Endosonography in solid and cystic pancreatic tumors

Contrast-enhanced harmonic endoscopic ultrasonography for the differential diagnosis of pancreatic masses: A systematic review and meta-analysis

Understanding the difference between malignant and benign pancreatic masses is critical in terms of diagnosis, although this is difficult to determine in clinical practice. The contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) technique was introduced in 2010, although, to the best of the authors' knowledge, there has been no systematic review or meta-analysis to date evaluating its diagnostic performance for the differentiation of pancreatic masses. The aim of the present study was to systematically evaluate the diagnostic performance of CH-EUS for the differentiation of pancreatic masses. Search key words and inclusion and exclusion criteria were initially presented. Two independent authors read and extracted the relevant information from the included studies. Disagreements were resolved through discussion with another two experienced authors. Metadisc and Stata software were used for the meta-analysis and the evaluation of bias. A total of 16 studies comprising 1,325 patients were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of CH-EUS were used to distinguish between malignant and benign tumors, and the values obtained were 93% [95% confidence interval (CI): 91-94%], 84% (95% CI: 80-87%), 5.58 (95% CI: 3.90-7.97), 0.09 (95% CI: 0.07-0.11) and 72.56 (95% CI: 48.93-107.60), respectively. The area under the summary receiver operating characteristic curve was determined to be 0.96. No publication bias was identified in this meta-analysis. Taken together, these results confirm that CH-EUS has a high accuracy rate for distinguishing between benign and malignant pancreatic space-occupying lesions, and it may therefore be used as an effective diagnostic tool for pancreatic masses.

[Value of endoscopic ultrasound-guided fine needle aspiration in pretest prediction and diagnosis of pancreatic ductal adenocarcinoma]

OBJECTIVE

To identify the predictive factors for differentiating pancreatic ductal adenocarcinoma (PDAC) from other neoplastic solid pancreatic lesions and assess the accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of PDAC.

METHODS

We retrospectively analyzed the clinical data of patients referred for EUS-FNA evaluation of pancreatic lesions in the Digestive Endoscopic Center of Nanfang Hospital between January, 2009 and May, 2016. The cases with unknown diagnosis, missing data, repeated punctures, cystic lesions and benign lesions were excluded from the analysis. The positivity rates of EUS-FNA were compared between patients with PDAC and those with non-PDAC lesions, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS-FNA were assessed in the diagnosis of PDAC. Univariate and multivariate logistic regression analyses were used to identify the factors for differentiating PDAC from non-PDAC lesions based on the demographic characteristics, clinical presentations, laboratory data, and endoscopic ultrasonography imaging features of the patients.

RESULTS

Among the 75 patients with solid neoplastic pancreatic lesions, 54 (72.0%) were found to have PDAC and 21 (28.0%) had non-PDAC lesions. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EUS-FNA for the diagnosis of PDAC were 77.8%, 100.0%, 100.0%, 63.6% and 84.0%, respectively. No significant difference was found in the positivity rate of EUS-FNA between patients with PDAC and those with non-PDAC lesions (77.8% vs 76.2%, P > 0.05). Multivariate regression analysis identified abdominal pain (OR=5.163, 95%CI: 1.093-24.389, P=0.038), lesion size (OR=0.926, 95%CI: 0.877-0.978, P=0.006), characteristics of the solid lesions (OR=7.105, 95%CI: 1.440-35.043, P=0.016), and evidence of metastases (OR=6.165, 95%CI: 1.332-28.533, P=0.020) as the independent factors for predicting PDAC.

CONCLUSIONS

The pretest characteristics including abdominal pain, evidence of metastases, and lesion size and lesion characteristics defined by endoscopic ultrasonography findings can reliably predict a diagnosis of PDAC. EUS-FNA has a high sensitivity and a high specificity for the diagnosis of PDAC.

Colon carcinoma staging by endoscopic ultrasonography miniprobes

Background and Objectives:

Due to the increasing use of endoscopic techniques for colon cancer resection, pretreatment locoregional staging may gain critical interest. The use of endoscopic ultrasonography (EUS) miniprobes in this context has been seldom reported. Our aim was to determine the accuracy of EUS miniprobes for colon cancer staging.

Materials and Methods:

Forty patients with colon cancer (2 in the cecum, 9 in the ascending colon, 5 in the transverse colon, 5 in the descending colon, and 19 in the sigmoid colon) were submitted to staging using 12 MHz EUS miniprobes. EUS and the anatomopathological results were compared with regard to the T and N stages. It was assessed if the location, longitudinal extension, or circumferential extension of the tumor had any influence on the accuracy in EUS staging.

Results:

Tumor staging was feasible in 39 (98%) patients except in one case with a stenosing tumor (out of 6). Globally, T stage was accurately determined in 88% of the cases. In the assessment of the presence or absence of lymph node metastasis, miniprobes presented an accuracy of 82% with a sensitivity of 67%. These results were neither affected by the location nor by the longitudinal or circumferential extension of the tumor.

Conclusions:

EUS miniprobes may play an important role in assessing T and N stages in colon cancer and may represent an incentive to the research of new therapeutic areas for this disease.

Effectiveness of contrast-enhanced harmonic endoscopic ultrasound for the evaluation of solid pancreatic masses

AIM

To evaluate the usefulness of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) in differentiating between pancreatic adenocarcinomas and other pancreatic disease.

METHODS

This retrospective cohort study evaluated 90 patients who were seen between November 2010 and May 2013. All these patients had solid pancreatic masses that had a hypoechoic appearance on EUS. All patients underwent CH-EUS to evaluate this diagnostic method's usefulness. The mass lesions observed on CH-EUS were classified into three categories based on their echo intensity: hypoenhanced, isoenhanced, and hyperenhanced lesions. We adjusted the sensitivity and the specificity of each category for detecting malignancies. We also estimated the accuracy of CH-EUS by comparing it to a pathological diagnosis.

RESULTS

Of the 90 patients, 62 had a pancreatic adenocarcinoma. Fifty-seven out of 62 pancreatic adenocarcinomas showed a hypoenhanced pattern on CH-EUS. The sensitivity was 92%, the specificity 68% and the accuracy approximately 82%. The area under the curve of the receiver operating characteristic analysis for CH-EUS was 0.799. There is a significant association between the hypoenhanced pattern on CH-EUS and pancreatic duct adenocarcinoma (χ(2) = 35.264, P < 0.001). In pathological examinations, the number of specimens for EUS-fine needle aspiration (EUS-FNA) was considered insufficient for diagnosis in three patients, and in two patients, the results were reported to be negative for malignancy. Pancreatic masses in all five patients revealed a hypoenhanced pattern with CH-EUS. Three patients were diagnosed with pancreatic adenocarcinoma based on the pathology results of a biopsy, and the remaining two patients were clinically diagnosed with malignancy.

CONCLUSION

CH-EUS is useful for distinguishing between pancreatic adenocarcinoma and other pancreatic disease. When a pancreatic mass shows a hypoenhanced pattern on CH-EUS but involves either insufficient samples or negative results with EUS-FNA, clinicians might consider performing another pathologic diagnosis on the basis of an EUS-FNA sample or a biopsy.

Diagnosis and treatment of pancreatic pseudocysts and cystic tumors based on own material and quoted literature

Pseudocysts constitute the most basic cystic lesions of the pancreas. Symptomatic cysts may be treated by means of both minimally invasive methods and surgery. Currently, it is believed that approximately 5% of cystic lesions in the pancreas may in fact, be neoplastic cystic tumors. Their presence is manifested by generally irregular multilocular structures, solid nodules inside the cyst or in the pancreatic duct, frequently vascularized, as well as fragmentary thickening of the cystic wall or septation.

Tumors and new endoscopic ultrasound-guided therapies

With the advent of linear echoendoscopes, endoscopic ultrasound (EUS) has become more operative and a new field of oncological application has been opened up. From tumor staging to tissue acquisition under EUS-guided fine-needle aspiration, new operative procedures have been developed on the principle of the EUS-guided puncture. A hybrid probe combining radiofrequency with cryotechnology is now available, to be passed through the operative channel of the echoendoscope into the tumor to create an area of ablation. EUS-guided fine-needle injection is emerging as a method to deliver anti-tumoral agents inside the tumor. Ethanol lavage, with or without paclitaxel, has been proposed for the treatment of cystic tumors in non-resectable cases and complete resolution has been recorded in up to 70%-80%. Many other chemical or biological agents have been investigated for the treatment of pancreatic adenocarcinoma: activated allogenic lymphocyte culture (Cytoimplant), a replication-deficient adenovirus vector carrying the tumor necrosis factor-α gene, or an oncolytic attenuated adenovirus (ONYX-015). The potential advantage of treatment under EUS control is the real-time imaging guidance into a deep target like the pancreas which is extremely difficult to reach by a percutaneous approach. To date there are no randomized controlled trials to confirm the real clinical benefits of these treatments compared to standard therapy so it seems wise to reserve them only for experimental protocols approved by ethics committees.

Tumor size as measured at initial X-ray examination, not length of bile duct stricture, predicts survival in patients with unresectable pancreatic cancer

Background

The survival of unresectable pancreatic cancer patients is extremely poor. The aim of this study was to examine if tumor size could predict survival length in order to optimize patient care.

Methods

A retrospective observational study was performed on 185 consecutive patients with unresectable pancreatic cancer (ICD10: C250-2 and C258) who were diagnosed from 2003 to May 2010. The patients' initial radiographs at presentation of symptoms were reviewed by the same radiologist, and tumor extent was determined.

Results

The largest tumor diameter of the primary tumor was measured in 132 patients, 22 by an ultrasound and the other patients by a CT scan. In 53 patients, the tumor size could not be delimited and measured. Seventy-five patients (41%) had liver metastases at presentation of symptoms. Median survival for the entire patient group was only 119 days. The median diameter of the patient’s largest tumor was 4.35 cm, while the sample groups ranged from 1.2 to 14 cm. Patients were divided into two groups: those with a largest tumor diameter of ≤ 4.3 cm (66 patients) and those with a largest tumor diameter of > 4.3 cm (66 patients). Median survival for these groups was 149 and 94 days (p = 0.019), respectively. Cox regression showed a hazard ratio for tumor size of 1.48 (95% CI 1.02, 2.07) (p = 0.038), adjusted for the gemcitabine treatment which had been given to 49 patients and the presence of liver metastasis. In 88 patients, stricture length could be measured at ERCP. When comparing stricture lengths of ≤ 2 cm and > 2 cm, no difference in survival time was noted within a Kaplan-Meier analysis.

Conclusion

The size of the maximum tumor diameter of the primary tumor during the initial X-ray examination of patients with pancreatic cancer may predict survival time for those patients who had no surgical resection. Stricture length at ERCP gave no information on survival.