David Martínez-Ares

Fecal immunochemical test accuracy in average-risk colorectal cancer screening.

AIM To assess the fecal immunochemical test (FIT) accuracy for colorectal cancer (CRC) and advanced neoplasia (AN) detection in CRC screening. METHODS We performed a multicentric, prospective, double blind study of diagnostic tests on asymptomatic average-risk individuals submitted to screening colonoscopy. Two stool samples were collected and the fecal hemoglobin concentration was determined in the first sample (FIT1) and the highest level of both samples (FITmax) using the OC-sensor™. Areas under the curve (AUC) for CRC and AN were calculated. The best FIT1 and FITmax cut-off values for CRC were determined. At this threshold, number needed to scope (NNS) to detect a CRC and an AN and the cost per lesion detected were calculated. RESULTS About 779 individuals were included. An AN was found in 97 (12.5%) individuals: a CRC in 5 (0.6%) and an advanced adenoma (≥ 10 mm, villous histology or high grade dysplasia) in 92 (11.9%) subjects. For CRC diagnosis, FIT1 AUC was 0.96 (95%CI: 0.95-0.98) and FITmax AUC was 0.95 (95%CI: 0.93-0.97). For AN, FIT1 and FITmax AUC were similar (0.72, 95%CI: 0.66-0.78 vs 0.73, 95%CI: 0.68-0.79, respectively, P = 0.34). Depending on the number of determinations and the positivity threshold cut-off used sensitivity for AN detection ranged between 28% and 42% and specificity between 91% and 97%. At the best cut-off point for CRC detection (115 ng/mL), the NNS to detect a CRC were 10.2 and 15.8; and the cost per CRC was 1814€ and 2985€ on FIT1 and FITmax strategies respectively. At this threshold the sensitivity, NNS and cost per AN detected were 30%, 1.76, and 306€, in FIT1 strategy, and 36%, 2.26€ and 426€, in FITmax strategy, respectively. CONCLUSION Performing two tests does not improve diagnostic accuracy, but increases cost and NNS to detect a lesion.

Endoscopic ultrasound-assisted endoscopic resection of carcinoid tumors of the gastrointestinal tract

INTRODUCTION Usually found in the gastrointestinal tract, carcinoids are the most frequent neuroendocrine tumors. Most of these lesions are located in areas that are difficult to access using conventional endoscopy (small intestine and appendix); carcinoid tumors found in the gastroduodenal tract and in the large intestine can be studied endoscopically; in these cases, if localized disease is confirmed, local treatment by endoscopic resection may be the treatment of choice. Since endoscopic ultrasonography has been shown to be the technique of choice for the study of tumors exhibiting submucosal growth, the selection of patients who are candidates for a safe and effective local resection should be based on this technique. PATIENTS AND METHOD We selected patients with gastrointestinal carcinoid tumors who were endoscopically treated between 1997 and 2002. Those patients with tumors measuring less than 10 mm, which had not penetrated the muscularis propria, and those with localized disease were considered candidates for endoscopic resection. The endpoints of this study were to assess the effectiveness (complete resection) and safety (complications) of the technique. Follow-up consisted of eschar biopsies performed one month and twelve months after the resection. RESULTS During the aforementioned period, we resected endoscopically 24 tumors in 21 patients (mean age: 51.7 years; 71.5% males). Most lesions were incidental discoveries made during examinations indicated for other reasons. Resection was indicated in most cases as a result of the suspected presence of a carcinoid tumor after endoscopic ultrasonography. Endoscopic ultrasonography also enabled us to clearly identify the layer where the lesion had originated, as well as the size of the lesion. The carcinoid tumor was removed in 13 cases (54.2%) by using the conventional snare polypectomy technique, in 9 cases (37.5%) assisted by a submucosal injection of saline solution and/or adrenaline, and in 2 cases (8.3%) after ligating the lesion with elastic bands. In all cases the resection was complete, with no recurrence during the follow-up period, and no major complications, except for a single case in which a post-polypectomy hemorrhage occurred that was endoscopically solved. CONCLUSIONS In properly selected patients, the endoscopic resection of carcinoid tumors is a safe and effective technique that permits a complete resection in all cases with few complications. Endoscopic ultrasonography is the technique of choice for selecting the patients who are candidates for endoscopic resection.

The value of abdominal ultrasound in the diagnosis of colon cancer

INTRODUCTION Colon cancer is one of the main causes of cancer death. Diagnosis requires the examination of the entire large bowel by means of radiological or endoscopic techniques. Many patients suspect of colon cancer are referred for colonoscopy but nevertheless this suspicion is not confirmed after endoscopic examination. The objective of this study is the evaluation of the reliability of abdominal ultrasound in the diagnosis of these tumors. MATERIAL AND METHOD We selected patients suspect of colon cancer referred to the endoscopy unit for a colonoscopy. An abdominal ultrasound was carried out on all patients prior to the endoscopy. Considering the endoscopic examination as a gold standard, the sensibility, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ultrasonography were evaluated. Likewise, a series of analytical and clinical parameters were evaluated, in an attempt to establish associated factors of a colon cancer. The statistical analysis was carried out by means of the statistical package SPSS 12.0 for Windows. RESULTS 145 patients were included in the study (56.6% males) with an average 66.72 years of age (22-89). A cancer was diagnosed in 42 cases (28.9%). In the diagnosis of colon cancer, abdominal ultrasound presents a sensitivity of 79.06%, a specificity of 92.15%, a PPV and a NPV of 80.9% and of 91.2%, respectively. Excluding from the analysis lesions of the rectal ampulla, which cannot be adequately evaluated by means of ultrasound, the figures for sensitivity, specificity, PPV and NPV increase to 91.8, 92.1, 80.9 and 96.9% respectively. The univariate analysis showed that an age over 65 years and the presence of microcytosis are associated to a greater risk of colon cancer while after multivariate analysis only the presence of microcytosis resulted to be an independent predictive factor of cancer. CONCLUSIONS Abdominal ultrasound presents high sensitivity, specificity, PPV and NPV in the diagnosis of colon cancer. The combination of an ultrasonography and a rectoscopy permits us to rule out the presence of a colorectal carcinoma. In patients with microcytosis of 65 years and over, if there is strong clinical suspicion, a negative ultrasound may not be sufficient to rule out a colorectal neoplasia.

Endoscopic resection of gastrointestinal submucosal tumors assisted by endoscopic ultrasonography.

BackgroundThe resection and histologic examination of the lesions is generally considered the treatment of choice in order to achieve diagnosis in gastointestinal submucosal tumors. Moreover, the degree of malignancy of the tumor depends on certain features that can only be studied on the entire resected piece.MethodsWe revised the cases of patients who underwent endoscopic resection of gastrointestinal submucosal tumors in the period from 1997 through 2002.ResultsFifty submucosal lesions were resected in 45 patients (64.4% men). Patient mean age was 55.31 years. Of the lesions, 52% were gastric tumors and 88% were located in the second layer. Mean size was 12.34 mm, and 54% were smaller than 10 mm. Resection with submucosal injection of saline solution and diluted adrenaline was performed on 46% of the lesions, and standard resection using polypectomy snare on 48%. Ligation was used in three cases. Resection was successful in 98% and major complications were observed in 4% (two cases of bleeding, endoscopically resolved).ConclusionsThe endoscopic resection of submucosal tumors is a safe and efficient technique: It has few associated complications and allows diagnosis in all the cases and cure of the lesion in the great majority of cases.

Endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) enables en bloc resection of certain types of early gastrointestinal neoplasias with the help of different knives, of which the insulated-tip, or IT, knife is the most frequently used. The IT knife is a variant of the needle knife, tipped with a ceramic ball to prevent cutting through muscularis propria. ESD is applied throughout the gastrointestinal tract, mostly in the stomach and colon. Although widely used in Japan, reports on ESD from western countries are infrequent. A total of six cases of ESD from two Czech gastroenterology centers are presented here.

Incidence and phenotype at diagnosis of inflammatory bowel disease. Results in Spain of the EpiCom study

INTRODUCTION Incidence of inflammatory bowel disease (IBD) is increasing progressively. Few recent epidemiological prospective studies are available in Spain. The Epicom study, a population-based inception cohort of unselected IBD patients developed within the European Crohns and Colitis Organization, was started in 2010. Vigo is the only Spanish area participating. OBJECTIVE To describe the incidence of IBD in the Vigo area and the phenotypical characteristics at diagnosis and to compare them with previous data available in Spain. MATERIAL AND METHODS Epidemiological, descriptive, prospective, and population-based study. All incident cases of IBD during 2010 and living in the Vigo area at diagnosis were included. The Copenhagen Diagnostic criteria were used to define cases. Background population at the start of the study was 579,632 inhabitants. Data were prospectively entered in the EpiCom database. RESULTS A total of 106 patients were included (57.5% men, median age 39.5 years). Of them 53 were diagnosed of as Crohns disease (CD), 47 ulcerative colitis (UC) and six IBD unclassified (IBDU). The incidence rate per 100,000 per year for patients aged 15 years or older was 21.4 (10.8 for CD, 9.4 for UC, 1.2 IBDU). Including pediatric population incidence rates were 18.3 (10.3 CD, 8.7 UC, 1.2 IBDU). Median time since onset of symptoms until diagnosis was 2 months. CONCLUSIONS The incidence rate of IBD in Vigo is the highest compared to former Spanish cohorts, especially in CD patients. Median time since onset of symptoms until diagnosis is relatively short.

Usefulness of endoscopic ultrasonography in the preoperative diagnosis of submucosal digestive tumours

Introduction: the preoperative diagnosis of submucosal lesions in the gut may be complicated. Conventional endoscopy does not allow to clearly establishing a diagnosis, and does not adequately assess lesion size. Furthermore, endoscopic biopsy is usually not diagnostic. Cytology as performed by means of fineneedle puncture does not have enough sensitivity and specificity to be considered the gold standard in the diagnosis of these lesions. We will now assess the usefulness of endoscopic ultrasonography in the study of submucosal digestive tumors. Materials and methods: we have prospectively collected ultrasonographic studies from all the patients with submucosal tumors who were treated surgically. We assessed the sensitivity and specificity of this technique in the diagnosis of malignancy in said lesions, alongside factors that predict malignant behavior with the highest reliability. We also valued the reliability of ultrasound endoscopy in the assessment of lesion size and the wall layer where lesions are located. The results of histological studies were considered the gold standard. Results: the average size of lesions as measured by ultrasound endoscopy was 37.42 mm, with no significant differences in surgical piece: 38.98 (p = 0.143). However, conventional endoscopy underestimates the size of lesions. Endoscopic ultrasonography was able to adequately establish the origin layer of lesions in all cases. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound endoscopy in the diagnosis of malignancy were 89.5, 90.9, 89.5, and 90.9%, respectively. In the univariate analysis, the ultrasonographic characteristics associated with a diagnosis of malignancy included presence of ulceration (p = 0.043), size above 4 cm (p = 0.049), irregular edges of lesion (p = 0.0001), a heterogeneous ultrasonographic pattern (p = 0.002), and the presence of cystic areas above 2 mm (p = 0.012). In the multivariate analysis, the last three factors were considered independent predictive factors for malignancy. Conclusions: endoscopic ultrasonography has a great sensitivity and specificity in the diagnosis of malignancy regarding submucosal lesions. The irregularity of lesion borders, a heterogeneous ultrasonographic pattern, and the presence of cystic areas above 2 mm in size were considered independent predictive factors for malignancy.

Experimental study of hybrid-knife endoscopic submucosal dissection (ESD) versus standard ESD in a Western country

BACKGROUND Endoscopic submucosal dissection (ESD) is an effective but time-consuming treatment for early neoplasia that requires a high level of expertise. OBJECTIVE The objective of this study was to assess the efficacy and learning curve of gastric ESD with a hybrid knife with high pressure water jet and to compare with standard ESD. MATERIAL AND METHODS We performed a prospective non survival animal study comparing hybrid-knife and standard gastric ESD. Variables recorded were: Number of en-bloc ESD, number of ESD with all marks included (R0), size of specimens, time and speed of dissection and adverse events. Ten endoscopists performed a total of 50 gastric ESD (30 hybrid-knife and 20 standard). RESULTS Forty-six (92 %) ESD were en-bloc and 25 (50 %) R0 (hybrid-knife: n = 13, 44 %; standard: n = 16, 80 %; p = 0.04). Hybrid-knife ESD was faster than standard (time: 44.6 +/- 21.4 minutes vs. 68.7 +/- 33.5 minutes; p = 0.009 and velocity: 20.8 +/- 9.2 mm(2)/min vs. 14.3 +/- 9.3 mm(2)/min (p = 0.079). Adverse events were not different. There was no change in speed with any of two techniques (hybrid-knife: From 20.33 +/- 15.68 to 28.18 +/- 20.07 mm(2)/min; p = 0.615 and standard: From 6.4 +/- 0.3 to 19.48 +/- 19.21 mm(2)/min; p = 0.607). The learning curve showed a significant improvement in R0 rate in the hybrid-knife group (from 30 % to 100 %). CONCLUSION despite the initial performance of hybrid-knife ESD is worse than standard ESD, the learning curve with hybrid knife ESD is short and is associated with a rapid improvement. The introduction of new tools to facilitate ESD should be implemented with caution in order to avoid a negative impact on the results.

Characteristics of Adenomas Detected by Fecal Immunochemical Test in Colorectal Cancer Screening

Background: Fecal immunochemical test (FIT) diagnostic accuracy for colorectal adenoma detection in colorectal cancer screening is limited. Methods: We analyzed 474 asymptomatic subjects with adenomas detected on colonoscopy in two blinded diagnostic tests studies designed to assess FIT diagnostic accuracy. We determined the characteristics of adenomas (number, size, histology, morphology, and location) and the risk of metachronous lesions (according to European guidelines). Finally, we performed a logistic regression to identify those variables independently associated with a positive result. Results: Advanced adenomas were found in 145 patients (75.6% distal and 24.3% only proximal to splenic flexure). Patients were classified as low (59.5%), intermediate (30.2%), and high risk (10.3%) according to European guidelines. At a 100-ng/mL threshold, FIT was positive in 61 patients (12.8%). Patients with advanced adenomas [odds ratio (OR), 8.8; 95% confidence interval (CI), 4.76–16.25], distal advanced adenomas (OR, 6.7; 95% CI, 1.9–8.8), high risk (OR, 20.1; 95% CI, 8.8–45.8), or intermediate risk lesions (OR, 6; 95% CI, 2.9–12.4) had more probabilities to have a positive test. The characteristics of adenomas independently associated were number of adenomas (OR, 1.22; 95% CI, 1.04–1.42), distal flat adenomas (OR, 0.44; 95% CI, 0.21–0.96), pedunculated adenomas (OR, 2.28; 95% CI, 1.48–3.5), and maximum size of distal adenomas (mm; OR, 1.24; 95% CI, 1.16–1.32). Conclusions: European guidelines classification and adenoma location correlates with the likelihood of a positive FIT result. Impact: This information allows us to understand the FIT impact in colorectal cancer prevention. Likewise, it should be taken into account in the development of new colorectal adenomas biomarkers. Cancer Epidemiol Biomarkers Prev; 23(9); 1884–92. ©2014 AACR.

Ultrasonography is an accurate technique for the diagnosis of gastrointestinal tumors in patients without localizing symptoms.

INTRODUCTION AND OBJECTIVES This study compared the accuracy of ultrasonography in the diagnosis of gastrointestinal tumors in patients with several degrees of clinical suspicion. MATERIAL AND METHODS We recruited patients that were suspect for gastrointestinal neoplasia but with no evidence of localizing symptoms (group A), and patients that were suspect for colon cancer (group B) or for gastric cancer (group C). Accuracy in the diagnosis was compared for: gastric cancer in groups A and C, and for colon cancer in groups A and B. The comparison was made by using the contingency coefficient, which quantifies coincidence of endoscopic and ultrasonographic diagnoses. RESULTS Seventy-nine patients were included in group A (48 males), wherein 12 colon and 5 gastric neoplasms were detected. Group B was comprised of 153 patients (78 males) and included 66 patients with colorectal cancer (CCR). Group C contained 58 patients (35 males), 31 of whom were diagnosed with gastric cancer. The accuracy of sonography for diagnosing colon cancer was 95.5% for group A and 87.5% for group B. The contingency coefficient for endoscopy vs. ultrasonography was greater for group A: 0.658 than for group B: 0.549. The diagnostic accuracy for gastric cancer was 97.4% for group A and 86.2% for group C. The contingency coefficient between endoscopic and ultrasonographic diagnoses was also greater in group A (0.618) than in group C (0.588). CONCLUSIONS The accuracy of ultrasonography in diagnosing colon and gastric cancer is not lower in patients without localizing symptoms.