A Novel Oncolytic Herpes Capable of Cell-Specific Transcriptional Targeting of CD133± Cancer Cells Induces Significant Tumor Regression.

The topic of cancer stem cells (CSCs) is of significant importance due to its implications in our understanding of the tumor biology as well as the development of novel cancer therapeutics. However, the question of whether targeting CSCs can hamper the growth of tumors remains mainly unanswered due to the lack of specific agents for this purpose. To address this issue, we have developed the first mutated version of herpes simplex virus-1 that is transcriptionally targeted against CD133+ cells. CD133 has been portrayed as one of the most important markers in CSCs involved in the biology of a number of human cancers, including liver, brain, colon, skin, and pancreas. The virus developed in this work, Signal-Smart 2, showed specificity against CD133+ cells in three different models (hepatocellular carcinoma, colorectal cancer, and melanoma) resulting in a loss of viability and invasiveness of cancer cells. Additionally, the virus showed robust inhibitory activity against in vivo tumor growth in both preventive and therapeutic mouse models as well as orthotopic model highly relevant to potential clinical application of this virus. Therefore, we conclude that targeting CD133+ CSCs has the potential to be pursued as a novel strategy against cancer. Stem Cells 2018;36:1154-1169.

The utility of lower endoscopic ultrasound-guided fine needle aspiration for the diagnosis of benign and malignant pelvic diseases.

BACKGROUND: The utility of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of pelvic masses has been suggested but limited data are available in the literature regarding its diagnostic accuracy. GOALS: To report our institutional experience with EUS-FNA for the diagnosis of a variety of pelvic diseases. METHODS: Patients who were referred for the evaluation of pelvic lesions using lower EUS-FNA were included in this retrospective analysis if they had available surgical pathology (obtained after EUS) which was considered the gold standard against which the EUS-FNA findings would have been compared. The diagnostic accuracy of EUS-FNA for pelvic masses was analyzed and any early or late complications after the procedure were reported. A pelvic mass was defined in the study as any mass seen with an imaging modality in the pelvic area including those involving the colonic wall. RESULTS: Twenty patients had EUS-FNA followed by surgery for whom FNA cytology and surgical pathology findings were available. EUS-FNA reached the correct diagnosis in 19 out of 20 patients, whereas for the missing 1 malignant lymph node wherein FNA revealed benign cytology, surgical specimen confirmed metastatic colon cancer. The sensitivity and specificity of EUS-FNA were 90% and 100%, respectively, with positive and negative predictive values of 100% and 90%, respectively. No early or late complications were encountered with this procedure for the sampling of cystic and noncystic masses. CONCLUSIONS: EUS-FNA has excellent diagnostic accuracy for pelvic masses. It represents a safe procedure with excellent yield and thus may be used as a first line modality for the evaluation and diagnosis of pelvic masses within its reach.

A randomized, double-blind, placebo-controlled, phase 2b study of the efficacy and safety of velusetrag in subjects with diabetic or idiopathic gastroparesis.

BACKGROUND: This study assessed the efficacy and safety of velusetrag-a 5-HT4 agonist with pan-gastrointestinal prokinetic activity-for gastroparesis symptom management and gastric emptying (GE). METHODS: In this multicenter, double-blind, randomized, placebo-controlled study, subjects with diabetic or idiopathic gastroparesis received velusetrag 5, 15, or 30 mg or placebo for 12 weeks. The primary efficacy outcome was a 7-day mean Gastroparesis Cardinal Symptom Index 24-h composite score (GCSI-24H) change from baseline at week 4; GE was evaluated using scintigraphy (GES) and breath tests, and safety from adverse events (AEs). KEY RESULTS: 232 subjects (183 females; 113 idiopathic gastroparesis) received treatment from February 2015 through June 2017. Least-squares mean improvement from baseline GCSI-24H (primary endpoint) at week 4 was -1.5 following velusetrag 5 mg vs -1.1 following placebo (treatment difference, -0.4; 95% confidence interval, -0.75 to -0.03; nominal p = 0.0327; Hochberg-adjusted p = 0.0980 [not significant]). Symptom improvement from baseline was achieved only with velusetrag 5 mg, which resulted in greater improvement from baseline vs placebo in all gastroparesis core symptoms, especially in subjects with idiopathic gastroparesis. Improvement from baseline GE by GES was greater in subjects receiving velusetrag (all doses) vs placebo; >70% of subjects receiving velusetrag 30 mg had GE normalization at 4 h. Treatment-emergent AEs were generally mild. CONCLUSIONS AND INFERENCES: Velusetrag treatment was generally well-tolerated and associated with improved GE vs placebo in subjects with diabetic or idiopathic gastroparesis; however, only the lowest dose, velusetrag 5 mg, was associated with short-term improvement in gastroparesis symptoms. CLINICALTRIALS: GOV: NCT02267525.

Overactivation of Ras signaling pathway in CD133+ MPNST cells.

Cancer stem cells (CSCs) are believed to be the regenerative pool of cells responsible for repopulating tumors. Gaining knowledge about the signaling characteristics of CSCs is important for understanding the biology of tumors and developing novel anti-cancer therapies. We have identified a subpopulation of cells positive for CD133 (a CSC marker) from human primary malignant peripheral nerve sheath tumor (MPNST) cells which were absent in non-malignant Schwann cells. CD133 was also found to be expressed in human tissue samples and mouse MPNST cells. CD133+ cells were capable of forming spheres in non-adherent/serum-free conditions. The activation levels of Ras and its downstream effectors such as ERK, JNK, PI3K, p38K, and RalA were significantly increased in this population. Moreover, the CD133+ cells showed enhanced invasiveness which was linked to the increased expression of ß-Catenin and Snail, two important proteins involved in the epithelial to mesenchymal transition, and Paxilin, a focal adhesion protein. Among other important characteristics of the CD133+ population, endoplasmic reticulum stress marker IRE1α was decreased, implying the potential sensitivity of CD133+ to the accumulation of unfolded proteins. Apoptotic indicators seemed to be unchanged in CD133+ cells when compared to the wild (unsorted) cells. Finally, in order to test the possibility of targeting CD133+ MPNST cells with Ras pathway pharmacological inhibitors, we exposed these cells to an ERK inhibitor. The wild population was more sensitive to inhibition of proliferation by this inhibitor as compared with the CD133+ cells supporting previous studies observing enhanced chemoresistance of these cells.

Are endoscopic ultrasonography imaging characteristics reliable for the diagnosis of small upper gastrointestinal subepithelial lesions?

PURPOSE OF THE STUDY: To compare the accuracy of endoscopic ultrasonography (EUS) imaging with histopathology in the diagnosis of upper gastrointestinal subepithelial lesions. METHODS: Thirty-seven patients (21 female; mean age: 55 y) underwent endoscopic submucosal resection (ESMR) of upper gastro intestinal subepithelial lesions at a tertiary care facility. All patients underwent EUS before ESMR of the lesion. Information regarding location, size, echogenecity, layer of origin, presumptive diagnosis based on EUS imaging, and histopathology diagnosis after ESMR of the subepithelial lesion was recorded. RESULTS: Twenty-seven subepithelial lesions were resected from the stomach, 5 from the esophagus, and 5 from the duodenum. The mean size of the lesions was 9 mm (range, 6-18 mm). Thirty-six lesions originated from the submucosa, and 1 from the muscularis propria. Using histopathology as the gold standard, the overall diagnostic accuracy of EUS imaging was 49% (18 out of 37). The accuracy of EUS imaging for the diagnosis of esophageal, gastric, and duodenal subepithelial lesions was 20%, 56%, and 40%, respectively. One patient developed a microperforation, and 1 developed bleeding during the ESMR procedure. No complications were reported with the EUS procedure. CONCLUSIONS: The diagnostic accuracy of EUS imaging is inferior to histopathology in the diagnosis of small upper gastrointestinal subepithelial lesions. Endoluminal resection is a relatively safe and noninvasive modality that not only provides tissue sample for accurate diagnostic interpretation, but also aids in the complete removal of small subepithelial lesions of the upper gastrointestinal tract.

A Rare Case of Complete Esophageal Obstruction Following Esophageal Variceal Band Ligation (EVBL) for Esophageal Varices Performed by Esophagogastroduodenoscopy (EGD).

BACKGROUND Esophageal variceal band ligation (EVBL) performed by esophagogastroduodenoscopy (EGD) is a routinely performed procedure for the treatment of esophageal varices that is undertaken to control bleeding and prevent further complications. This report is of a case of a rare complication of complete esophageal obstruction following EVBL. CASE REPORT A 69-year-old woman underwent EVBL for esophageal varices. She subsequently presented with complete obstruction of the esophageal lumen with ulceration, which was seen on repeat EGD. Following conservative management, EGD demonstrated scarring around the ulcerated region and a patent esophagus. CONCLUSIONS This case report serves to remind physicians of the potential complications that may arise with the use of EVBL treatment for bleeding esophageal varices and to consider the use of a loop cutter, to grasp and remove the esophageal band to improve patient recovery.

Ral signaling pathway in health and cancer.

The Ral (Ras-Like) signaling pathway plays an important role in the biology of cells. A plethora of effects is regulated by this signaling pathway and its prooncogenic effectors. Our team has demonstrated the overactivation of the RalA signaling pathway in a number of human malignancies including cancers of the liver, ovary, lung, brain, and malignant peripheral nerve sheath tumors. Additionally, we have shown that the activation of RalA in cancer stem cells is higher in comparison with differentiated cancer cells. In this article, we review the role of Ral signaling in health and disease with a focus on the role of this multifunctional protein in the generation of therapies for cancer. An improved understanding of this pathway can lead to development of a novel class of anticancer therapies that functions on the basis of intervention with RalA or its downstream effectors.

RalA signaling pathway as a therapeutic target in hepatocellular carcinoma (HCC).

Ral (Ras like) leads an important proto-oncogenic signaling pathway down-stream of Ras. In this work, RalA was found to be significantly overactivated in hepatocellular carcinoma (HCC) cells and tissues as compared to non-malignant samples. Other elements of RalA pathway such as RalBP1 and RalGDS were also expressed at higher levels in malignant samples. Inhibition of RalA by gene-specific silencing caused a robust decrease in the viability and invasiveness of HCC cells. Additionally, the use of geranyl-geranyl transferase inhibitor (GGTI, an inhibitor of Ral activation) and Aurora kinase inhibitor II resulted in a significant decrease in the proliferation of HCC cells. Furthermore, RalA activation was found to be at a higher level of activation in HCC stem cells that express CD133. Transgenic mouse model for HCC (FXR-Knockout) also revealed an elevated level of RalA-GTP in the liver tumors as compared to background animals. Finally, subcutaneous mouse model for HCC confirmed effectiveness of inhibition of aurora kinase/RalA pathway in reducing the tumorigenesis of HCC cells in vivo. In conclusion, RalA overactivation is an important determinant of malignant phenotype in differentiated and stem cells of HCC and can be considered as a target for therapeutic intervention.

Pro-oncogenic cell signaling machinery as a target for oncolytic viruses.

Viruses function in close harmony with the signaling machinery of their host. Upon exposure to the cell, a battery of viral products become engaged in boosting friendly signaling elements of the host or suppressing harmful ones. The efficiency of viral replication is indeed the biological outcome of this interaction between cellular and host signaling molecules. Oncolytic viruses, natural or man-made, follow the same set of rules of engagement. Pro-oncogenic cell signaling machinery, therefore, is undoubtedly the most important area influencing the development of the next generation of effective, specific and rationally designed oncolytic viruses. Ras signaling, with its central role in what is known today as molecular oncology, is an attractive topic for studying the behavior of viruses versus cancer cells and to develop strategies to target cancer cells on the basis of such platform. This work reviews the development of oncolytic herpes viruses capable of targeting Ras signaling pathway along with a few other examples of viruses which are developed to contain specificity for certain pro-oncogenic characteristics of their host cells.

Inhibition of mesothelin as a novel strategy for targeting cancer cells.

Mesothelin, a differentiation antigen present in a series of malignancies such as mesothelioma, ovarian, lung and pancreatic cancer, has been studied as a marker for diagnosis and a target for immunotherapy. We, however, were interested in evaluating the effects of direct targeting of Mesothelin on the viability of cancer cells as the first step towards developing a novel therapeutic strategy. We report here that gene specific silencing for Mesothelin by distinct methods (siRNA and microRNA) decreased viability of cancer cells from different origins such as mesothelioma (H2373), ovarian cancer (Skov3 and Ovcar-5) and pancreatic cancer (Miapaca2 and Panc-1). Additionally, the invasiveness of cancer cells was also significantly decreased upon such treatment. We then investigated pro-oncogenic signaling characteristics of cells upon mesothelin-silencing which revealed a significant decrease in phospho-ERK1 and PI3K/AKT activity. The molecular mechanism of reduced invasiveness was connected to the reduced expression of ß-Catenin, an important marker of EMT (epithelial-mesenchymal transition). Ero1, a protein involved in clearing unfolded proteins and a member of the ER-Stress (endoplasmic reticulum-stress) pathway was also markedly reduced. Furthermore, Mesothelin silencing caused a significant increase in fraction of cancer cells in S-phase. In next step, treatment of ovarian cancer cells (OVca429) with a lentivirus expressing anti-mesothelin microRNA resulted in significant loss of viability, invasiveness, and morphological alterations. Therefore, we propose the inhibition of Mesothelin as a potential novel strategy for targeting human malignancies.

Inhibition of RalA signaling pathway in treatment of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and relatively resistant to chemotherapy. The most prevalent molecular abnormality in NSCLC is the overactivation of K-Ras proto-oncogene; therefore, elucidating down-stream Ras signaling in NSCLC is significantly important in developing novel therapies against this malignancy. Our work indicates that RalA, an important effector of Ras, is activated in NSCLC cell lines. While RalA was also overactivated in fetal human broncho-epithelial cells, RalBP1 (Ral binding protein-1), an important down-stream effector of RalA, was expressed at higher levels in cancer cell lines. Aurora kinase-A (AKA), an upstream activator of RalA, was also found to be active only in malignant cells. The outcome of inhibition of RalA (by gene specific silencing using a lentivirus) on the malignant phenotype of A549 cells was also studied. While proliferation and invasiveness of A549 cells were reduced upon silencing RalA, apoptosis and necrosis were elevated in such conditions. Additionally, the in vivo tumorigenesis of A549 cells was reduced upon partial inhibition of RalA and AKA using pharmacological inhibitors. Finally, we were interested in evaluating the level of active RalA in the fraction of NSCLC cells expressing cancer stem cell markers. For this purpose cells with increased expression of CD44 were separated from A549 cells and compared with cells with low level of expression of this marker and an unsorted population. A significant enhancement of RalA activation in high CD44+ cells was found as potential evidence for involvement of RalA signaling in initiation of the neoplastic procedure and an important contributor for tumor maintenance in NSCLC. Further studies can reveal therapeutic, preventive and diagnostic value of RalA pathway in this deadly disease.

Utilizing ras signaling pathway to direct selective replication of herpes simplex virus-1.

Re-engineering the tropism of viruses is an attractive translational strategy for targeting cancer cells. The Ras signal transduction pathway is a central hub for a variety of pro-oncogenic events with a fundamental role in normal and neoplastic physiology. In this work we were interested in linking Ras activation to HSV-1 replication in a direct manner in order to generate a novel oncolytic herpes virus which can target cancer cells. To establish such link, we developed a mutant HSV-1 in which the expression of ICP4 (infected cell protein-4, a viral protein necessary for replication) is controlled by activation of ELK, a transcription factor down-stream of the Ras pathway and mainly activated by ERK (extracellular signal-regulated kinase, an important Ras effector pathway). This mutant HSV-1 was named as Signal-Smart 1 (SS1). A series of prostate cells were infected with the SS1 virus. Cells with elevated levels of ELK activation were preferentially infected by the SS1 virus, as demonstrated by increased levels of viral progeny, herpetic glycoprotein C and overall SS1 viral protein production. Upon exposure to SS1, the proliferation, invasiveness and colony formation capabilities of prostate cancer cells with increased ELK activation were significantly decreased (p<0.05), while the rate of apoptosis/necrosis in these cells was increased. Additionally, high Ras signaling cells infected with SS1 showed a prominent arrest in the G1 phase of the cell cycle as compared to cells exposed to parental HSV-1. The results of this study reveal the potential for re-modeling the host-herpes interaction to specifically interfere with the life of cancer cells with increased Ras signaling. SS1 also serves as a "prototype" for development of a family of signal-smart viruses which can target cancer cells on the basis of their signaling portfolio.

Transcription factors down-stream of Ras as molecular indicators for targeting malignancies with oncolytic herpes virus.

Overactivation in Ras signaling has been under intensive study as the molecular basis for development of cancer. Such overactivation can occur in the presence or absence of mutations in Ras gene resulting in activation of a series of down-stream effectors such as transcription factors. Different studies have shown the activation of Ras down-stream effectors in non-Hodgkin lymphoma (NHL) although mutations in Ras are not prevalent in this malignancy. Since overactivation in Ras signaling also increases permissiveness of cancer cells to infection by oncolytic versions of herpes simplex virus (e.g. R3616), we were interested in evaluating the value of transcription factors down-stream of Ras as molecular indicators for permissiveness to herpes therapy. In order to accomplish this, and also to assess the permissiveness of lymphoma cells to infection with R3616, we used NHL cell lines Daudi, Jurkat, NC37, Raji, Ramos and ST486. Once the levels of phosphorylation (activation) of extracellular-signal regulated kinase (ERK, a Ras effector pathway) and its down-stream transcription factor ELK were evaluated, Raji and NC37 showed a significant increase in the phosphorylation levels of both molecules while ATF2 (another transcription factor down-stream of p38-kinase pathway) seemed to be activated in all studied cells. Raji and NC37 cells were also most permissive cells to infection with R3616 while their permissiveness was decreased upon treatment of cells with an inhibitor of ELK-DNA binding portraying ERK/ELK as a suitable predictive indicator for selection of cancer cells with increased sensitivity to R3616. This study, therefore, for the first time documents permissiveness of lymphoma cells to oncolytic herpes viruses and introduces ELK as a suitable factor for predicting tumor susceptibility to these novel anticancer agents.

Ral overactivation in malignant peripheral nerve sheath tumors.

Ras leads an important signaling pathway that is deregulated in neurofibromatosis type 1 and malignant peripheral nerve sheath tumor (MPNST). In this study, we show that overactivation of Ras and many of its downstream effectors occurred in only a fraction of MPNST cell lines. RalA, however, was overactivated in all MPNST cells and tumor samples compared to nontransformed Schwann cells. Silencing Ral or inhibiting it with a dominant-negative Ral (Ral S28N) caused a significant reduction in proliferation, invasiveness, and in vivo tumorigenicity of MPNST cells. Silencing Ral also reduced the expression of epithelial mesenchymal transition markers. Expression of the NF1-GTPase-related domain (NF1-GRD) diminished the levels of Ral activation, implicating a role for neurofibromin in regulating RalA activation. NF1-GRD treatment caused a significant decrease in proliferation, invasiveness, and cell cycle progression, but cell death increased. We propose Ral overactivation as a novel cell signaling abnormality in MPNST that leads to important biological outcomes with translational ramifications.

Value of a negative colonoscopy in patients with non-specific gastrointestinal symptoms.

BACKGROUND: The yield of colonoscopy for neoplasia among patients aged <50 years with non-specific gastrointestinal symptoms is very low. However, a negative colonoscopy may benefit these patients by decreasing anxiety and thereby reducing subsequent health resource utilization. This study sought to characterize the effect of a negative colonoscopy in terms of: (i) reassurance value; and (ii) decreasing health resource utilization, in patients under 50 years of age with non-specific gastrointestinal symptoms (abdominal pain, diarrhea, constipation). METHODS: Consecutive patients, aged 18-49 years, undergoing their first colonoscopy for evaluation of non-specific gastrointestinal symptoms (abdominal pain, diarrhea, constipation) were prospectively enrolled. Health-related anxiety was evaluated before and immediately after disclosure of the negative result of colonoscopy using a validated questionnaire and at 1-, 2- and 6-month intervals postcolonoscopy by telephone follow-up. Symptom scores and health resource utilization were assessed prior to colonoscopy and at 2 and 6 months postcolonoscopy. RESULTS: Fifty-nine patients were prospectively enrolled. Mean health anxiety score declined immediately after colonoscopy from 20.6 to 17.8. Sustained improvement was seen in anxiety scores at 1, 2 and 6 months. Symptom scores also decreased at 6 months for abdominal pain (2.3 to 1.5), diarrhea (2.3 to 1.6) and constipation (1.9 to 1.6). There was a significant decrease in all four measures of health resource utilization at 6 months postcolonoscopy. CONCLUSIONS: Despite minimal diagnostic yield, colonoscopy for non-specific gastrointestinal symptoms in patients <50 years of age is associated with a decline in health-related anxiety and symptom scores. These effects appear to translate into reductions in health resource utilization.

Gastrointestinal plasmacytoma that caused anemia in a patient with multiple myeloma.

BACKGROUND: A 70-year-old white male diagnosed with IgA lambda multiple myeloma, who had been treated with two cycles of melphalan and prednisone, was evaluated for persistent anemia. He had required more than 15 U of packed red blood cells within a 2-month period for his anemia, despite recombinant erythropoietin treatment, and his hemoglobin level was persistently below 9 g/dl. INVESTIGATIONS: Physical examination and laboratory tests, which included a red blood cell mean corpuscular volume, platelet counts, coagulation studies, a peripheral blood smear, lactate dehydrogenase level, haptoglobin and bilirubin level, vitamin B12 and folate level, serum iron studies, bone marrow biopsy and immunophenotyping. Additionally, Congo red staining of the subcutaneous fat aspirate and a bone marrow biopsy were carried out, as well as esophagogastroduodenoscopy with gastric and duodenal biopsies. DIAGNOSIS: Gastrointestinal plasmacytoma. MANAGEMENT: Control of underlying disease (multiple myeloma) with 2 cycles of treatment with melphalan and prednisone followed by high-dose pulse dexamethasone chemotherapy as outlined by the oncologist. PPI therapy was continued and NSAIDs were avoided. The patient died because of infectious complications with subsequent multi-organ failure while awaiting work up for autologous stem cell transplantation.

Effects of a cannabinoid receptor agonist on colonic motor and sensory functions in humans: a randomized, placebo-controlled study.

Cannabinoid receptors (CBR) are located on cholinergic neurons in the brain stem, stomach, and colon. CBR stimulation inhibits motility in rodents. Effects in humans are unclear. Dronabinol (DRO), a nonselective CBR agonist, inhibits colonic motility and sensation. The aim of this study was to compare effects of DRO and placebo (PLA) on colonic motility and sensation in healthy volunteers. Fifty-two volunteers were randomly assigned (double-blind) to a single dose of 7.5 mg DRO or PLA postoperative with concealed allocation. A balloon-manometric assembly placed into the descending colon allowed assessment of colonic compliance, motility, tone, and sensation before and 1 h after oral ingestion of medication, and during fasting, and for 1 h after 1,000-kcal meal. There was an overall significant increase in colonic compliance (P = 0.045), a borderline effect of relaxation in fasting colonic tone (P = 0.096), inhibition of postprandial colonic tone (P = 0.048), and inhibition of fasting and postprandial phasic pressure (P = 0.008 and 0.030, respectively). While DRO did not significantly alter thresholds for first gas or pain sensation, there was an increase in sensory rating for pain during random phasic distensions at all pressures tested and in both genders (P = 0.024). In conclusion, in humans the nonselective CBR agonist, DRO, relaxes the colon and reduces postprandial colonic motility and tone. Increase in sensation ratings to distension in the presence of relaxation of the colon suggests central modulation of perception. The potential for CBR to modulate colonic motor function in diarrheal disease such as irritable bowel syndrome deserves further study.

Dysphagia: a cost analysis of the diagnostic approach.

OBJECTIVES: The initial diagnostic approach for dysphagia is controversial. The choices include barium swallow (BaS) versus esophagogastroduodenoscopy (EGD). The aim of this study was to determine the clinical cost of establishing a diagnosis and treating dysphagia based on initial diagnostic approach (BaS vs EGD). METHODS: Clinical outcome of patients with undiagnosed dysphagia evaluated by either internists in a primary care clinic (n = 100) or gastroenterologists (n = 120) were determined based on the initial diagnostic test: BaS versus EGD. Final diagnoses in each group were determined based on any testing performed subsequent to the initial studies. Total cost in achieving the final diagnosis for each group were determined based on 2002 Medicare reimbursement cost. RESULTS: BaS (66% and 62%) and EGD (34% and 38%) were ordered in equal prevalence by gastroenterologists and internists, respectively. Final diagnoses included: benign obstruction (37% and 36%), gastroesophageal reflux disease (GERD) (18% and 44%), achalasia (17% and 1%), nonspecific esophageal motility disorder (NSEMD) (17% and 11%), neoplasm (7% and 6%), and infectious esophagitis (4% and 2%) in subspecialty and primary care clinics, respectively. Motility disorders (NSEMD and achalasia) was diagnosed more often by gastroenterologists (40 of 120, 34%) than by internists (12 of 100, 12%) (p < 0.001). GERD was the predominant diagnosis made by internists (44 of 100, 44%) compared to gastroenterologists (22 of 120, 18%) (p < 0.001). Although the cost of diagnosing benign obstruction was less for BaS ($73 +/- 13) than EGD ($370 +/- 5, p < 0.001), subsequent therapy with dilation increased the cost for barium testing first (BaS $602 +/- 22 vs EGD $515 +/- 5, p < 0.02). Cost of diagnosis or treatment of esophageal dysmotility (achalasia/NSEMD) was significantly (p < 0.001) less using BaS as the initial test. CONCLUSIONS: 1) BaS is less costly than EGD for diagnoses and treatment involving abnormal motility. 2) Initial EGD with therapeutic intent is less costly for patients with history suggesting benign obstruction. 3) Primary care physicians identified GERD and benign obstructions as the cause of dysphagia more often in their patient group than the gastroenterologists, making EGD a reasonable initial test in this setting instead of currently practiced BaS.