cancer were identified; 17 patients had minimally invasive T3 disease and 22 had advanced disease. All patients underwent neoadjuvant chemoradiation therapy followed by esophagectomy. Median follow up was 13 months. Adjusting for age and sex, minimally invasive disease was not associated with a statistically significant improvement in recurrence-free survival (hazard ratio, 1.45; 95% CI, 0.88-2.41, P = 0.14) or mortality (hazard ratio, 0.96; 95% CI: 0.49-1.78, P = 0.91). CONCLUSIONS: The extent of invasion of T3 esophageal cancer beyond MP, as determined by EUS, is not a significant predictor of tumor recurrence or mortality.     

Staging accuracy of esophageal cancer by endoscopic ultrasound：A meta-analysis and systematic review

AIM： To evaluate the accuracy of endoscopic ultrasound （EUS） in the staging of esophageal cancer. METHODS： Only EUS studies confirmed by surgery were selected. Articles were searched in Medline and Pubmed. Two reviewers independently searched and extracted data. Meta-analysis of the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio. Pooling was conducted by both the Mantel-Haenszel method （fixed effects model） and DerSimonian Laird method （random effects model）. The heterogeneity of studies was tested using Cochran’s Q test based upon inverse variance weights. RESULTS： Forty-nine studies （n = 2558） which met the inclusion criteria were included in this analysis. Pooled sensitivity and specificity of EUS to diagnose T1 was 81.6% （95% CI： 77.8-84.9） and 99.4% （95% CI： 99.0-99.7）, respectively. To diagnose T4, EUS had a pooled sensitivity of 92.4% （95% CI： 89.2-95.0） and specificity of 97.4% （95% CI： 96.6-98.0）. With Fine Needle Aspiration （FNA）, sensitivity of EUS to diagnose N stage improved from 84.7% （95% CI： 82.9-86.4） to 96.7% （95% CI： 92.4-98.9）. The P value for the χ2 test of heterogeneity for all pooled estimates was 〉 0.10. CONCLUSION： EUS has excellent sensitivity and specificity in accurately diagnosing the TN stage of esophageal cancer. EUS performs better with advanced （T4） than early （T1） disease. FNA substantially improves the sensitivity and specificity of EUS in evaluating N stage disease. EUS should be strongly considered for staging esophageal cancer.     

食管癌内镜治疗进展

食管癌(esophageal cancer)是全球第九大常见恶性肿瘤,目前早期食管癌的诊断率还很低,患者确诊时多已失去手术机会,而晚期食管癌患者由于吞咽梗阻而不能正常进食,全身情况极差,有时根本不能耐受常规放、化疗,因而食管癌的内镜下治疗显得更重要.近年来,随着内镜技术的迅速发展,许多早期或中晚期食管癌的患者均可通过镜下治疗获得满意的效果.     

Cost-benefit analysis of esophageal cancer endoscopic screening in high-risk areas of China

AIM: To estimate the cost-benefit of endoscopic screening strategies of esophageal cancer (EC) in high-risk areas of China.METHODS: Markov model-based analyses were conducted to compare the net present values (NPVs) and the benefit-cost ratios (BCRs) of 12 EC endoscopic screening strategies. Strategies varied according to the targeted screening age, screening frequencies, and follow-up intervals. Model parameters were collected from population-based studies in China, published literatures, and surveillance data.RESULTS: Compared with non-screening outcomes, all strategies with hypothetical 100 000 subjects saved life years. Among five dominant strategies determined by the incremental cost-effectiveness analysis, screening once at age 50 years incurred the lowest NPV (international dollar-I$55 million) and BCR (2.52). Screening six times between 40-70 years at a 5-year interval [i.e., six times(40)f-strategy] yielded the highest NPV (I$99 million) and BCR (3.06). Compared with six times(40)f-strategy, screening thrice between 40-70 years at a 10-year interval resulted in relatively lower NPV, but the same BCR.CONCLUSION: EC endoscopic screening is cost-beneficial in high-risk areas of China. Policy-makers should consider the cost-benefit, population acceptance, and local economic status when choosing suitable screening strategies.     

Endoscopic ultrasound errors in esophageal cancer

BACKGROUND: Previous assessments of endoscopic ultrasound (EUS) classification of esophageal cancer are dominated by symptomatic patients with advanced stage disease. Fewer data exist on EUS errors in a cohort balanced between early and advanced disease. PURPOSE: Assess EUS errors in classification of esophageal cancer in a more balanced cohort, and identify clinical and tumor characteristics associated with EUS errors. METHODS: A total of 266 patients underwent EUS and esophagectomy without preoperative chemoradiotherapy. Pathologic classification of disease extent: 108 (41%) tumors were confined to the esophageal wall (pTis-pT2, pN0, pM0); 158 (59%) were advanced beyond (pT3-pT4, pN1, or pM1). Logistic regression analysis was performed to identify correlates of error in T classification and disease extent using 10 clinical and tumor characteristics (gender, age, dysphagia, weight loss, tumor length, location, traversability, morphology, histopathologic type, and histologic grade). RESULTS: EUS erroneously predicted pathologic T (pT) in 119 patients (45%). When T classification was dichotomized into tumors whose depth of invasion was not beyond the muscularis propria (pTis-pT2) and those beyond (pT3-pT4), errors occurred in 42 patients (16%). EUS erroneously predicted N classification in 67 patients (25%), and was insensitive to the presence of distant metastases. EUS misclassified disease extent in 40 patients (15%). Logistic regression analysis indicated that weight loss and tumor length were the only clinical and tumor characteristics correlated with EUS errors; more weight loss was associated with decreased odds of misclassification, while the odds of misclassification were four to six times greater for intermediate length tumors than for shorter tumors. CONCLUSIONS: EUS errors, particularly in predicting pT, are more frequent than previously reported. Weight loss and tumor length are the only clinical and tumor characteristics correlated with EUS errors.     

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration(EUS-FNA),EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma(PDAC).The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC.Initially,its use for detection,diagnosis and staging will be described.EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC,this high accuracy,however,is decreased in specific situations particularly in the presence of chronic pancreatitis.Novel techniques such as contrast-enhanced EUS,elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed.EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC.Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control,EUS-guided fiducial and brachytherapy seed placement,fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage.The future role of EUS and EUS in management of PDAC is still emerging.     

Role of endoscopic ultrasound in pancreatic cancer

Pancreatic cancer (PC) is the fourth most common cause of cancer deaths in Western societies. It is an aggressive tumor with an overall 5-year survival rate of less than 5%. Surgical resection offers the only possibility of cure and long-term survival for patients suffering from PC; however, unfortunately, fewer than 20% of patients suffering from PC have disease that is amendable to surgical resection. Therefore, it is important to accurately diagnose and stage these patients to enable optimal treatment of their disease. The imaging modalities involved in the diagnosis and staging of PC include multidetector CT scanning, endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreaticography and MRI. The roles and relative importance of these imaging modalities have changed over the last few decades and continue to change owing to the rapid technological advances in medical imaging, but these investigations continue to be complementary. EUS was first introduced in the mid-1980s in Japan and Germany and has quickly gained acceptance. Its widespread use in the last decade has revolutionized the management of pancreatic disease as it simultaneously provides primary diagnostic and staging information, as well as enabling tissue biopsy. This article discusses the potential benefits and drawbacks of EUS in the primary diagnosis, staging and assessment of resectability, and EUS-guided fine-needle aspiration in PC. Difficult diagnostic scenarios and pitfalls are also discussed. A suggested management algorithm for patients with suspected PC is also presented.