Characterization of subepithelial lesions of the stomach and esophagus by contrast-enhanced EUS: A retrospective study

Background and Objectives:

Subepithelial lesions (SELs) of the upper part of the digestive tract are rare, and it can be difficult to characterize them. Recently, contrast-enhanced endosonography (EUS) and elastometry have been reported as useful adjuncts to EUS and EUS-guided fine needle aspiration (EUS-FNA) in cases of pancreatic mass and lymph node involvement. The aim of this retrospective analysis was to evaluate whether contrast-enhanced EUS can discriminate benign submucosal lesions from malignant ones. We describe our retrospective experience using the contrast agent SonoVue^® (Bracco Imaging, Milan, Italy) in an attempt to increase the diagnostic yield.

Patients and Methods:

Between May 2011 and September 2014, 14 patients (5 men, 9 women; median age 64 years, range 31–80 years) with SELs of the stomach or esophagus underwent EUS with SonoVue^® (low mechanical index). There were 3 esophageal lesions and 11 gastric lesions. Mean size of the lesions was 30 mm (range 11–50 mm). They were discovered after anemia (n = 5), dysphagia (n = 1), and pain (n = 4) and during follow-up for resected gastrointestinal stromal tumors (GISTs) (n = 1) and a standard upper gastrointestinal endoscopy (n = 3). On endoscopic sonograms, 10 of these lesions were hypoechoic and located in the fourth layer (muscularis), and 4 were in the second or third layer (mucosa and submucosa). Contrast enhancement was assessed in the early phase (after several seconds) and late phase (>30 seconds); a final diagnosis was made based on the findings of EUS-FNA using a 19-gauge ProCore (Cook Medical, Bloomington, IN) (n = 9) or 22-gauge FNA system (Cook Medical) (n = 1), the resected specimen (n = 3), or deep biopsy (n = 1). Different immunostaining was used in the pathologic studies (RNA was analyzed later using the C-kit, CD-117, CD-34, desmin, DOG-1, α-smooth actin, caldesmon, PS-100, and Ki-67 antibodies).

Results:

Final diagnoses were leiomyoma (n = 4), GIST (n = 5), schwannoma (n = 1), inflammatory tumor of Helvig (n = 1), pancreas rest (n = 2), and fibrosis (n = 1). No complications occurred. All 5 GISTs showed enhancement in the early and late phases, whereas the 8 remaining lesions did not show any enhancement. Only 1 leiomyoma showed heterogeneous enhancement.

Limitations:

The monocentric and retrospective study design and small number of patients.

Conclusions:

In cases of SELs of the stomach or esophagus, SonoVue^® could be a complementary tool to endosonography to differentiate GISTs (early and clear enhancement) from other SELs (few or no enhancement), such as leiomyomas or pancreatic rest. These results are similar to those of the few, small studies published on this topic, but more studies with a larger number of patients are needed to confirm these findings.

Comparison of pancreatic histology specimens obtained by EUS 19G versus 22G core biopsy needles: A prospective multicentre study among experienced pathologists

BACKGROUND AND AIM

Scanty data about inter-observer agreement (IOA) among pathologists in the evaluation of pancreatic samples acquired with EUS histology needle are available. The aim of this study was to determine IOA on adequacy of pancreatic histology specimens obtained with a 22G needle by a panel of experienced pathologist, in comparison with the 19G needle.

METHODS

This multicentre prospective study involved 73 pancreatic specimens prepared using histology needles of different calibres. Five pathologists independently reviewed all the samples, assessing the presence of a core, specimen adequacy and the possibility to perform additional analyses. IOA determined by Fleiss' Kappa statistic was used as the primary outcome measure. Secondary outcome was to compare 22G versus 19G needle results.

RESULTS

A core was present in 57% of pancreatic specimens obtained by 22G needle. The specimens were considered adequate in 72% of cases, with poor agreement among pathologists (p = 0.02, Fleiss' κ = 0.26). The possibility to perform further analyses was rated as 'positive' in 66% of cases without significant difference among observers (p = 0.80). When comparing the results, the presence of a core and the adequacy of tissue slides were significantly better for the 19G needle (57% vs. 84% p = 0.002; 72% vs. 83% p = 0.004, respectively). Reproducibility in the assessment of pancreatic sample adequacy was significantly better with the 19G needle (κ = 0.26 for 22G samples vs. κ = 0.81 for 19G samples).

CONCLUSIONS

Our results suggest that histology sampling of pancreatic masses should be performed with a 19G histology needle, since is able to provide a core in the majority of cases, with 83% of adequate specimens and excellent results in term of reproducibility among pathologists.

Pasireotide and octreotide antiproliferative effects and sst2 trafficking in human pancreatic neuroendocrine tumor cultures

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) raise difficult therapeutic problems despite the emergence of targeted therapies. Somatostatin analogs (SSA) remain pivotal therapeutic drugs. However, the tachyphylaxis and the limited antitumoral effects observed with the classical somatostatin 2 (sst2) agonists (octreotide and lanreotide) led to the development of new SSA, such as the pan sst receptor agonist pasireotide. Our aim was to compare the effects of pasireotide and octreotide on cell survival, chromogranin A (CgA) secretion, and sst2 phosphorylation/trafficking in pancreatic NET (pNET) primary cells from 15 tumors. We established and characterized the primary cultures of human pancreatic tumors (pNETs) as powerful preclinical models for understanding the biological effects of SSA. At clinically relevant concentrations (1-10 nM), pasireotide was at least as efficient as octreotide in inhibiting CgA secretion and cell viability through caspase-dependent apoptosis during short treatments, irrespective of the expression levels of the different sst receptors or the WHO grade of the parental tumor. Interestingly, unlike octreotide, which induces a rapid and persistent partial internalization of sst2 associated with its phosphorylation on Ser341/343, pasireotide did not phosphorylate sst2 and induced a rapid and transient internalization of the receptor followed by a persistent recycling at the cell surface. These results provide the first evidence, to our knowledge, of striking differences in the dynamics of sst2 trafficking in pNET cells treated with the two SSAs, but with similar efficiency in the control of CgA secretion and cell viability.

Yield of Contrast-Enhanced Power Doppler Endoscopic Ultrasonography and Strain Ratio Obtained by EUS-Elastography in the Diagnosis of Focal Pancreatic Solid Lesions

OBJECTIVE

Although endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is the gold standard for diagnosing pancreatic lesions, its negative predictive value is suboptimal. Our aim was to evaluate the yield of contrast-enhanced EUS (CED-EUS) and of strain ratio EUS-elastography (SR-E-EUS) for differentiating pancreatic solid lesions.

METHODS

Forty-seven patients (27 men, 20 women, 70 ± 11 years) were consecutively involved in this single-center, prospective study. They were submitted to EUS, SR-E-EUS, CED-EUS with Sonovue(®), and EUS-FNA. The final diagnosis was based on the histological assessment of EUS-FNA and/or surgical specimens when available, and on follow-up of at least 6 months.

RESULTS

From the 47 focal pancreatic lesions included, 13 (28%) were benign and 34 (72%) malignant. Patients with malignancy were older (70 ± 11 vs. 61 ± 8, P = 0.003), and had larger lesions (34 ± 12 mm vs. 22 ± 11 mm, P = 0.03). Malignant lesions had higher SR-E-EUS (31 ± 32 vs. 8 ± 9, P = 0.001) and more hypovascular pattern (93% vs. 33%, P < 0.001). Logistic regression determined that only hypovascularity (OR = 2.6, 95%CI: 1.5-130, P = 0.02) was independently predictive of malignancy. ROC analysis for SR-E-EUS yielded an optimal cutoff of 8 (AUC 0.91, 95%CI: 0.74-0.98) for the best power distinction for malignancy. There was no significant difference concerning sensitivity (79%, 90%, 93%) and specificity rates (85%, 75%, 67%) of EUS-FNA, SR-E-EUS, and CED-EUS, respectively. By analysis of the inconclusive EUS-FNA subset (9 patients, 19%), SR-E-EUS > 8 and hypovascularity showed sensitivity of 80% and 100%, and specificity of 67% and 67%, respectively.

CONCLUSION

The clinical utility of CED-EUS and SR-E-EUS remains questionable. The accuracies of CED-EUS and SR-E-EUS are similar to EUS-FNA. Hypovascularity was independently predictive of malignancy. Patients with inconclusive EUS-FNA could benefit from CED-EUS due to the high sensitivity of hypovascularity for diagnosing malignancy.

Distant lymph node metastases in gastroesophageal junction adenocarcinoma: impact of endoscopic ultrasound-guided fine-needle aspiration

OBJECTIVE

Endoscopic ultrasound (EUS) is established as the most accurate technique for pre-operative locoregional staging of gastroesophageal junction (GEJ) adenocarcinoma, the purpose of the present study was to evaluate the distant lymph nodes (LNs) EUS-fine-needle aspiration (FNA) impact in therapeutic decision for patients with GEJ adenocarcinoma.

MATERIALS AND METHODS

Retrospective study was made, with cross-sectional, non-probabilistic analysis from prospectively collected database for all GEJ adenocarcinoma staging patients referred between January 2009 and August 2012 in Paoli-Calmette Institute in Marseille-France.

RESULTS

A total of 154 patients with GEJ adenocarcinoma were managed in our institution, of whom 113 (73.3%) had non-distant metastatic disease at computed tomography (CT) scan and underwent EUS for initial tumor staging prior to a treatment decision. On A total of 113 patients undergoing EUS, 8 (7%) patients underwent endoscopic resection and 6 (5.3%) underwent direct surgical resection. Of the remaining 99 patients (87.6%), 24 (21.2%) distant LN EUS-FNA were made. Seventeen LN had EUS malignant features, including 9 (52.9%) that were confirmed as malignant and underwent palliative treatment with chemotherapy. Ninety (79.6%) patients were treated with pre-operative neoadjuvant therapy and were revaluated after. 4 (4.4%) had metastatic disease at CT scan (underwent palliative treatment) and 65 (72.2%) underwent EUS restaging to treatment decision revaluation. Of these, twelve (18.4%) distant LN EUS-FNA were performed. Seven had LN EUS malignancy features, including 4 (57.1%) that were confirmed as malignant and underwent palliative treatment. The remaining 61 patients underwent surgery. As stated above, 21 patients (23.3%) did not undergo EUS restaging, including 10 (47.6%) that did not go to surgery because patient's age, poor general status and comorbidities, 6 (28.5%) had a loss of follow-up, 1 (4.7%) underwent to surgery due to chemotherapy collateral effects, 3 (14.2%) were still on pre-operative chemotherapy and 1 (4.7%) died for sepsis after mediastinal EUS-FNA, this was the only complication event evidenced. EUS-FNA changed clinical management in 54.2% of patients who met the criteria inclusion (distant LN with malignancies EUS features), which corresponds to 11.5% of patients with GEJ adenocarcinoma.

CONCLUSION

EUS-FNA was able to provide a different tumor staging and these differences were associated with treatment received. EUS-FNA had a significant impact on treatment decision.

Ethanol lavage of 14 mucinous cysts of the pancreas: A retrospective study in two tertiary centers

Background:

Mucinous cysts are lesions with malignant potential. Their management is stil difficult. Ethanol lavage under EUS can be used and could be a good alternative treatment. We report a bi-center experience of ethanol lavage in mucinous cysts of the pancreas.

Patients and methods:

A total of 13 patients in 2 tertiary centers (7 men, 6 women, mean age=68.5 years) underwent ethanol lavage for mucinous cysts under endoscopic ultrasound (EUS) from 2001 to 2010. One of the patients had 2 cysts treated during the same procedure. One patient underwent a second procedure of ethanol lavage. Mucinous cyst diagnosis required: (1) EUS showing cystic lesion without nodule and without communication with pancreatic branch duct. Six cysts were located in the isthmus of the pancreas, 3 in the head, 3 in the body, and 2 in the tail. The mean size was 24 mm (11-50); and (2) Intra-cystic ACE level >400 UI/l and/or histologic proof. Diagnosis of mucinous cyst was obtained using ACE levels in 5 cases, histology in 8 cases, and both in 1 case.

Results:

No complication was reported. Complete responses were observed in 11 cases (85%), with no responses in 2 cases (15%). Mean follow-up was 26 months (4-118 months). Contact was lost with 1 patient. No recurrence was noticed in patients with complete responses.

Conclusion:

This study confirms the feasibility and effectiveness of a loco-regional treatment under EUS for pancreatic cysts. The good ratio of response is probably explained by the lack of septa and the small size of the cysts. The follow-up is still short and needs to be increased. Nethertheless loco-regional treatment of pancreatic cysts lesions under EUS should form a part of the management of pancreatic lesions.

Feasibility of Intratumoral Confocal Microscopy under Endoscopic Ultrasound Guidance

The primary goal of this study was to develop descriptive image interpretation criteria and a classification of endoscopic ultrasound-confocal microscopy (EUS-CM) findings in pancreatic masses and lymph nodes through a review of prospectively obtained EUS-CM videos from proven malignant and benign cases, and to propose diagnostic criteria for predicting malignancy. The material used was a 19-G EUS-needle in which the stylet was replaced by the confocal mini-probe. The mini-probe pre-loaded in the EUS-needle was guided endosonographically in the target then the mini-probe was pushed under EUS guidance into the lesion. Eleven patients mean age 62.3 years underwent EUS for the staging of a pancreatic mass (3 cystic and 4 solid) or for the diagnosis of celiac and/or mediastinal LN (n = 4). Benign intraductal papillary mucinous neoplasm (IPMN) was characterized by the aspect of finger-like projections which correspond to the villous changes of intestinal IPMN type. In pancreatic adenocarcinomas, EUS-CM found vascular leakage with irregular vessels with leakage of fluorescein into the tumor, large dark clumps which correspond to humps of malignant cells. Inflammatory lymph nodes were characterized by the presence of diffuse small cells into a homogeneous stroma with a normal vascularization. At the opposite, EUS-CM showed in malignant lymph node glandular structures with dark cells, large dark clumps and an important neo-vascularization with huge leakage of fluorescein.

Distant lymph node metastases in gastroesophageal junction adenocarcinoma: impact of endoscopic ultrasound-guided fine-needle aspiration

OBJECTIVE

Endoscopic ultrasound (EUS) is established as the most accurate technique for pre-operative locoregional staging of gastroesophageal junction (GEJ) adenocarcinoma, the purpose of the present study was to evaluate the distant lymph nodes (LNs) EUS-fine-needle aspiration (FNA) impact in therapeutic decision for patients with GEJ adenocarcinoma.

MATERIALS AND METHODS

Retrospective study was made, with cross-sectional, non-probabilistic analysis from prospectively collected database for all GEJ adenocarcinoma staging patients referred between January 2009 and August 2012 in Paoli-Calmette Institute in Marseille-France.

RESULTS

A total of 154 patients with GEJ adenocarcinoma were managed in our institution, of whom 113 (73.3%) had non-distant metastatic disease at computed tomography (CT) scan and underwent EUS for initial tumor staging prior to a treatment decision. On A total of 113 patients undergoing EUS, 8 (7%) patients underwent endoscopic resection and 6 (5.3%) underwent direct surgical resection. Of the remaining 99 patients (87.6%), 24 (21.2%) distant LN EUS-FNA were made. Seventeen LN had EUS malignant features, including 9 (52.9%) that were confirmed as malignant and underwent palliative treatment with chemotherapy. Ninety (79.6%) patients were treated with pre-operative neoadjuvant therapy and were revaluated after. 4 (4.4%) had metastatic disease at CT scan (underwent palliative treatment) and 65 (72.2%) underwent EUS restaging to treatment decision revaluation. Of these, twelve (18.4%) distant LN EUS-FNA were performed. Seven had LN EUS malignancy features, including 4 (57.1%) that were confirmed as malignant and underwent palliative treatment. The remaining 61 patients underwent surgery. As stated above, 21 patients (23.3%) did not undergo EUS restaging, including 10 (47.6%) that did not go to surgery because patient's age, poor general status and comorbidities, 6 (28.5%) had a loss of follow-up, 1 (4.7%) underwent to surgery due to chemotherapy collateral effects, 3 (14.2%) were still on pre-operative chemotherapy and 1 (4.7%) died for sepsis after mediastinal EUS-FNA, this was the only complication event evidenced. EUS-FNA changed clinical management in 54.2% of patients who met the criteria inclusion (distant LN with malignancies EUS features), which corresponds to 11.5% of patients with GEJ adenocarcinoma.

CONCLUSION

EUS-FNA was able to provide a different tumor staging and these differences were associated with treatment received. EUS-FNA had a significant impact on treatment decision.

Interobserver agreement among pathologists regarding core tissue specimens obtained with a new endoscopic ultrasound histology needle; a prospective multicentre study in 50 cases

AIM

To evaluate the interobserver agreement among pathologists in grading the quality of specimens obtained with a new 19-gauge endoscopic ultrasound histology needle.

METHODS AND RESULTS

This multicentre prospective study involved 50 slides prepared using material obtained with the new needle. Five experienced pathologists independently reviewed all of the samples, and made assessments of the following features: the presence of a core, the adequacy of the specimen, the interpretability of the specimen, and the possibility of performing additional analyses using the material. Interobserver agreement, determined by Fleiss' kappa statistic and 95% confidence intervals (CIs), was used as the primary outcome measure. Overall, the presence of a core was reported in 88% of cases with good agreement among the pathologists (κ = 0.61; 95% CI 0.52-0.70). The specimens were adequate in 91.2% of cases, and Fleiss' κ was 0.73 (95% CI 0.61-0.81). The interpretation of the specimens was reported to be 'easy' in approximately 87% of cases, with moderate agreement among the pathologists (κ = 0.44; 95% CI 0.35-0.53). The possibility of performing additional analyses from the same sample was rated as positive in approximately 91%, with good agreement (κ = 0.66; 95% CI 0.58-0.75).

CONCLUSIONS

There was excellent interobserver agreement among pathologists in the assessment of the histological material, especially with regard to sample adequacy.

Assessment of HER2 status from an epidemiology study in tumor tissue samples of gastric and gastro-esophageal junction cancer: Results from the french cohort of the HER-EAGLE study

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Background: HER2 is an important prognostic and also a predictive biomarker for trastuzumab response in gastric cancer. Therefore, HER2 status should be tested in all gastro-esophageal junction (GEJ) and gastric cancer (GC) patients. ToGA phase III study showed a benefit in overall survival of trastuzumab added to standard chemotherapy in patients with HER2-positive advanced GEJ/GC. The objective of the HER-EAGLE study was to assess the incidence of HER2 positivity in GEJ/GC cancer. Methods: HER-EAGLE was an international epidemiological, non-interventional study assessing HER2 status by IHC/ISH in tumor samples from any stage in patients with GEJ/GC. Samples were obtained by excision or core biopsy and routinely analyzed via validated Ventana or Dako methods and scoring criteria used in ToGA: HER2-positive if IHC 3+ or IHC 2+ (FISH/SISH confirmed; HER2/CEP17 ratio ≥ 2.0); HER2-negative if IHC 0 or IHC 1+ or IHC 2+ if FISH/SISH negative ratio < 2.0. Overall and subgroup estimates calculated with 95% CI. Data from the French cohort are presented. Results: The HER-EAGLE French cohort included 267 patients (68.6% males) from 7 centers (May 2007 to March 2012), with 150 biopsies (56.2%) and 117 excisions (43.8%). Tumor locations were 65.9% stomach and 34.1% GEJ, and adenocarcinoma types were according to Lauren classification: 170 intestinal (63.7%), 72 diffused (27%), 22 mixed (8.2%) and 3 not available (1.1%). HER2 status was: 36 cases IHC 3+ (13.5%), 51 IHC 2+ (19.1%) whereof 18 ISH positive (35.3%), 35 IHC 1+ (13.1%) and 145 IHC 0 (54.3%). Overall HER2 positivity (IHC 3+ or IHC 2+/ISH+) was 20.2%. Heterogeneity for HER2 staining was observed in 81 samples (30.3%). No statistical difference was found according to cancer stage. HER2 positivity was higher in GEJ (31.9%) than in GC (14.2%), p<0,001, and higher in intestinal (28.2%) compared to diffused adenocarcinomas (5.6%), p<0,001. Conclusions: HER-EAGLE French cohort results confirmed the feasibility of HER2 testing in GEJ/GC in routine practice. The incidence of HER2 overexpression was similar to the literature review, and it was higher in GEJ and intestinal adenocarcinomas type.

A distinctive epitheliomesenchymal biphasic tumor in the duodenum: the first case of duodenoblastoma?

Epitheliomesenchymal biphasic neoplasms are extremely rare in the duodenum, and most of these are carcinosarcomas. Miettinen et al. (Am J Surg Pathol 33:1370-7, 2009) recently reported three cases of a novel distinctive epitheliomesenchymal biphasic tumor of the stomach in young adults. In view of the resemblance to other childhood blastomas, they proposed to refer to this entity as a gastroblastoma. Since none of the components were sufficiently atypical, the gastroblastoma seemed more comparable to this kind of tumor than carcinosarcomas or other aggressive and malignant biphasic tumors. This report describes a duodenal location of a similar epitheliomesenchymal biphasic tumor in a 22-year-old woman. To our knowledge, this is the first reported case occurring primarily in the duodenum and might be the first case of "duodenoblastoma."

Radiofrequency ablation associated to mucosal resection in the oesophagus: experience in a single centre

Endoscopic resection (EMR) and radiofrequency ablation (RFA) form part of the treatment of Barrett's oesophagus (BO), dysplasia, superficial adenocarcinoma (OAC) associated with BO.

PATIENTS AND METHODS

Between June 2008 and April 2011, 34 patients underwent treatment with RFA (HALO system(®)), in a tertiary centre. For the study, patients were divided into two groups. Group 1 (16 patients of average 60 years old; 14 men, two women) received EMR and RFA. Group 2 (18 patients averaging 59 years age; 14 men, four women) received RFA without EMR in the year preceding the RFA.

RESULTS

In group 1, high grade dysplasia (HGD) was eradicated in 12 cases (92%), low grade dysplasia (LGD) in three cases (100%). Complete response occurred in nine cases (56%), partial response in 100% of cases. Mean follow-up was 15 months. In group 2, HGD was eradicated in one patient (100%), LGD in three patients (64%). A complete response was achieved in eight patients, partial response in four cases (77%). Mean follow-up was 10 months. The complication rate for groups 1 and 2 was of 18% and 10% respectively. No complication prevented completion of treatment or continued monitoring. Recurrence was evaluated to 5% in both groups.

CONCLUSION

RFA associated with EMR is feasible, offering probably better results and a very important advantage: a more complete histology before follow-up. Our results show effective treatment of BO and associated dysplasia with a low rate of complication. Nevertheless, when new techniques of BO ablation are used, the need to obtain histology before treatment should not be forgotten.

Well-differentiated grade 3 digestive neuroendocrine tumors: Myth or reality? The PRONET study group

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Background: In contrast to the 2000 World Health Organization (WHO) classification of digestive neuroendocrine tumors (NET) in which morphologic differentiation was the first criterion, the 2010 WHO classification of NET is based mostly on histologic grade. NET are now classified into three main categories: NET G1 (mitotic count <2/10 HPF and/or ≤2% Ki67 index), NET G2 (2-20/10 HPF and/or 3-20%), and neuroendocrine carcinoma (NEC) of small or large cell type. While NET G1 and G2 are well-differentiated tumors, NEC are considered poorly differentiated G3 tumors. We looked at the agreement between grade and differentiation to determine whether all NET can be readily classified according to the 2010 WHO classification. Methods: We designed a 1-year prospective, epidemiologic study to assess the characteristics of newly diagnosed NET, including diagnostic pathology. From August 2010 to July 2011, all pathology laboratories in France were invited to register all incident cases of gastroenteropancreatic (GEP) and thoracic NET, excluding small cell carcinoma. For GEP-NET, investigators were asked to indicate morphologic differentiation (according to WHO 2000) and elements of histologic grade (mitotic index, Ki67 index), according to ENETS. Results: Of 500 invited centers, 80 participated; 1417 incidental cases were included and 77 excluded (duplicates or exclusion criteria), totaling 1340 cases; 778 (58.1%) were GEP-NET; 660/778 (85%) were well differentiated, 72 (9%) poorly differentiated, and 46 (6%) adenocarcinoid, nonclassified, or not evaluable; 422 (54.2%) were G1, 220 (28%) G2, 104 (13.5%) G3, and 32 (4.1%) had missing grades. Of those deemed G3, 72 (69%) were described as poorly differentiated, 21 (20%) as well differentiated (mean Ki67 index 35%, range 25%-60%), and 11 (10.5%) as adenocarcinoid. Conclusions: In this prospective, epidemiologic study, overall agreement between grade and differentiation was good. However, a significant proportion of G3 NET were classified as well differentiated and thus unclassifiable by 2010 WHO classification. This group of tumor deserves to be included in future classifications to help the clinician decide whether they should be treated as NET G1/G2 or NEC G3.

Feasibility and yield of a new EUS histology needle: results from a multicenter, pooled, cohort study

BACKGROUND

EUS-guided FNA is an efficacious technique for sampling intraintestinal and extraintestinal mass lesions. However, cytology has limitations to its final yield and accuracy, which may be overcome if histological specimens are provided to the pathologist.

OBJECTIVE

To evaluate feasibility, yield, and diagnostic accuracy of a newly developed 19-gauge, fine-needle biopsy (FNB) device.

DESIGN

Multicenter, pooled, cohort study.

SETTING

Five medical centers.

PATIENTS

This study involved 109 consecutive patients with 114 intraintestinal or extraintestinal mass lesions and/or peri-intestinal lymph nodes.

INTERVENTION

EUS-guided FNB (EUS-FNB) with a newly developed, 19-gauge, FNB device.

MAIN OUTCOME MEASUREMENTS

Percentage of cases in which pathologists classified the sample quality as optimal for histological evaluation and the overall diagnostic accuracy compared with a composite criterion-standard diagnosis.

RESULTS

We evaluated 114 lesions (mean [± standard deviation] size 35.1 ± 18.7 mm; 84 malignant [73.7%] and 30 [26.3%] benign). EUS-FNB was technically feasible in 112 lesions (98.24%). Sample quality was adequate for full histological assessment in 102 lesions (89.47%). In 98 cases (85.96%), diagnosis proved to be correct according to criterion-standard diagnosis. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for diagnosis of malignancy were 90.2%, 100%, 100%, 78.9%, and 92.9%, respectively.

LIMITATIONS

Use of a surrogate criterion-standard diagnosis, including clinical follow-up when no surgical specimens were available, mainly in benign diagnoses.

CONCLUSION

Performing an EUS-FNB with a new 19-gauge histology needle is feasible for histopathology diagnosis of intraintestinal and extraintestinal mass lesions, offering the possibility of obtaining a core sample for histological evaluation in the majority of cases, with an overall diagnostic accuracy of over 85%.

DNA mismatch repair status and colon cancer recurrence and survival in clinical trials of 5-fluorouracil-based adjuvant therapy

BACKGROUND

Approximately 15% of colorectal cancers develop because of defective function of the DNA mismatch repair (MMR) system. We determined the association of MMR status with colon cancer recurrence and examined the impact of 5-fluorouracil (FU)-based adjuvant therapy on recurrence variables.

METHODS

We included stage II and III colon carcinoma patients (n = 2141) who were treated in randomized trials of 5-FU-based adjuvant therapy. Tumors were analyzed for microsatellite instability by polymerase chain reaction and/or for MMR protein expression by immunohistochemistry to determine deficient MMR (dMMR) or proficient MMR (pMMR) status. Associations of MMR status and/or 5-FU-based treatment with clinicopathologic and recurrence covariates were determined using χ(2) or Fisher Exact or Wilcoxon rank-sum tests. Time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) were analyzed using univariate and multivariable Cox models, with the latter adjusted for covariates. Tumors showing dMMR were categorized by presumed germline vs sporadic origin and were assessed for their prognostic and predictive impact. All statistical tests were two-sided.

RESULTS

In this study population, dMMR was detected in 344 of 2141 (16.1%) tumors. Compared with pMMR tumors, dMMR was associated with reduced 5-year recurrence rates (33% vs 22%; P < .001), delayed TTR (P < .001), and fewer distant recurrences (22% vs 12%; P < .001). In multivariable models, dMMR was independently associated with delayed TTR (hazard ratio = 0.72, 95% confidence interval = 0.56 to 0.91, P = .005) and improved DFS (P = .035) and OS (P = .031). In stage III cancers, 5-FU-based treatment vs surgery alone or no 5-FU was associated with reduced distant recurrence for dMMR tumors (11% vs 29%; P = .011) and reduced recurrence to all sites for pMMR tumors (P < .001). The dMMR tumors with suspected germline mutations were associated with improved DFS after 5-FU-based treatment compared with sporadic tumors where no benefit was observed (P = .006).

CONCLUSIONS

Patients with dMMR colon cancers have reduced rates of tumor recurrence, delayed TTR, and improved survival rates, compared with pMMR colon cancers. Distant recurrences were reduced by 5-FU-based adjuvant treatment in dMMR stage III tumors, and a subset analysis suggested that any treatment benefit was restricted to suspected germline vs sporadic tumors.

DNA mismatch repair status and colon cancer recurrence and survival in clinical trials of 5-fluorouracil-based adjuvant therapy

BACKGROUND

Approximately 15% of colorectal cancers develop because of defective function of the DNA mismatch repair (MMR) system. We determined the association of MMR status with colon cancer recurrence and examined the impact of 5-fluorouracil (FU)-based adjuvant therapy on recurrence variables.

METHODS

We included stage II and III colon carcinoma patients (n = 2141) who were treated in randomized trials of 5-FU-based adjuvant therapy. Tumors were analyzed for microsatellite instability by polymerase chain reaction and/or for MMR protein expression by immunohistochemistry to determine deficient MMR (dMMR) or proficient MMR (pMMR) status. Associations of MMR status and/or 5-FU-based treatment with clinicopathologic and recurrence covariates were determined using χ(2) or Fisher Exact or Wilcoxon rank-sum tests. Time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) were analyzed using univariate and multivariable Cox models, with the latter adjusted for covariates. Tumors showing dMMR were categorized by presumed germline vs sporadic origin and were assessed for their prognostic and predictive impact. All statistical tests were two-sided.

RESULTS

In this study population, dMMR was detected in 344 of 2141 (16.1%) tumors. Compared with pMMR tumors, dMMR was associated with reduced 5-year recurrence rates (33% vs 22%; P < .001), delayed TTR (P < .001), and fewer distant recurrences (22% vs 12%; P < .001). In multivariable models, dMMR was independently associated with delayed TTR (hazard ratio = 0.72, 95% confidence interval = 0.56 to 0.91, P = .005) and improved DFS (P = .035) and OS (P = .031). In stage III cancers, 5-FU-based treatment vs surgery alone or no 5-FU was associated with reduced distant recurrence for dMMR tumors (11% vs 29%; P = .011) and reduced recurrence to all sites for pMMR tumors (P < .001). The dMMR tumors with suspected germline mutations were associated with improved DFS after 5-FU-based treatment compared with sporadic tumors where no benefit was observed (P = .006).

CONCLUSIONS

Patients with dMMR colon cancers have reduced rates of tumor recurrence, delayed TTR, and improved survival rates, compared with pMMR colon cancers. Distant recurrences were reduced by 5-FU-based adjuvant treatment in dMMR stage III tumors, and a subset analysis suggested that any treatment benefit was restricted to suspected germline vs sporadic tumors.

[Predictive factors of tumour response after neoadjuvant chemoradiation for locally advanced rectal cancer and correlation of these factors with survival]

PURPOSE

Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumour response to survival and to identify predictive factors for tumour response after chemoradiation.

PATIENTS AND METHODS

From 1998 to 2008, 168 patients with histologically-proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluoro-uracil-based chemotherapy. Analysis of tumour response was based on the lowering of T stage between pre-treatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival was correlated with tumour response. Tumour response was analysed with predictive factors.

RESULTS

The median follow-up was 34 months. Five-year disease-free survival and overall survival were respectively of 44.4% and 74.5% in the whole population, 83.4% and 83.4% in patients with pathological complete response, 38.6% and 71.9% in patients with tumour downstaging, 29.1% and 58.9% in patients with absence of response. A pre-treatment concentration of carcinoembryonnic antigen below 5 ng/mL was significantly associated with tumour downstaging and significantly independently associated with pathologic complete tumour response (P = 0.019).

CONCLUSION

Downstaging and complete response after chemoradiation improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pre-treatment concentration of carcinoembryonnic antigen below 5 ng/mL was associated with complete tumour response, hence with tumour downstaging.

Results of a phase I-II study on intraductal confocal microscopy (IDCM) in patients with common bile duct (CBD) stenosis

BACKGROUND

Confocal endomicroscopy is an emergent technique and allows real optical biopsies in the gastrointestinal (GI) tract. The aim of this study was to evaluate a new intraductal confocal miniprobe in patients with a normal common bile duct (CBD) or with a suspicion of a malignant stenosis (cholangiocarcinoma).

METHODS

Thirty-seven patients (23 males) underwent endoscopic retrograde cholangiopancreatography (ERCP) for bile duct stone removal (7 cases) or bile duct stenosis (30 cases). Intraductal confocal microscopy (IDCM) was performed during the ERCP using a probe-based confocal laser endomicroscopy (pCLE) technique. IDCM was done with the CholangioFlex probe with Cellvizio (Mauna Kea Technologies, Paris, France). The depth of penetration of theCholangioFlex probe was 40-70 μm and magnification was 400×. Images were reviewed by an experienced pathologist in GI disease and compared to ERCP findings, CBD biopsies performed during ERCP or EUS, and in 15 patients to the resected specimen (Wipple resection).

RESULTS

No complications related to the CholangioFlex insertion occurred after the ERCP. Good images were obtained in 33 patients. Final histology diagnosis was a normal CBD in 7 cases, 23 malignant stenoses (4 ampullary carcinomas, 13 cholangiocarcinomas, and 6 pancreatic cancer), and 7 inflammatory stenoses (4 chronic pancreatitis, 1 stenosis of hepaticojejunal anastomosis, 1 postcholecystectomy CBD stenosis, and 1 primary sclerosing cholangitis). IDCM of a normal CBD showed a thin black band (<20 μm), normal vessels (thin and regular), and no visible glands. IDCM of malignant strictures revealed irregular vessels with lack of contrast in the CBD wall, large black band (>20 μm), and an aggregate of irregular black cells (black clumps). These aspects were seen in all malignant stenoses and none were seen in benign or normal CBD. The presence of irregular vessels, large black bands, and black clumps seen with confocal laser microscopy enabled prediction of neoplasia with an accuracy rate of 86%, sensitivity of 83%, and specificity of 75%. The respective numbers for standard histopathology were 53, 65, and 53%.

CONCLUSION

This phase I-II study on IDCM showed that IDCM is feasible. This new technique will open a new door for optical biopsy of the CBD.

Results of a phase I-II study on intraductal confocal microscopy (IDCM) in patients with common bile duct (CBD) stenosis

BACKGROUND

Confocal endomicroscopy is an emergent technique and allows real optical biopsies in the gastrointestinal (GI) tract. The aim of this study was to evaluate a new intraductal confocal miniprobe in patients with a normal common bile duct (CBD) or with a suspicion of a malignant stenosis (cholangiocarcinoma).

METHODS

Thirty-seven patients (23 males) underwent endoscopic retrograde cholangiopancreatography (ERCP) for bile duct stone removal (7 cases) or bile duct stenosis (30 cases). Intraductal confocal microscopy (IDCM) was performed during the ERCP using a probe-based confocal laser endomicroscopy (pCLE) technique. IDCM was done with the CholangioFlex probe with Cellvizio (Mauna Kea Technologies, Paris, France). The depth of penetration of theCholangioFlex probe was 40-70 μm and magnification was 400×. Images were reviewed by an experienced pathologist in GI disease and compared to ERCP findings, CBD biopsies performed during ERCP or EUS, and in 15 patients to the resected specimen (Wipple resection).

RESULTS

No complications related to the CholangioFlex insertion occurred after the ERCP. Good images were obtained in 33 patients. Final histology diagnosis was a normal CBD in 7 cases, 23 malignant stenoses (4 ampullary carcinomas, 13 cholangiocarcinomas, and 6 pancreatic cancer), and 7 inflammatory stenoses (4 chronic pancreatitis, 1 stenosis of hepaticojejunal anastomosis, 1 postcholecystectomy CBD stenosis, and 1 primary sclerosing cholangitis). IDCM of a normal CBD showed a thin black band (<20 μm), normal vessels (thin and regular), and no visible glands. IDCM of malignant strictures revealed irregular vessels with lack of contrast in the CBD wall, large black band (>20 μm), and an aggregate of irregular black cells (black clumps). These aspects were seen in all malignant stenoses and none were seen in benign or normal CBD. The presence of irregular vessels, large black bands, and black clumps seen with confocal laser microscopy enabled prediction of neoplasia with an accuracy rate of 86%, sensitivity of 83%, and specificity of 75%. The respective numbers for standard histopathology were 53, 65, and 53%.

CONCLUSION

This phase I-II study on IDCM showed that IDCM is feasible. This new technique will open a new door for optical biopsy of the CBD.

Detecting deficient DNA mismatch repair in stage II and III colon cancers

419

Background: Deficient DNA mismatch repair (MMR) results in microsatellite instability (MSI) that is detected in ∼15% of sporadic colon cancers. MMR status has been shown to provide prognostic and predictive information. We developed a model to predict MMR deficiency using clinically available data, and thereby facilitate the selection of patient tumors for MMR testing.

Methods: Data were utilized from stage II and III colon carcinoma patients (n = 2016) who participated in 5-fluorouracil-based adjuvant studies (NCCTG, FFCD, NCIC, GIVIO, NSABP) and an Italian cohort. MMR status in tumors had been determined by MSI testing or by immunohistochemistry for hMLH1 and hMSH2 proteins. Logistic regression and a recursive partitioning and amalgamation analysis was used to identify factors (histologic grade, gender, tumor site, stage, age, lymph node status, T-stage) predictive of MMR status.

Results: Of the cancers, 357 (17.7%) showed deficient MMR. Tumor site was the most important predictor of MMR status followed by histologic grade, then stage (II vs. III) and then gender. Distal tumors had a low likelihood of deficient MMR (5% rate overall), whereas proximal tumors had a greater likelihood of deficient MMR (30%). For patients with proximal tumors, the addition of histologic grade and stage increased the prediction of deficient MMR (Table). Using tumor site, histologic grade, and stage, the logistic regression model showed excellent discrimination (c-statistic = 0.80).

Conclusions: Routine clinicopathological data can facilitate the identification of MMR deficient cases. Tumor site and histologic grade were the strongest predictors of MMR deficiency. Within proximal, poorly differentiated tumors, stage was highly predictive. These findings suggest that our model can assist in selecting sporadic colon cancers for MMR testing for use in clinical decision-making, especially for stage II patients.

[Table: see text]

[Table: see text]

Predictive factors of tumor response after neoadjuvant chemoradiation for locally advanced rectal cancer

PURPOSE

Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumor response to survival and to identify predictive factors for tumor response after chemoradiation.

METHODS AND MATERIALS

From 1998 to 2008, 168 patients with histologically proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluorouracil (5-FU)-based chemotherapy. Analysis of tumor response was based on lowering of the T stage between pretreatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival rates were correlated with tumor response. Tumor response was analyzed with predictive factors.

RESULTS

The median follow-up was 34 months. Five-year disease-free survival and overall survival rates were, of 44.4% and 74.5% in the whole population, 83.4% and 83.4%, respectively, in patients with pathological complete response, 38.6% and 71.9%, respectively, in patients with tumor downstaging, and 29.1 and 58.9% respectively, in patients with absence of response. A pretreatment carcinoembryonic antigen (CEA) level of <5 ng/ml was significantly independently associated with pathologic complete tumor response (p = 0.019). Pretreatment small tumor size (p = 0.04), pretreatment CEA level of <5 ng/ml (p = 0.008), and chemotherapy with capecitabine (vs. 5-FU) (p = 0.04) were significantly associated with tumor downstaging.

CONCLUSIONS

Downstaging and complete response after CRT improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pretreatment CEA level of <5 ng/ml was associated with complete tumor response. Thus, small tumor size, a pretreatment CEA level of < 5 ng/ml, and use of capecitabine were associated with tumor downstaging.

Defective mismatch repair as a predictive marker for lack of efficacy of fluorouracil-based adjuvant therapy in colon cancer

PURPOSE

Prior reports have indicated that patients with colon cancer who demonstrate high-level microsatellite instability (MSI-H) or defective DNA mismatch repair (dMMR) have improved survival and receive no benefit from fluorouracil (FU) -based adjuvant therapy compared with patients who have microsatellite-stable or proficient mismatch repair (pMMR) tumors. We examined MMR status as a predictor of adjuvant therapy benefit in patients with stages II and III colon cancer.

METHODS

MSI assay or immunohistochemistry for MMR proteins were performed on 457 patients who were previously randomly assigned to FU-based therapy (either FU + levamisole or FU + leucovorin; n = 229) versus no postsurgical treatment (n = 228). Data were subsequently pooled with data from a previous analysis. The primary end point was disease-free survival (DFS).

RESULTS

Overall, 70 (15%) of 457 patients exhibited dMMR. Adjuvant therapy significantly improved DFS (hazard ratio [HR], 0.67; 95% CI, 0.48 to 0.93; P = .02) in patients with pMMR tumors. Patients with dMMR tumors receiving FU had no improvement in DFS (HR, 1.10; 95% CI, 0.42 to 2.91; P = .85) compared with those randomly assigned to surgery alone. In the pooled data set of 1,027 patients (n = 165 with dMMR), these findings were maintained; in patients with stage II disease and with dMMR tumors, treatment was associated with reduced overall survival (HR, 2.95; 95% CI, 1.02 to 8.54; P = .04).

CONCLUSION

Patient stratification by MMR status may provide a more tailored approach to colon cancer adjuvant therapy. These data support MMR status assessment for patients being considered for FU therapy alone and consideration of MMR status in treatment decision making.

Defective mismatch repair as a predictive marker for lack of efficacy of fluorouracil-based adjuvant therapy in colon cancer

PURPOSE

Prior reports have indicated that patients with colon cancer who demonstrate high-level microsatellite instability (MSI-H) or defective DNA mismatch repair (dMMR) have improved survival and receive no benefit from fluorouracil (FU) -based adjuvant therapy compared with patients who have microsatellite-stable or proficient mismatch repair (pMMR) tumors. We examined MMR status as a predictor of adjuvant therapy benefit in patients with stages II and III colon cancer.

METHODS

MSI assay or immunohistochemistry for MMR proteins were performed on 457 patients who were previously randomly assigned to FU-based therapy (either FU + levamisole or FU + leucovorin; n = 229) versus no postsurgical treatment (n = 228). Data were subsequently pooled with data from a previous analysis. The primary end point was disease-free survival (DFS).

RESULTS

Overall, 70 (15%) of 457 patients exhibited dMMR. Adjuvant therapy significantly improved DFS (hazard ratio [HR], 0.67; 95% CI, 0.48 to 0.93; P = .02) in patients with pMMR tumors. Patients with dMMR tumors receiving FU had no improvement in DFS (HR, 1.10; 95% CI, 0.42 to 2.91; P = .85) compared with those randomly assigned to surgery alone. In the pooled data set of 1,027 patients (n = 165 with dMMR), these findings were maintained; in patients with stage II disease and with dMMR tumors, treatment was associated with reduced overall survival (HR, 2.95; 95% CI, 1.02 to 8.54; P = .04).

CONCLUSION

Patient stratification by MMR status may provide a more tailored approach to colon cancer adjuvant therapy. These data support MMR status assessment for patients being considered for FU therapy alone and consideration of MMR status in treatment decision making.

EUS-FNA predicts 5-year survival in pancreatic endocrine tumors

BACKGROUND

Pancreatic endocrine tumors (PETs) differ in clinical behavior and prognosis. Determination of malignant potential through specimens obtained by EUS-FNA can help in the management of these patients.

OBJECTIVE

To determine the value of EUS-FNA for diagnosing PETs and for classifying their underlying malignant potential based on the World Health Organization (WHO) classification.

DESIGN

Single-center, retrospective, cohort study.

SETTING

Tertiary referral hospital.

PATIENTS

This study involved 86 consecutive patients (44 men, mean age 58 +/- 14 years) who had been diagnosed with PETs and submitted to EUS-FNA from January 1999 to August 2008.

INTERVENTION

EUS-FNA of a pancreatic mass and/or a metastasis site. Immunohistochemistry on microbiopsies or on monolayer cytology was routinely used. The lesions were classified as recommended by the WHO.

MAIN OUTCOME MEASUREMENTS

EUS-FNA sensitivity and 5-year survival rate.

RESULTS

Overall, in 90% (77 of 86) of patients in this study, PET was diagnosed with EUS-FNA. The sensitivity did not vary with tumor size, type, location, or the presence of hormonal secretion. Of 86 patients, 30 (35%) were submitted to surgical resection. The kappa correlation index between the WHO classification obtained by EUS-FNA and by surgery was 0.38 (P = .003). Major discrepancies were found in the group of patients diagnosed with endocrine tumor of uncertain behavior by EUS-FNA, because 72% turned out to have well-differentiated endocrine carcinoma. Sixteen patients (27%) died during a mean follow-up period of 34 +/- 27 months. The 5-year survival rates were 100% for endocrine tumors, 68% for well-differentiated endocrine carcinomas, and 30% for poorly differentiated endocrine carcinomas (P = .008, log-rank test).

LIMITATIONS

Retrospective design, selection bias, and small sample size.

CONCLUSIONS

This largest single-center experience to date demonstrated the accuracy of EUS-FNA in diagnosing and determining the malignant behavior of PETs. EUS-FNA findings predict 5-year survival in patients with PETs.

Cystic pancreatic endocrine tumors: an endoscopic ultrasound-guided fine-needle aspiration biopsy study with histologic correlation

BACKGROUND

Cystic pancreatic endocrine tumors (PETs) are rare neoplasms with a preoperative diagnostic challenge. The aim of this study was to evaluate the preoperative diagnostic strategy for these tumors and to assess the clinical and pathologic characteristics.

METHODS

Six cases of cystic PET were retrospectively enrolled. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) was performed in 4 cases. All cytomorphologic data from conventional smears, ThinPrep preparations, and cell block preparations were reported in detail.

RESULTS

There were 3 male and 3 female patients with a mean age of 52.3 years. Tumor size ranged from 10 mm to 60 mm (mean, 29.8 mm). EUS-FNAB contributed to an accurate diagnosis in all cases. Cytologically, loosely cohesive aggregates and single cells were predominant. Cells were small and typically plasmacytoid, with occasional cytoplasmic vacuolization. Nuclei were round or oval, uniform, with finely and evenly distributed chromatin. Immunocytochemistry confirmed the endocrine differentiation. Histologic findings were typical for endocrine proliferation. All tumors were well differentiated.

CONCLUSIONS

Cystic PET is an unusual finding that presents diagnostic challenges for both endoscopists and cytologists. EUS-FNAB with the Thinprep preparation technique and cell block material were found to be helpful in improving diagnostic accuracy. Immunocytochemical staining with endocrine markers confirmed the diagnosis.

Molecular epidemiology of GISTs: Incidence of PDGFRA and KIT exon 9 mutations in the large French population-based study molecGIST

10535

Background: KIT exon 11, KIT exon 9, and PDGFRA exon 18 mutations are present in 67%, 10% and 5% of gastrointestinal stromal tumors (GIST). However most of these data are based on analyses of patients with overtly metastatic tumors. The MolecGIST study was design to evaluated prospectively the histological, molecular and clinical characteristics of all GISTs diagnosed at all stages. Methods: All patients leaving in France, whose diagnosis of GIST was achieved between June 1, 2006 and May 31, 2008 were includable in the study. MolecGIST was approved by French ethical comities. Samples were collected in 11 reference centers for histology review, immunohistochemistry and detection of mutations within exon 9, 11, 13, and 17 of KIT and 12, 14, and 18 of PDGFRA. Results: In December 2008, 738 patients were referred to MolecGIST, corresponding to 5.95/million/year incidence of GIST en France (62 millions inhabitants). The median age at diagnosis 63.1 years (range [15–96]), and female/male ratio 0.98. GIST originated in the stomach in 56.3% and small bowel in 29.3% of the cases. Tumors were KIT+ in 90,4% of cases. CD34 was expressed by more than 20% of tumor cells in 83.8% of gastric GIST and 39.7% of small bowel GIST respectively (P<0.0001). The risk of metastatic relapse was moderate or high in 62.7% of the patients, according to Fletcher classification, while only in 44% according to Miettinen's. Mutation analyses were achieved in 438 cases (to be updated), and mutations of either KIT or PDGFRA were detected in 66.2% and 12.6% of the patients, and absent in 21.2%. The most frequent mutations were KIT exon 11 (59.1%), PDGFRA exon 18 (9.8%) and KIT exon 9 (4.3%). The incidence of PDGFRA exon 18 and KIT exon 9 were significantly different than the published data (P=0.0008 and P<0.0001 respectively). Among GIST of the small bowel, the mutations were KIT exon 11 (69.1%) and KIT exon 9 (13.1%). Conclusions: The PDGFRAexon18/KITexon9 mutation ratio is 4.5 times higher in our population based study than in patients included in phase III trials. The incidence of GIST with PDGFRA mutations and intestinal GIST exon KIT exon 11 mutations is underestimated in published series as compared to ours, probably because of the better prognosis.

[Table: see text]

p53 and Ki-67 in Barrett's carcinoma: is there any value to predict recurrence after circumferential endoscopic mucosal resection?

BACKGROUND

There are situations in which the specimens obtained after endoscopic mucosal resection of superficial adenocarcinoma arising from Barrett's esophagus are not adequate for histopathological assessment of the margins. In these cases, immunohistochemistry might be an useful tool for predicting cancer recurrence.

AIM

To evaluate the value of p53 and Ki-67 immunohistochemistry in predicting the cancer recurrence in patients with Barrett's esophagus-related cancer referred to circumferential endoscopic mucosal resection.

METHODS

Mucosectomy specimens from 41 patients were analyzed. All endoscopic biopsies prior to endoscopic mucosal resection presented high-grade dysplasia and cancer was detected in 23 of them. Positive reactions were considered the intense coloration in the nuclei of at least 90% of the cells in each high-power magnification field, and immunostaining could be classified as superficial or diffuse according to the mucosal distribution of the stained nuclei.

RESULTS

Endoscopic mucosal resection samples detected cancer in 21 cases. In these cases, p53 immunohistochemistry revealed a diffuse positivity for the great majority of these cancers (90.5% vs. 20%), and Ki-67 showed a diffuse pattern for all cases (100% vs. 30%); conversely, patients without cancer revealed a superficial or negative pattern for p53 (80% vs. 9.5%) and Ki-67 (70% vs. 0%). During a mean follow-up of 31.6 months, 5 (12.2%) patients developed six episodes of recurrent cancer. Endoscopic mucosal resection specimens did not show any significant difference in the p53 and Ki-67 expression for patients developing cancer after endoscopic treatment.

CONCLUSIONS

p53 and Ki-67 immunohistochemistry were useful to confirm the cancer; however, they had not value for predicting the recurrent carcinoma after circumferential endoscopic mucosal resection of Barrett's carcinoma.

Multicystic peritoneal mesothelioma: report of three cases

Multicystic peritoneal mesothelioma is a rare lesion occurring mainly in women in a reproductive age. Its pathogenesis is unclear. We report three cases of multicystic peritoneal mesothelioma in patients that were 28, 38 and 47 years of age (one male, two females). A history of abdominal surgery was reported in two cases. Explorative laparotomy was presumptive of a pseudomyxoma peritoni in two cases, and hyperthermic intraperitoneal chemotherapy was performed. Histological examination demonstrated multicystic lesions with mesothelial cells lining confirmed by immunohistochemical analysis. Unusual findings such as hyperplasia, hobnail features, cytoplasmic vacuolisation and papillary pattern were occasionally noted. The clinical presentation, pathogenesis and pathologic features including differential diagnosis of multicystic peritoneal mesothelioma are discussed.

Incidence of gastrointestinal stromal tumors (GISTs) in France: Results of the PROGIST survey conducted among pathologists

10047

Background: GISTs are the most common mesenchymal tumors of the gastrointestinal tract but data on the annual incidence of this tumor is scarce due to previous lack of well-defined pathologic criteria. The aim of this study was to investigate the incidence of GISTs in France and describe the distribution according to age, sex, circumstances of discovery, localization and risk categories. Methods: This prospective epidemiologic study was performed among pathologists who were asked to declare all the cases of GIST over a one year period. All pathology centers (330 centers) in France were proposed to participate and asked to report exhaustively the cases diagnosed from 1 December 2004 to 30 November 2005. Results: 591 cases of GISTs were reported, 535 new cases and 56 cases of relapse. However, some large centers were not able to participate. So, the annual estimated incidence was 12 cases/million inhabitants in France. The main characteristics of the new cases of GIST were as follows: mean age 65 (± 13.2) (range: 16–93) years, 48.6% men and 51.4% women, circumstances of discovery: fortuitous 163 (30.5%), symptomatic 249 (46.5%), unknown 123 (23%). The primary tumor locations were: stomach 341 (63.7 %), small intestine 115 (21.5%), mesentery 35 (6.5%), colon/rectum 17 (3.2%), esophagus 4 (0.7%), unknown 23 (4.3%). 95.3% of GISTs were cKIT (CD117) + and 3.7 % were cKIT -. According to the Fletcher consensus criteria, based on tumor size and mitotic rate, among the 490 localized GISTs 14.7% were considered to be at very low prognostic risk, 25.5% at low-risk, 23.1 % at intermediate risk and 23.1 % at high-risk. For 13.6 % data were missing. Conclusions: This study is providing for the first time an estimation of the annual incidence of GISTs and a description of the characteristics of these tumors in France based on pathology registration. The true incidence may be slightly higher as some large centers were not able to reported their cases. These results are comparable to what has been reported in recent studies in other European countries.

No significant financial relationships to disclose.

Circumferential endoscopic resection of Barrett's esophagus with high-grade dysplasia or early adenocarcinoma

BACKGROUND

Barrett's esophagus-related high-grade dysplasia or mucosal cancer can be treated by endoscopic mucosal resection (EMR), but the adjacent metaplastic epithelium remains at risk for developing further lesions. Our objective was to evaluate the results of the circumferential EMR in removing not only the neoplastic lesion but also the remaining Barrett's epithelium.

METHODS

Forty-one consecutive patients (mean age: 66 years) with Barrett's esophagus were submitted to 63 EMR sessions in one single-referral endoscopic unit. All patients had high-grade dysplasia, and cancer was detected in 23 of these cases, most of them classified as T1N0 (20 patients) by endosonography. Mucosectomy after saline submucosal injection was performed for the neoplastic lesions and, if necessary, the residual Barrett's epithelium was removed by the same technique one month later.

RESULTS

A retrospective evaluation showed that, during a mean follow-up of 31.6 months, Barrett's epithelium was completely replaced by squamous epithelium in 31 (75.6%) cases. There were 10 complications, all of which were managed endoscopically: 8 cases of bleeding and two perforations occurred in 9 (14.3%) patients. One patient developed an esophageal stricture. Barrett's epithelium recurred in 10 (24.4%) patients and recurrent or metachronous early cancer was detected in 5 (12.2%), all but one of which were treated again by EMR; the fifth patient was referred to surgery. Argon plasma coagulation was used in 6 cases to treat Barrett's epithelium, and two patients received concomitant chemoradiotherapy as adjuvant therapy.

CONCLUSIONS

Circumferential EMR provides an effective endoscopic approach to the management of Barrett's esophagus-related high-grade dysplasia and mucosal cancer. Additional studies are necessary to evaluate the long-term results.

Preoperative radiotherapy and docetaxel in resectable pancreatic adenocarcinoma: A phase II trial

4099

Background: We previously reported results a phase I trial of weekly docetaxel concurrently with radiation therapy in patients (pts) with locally advanced pancreatic adenocarcinoma (Pancreas, Vol 27, N°3, 2003). We prospectively explored this regimen in 34 pts with biopsy proven potentially resectable pancreatic adenocarcinoma. Methods: Treatment consisted of concomitant radiotherapy (45 Gy within 5 weeks directed at the pancreatic tumor and regional lymphatics) with 5 weekly doses of docetaxel (30 mg/m2/week) by 1-hour infusion, followed by a complete staging evaluation 3–4 weeks after chemo-radiation. Pts without disease progression underwent surgery. Results: From May, 2003 to July, 2005, this study enrolled 34 pts (59% men) with median age 62 years (range 45–72). Median tumor size was 3 cm. Pretreatment Endoscopic Ultrasound (EUS) staging was uT1 (7 pts), uT2 (25 pts), uT3 (2pts), uN0 (26 pts) and uN1 (8 pts). Median pretreatment CA 19.9 levels was 114 (range 1–9432). All pts (97%) but one completed radiation and 91% (31 pts) received the 5 weekly doses of docetaxel. Adverse events included grade 3/4 asthenia (28%), grade 3/4 nausea/vomiting (10%), grade 3/4 anemia (7%) and grade 3/4 neutropenia (7%). Median time between diagnosis and surgery was 3.7 months (range 2.8–8.7). Ten pts (29%) presented progressive disease after chemo-radiation and one additional patient (pt) voluntary stopped treatment procedure. Twenty three pts (68%) underwent surgical procedure, which was with curative intent in 17 pts (50%). One pt died within the 30-day post operative period. Pathological response was observed in 7 pts (30%), including 2 complete response. The median Disease Free Survival (DFS) was 11 months and the 2-year DFS was 21%. The median overall survival (OS) was 14 months. The 2-year DFS for the 17 pts resected with a curative intent was 50.4%. In this subgroup, median overall survival was not reached. Conclusions: Pre-operative combination of radiotherapy and docetaxel is feasible with tolerable toxicity and with promising pathological response. A randomized phase III study comparing this regimen (radiotherapy and docetaxel) and surgery versus surgery alone is starting. Supported in part by Sanofi Aventis, France.

No significant financial relationships to disclose.

Endoscopic ultrasound elastography: the first step towards virtual biopsy? Preliminary results in 49 patients

BACKGROUND AND STUDY AIMS

It is well known that some diseases, such as cancer, lead to changes in the hardness of tissue. Sonoelastography, a technique that allows the elasticity of tissue to be assessed during ultrasound examination, provides the ultrasonographer with important additional information that can be used for diagnosis. The aim of this study was to evaluate the ability of endoscopic ultrasound elastography to differentiate between benign and malignant pancreatic masses and lymph nodes.

PATIENTS AND METHODS

During a 12-month period, 49 patients underwent endoscopic ultrasound (EUS) examinations with elastography, conducted by a single endoscopist. Twenty-four patients underwent evaluation of a pancreatic mass (mean diameter 24.7 +/- 11.1 mm) and 25 underwent evaluation of 31 lymph nodes. The mean diameter of the lymph nodes was 19.7 +/- 8.6 mm, and they were found in the cervical area (n = 3), mediastinum (n = 17), celiac arterial trunk region (n = 5), and aortocaval region (n = 6).

RESULTS

The sonoelastography images of pancreatic masses were interpreted as benign in four cases and malignant in 20. The sensitivity and specificity of sonoelastography in the diagnosis of malignant lesions were 100% and 67%, respectively. The sonoelastography images of the lymph nodes were interpreted as showing malignancy in 22 cases, benign conditions in seven, and indeterminate status in two. The sensitivity and specificity of sonoelastography for evaluating malignant lymph-node invasion were 100% and 50%, respectively.

CONCLUSIONS

EUS elastography is potentially capable of further defining the tissue characteristics of benign and malignant lesions but specifity has to be improved. It can be used to guide biopsy sampling for diagnosis.

Endoscopic mucosal resection for advanced sessile adenoma and early-stage colorectal carcinoma

BACKGROUND AND STUDY AIMS

The aim of this study was to evaluate the efficacy and outcomes of treatment by endoscopic mucosal resection (EMR) of patients with high-grade dysplasia (HGD) or carcinoma.

PATIENTS AND METHODS

Between January 1995 and January 2002, 50 patients (35 men, 15 women) were treated by EMR for 52 sessile polyps. The median size of the polyps was 27.5 mm (range 10-60). The "lift and cut" EMR technique was used. If the lesion was poorly differentiated or infiltrated the muscularis mucosae to more than 1000 microm, the patient was referred for colectomy. In the other cases, follow-up was proposed.

RESULTS

Complications occurred in 9.6 % of cases and were always treated conservatively. The rate of endoscopically complete resection was judged to be 98.1 %. Argon plasma coagulation was applied to the margins of the lesion in 21.6 % of cases. Histological examination showed 38 HGDs and 14 carcinomas. Seven patients had a lesion reaching the deep or lateral margin; four were referred for surgery; two patients for whom surgery would have been high risk were followed up, and both developed local recurrence; and one patient was followed up, without recurrence, because infiltration was less than 1000 microm. A total of 43 patients were followed up after complete excision. Two patients died during follow-up; neither death could be reliably attributed to colorectal carcinoma. Seven patients were lost during the follow-up. For 34 patients, information from a mean follow-up of 17.3 months (6 - 57) was available and recurrence was observed in five cases (15 %).

CONCLUSIONS

EMR appears to be a safe and efficient treatment of HGD and early colorectal cancer. However, correct analysis of submucosal infiltration is essential to assess the completeness of the resection.