Clinicopathological features and prognosis of primary small bowel adenocarcinoma: a large multicenter analysis of the JSCCR database in Japan.

BACKGROUND: The clinicopathological features and prognosis of primary small bowel adenocarcinoma (PSBA), excluding duodenal cancer, remain undetermined due to its rarity in Japan. METHODS: We analyzed 354 patients with 358 PSBAs, between January 2008 and December 2017, at 44 institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum. RESULTS: The median age was 67 years (218 males, 61.6%). The average tumor size was 49.9 (7-100) mm. PSBA sites consisted of jejunum (66.2%) and ileum (30.4%). A total of 219 patients (61.9%) underwent diagnostic small bowel endoscopy, including single-balloon endoscopy, double-balloon endoscopy, and capsule endoscopy before treatment. Nineteen patients (5.4%) had Lynch syndrome, and 272 patients (76.8%) had symptoms at the initial diagnosis. The rates for stages 0, I, II, III, and IV were 5.4%, 2.5%, 27.1%, 26.0%, and 35.6%, respectively. The 5-year overall survival rates at each stage were 92.3%, 60.0%, 75.9%, 61.4%, and 25.5%, respectively, and the 5-year disease-specific survival (DSS) rates were 100%, 75.0%, 84.1%, 59.3%, and 25.6%, respectively. Patients with the PSBA located in the jejunum, with symptoms at the initial diagnosis or advanced clinical stage had a worse prognosis. However, multivariate analysis using Cox-hazard model revealed that clinical stage was the only significant predictor of DSS for patients with PSBA. CONCLUSIONS: Of the patients with PSBA, 76.8% had symptoms at the initial diagnosis, which were often detected at an advanced stage. Detection during the early stages of PSBA is important to ensure a good prognosis.

Outcomes of Metastatic and Unresectable Small Bowel Adenocarcinoma in Japan According to the Treatment Strategy: A Nationwide Observational Study.

PURPOSE: Limited information is available regarding the characteristics and outcomes of stage IV small bowel adenocarcinoma (SBA) in Japan. This study examined the clinical and pathological characteristics and outcomes according to the treatment strategies in patients with stage IV SBA. METHODS: This retrospective observational study used the data of patients with jejunal or ileal adenocarcinoma collected by the Small Bowel Malignant Tumor Project of the Japanese Society for Cancer of the Colon and Rectum. Descriptive statistics were expressed as the mean (standard deviation) or median (range). Survival analysis was performed using Kaplan-Meier curves and pairwise log-rank tests. RESULTS: Data from 128 patients were analyzed. The treatment strategies were chemotherapy alone (26 of 128, 20.3%), surgery alone (including palliative surgery; 21 of 128, 16.4%), surgery + chemotherapy (74 of 128, 57.8%), and best supportive care (7 of 128, 5.5%). The median (range) overall survival was 16 (0-125) months overall, and 11 (1-38) months, 8 (0-80) months, 18 (0-125) months, and 0 (0-1) months for the chemotherapy, surgery, surgery + chemotherapy, and best supportive care groups, respectively. Three main categories of chemotherapeutic regimen were used: a combination of fluoropyrimidine and oxaliplatin (F + Ox), fluoropyrimidine and irinotecan (F + Iri), and single-agent fluoropyrimidine. Among patients treated with chemotherapy, the median (range) OS was 16 (1-106) months overall, and 17 (1-87) months, 29 (7-39) months, and 16 (1-106) months in patients treated with fluoropyrimidine, F + Iri, and F + Ox, respectively. CONCLUSION: Patients treated with surgery, chemotherapy, or both had a better prognosis than those who received best supportive care. Among patients who received chemotherapy, survival did not differ according to the chemotherapeutic regimen.

Relationship Between Immunophenotypes, Genetic Profiles, and Clinicopathologic Characteristics in Small Bowel Adenocarcinoma.

Small bowel adenocarcinoma (SBA) is rare, and scant data exist regarding its molecular and clinicopathologic characteristics. This study aimed to clarify the correlation between immunophenotypes, DNA mismatch repair status, genomic profiling, and clinicopathologic characteristics in patients with SBA. We examined 68 surgical resections from patients with primary SBA for immunohistochemical analyses of CK7, CK20, CD10, CDX2, MUC1, MUC2, MUC4, MUC5AC, and MUC6 expression as well as mismatch repair status. Genomic profiling was performed on 30 cases using targeted next-generation sequencing. Tumor mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null based on MUC2, MUC5AC, MUC6, and CD10 immunostaining. The expression of these proteins was categorized into 3 classifications according to their relationship to: (1) tumor location: CK7/CK20, MUC4, and MUC6; (2) histologic type: mucinous adenocarcinoma was positive for MUC2 and negative for MUC6; and (3) TNM stage: CD10 was downregulated, whereas MUC1 was upregulated in advanced TNM stages. CDX2 was a specific marker for SBA generally expressed in the small intestine. MUC1 and MUC4 expression was significantly associated with worse prognosis. MUC2 expression correlated with better prognosis, except for mucinous adenocarcinoma. Although the difference was not statistically significant, gastric-type tumors were more frequently located in the duodenum and were absent in the ileum. APC and CTNNB1 mutations were not found in the gastric-type tumors. The SBA immunophenotype correlated with tumor location, biological behavior, and genomic alterations. Our results suggest that the molecular pathway involved in carcinogenesis of gastric-type SBA differs from that of intestinal-type SBA.

Guidelines for endoscopic balloon dilation in treating Crohn's disease-associated small intestinal strictures (supplement to the Clinical Practice Guidelines for Enteroscopy).

Balloon-assisted enteroscopy allows endoscopic treatments in the deeper segments of the small bowel. Endoscopic balloon dilation has become a popular minimally invasive alternative for the treatment of Crohn's disease-associated small intestinal strictures. As a supplement to the Clinical Practice Guidelines for Enteroscopy, the Japan Gastroenterological Endoscopy Society's Working Committee has developed the present "Guidelines for endoscopic balloon dilation in treating Crohn's disease-associated small intestinal strictures," based on new scientific techniques and evidence. The guidelines cover standard procedures for the insertion route of the balloon endoscope, bowel preparation, indications, procedure-related complications, efficacy, target diameter and duration, management of multiple strictures, and the current state of combined and alternative treatments. Unresolved future research questions are also listed in this guideline.

Novel ultrathin double-balloon endoscopy for the diagnosis of small-bowel diseases: a multicenter nonrandomized study.

BACKGROUND: This study aimed to compare the markers of potential pancreatic injury during antegrade double-balloon endoscopy (DBE) using the newly developed ultrathin EN-580XP system and the conventional EN-580T system. METHODS: Patients who were scheduled for antegrade DBE during daily clinical practice were enrolled. Clinical background, adverse events, and laboratory data of patients were compared between those who underwent endoscopy using the EN-580XP system and those in whom the EN-580T system was used. The primary end points were pancreatic hyperamylasemia and hyperlipasemia after DBE. RESULTS: A total of 295 cases were registered. Pancreatic hyperamylasemia occurred in 2 of 92 patients (2.2 %) in the EN-580XP group and in 28 of 147 patients (19.1 %) in the EN-580 T diagnosis group (P < 0.001). Hyperlipasemia was significantly different between the two groups (1.1 % [EN-580XP] vs. 13.6 % [EN-580 T diagnosis]; P < 0.001). Acute pancreatitis occurred in four patients (7.1 %) in the EN-580 T therapy group. Multiple logistic regression analyses revealed that the endoscope type EN-580 T was significantly associated with pancreatic hyperamylasemia (adjusted odds ratio [OR] 8.63, 95 % confidence interval [CI] 1.97 - 37.70; P < 0.01) and hyperlipasemia (adjusted OR 13.10, 95 %CI 1.70 - 100.70; P = 0.01). CONCLUSIONS: The EN-580XP system seemed less harmful to the pancreas during antegrade DBE.

Characterization of a GH Family 20 Exo-ß-N-acetylhexosaminidase with Antifungal Activity from Streptomyces avermitilis.

We characterized SaHEX, which is a glycoside hydrolase (GH) family 20 exo-ß-N-acetylhexosaminidase found in Streptomyces avermitilis. SaHEX exolytically hydrolyzed chitin oligosaccharides from their non-reducing ends, and yielded N-acetylglucosamine (GlcNAc) as the end product. According to the initial rate of substrate hydrolysis, the rates of (GlcNAc)3 and (GlcNAc)5 hydrolysis were greater than the rates for the other oligosaccharides. The enzyme exhibited antifungal activity against Aspergillus niger, which was probably due to hydrolytic activity with regard to chitin in the hyphal tips. Therefore, SaHEX has potential for use in GlcNAc production and food preservation.

Pilot Study Indicates Helicobacter pylori Infection May Induce Small Intestinal Mucosal Injury.

BACKGROUND AND AIM: Helicobacter pylori infection is a primary cause of gastroduodenal ulcers. To investigate whether there is an association between H. pylori infection and small intestinal mucosal injury. METHODS: Patients were selected from a general pool of subjects who underwent capsule endoscopy for current or past obscure gastrointestinal bleeding. Characteristics including age, gender, history, treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) and/or acid suppressant, diagnosis, and H. pylori infection were investigated. Patients infected with H. pylori had positive test result, ranging 30 days before to 30 days after capsule endoscopy. Patients diagnosed with inflammatory diseases, malignant tumors, etc. were excluded. All video images were re-evaluated to count small intestinal mucosal breaks. Eligible patient variables were compared. RESULTS: A total of 92 patients (30 infected with H. pylori/62 uninfected) were eligible. By univariate analysis of the number of mucosal breaks, patients treated with NSAIDs were found to have more mucosal breaks than patients untreated (38%: 8/21 vs. 18%: 13/71; p = 0.004), and the possible association was detected between patients infected with H. pylori and those who were not (67%: 14/21 vs. 37%: 26/71; p = 0.081). When comparing the H. pylori infected and uninfected patients, the rate of patients with mucosal breaks was greater in infected patients (47%: 14/30 vs. 11%: 7/62; p = 0.001). After excluding patients treated with NSAIDs, the number of mucosal breaks was also greater in patients infected with H. pylori (1.2 ± 1.5 vs. 0.38 ± 0.62; p = 0.001). CONCLUSION: There is a possibility that H. pylori infection induces small intestinal mucosal injury.

Retrieval of Retained Capsule Endoscopy at Small Bowel Stricture by Double-Balloon Endoscopy Significantly Decreases Surgical Treatment.

GOALS: The aim is to elucidate the efficacy and safety of double-balloon endoscopy (DBE) for small bowel capsule endoscopy (SBCE) retrieval from small bowel stricture and to follow the outcome of the stricture where the SBCE was entrapped. BACKGROUND: The retention of SBCE is a serious adverse event and most retained capsules are retrieved by surgery. There is still no report analyzing the follow-up of patients with stricture after retrieval of entrapped SBCEs by DBE. METHODS: This study was designed a retrospective cohort study. Subjects were 12 consecutive patients with small bowel stricture where retrieval of entrapped SBCE was attempted using DBE. Success rate of the SBCE retrieval by DBE, surgical rate of the small bowel stricture, adverse events of DBE, and outcomes in the follow-up period were evaluated. RESULTS: Diagnoses were Crohn's disease, nonsteroidal anti-inflammatory drugs-induced enteropathy, ischemic enteritis, and carcinoma in 8, 2, 1, and 1 patients, respectively. SBCE was successfully retrieved in 11 of the 12 patients (92%). No adverse events were encountered in all endoscopic procedures such as retrieval of SBCEs and dilation of the strictures. Nine of the 12 patients (75%) did not undergo surgical treatment for the stricture where SBCE was entrapped through the follow-up period (mean, 1675±847 d). CONCLUSIONS: Retrieval of SBCEs using DBE was safe, had a high success rate, and was useful to evaluate the need for surgery. Seventy-five percent of patients with small bowel stricture where the SBCE was entrapped did not require surgery through approximately 5 years.

Localization of phosphorylated ErbB1-4 and heregulin in colorectal cancer.

BACKGROUND: The ErbB family consists of four proteins including (EGFR)/ErbB1, ErbB2, ErbB3, and ErbB4, and plays a crucial role in the promotion of multiple tumorigenic processes. In addition to the traditional pathways of EGFR signaling, EGFR translocates to the nucleus and acts as a transcription factor in the proliferation of cancer cells. Heregulin is known as both an ErbB3 and an ErbB4 ligand. This study aimed to investigate the expression of heregulin and its relevant EGFR family members as well as their phosphorylated forms in human colorectal cancer (CRC) tissues and to determine the relationship between their expression and clinicopathological factors including patient prognosis. METHODS: We analyzed the effects of exogenous heregulin on ErbB2, ErbB3 and ErbB4 phosphorylation in Caco-2, DLD-1, and HCT 116 colon cancer cell lines by western blot analysis. We examined 155 surgical resections from colorectomy patients. Cellular localization of ErbB1-4, their phosphorylated forms and heregulin protein was analyzed in CRC surgical resections by immunohistochemical analysis. Immunohistochemical results were compared with clinicopathological factors and patient prognosis. RESULTS: Phosphorylated ErbB2 (pErbB2) and phosphorylated ErbB3 (pErbB3) were detected in both nuclear and cytosolic fractions of Caco-2 and DLD-1 cells stimulated by exogenous heregulin. Whereas, phosphorylated ErbB4 (pErbB4) was detected only in cytosolic fractions of HCT 116 cells stimulated by exogenous heregulin. Phosphorylated EGFR (pEGFR) immunoreactivity was observed in the cytoplasm and nuclei of cancer cells, whereas the pattern of EGFR staining was membranous and cytoplasmic. Subcellular localization of pErbB2, cytoplasmic, membranous, or nuclear, varied among cases. pErbB3 immunoreactivity was exclusively observed in the nuclei of cancer cells. pErbB4 immunoreactivity was observed in the cell membrane of cancer cells. Statistically, heregulin immunoreactivity correlated with pErbB2 and pErbB4 expression. In multivariate analysis for disease free survival, lymph node status, pErbB3 and pErbB4 expression retained independent prognostic significance. In multivariate analysis for overall survival, lymph node status, pEGFR and pErbB4 retained independent prognostic significance. CONCLUSIONS: ErbB2 and ErbB3 phosphorylated by heregulin localized in the nucleus of CRC cells. Phosphorylated ErbB1-4 and heregulin contribute to poorer patient prognosis in CRC. This heregulin-ErbB family member autocrine loop may be a candidate for targeted treatment of CRC.

[A case of multiple primary small intestinal adenocarcinomas].

A 62-year-old woman, with a past history of long-term non-steroidal anti-inflammatory drug use and gastric ulcer, was hospitalized for intestinal obstruction in April 2012. Two stenoses were identified in the ileum in association with small intestinal ulcers, and she underwent partial resection of the small intestine. Histologically, the two lesions were poorly differentiated adenocarcinomas; metastatic small intestinal cancer was suspected, but whole body examination revealed no other lesions. The final diagnosis was multiple primary small intestinal malignancies, necessitating additional resection of the small intestine in July. We report this case to raise awareness among physicians of the possibility of primary small intestinal cancer in patients with multiple small intestinal stenoses.

Rebamipide has the potential to reduce the intensity of NSAID-induced small intestinal injury: a double-blind, randomized, controlled trial evaluated by capsule endoscopy.

BACKGROUND: A study reported that rebamipide was effective at reducing short-term nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy. The purpose of this study was to re-evaluate the effect of the co-administration of rebamipide on small intestinal injuries induced by short-term NSAID treatment. METHODS: Eighty healthy male volunteers were randomly assigned to two study groups: a control group (N = 40), which received NSAID (diclofenac sodium, 75 mg/day) and omeprazole (20 mg/day) treatment along with a placebo; and a rebamipide group, which received NSAID, omeprazole and rebamipide (300 mg/day). Small intestinal injuries (mucosal breaks plus denuded areas) were evaluated by capsule endoscopy before and after 14 days of treatment. RESULTS: A total of 38 control subjects and 34 rebamipide subjects completed the treatment and were evaluated by capsule endoscopy. NSAID therapy increased the mean number of mucosal injuries per subject from a basal level of 0.1 ± 0.3 to 16 ± 71 and 4.2 ± 7.8 in the control and rebamipide groups, respectively, but the difference was not significant. The difference in the percentage of subjects with at least one mucosal injury post-treatment was also not significant (control 63%; rebamipide 47%). Limiting our analysis to subjects with mucosal injuries, rebamipide co-treatment had the tendency to reduce the mean number of mucosal injuries per subject from 25 in the control group to 8.9 in the rebamipide group (multiple comparisons test; p = 0.088, Mann-Whitney U test; p = 0.038). CONCLUSIONS: Rebamipide co-therapy had the potential to reduce the intensity of small intestinal injury induced by 2-week administration of diclofenac.

[Carcinoma of the small intestine diagnosed by double balloon endoscopy].

There are no specific symptoms of patients with carcinoma of the small intestine. Therefore, it is difficult to diagnose in the early stage by imaging modalities such as radiological enteroclysis, computed tomography, and classical endoscopy. However, double balloon endoscopy makes it possible to diagnose the carcinoma of the entire small bowel by taking tissue samples for pathological assessment. The characteristic of endoscopic findings is irregular ulcerated tumor with malignant stricture. It is still difficult to find carcinoma of small intestine in patients without symptoms and most cases are advanced when diagnosis is achieved. We should try to diagnose in early stage by combining images modalities, capsule endoscopy and double balloon endoscopy safely and efficiently, resulting in improving the patients' prognosis.

Prevention of traditional NSAID-induced small intestinal injury: recent preliminary studies using capsule endoscopy.

Capsule endoscopy and balloon endoscopy, advanced modalities that now allow for full investigation of the entire small intestine, have revealed that non-steroidal anti-inflammatory drugs (NSAIDs) can cause a variety of abnormalities in the small intestine. Traditional NSAIDs can induce small intestinal injuries in over 50% of patients. Several studies have shown that the preventive effect of proton pump inhibitors does not extend to the small intestine, suggesting that concomitant therapy may be required to prevent small intestinal side effects associated with traditional NSAIDs use. Recently, several randomized controlled trials used capsule endoscopy to evaluate the preventive effect of certain drugs on NSAID-induced small intestinal injuries. These studies show that misoprostol and rebamipide have a preventive effect for NSAID-induced small intestinal mucosal injuries. However, these studies included only a small series of healthy volunteers and tested short-term NSAID treatment. Therefore, further extensive studies are clearly required to ascertain the beneficial effect of these drugs.

Distribution of small intestinal mucosal injuries as a result of NSAID administration.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) induce small intestinal mucosal injuries. The concentrations of NSAIDs, bile acids and intestinal flora may differ in the proximal and distal parts of the small intestine. This study aimed to analyse types and distributions of NSAID-induced small intestinal injuries. SUBJECTS AND METHODS: In total 55 healthy male volunteers were examined using baseline capsule endoscopy (CE). Subjects then undertook a 14-day regimen of NSAID medication (diclofenac sodium, 75 mg day(-1)) with proton-pump inhibitors (omeprazole 20 mg day(-1)) as gastroprotection. After 14 days, subjects underwent post-treatment CE and were assessed for three types of small intestinal injuries: denuded areas, erosions and ulcers. The proximal and distal parts of the small intestine were arbitrarily classified according to CE transit time from the duodenal bulb. RESULTS: Baseline CE revealed six mucosal lesions in 6 of 55 subjects (11%), consisting of three denuded areas and three erosions. Post-treatment CE identified 636 lesions in 32 of 53 subjects (60%); including 115 denuded areas in 16 subjects, 498 erosions in 22 subjects and 23 ulcers in 8 subjects. The distribution of small intestinal injuries differed according to type; denuded areas (90%: 103/115) were predominantly located in the proximal part, erosions throughout the small intestine and all ulcers in the distal part. The location of ulcers and denuded areas differed statistically (P < 0.0001). CONCLUSIONS: The impact of short-term NSAID medication on the small intestine differed according to intestinal site, with most denuded areas identified in the proximal part and all ulcers in the distal part.

Rare cause of obscure gastrointestinal bleeding due to pyogenic granuloma in the ileum detected by capsule endoscopy and treated with double balloon endoscopy.

Pyogenic granuloma is a lobular capillary hemangioma that occurs mostly on the skin, and occasionally on the mucosal surface of the oral cavity, but very rarely in the gastrointestinal tract. We report the case of a 63-year-old woman who suffered from palpitations, and iron deficiency anemia for 5 years. Esophagogastroduodenoscopy and colonoscopy could not reveal significant bleeding focus. She had not received medical treatment except for oral iron. Capsule endoscopy revealed a bleeding focus in the small intestine. Afterwards, we carried out double balloon endoscopy to treat the lesion. We found a subpedunculated polyp in the small intestine at 100 cm away from ileocecal valve by double balloon endoscopy and resected it endoscopically. The histological features of the polyp were consistent with pyogenic granuloma. Anemia had improved gradually without giving oral iron after polypectomy.

Heregulin-induced VEGF expression via the ErbB3 signaling pathway in colon cancer.

BACKGROUND/AIMS: Heregulin (HRG/NRG) ligation to erbB3/4 promotes their respective heterodimerization with erbB2, and consequent erbB2 tyrosine phosphorylation. Although HRG has been shown to be expressed in a variety of cancer tissues, its expression and role in colon cancer have yet to be clarified. We therefore examined the link between the expression of these erbB receptors, and the relationship between HRG and vascular endothelial growth factor (VEGF) expression in colon cancer. METHODS: We analyzed the effects of HRG on VEGF secretion in 6 colorectal cancer cell lines by enzyme-linked immunosorbent assay, and HRG-induced p85 subunit of phosphatidylinositol 3-kinase (p85 PI-3K), Akt, extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 mitogen-activated protein kinase (p38 MAPK) activation in Caco-2 colon cancer cell lines by Western blot. We also examined HRG and VEGF mRNA expression in 16 colon cancer biopsy samples by real-time PCR. The localization of HRG and VEGF protein expression in colon cancer tissue was detected by immunohistochemistry. RESULTS: Exogenous HRG stimulated VEGF secretion in all cell lines examined, and VEGF mRNA expression in Caco-2 cells. HRG also activated p85 PI-3K, Akt, ERK1/2, and p38 MAPK. VEGF secretion was inhibited by both specific p38 MAPK inhibitor and proteasome inhibitor that inhibit nuclear factor kappa B (NF-kappaB) activation. In colon cancer biopsy samples, HRG mRNA expression correlated with VEGF mRNA expression. HRG immunoreactivity was observed both in cancer cells and in mesenchymal cells in colon cancer tissues. CONCLUSION: These data suggest that HRG might affect colon cancer growth by regulating VEGF secretion via the erbB3 signaling pathway through autocrine and paracrine mechanisms.

Role of double-balloon endoscopy in the diagnosis of small-bowel tumors: the first Japanese multicenter study.

BACKGROUND: The early diagnosis of small-bowel tumors (SBT) was a difficult task until the advent of capsule endoscopy (CE) and double-balloon endoscopy (DBE) allowed access to the disease site. However, although CE and DBE have greatly simplified the task, DBE studies have yet to provide sufficient data on the diagnosis and outcome of patients with SBTs. OBJECTIVE: To determine the efficacy of DBE examination in the detection and diagnosis of SBT. DESIGN: A retrospective analysis of cross-sectional case series. SETTING: Seven major medical centers in Japan. PATIENTS: The first 1035 consecutive DBE cases at these major Japanese centers since the introduction of DBE. MAIN OUTCOME MEASUREMENTS: The percentage of subjects with SBT and a diagnosis of SBT, their indications for DBE, and diagnostic and therapeutic DBE procedures carried out for SBT. RESULTS: SBTs were identified in 144 of 1035 subjects (13.9%) who underwent DBE between September 2000 and December 2005. For subjects with SBT, the most common indication for DBE was the suspected presence of a SBT (61/144 [42.4%]). For subjects without SBT, the most common indication was obscure GI bleeding (OGIB) (419/891 [47.0%]). Malignant lymphoma and GI stromal tumor (GIST) were the most frequent (31/144 [21.5%]) and the second-most frequent SBTs (27/144 [18.8%]), respectively, in this database. We also performed 85 biopsies and 45 therapeutic procedures for the evaluation and treatment of SBTs in 144 patients. Although complications were encountered in 5.3% of cases (14/266 sessions), none of these were life threatening in the present study. CONCLUSION: DBE proved a valuable tool for the detection and diagnosis of SBTs, especially when tumors were suspected. Biopsies and therapeutic procedures were also possible in most of these patients, which directed our management of the disease.