Cap-assisted endoscopic mucosal resection as a salvage technique for challenging colorectal laterally spreading tumors.

BACKGROUND: Cap-assisted endoscopic mucosal resection (EMR-c) has emerged as a potential alternative to standard piecemeal wide-field EMR (WF-EMR) for the resection of laterally spreading tumors (LSTs). However, clear indications for this technique are still lacking. Our objective was to investigate the performance of salvage EMR-c after WF-EMR failure in the resection of large colorectal LSTs. METHODS: The data of consecutive patients undergoing WF-EMR for large colorectal LSTs (2015-2021) were analyzed in this single-center, retrospective, observational study. In the event of a WF-EMR failure, the procedure was switched to EMR-c in the same session. The efficacy of the two techniques was evaluated in terms of complete endoscopic resection, R0 resection, and recurrence rate. Safety was also assessed. RESULTS: Overall, the data from 81 WF-EMRs were collected. Eighteen cases of WF-EMR failure were switched to EMR-c in the same session and complete endoscopic resection was achieved in 17/18 patients (94.4%). No statistically significant difference was observed between WF-EMR and salvage EMR-c in terms of macroscopic radicality (P = 0.40) and R0 resection (P = 0.12). However, recurrence was more common with EMR-c (44.4% vs. 23.5%; P = 0.05), as were adverse events, particularly intraprocedural bleeding (27.8% vs. 7.9%; P = 0.04). CONCLUSION: EMR-c is an effective salvage technique for challenging colorectal LSTs following WF-EMR failure. Due to the elevated risk of adverse events associated with this procedure, careful patient selection, endoscopic expertise, and close follow-up are strongly recommended.

Appendiceal collision tumors: case reports, management and literature review.

Appendiceal tumors are incidentally detected in 0.5% cases of appendectomy for acute appendicitis and occur in approximately 1% of all appendectomies. Here, we report two cases of appendiceal collision tumors in two asymptomatic women. In both cases, imaging revealed right-lower-quadrant abdominal masses, which were laparoscopically resected. In both cases, histological examinations revealed an appendiceal collision tumor comprising a low-grade appendiceal mucinous neoplasm and well-differentiated neuroendocrine neoplasm (NEN). For complete oncological control, right hemicolectomy was performed in one patient for the aggressive behavior of NEN; however, histology revealed no metastasis. The other patient only underwent appendectomy. No further treatment was recommended. According to the latest guidelines, exact pathology needs to be defined. Proper management indicated by a multidisciplinary team is fundamental.

Peptide Receptor Radionuclide Therapy (PRRT): Innovations and Improvements.

Neuroendocrine neoplasms (NENs) are tumors originating from neuroendocrine cells distributed throughout the human body. With an increasing incidence over the past few decades, they represent a highly heterogeneous group of neoplasms, mostly expressing somatostatin receptors (SSTRs) on their cell surface. Peptide receptor radionuclide therapy (PRRT) has emerged as a crucial strategy for treating advanced, unresectable neuroendocrine tumors by administering radiolabeled somatostatin analogs intravenously to target SSTRs. This article will focus on the multidisciplinary theranostic approach, treatment effectiveness (such as response rates and symptom relief), patient outcomes, and toxicity profile of PRRT for NEN patients. We will review the most significant studies, such as the phase III NETTER-1 trial, and discuss promising new radiopharmaceuticals, including alpha-emitting radionuclide-labeled somatostatin analogs and SSTR antagonists.

Adverse events in gastrointestinal endoscopy: Validation of the AGREE classification in a real-life 5-year setting.

BACKGROUND: The novel AGREE classification for adverse events (AEs) in gastrointestinal (GI) endoscopy has not yet been validated in a real-world setting. AIMS: Our study aims to evaluate the correlation between the grades of AEs in the ASGE and AGREE classifications and to assess the interobserver agreement of the two classification systems. METHODS: The correlation and association between the AE grades of the ASGE and AGREE classifications were analyzed using the Spearman rank correlation test and the chi-squared analysis, respectively. A weighted Cohen's kappa coefficient analysis was performed to determine the interobserver agreement of both classification systems. RESULTS: We prospectively collected the AEs that occurred in our endoscopy unit over the past five years. A total of 226 AEs (226/84,863, 0.3%) occurred. There was a correlation between the ASGE and AGREE classifications (ρ = 0.61) and a moderately significant association (p < 0.01, Cramer's V = 0.7). The interobserver agreement for the ASGE classification was fair (kappa 0.60, 95% confidence interval [CI]: 0.54, 0.67), whereas it was good for the AGREE classification (kappa 0.80, 95% CI: 0.62, 0.87). CONCLUSIONS: The AGREE classification was validated for the first time in a real-world setting and showed a positive correlation and higher interobserver agreement than the ASGE classification.

Recurrence rates after piecemeal endoscopic mucosal resection of large colorectal laterally spreading tumors.

Background: Piecemeal endoscopic mucosal resection (pEMR) is routinely employed for large laterally spreading tumors (LSTs). Recurrence rates following pEMR are still unclear, especially when cap-assisted EMR (EMR-c) is performed. We assessed the recurrence rates and recurrence risk factors post-pEMR for large colorectal LSTs, including both wide-field EMR (WF-EMR) and EMR-c. Methods: This was a single-center, retrospective study of consecutive patients who underwent pEMR for colorectal LSTs ≥20 mm at our institution between 2012 and 2020. Patients had a post-resection follow-up period of at least 3 months. A risk factor analysis was carried out using the Cox regression model. Results: The analysis included 155 pEMR: 51 WF-EMR and 104 EMR-c, with a median lesion size of 30 (range: 20-80) mm and a median endoscopic follow up of 15 (range: 3-76) months. Overall, disease recurrence occurred in 29.0% of cases; there was no significant difference in recurrence rates between WF-EMR and EMR-c. Recurrent lesions were safely managed by endoscopic removal, and at risk analysis lesion size was the only significant risk factor for recurrence (mm; hazard ratio 1.03, 95% confidence interval 1.00-1.06, P=0.02). Conclusions: Recurrence of large colorectal LSTs after pEMR occurs in 29% of cases. This rate is mainly dependent on lesion size, and the use of a cap during pEMR has no effect on recurrence. Prospective controlled trials are needed to validate these results.

Heart Team for Left Appendage Occlusion without the Use of Antithrombotic Therapy: The Epicardial Perspective.

BACKGROUND: Left atrial appendage occlusion is an increasingly proposed treatment for patients with atrial fibrillation and poor tolerance to anticoagulants. All endovascular devices require antithrombotic therapy. Anatomical and clinical variables predisposing to device-related thrombosis, as well as post-procedural peri-device leaks, could mandate the continuation or reintroduction of aggressive antithrombotic treatment. Because of the absence of foreign material inside the heart, epicardial appendage closure possibly does not necessitate antithrombotic therapy, but data of large series are missing. METHODS: Multidisciplinary team evaluation for standalone totally thoracoscopic epicardial appendage closure was done in 180 consecutive patients with atrial fibrillation and poor tolerance to antithrombotic therapy. One hundred and fifty-two patients consented (male 66.1%, mean age 76.1 ± 7.4, CHA2DS2VASc mean 5.3 ± 1.6, HASBLED mean 3.8 ± 1.1). Indications were cerebral hemorrhage (48%), gastro-intestinal bleeding (33.3%), and other bleeding (20.7%). No antithrombotic therapy was prescribed from the day of surgery to the latest follow up. RESULTS: Procedural success was 98.7%. At a mean follow up of 38.2 ± 18.8 months, cardioembolic and bleeding events were 1.3% and 0.6%, respectively. Among patients with a history of blood transfusions (41.1%), none needed further transfusions or treatment post procedure. CONCLUSION: Epicardial appendage occlusion without any antithrombotic therapy appears to be safe and effective. This strategy could be advised when minimization of bleeding risk concomitant to stroke prevention is needed.

High rate of Ki-67 increase in entero-pancreatic NET relapses after surgery with curative intent.

Neuroendocrine neoplasms (NENs) present with advanced disease at diagnosis in up to 28% of cases, precluding the possibility of curative-intent surgery. Histopathological heterogeneity of this disease can be observed inter-individually as well as intra-individually during disease course. The present study aimed to assess the frequency of Ki-67 change after radical surgery, in a series of patients with radically resected entero-pancreatic neuroendocrine tumors (EP-NETs). We present the analysis of a multicenter, retrospective, series of EP-NETs G1-G2 recurring after radical resection and with histological re-evaluation at disease recurrence (DR). The primary endpoint was the description of Ki-67 change at DR compared to time of surgery. The secondary endpoint was assessment of recurrence-free survival (RFS) rates. In total, 47 patients had a second histological evaluation and could be included in the present study. Median Ki-67 at surgery was 3% (range 1-15%) but, at DR, a significant increase in the value was observed (7%, range 1-30%; p < .01) and involved 66.0% of cases, with a corresponding increase in tumor grading in 34.0% (p = .05). Median RFS of the overall population was 40 months, and was worse when Ki-67 increased at DR vs. stable Ki-67 value (36 vs. 61 months, respectively; p = .02). In conclusion, in more than half of the cases with relapse after radical surgery, a higher proliferative index with a potentially more aggressive potential was observed. Therefore, histological reassessment should be considered on DR because tailored therapeutic strategies may be required for these patients.

Hepatitis C virus burden: Treating and educating people without prejudice.

BACKGROUND: Hepatitis C virus (HCV) infection has a worldwide incidence of 1.1%. In Italy, 60% of people who inject drugs (PWIDs) and are receiving assistance for substance use disorder are infected with HCV. However, this subset of patients has extremely limited access to care due to multiple factors, including alcohol abuse, psychological comorbidities, and homeless status. AIM: To describe the impact of our HCV-dedicated service for substance use disorder (SSUD) service on PWIDs receiving anti-HCV therapy. METHODS: A dedicated, multidisciplinary team was set up at the SSUD of Trento in October 2020 to provide antiviral treatment to HCV RiboNucleic Acid-positive patients with an active or previous history of substance abuse. The treatment was followed by a health education program. Patients were treated with Direct-Acting Antivirals (DAAs). Data were retrospectively analyzed to assess the efficacy of our dedicated program in terms of therapy completion, HCV eradication, and compliance (primary endpoint). The rate of HCV reinfection and DAA-related toxicity were also assessed (secondary endpoints). RESULTS: A total of 40 patients were enrolled in the study: 28 (70.0%) were treated with Sofosbuvir/Velpatasvir, while 12 (30.0%) received Glecaprevir/Pibrentasvir. At the time of inclusion in the study, 36 patients were receiving opioid agonist maintenance therapy, whilst another 4 had just finished the treatment. 37.5% had a history of alcoholism and 42.5% received concomitant psychiatric treatment. All 40 patients (100.0%) completed the therapy cycle and 92.5% of patients adhered to the program. All patients tested negative for viral load at the end of the treatment. There were no significant drug interactions with common psychiatric treatments and no side effects were observed. The sustained virological response was achieved in 92.5% of cases with good tolerability, although two patients discontinued treatment temporarily. After HCV eradication, one patient died from an overdose, another from complications of cirrhosis, and one reinfection occurred. CONCLUSION: Very high adherence to therapy and good tolerability was observed in our series of HCV patients treated at the SSUD, regardless of the substance abuse condition. Further validation in a larger population is required.

Evaluation of multidisciplinary team decisions in neuroendocrine neoplasms: Impact of expert centres.

OBJECTIVE: To evaluate the impact of multidisciplinary team (MDT) meetings on the management of patients with neuroendocrine neoplasms (NENs). METHODS: All newly referred gastro-entero-pancreatic (GEP)-NEN patients discussed from 1 April to 1 October 2017 in the MDT of seven European expert centres were prospectively included. The impact on patients' management was defined as a change in diagnosis, grade, stage or treatment. RESULTS: A total of 292 patients were included, mainly small intestinal (siNENs) (32%) and pancreatic NENs (28%), with distant metastases in 51%. Patients had received prior surgery in 43% of cases and prior medical treatment in 32%. A significant change occurred in 61% of NENs: 7% changes in diagnosis, 8% in grade and 16% in stage. The MDT recommended a new treatment for 51% of patients, mainly surgery (9%) or somatostatin analogues (20%). A significant change was most frequently observed in patients with Stage IV disease (hazard ratio [HR] 3.6, 95% confidence interval [CI]: 1.9-6.9 vs. Stage I) and G2 NENs (vs. G1, HR 2.1 95% CI: 1.2-3.8). CONCLUSION: NEN-dedicated MDT discussion in expert centres yields significant management changes in over 60% of patients and thus represents the gold standard for the management of these patients.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives.

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

Multicenter Analysis of Treatment Outcomes for Systemic Therapy in Well Differentiated Grade 3 Neuroendocrine Tumors (NET G3).

Well-differentiated grade 3 neuroendocrine tumors (NET G3) have been distinguished from poorly differentiated neuroendocrine carcinomas (NEC) in the most current WHO classifications. Commonly applied first-line chemotherapy protocols with cisplatin or carboplatin in combination with etoposide (PE) are less effective in NET G3 than NEC. Suggested alternative treatment protocols have not been studied in first-line therapy of NET G3 so far. We performed a retrospective analysis of patients with NET G3 in the databases of 3 German cancer centers. Out of 142 patients, 136 patients received palliative first-line therapy: overall response rate (ORR) was 35.1% for PE (n = 37), 56.4% for FOLFOX (n = 39), 27.3% for temozolomide/capecitabine (TEM/CAP) (n = 22), 45.0% for streptozotocin/5-fluorouracil (STZ/5-FU) (n = 20), and 16.7% for other (n = 18). Median progression-free survival (PFS) for PE was 6.9 months. Compared to PE, PFS in the other treatment groups was 6.9 months for FOLFOX (p = 0.333), 12.0 months for TEM/CAP (p = 0.093), 4.8 months for STZ/5-FU (p = 0.919), and 14.1 months for other (p = 0.014). In a univariate setting, all non-PE patients combined showed a significantly prolonged PFS vs. PE (9.0 months; p = 0.049) which could not be confirmed in a multivariate analysis. In conclusion, NET G3 with FOLFOX showed the highest ORR, and with TEM/CAP showed the longest PFS. Further prospective evaluation of the optimal therapeutic strategy for this tumor entity is needed.

Optimal timing of endoscopy for acute upper gastrointestinal bleeding: a systematic review and meta-analysis.

Acute upper gastrointestinal bleeding (UGIB) is the most common indication for urgent endoscopy, but the correct timing of endoscopy in these patients is still debated. Our systematic review with meta-analysis was aimed at investigating the potential clinical benefit of very early endoscopy for UGIB patients. We performed an electronic literature search of PubMed, Scopus, Web of Science and the Cochrane Library up to 23rd May 2020 and considered only randomised controlled trials (RCTs) comparing management of UGIB patients by very early vs early endoscopy. Only five RCTs were considered eligible for quantitative analysis, with a total population of 926 cases (468 in the very early endoscopy arm and 458 in the early). The meta-analysis showed no statistically significant benefit for very early endoscopy compared to early endoscopy in terms of risk of rebleeding, mortality, ICU admission, blood transfusion, surgery and length of hospital stay. However, our results showed a significantly higher need for haemostatic treatment when very early endoscopy was performed (RR 1.23, 95% CI 1.06-1.42, p < 0.01) in comparison to early endoscopy.

Histopathological Revision for Gastroenteropancreatic Neuroendocrine Neoplasms in Expert Centers: Does It Make the Difference?

BACKGROUND: The correct histopathological diagnosis of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) is crucial for treatment selection and prognostication. It is also very challenging due to limited experience in nonexpert centers. Revision of pathology is standard of care for most patients who are referred to NEN expert centers. OBJECTIVES: To describe the clinical impact of histopathological revision for GEP-NEN patients referred to an expert center. METHODS: Retrospective multicenter analysis of all GEP-NENs receiving a histopathological revision in 6 European NEN expert centers (January 2016 to December 2016) to evaluate the impact on patient management. RESULTS: 175 patients were included and 14.7% referred for a second opinion. Histological samples were 69.1% biopsies, 23.4% surgical specimens, and 7.5% endoscopic resections. Histopathological changes due to revision included first assessment of Ki67 in 8.6% of cases, change in grading in 11.4% (3.4% G1 to G2; 5.7% G2 to G1; 0.6% G2 to G3; 1.7% G3 to G2), definition of tumor invasion in 10.8%, additional immunohistochemical staining in 2.3%, diagnosis of mixed adenoneuroendocrine carcinoma in 3.4%, exclusion of NEN in 3.4%, first diagnosis of NEN in 2.3%, and tumor differentiation for G3 in 1.7%. The revision had a clinical impact in 36.0% of patients, leading to a new therapeutic indication in 26.3%. The indication to then perform a new imaging test occurred in 21.1% and recommendation to follow-up with no further treatment in 6.3%. CONCLUSIONS: Histopathological revision in expert centers for NENs can change the diagnosis, with a significant clinical impact in about one third of patients.

Somatostatin Analogs for Pancreatic Neuroendocrine Tumors: Any Benefit When Ki-67 Is ≥10%?

BACKGROUND: Long-acting somatostatin analogs (SSAs) are the primary first-line treatment of well-differentiated advanced gastroenteropancreatic neuroendocrine tumors (NETs), but data about their efficacy in pancreatic NETs (panNETs) with Ki-67 ≥10% are still limited. MATERIALS AND METHODS: To assess the clinical outcomes of advanced, nonfunctioning, well-differentiated panNETs with Ki-67 ≥10% receiving first-line long-acting SSAs in a real-world setting, we carried out a retrospective, multicenter study including patients treated between 2014-2018 across 10 centers of the NET CONNECT Network. The primary endpoints were time to next treatment (TNT) and progression-free survival (PFS), whereas overall survival (OS) and treatment safety were secondary endpoints. RESULTS: A total of 73 patients were included (68 grade [G]2, 5 G3), with liver metastases in 61 cases (84%). After a median follow-up of 36.4 months (range, 6-173), the median TNT and PFS were 14.2 months (95% confidence interval [CI], 11.6-16.2) and 11.9 months (95% CI, 8.6-14.1) respectively. No statistically significant difference was observed according to the somatostatin analog used (octreotide vs. lanreotide), whereas increased tumor grade (hazard ratio [HR], 4.4; 95% CI, 1.2-16.6; p = .04) and hepatic tumor load (HR, 2; 95% CI, 1-4; p = .03) were independently associated with shortened PFS. The median OS recorded was 86 months (95% CI, 56.8-86 months), with poor outcomes observed when the hepatic tumor burden was >25% (HR, 3.4; 95% CI, 1.2-10; p = .01). Treatment-related adverse events were reported in 14 patients, most frequently diarrhea. CONCLUSION: SSAs exert antiproliferative activity in panNETs with Ki-67 ≥10%, particularly in G2 tumors, as well as when hepatic tumor load is ≤25%. IMPLICATIONS FOR PRACTICE: The results of the study call into question the antiproliferative activity of somatostatin analogs (SSAs) in pancreatic neuroendocrine tumors with Ki-67 ≥10%. Patients with grade 2 tumors and with hepatic tumor load ≤25% appear to derive higher benefit from SSAs. Prospective studies are needed to validate these results to optimize tailored therapeutic strategies for this specific patient population.

Gastrointestinal tract injuries after thermal ablative therapies for hepatocellular carcinoma: A case report and review of the literature.

BACKGROUND: Radiofrequency ablation (RFA) and microwave ablation (MWA) represent the standard of care for patients with early hepatocellular carcinoma (HCC) who are unfit for surgery. The incidence of reported adverse events is low, ranging from 2.4% to 13.1% for RFA and from 2.6% to 7.5% for MWA. Gastrointestinal tract (GIT) injury is even more infrequent (0.11%), but usually requires surgery with an unfavourable prognosis. Due to its low incidence and the retrospective nature of the studies, the literature reporting this feared complication is heterogeneous and in many cases lacks information on tumour characteristics, comorbidities and treatment approaches. CASE SUMMARY: A 77-year-old man who had undergone extended right hepatectomy for HCC was diagnosed with early disease recurrence with a small nodule compatible with HCC in the Sg4b segment of the liver with a subcapsular location. He was treated with percutaneous RFA and a few week later he was urgently admitted to the Surgery ward for abdominal pain and fever. A subcutaneous abscess was diagnosed and treated by percutaneous drainage. A fistulous tract was then documented by the passage of contrast material from the gastric antrum to the abdominal wall. The oesophagogastroduodenoscopy confirmed a circular wall defect at the lesser curvature of gastric antrum, leading directly to the purulent abdominal collection. An over-the-scope clip (OTSC) was used to successfully close the defect. CONCLUSION: This is the first reported case of RFA-related GIT injury to have been successfully treated with an OTSC, which highlights the role of this endoscopic treatment for the management of this complication.

Efficacy and Toxicity of 5-Fluorouracil-Oxaliplatin in Gastroenteropancreatic Neuroendocrine Neoplasms.

OBJECTIVES: The objective of this study was to investigate the efficacy and tolerability of 5-fluorouracil-oxaliplatin (FOLFOX) in advanced gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). METHODS: Retrospective analysis of consecutive 72 advanced GEP-NENs treated with FOLFOX between 2005 and 2016 at a single German referral center for NENs was performed. We assessed treatment response by response evaluation criteria in solid tumors 1.0 criteria, progression-free survival by Kaplan-Meyer method, and risk factor analysis by Cox-regression model. RESULTS: Patients were 44.5% G1/G2, 55.5% G3, receiving a median of 7 treatment cycles (range, 2-21), and had a median of 18 months of follow-up (range, 3-111 months). Disease control was achieved in 75.0% of cases but 91.3% in the 23 patients receiving FOLFOX as first line (P = 0.04). Median progression-free survival of the overall population was 8 months. A better outcome was significantly related to treatment duration (P = 0.02) and grade of histological differentiation for G3 patients (well differentiated vs poorly differentiated, P = 0.03). Adverse events occurred in 88.8% of patients, mostly grade 1 and 2 hematotoxicity and chemotherapy-induced peripheral sensory neuropathy (84.1% and 50.0% of patients, respectively). CONCLUSIONS: Our results support FOLFOX as therapeutic option in advanced GEP-NENs with poor prognosis, either at first or further therapy line. Longer duration of therapy was associated with a more durable benefit.

Radical intended surgery for highly selected stage IV neuroendocrine neoplasms G3.

BACKGROUND: Stage IV gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) G3 are the NENs with the worst prognosis. According to ENETS guidelines, platinum-based chemotherapy is the standard treatment for this population. Surgery is only considered in highly selected "resectable" NENs with usually lower Ki67. However, the role of surgery with curative intent has been poorly investigated. OBJECTIVE: To describe, in a retrospective series of stage IV GEP-NENs G3, overall survival (OS) and recurrence-free survival (RFS) rates after curatively intended surgery. METHODS: Multicenter analysis of stage IV GEP-NENs G3 receiving radical resection (R0/R1) from 2007 to 2017, with minimum post-surgical follow-up time of 3 months. RESULTS: Fifteen patients from 6 NEN referral centers, with median follow-up of 29 months (8-86), were included. Eight cases had a neuroendocrine carcinoma (NEC) and 7 a neuroendocrine tumor G3 (NET G3). Median OS after radical surgery was 59 months. All patients recurred, with a median RFS of 8 months. CONCLUSIONS: Radical surgery might be considered for highly selected stage IV GEP-NENs G3. Larger series are needed to confirm these results.