Abstract 557A: The clinicopathoogical significance of FBXW7 expression in GIST

Objective: Gastrointestinal stromal tumor (GIST) is a rare mesenchymal tumor originated from the interstitial cells of Cajal in the gastrointestinal tract. A significant breakthrough was achieved with the identification of the expression of the c-kit (CD117) antigen in GISTs. However, alternate oncogenic pathways have not sufficiently been understood. FBXW7 is a ubiquitin ligase that mediates ubiquitylation of oncoproteins, which is known as tumor-suppressor gene in various malignancies. Previous reports showed that FBXW7 is associated with tumor progression by regulating some oncoprotein such as c-myc and c-jun. The aim of this study is to elucidate the clinicopathological significance of FBXW7 in GIST.

Methodology: (i) We examined the FBXW7 expression in GIST cells by immunostaining and correlation clinicopathological characteristics. (ii) We examined cell proliferation by Cytotoxicity assays in GIST-T1 cells suppressed by FBXW7-specific siRNA.

Results: (i) In 90 cases of GIST samples with surgical resection, high FBXW7 and observed are 47 cases and low expression are 43 cases. There are significantly more large size, located small intestine, high mitotic index in low FBXW7 cases (P=0.05, P=0.01, P=0.04). There are significantly more high risk cases in modified-Fletcher classification in low FBXW7 expression cases (P=0.0008). There are significantly higher value of SUV max in high risk cases of modified-Fletcher

classification and low FBXW7 expression cases (P=0.007, P=0.02). In GIST cases with distant metastasis, there are significantly more low FBXW7 expression cases than GIST cases without distant metastasis (P=0.009). FBXW7 expression is significantly inversely correlated with C-MYC expression (P=0.0004). (ii) The GIST cells suppressed FBXW7 expression by siRNA have higher proliferation rate compared to control GIST cells (P=0.02).

Conclusion: We demonstrated that FBXW7 expression is correlated with modified-Fletcher classification, SUV max value, c-myc expression and cell proliferation in GIST. These results are suggesting that FBXW7 may be associated with tumor progression. These findings suggest that it is possible that FBXW7 can be a promising biomarker for disease progression of GIST.

Citation Format: Yuki Koga, Masaaki Iwatsuki, Kouhei Yamashita, Yuki Kiyozumi, Hiroshi Sawayama, Yukiharu Hiyoshi, Yoshihfumi Baba, Yuji Miyamoto, Naoya Yoshida, Hideo Baba. The clinicopathoogical significance of FBXW7 expression in GIST [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 557A.

A Qualitative and Quantitative Correlation Study of Lumbar Intervertebral Disc Degeneration Using Glycosaminoglycan Chemical Exchange Saturation Transfer, Pfirrmann Grade, and T1-ρ

BACKGROUND AND PURPOSE

Glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging allows the direct measurement and mapping of glycosaminoglycans. In this study, we aimed to evaluate the usefulness of gagCEST imaging in the quantitative assessment of intervertebral disc degeneration in a comparison with Pfirrmann grade and T1-ρ measurements.

MATERIALS AND METHODS

Ninety-six lumbar intervertebral discs in 24 volunteers (36.0 ± 8.5 years of age, 21 men and 3 women) were examined with both gagCEST imaging and T1-ρ measurements. The gagCEST imaging was performed at 3T with a saturation pulse with 1.0-second duration and the B₁ amplitude of 0.8 μT followed by imaging by a 2D fast spin-echo sequence. The Z-spectra were obtained at 25 frequency offsets from -3 to +3 ppm (step, 0.25 ppm). A point-by-point B₀ correction was performed with a B₀ map. The gagCEST signal and T1-ρ values were measured in the nucleus pulposus in each intervertebral disc. The Pfirrmann grades were assessed on T2-weighted images.

RESULTS

The gagCEST signal at grade I (5.36% ± 2.79%) was significantly higher than those at Pfirrmann grade II (3.15% ± 1.40%, P = .0006), grade III (0.14% ± 1.03%, P < .0001), grade IV (-1.75% ± 2.82%, P < .0001), and grade V (-1.47% ± 0.36%, P < .0001). The gagCEST signal at grade II was significantly higher than those of grade III (P < .0001), grade IV (P < .0001), and grade V (P < .0001). The gagCEST signal was significantly correlated negatively with Pfirrmann grade (P < .0001) and positively correlated with T1-ρ (P < .0001).

CONCLUSIONS

GagCEST imaging could be a reliable and quantitative technique for assessing intervertebral disc degeneration.

Transcription factor EB influences invasion and migration in oral squamous cell carcinomas

OBJECTIVE

Transcription factor EB (TFEB) is a master regulator of lysosomal biogenesis and plays an important role in various cancers. However, the function of TFEB in oral squamous cell carcinomas has not been examined. The aim of this study was to elucidate the role of TFEB in oral squamous cell carcinomas.

MATERIALS AND METHODS

Expression levels of TFEB were examined in six different human oral squamous carcinoma cells: HSC2, HSC3, HSC4, SAS, OSC20, and SCC25. Knockdown of TFEB using small interfering RNA in HSC2 and HSC4 cells was performed. Cell morphology was observed by immunofluorescence microscopy. Cell proliferation, invasion, and adhesion were analyzed.

RESULTS

Expression levels of TFEB were high in HSC2, moderate in HSC4 and SCC25, and low in HSC3 and OSC20 cells. Knockdown of TFEB did not affect proliferation of HSC2 and HSC4 cells, but did induced enlargement of lysosomes and endosomes in HSC4 cells. TFEB silencing reduced invasion and migration of these HSC cell squamous carcinoma cells; however, increased cell adhesion was also observed.

CONCLUSION

TFEB knockdown reduces invasion and migration of cancer cells, likely through lysosomal regulation. Taken together, TFEB influences cell invasion and migration of oral squamous cell carcinomas.

Factors Influencing Arteriovenous Fistula Dysfunction in Japanese Patients on Chronic Hemodialysis

Arteriovenous fistula dysfunction is a constant problem in chronic hemodialysis patients. We investigated the factors influencing fistula dysfunction in 184 patients on chronic hemodialysis. Stepwise regression analysis and Cox proportional hazards model were used to assess the relationship between fistula dysfunction and age, sex, duration of hemodialysis, diabetes mellitus, hematocrit, serum creatinine, blood urea nitrogen, KW, prothrombin time, blood pressure, anticoagulant therapy, dose of erythropoietin, calcium channel blocker therapy, and angiotensin-converting enzyme inhibitor therapy. Fistula dysfunction showed a significant relationship with a low systolic blood pressure, a low hematocrit, the presence of diabetes mellitus, and angiotensin-converting enzyme inhibitor therapy. These results suggested that treatment with angiotensin-converting enzyme inhibitors may help to prevent fistula dysfunction.

A Case of Antiphospholipid Antibody Syndrome Diagnosed after Thrombosis of an Arteriovenous Shunt

A 32-year-old male dialysis patient with lupus nephritis was admitted because of shunt obstruction. The arteriovenous fistula was reconstructed, but obstruction recurred twice within several hours after surgery. A high blood level of anticardiolipin β2-glycoprotein I antibody suggested that shunt obstruction was caused by a thrombotic tendency related to the antiphospholipid antibody syndrome. Accordingly, for the third shunt procedure, antiplatelet therapy (which had been commenced for systemic lupus erythematosus) was combined with dalteparin sodium from before surgery and warfarin was added postoperatively. This regimen prevented shunt obstruction. In conclusion, hemodialysis patients who suffer repeated shunt obstruction should be examined for antiphospholipid antibody syndrome.

Monitoring sputum culture in resected esophageal cancer patients with preoperative treatment

Pneumonia is a major cause of postesophagectomy mortality and worsens the long-term survival in resected esophageal cancer patients. Moreover, preoperative treatments such as chemotherapy or chemoradiotherapy (which have recently been applied worldwide) might affect the bacterial flora of the sputum. To investigate the association among preoperative treatments, the bacterial flora of sputum, and the clinical and pathological features in resected esophageal cancer patients, this study newly investigates the effect of preoperative treatments on the bacterial flora of sputum. We investigated the association among preoperative treatments, the bacterial flora of sputum, and clinical and pathological features in 163 resected esophageal cancer patients within a single institution. Pathogenic bacteria such as Candida (14.1%), Staphylococcus aureus (6.7%), Enterobacter cloacae (6.1%), Haemophilus parainfluenzae (4.9%), Klebisiella pneumoniae (3.7%), Methicillin-resistant Staphylococcus aureus (MRSA) (3.7%), Pseudomonas aeruginosa (2.5%), Escherichia coli (1.8%), Streptococcus pneumoniae (1.8%), and Haemophilus influenzae (1.2%) were found in the sputum. The pathogen detection rate in the present study was 34.3% (56/163). In patients with preoperative chemotherapy and chemoradiotherapy, the indigenous Neisseria and Streptococcus species were significantly decreased (P= 0.04 and P= 0.04). However, the detection rates of pathogenic bacteria were not associated with preoperative treatments (all P> 0.07). There was not a significant difference of hospital stay between the sputum-monitored patients and unmonitored patients (35.5 vs. 49.9 days; P= 0.08). Patients undergoing preoperative treatments exhibited a significant decrease of indigenous bacteria, indicating that the treatment altered the bacterial flora of their sputum. This finding needs to be confirmed in large-scale independent studies or well-designed multicenter studies.

Occurrence and improvement of renal dysfunction and serum potassium abnormality during administration of liposomal amphotericin B in patients with hematological disorders: A retrospective analysis

Liposomal amphotericin B (L-AMB) has the potential to cause two major adverse events, renal dysfunction and serum potassium abnormality; however, appropriate clinical management of these events remains unclear. We retrospectively analyzed data regarding 128 hematology patients who received L-AMB in our institute and examined the association between clinical characteristics and renal dysfunction or serum potassium abnormality. We found that the median weight-normalized dose of L-AMB was 2.69mg/kg and the median administration period was 16days. The overall occurrence rates of renal dysfunction and hypokalemia were 55.7% and 76.6%, respectively. Multivariate analysis revealed that pre-existing renal dysfunction (P=0.017) and concomitant use of nephrotoxic (P<0.0001) or antifungal drugs (P=0.012) were independent risk factors for renal dysfunction. A higher infusion volume did not mitigate the risk of renal dysfunction. Hypokalemia occurred significantly less often in men (P=0.028) and in patients who concomitantly used nephrotoxic drugs (P=0.013). Approximately 40% of the adverse events were improved at 30days after L-AMB termination and there was no significant association between these adverse events improvement and L-AMB dosage or infusion volume. Of note, hyperkalemia was observed in more patients who received allogeneic hematopoietic stem cell transplantation (P=0.0303) and concomitant treatment with nephrotoxic drugs (P=0.0281). These results suggest that imprudent reduction of L-AMB dose or redundant intravenous infusion may have minimal benefit for critical patients with suspected invasive fungal infection.

Comparison of short-term outcomes between 2- and 3-field lymph node dissection for esophageal cancer

Although 3-field lymph node dissection (3-FLD) is often performed for thoracic esophageal squamous cell carcinoma (ESCC), the clinical effects of cervical lymph node dissection in addition to mediastinal and abdominal dissections on postoperative complications remain unclear. A total of 367 ESCC patients who underwent curative esophagectomy for thoracic esophageal cancer in our hospital from 2010 to 2015 were included in the study: 157 patients who underwent 2-field lymph node dissection (2-FLD) and 210 patients who underwent 3-FLD. Clinicopathological parameters and postoperative complications based on the Clavien-Dindo classification were compared between the two groups. We performed propensity score matching (PSM) analyses to compare the groups with well-balanced backgrounds. In terms of patient background, clinical T (p < 0.001), N (p < 0.001), and M (p = 0.002) stage of tumor was significantly more advanced; therefore, preoperative treatment was more frequently performed in the 3-FLD group than in the 2-FLD group (91.0% vs. 79.0%, P< 0.001). However, perioperative parameters including operation time, blood loss, and the number of dissected mediastinal and abdominal lymph nodes did not differ between the groups. In terms of postoperative complications, the occurrence rate of pneumonia increased significantly in patients with 3-FLD compared to 2-FLD (grade III or higher: 10.5% vs. 3.2%, P= 0.025). Although the duration of systemic inflammatory response syndrome (SIRS) was longer in the 3-FLD group than in the 2-FLD group (median 3 days vs. 2 days, P= 0.025), other postoperative parameters (including the highest level of postoperative serum C-reactive protein, intensive care unit stay, re-operation rate, and postoperative hospital stay) were similar between the groups. After PSM, the differences in the background between the groups disappeared. PSM analysis showed that there was no significant difference in each complication between the groups. The duration of SIRS tended to be longer in the 3-FLD group than in the 2-FLD group, but the difference was not significant. The field of lymphadenectomy negatively impacted the short-term outcome in ESCC patients in terms of pneumonia and inflammatory response. However, because the results of the PSM analyses indicate that the short-term outcome was similar between the two groups, 3-FLD could be as feasible as 2-FLD in ESCC patients.

Failure of neoadjuvant chemotherapy for resectable esophageal squamous cell carcinoma

Neoadjuvant treatment has become standard care for patients with resectable esophageal cancer. However, some patients cannot undergo surgery or curative resection because of disease progression during neoadjuvant treatment. The aim of this study is to identify the pretreatment characteristics of patients in whom neoadjuvant treatment failed. The study enrolled 231 patients who underwent chemotherapy with cisplatin and 5-fluorouracil (CF) as neoadjuvant therapy for T1N1-3 or T2-3 any-N esophageal squamous cell carcinoma (ESCC). Of these patients, 201 (87.0%) underwent curative resection (R0) and 30 (13.0%) could not undergo curative resection; 19 patients (8.2%) underwent incomplete resection (R1 or R2), and 11 patients (4.8%) could not undergo surgery because of disease progression. We compared clinical characteristics and survival between patients who underwent curative resection (curative group) and those who could not undergo curative resection (noncurative group) to determine the factors predicting noncurative treatment. The noncurative group had significantly worse disease-specific survival than the curative group (P < 0.001). All patients in the noncurative group had cT3 tumors. In 141 patients with cT3 tumors, those in the noncurative group were more likely to have higher serum SCC antigen concentration (P = 0.021), location of the main tumor in the upper to the middle third of the esophagus (P = 0.071), intramural metastases (P < 0.001), advanced N category (P = 0.016), and bulky lymph node metastases (P = 0.060). Multivariate logistic regression analysis identified location of the main tumor in the upper to the middle third of the esophagus (P = 0.047), intramural metastases (P = 0.002), and nodal metastases (N1, P = 0.014; N2, P = 0.015, respectively) as independent predictors of treatment failure in patients with cT3 tumors. Neoadjuvant CF therapy alone may not be effective for patients with cT3 tumors accompanied by these risk factors, and the efficacy of alternative strategies, such as triplet chemotherapy or chemoradiotherapy, should be evaluated.

Chronic Kidney Disease in Long-Term Survivors after Allogeneic Hematopoietic Stem Cell Transplantation: Retrospective Analysis at a Single Institute

The number of patients eligible for allogeneic stem cell transplantation (allo-HSCT) has increased because of improvements in transplantation procedures. Among long-term survivors of allo-HSCT, chronic kidney disease (CKD) is a major cause of morbidity. We retrospectively analyzed the clinical data of 106 consecutive patients with a median age of 43 years (range, 17 to 73) who had undergone allo-HSCT at our institution between January 2001 and September 2009. Patients who died within 5 years after transplantation or had CKD at the time of transplantation were excluded from study. CKD was defined as a persistent decrease in the estimated glomerular filtration rate to below 60 mL/min/1.73 m². CKD occurred in 32 patients (30.2%) at a median time of 55 months after transplantation. Three patients required maintenance hemodialysis. In multivariate analysis older age at the time of transplantation (hazard ratio [HR], 1.07/year; 95% confidence interval [CI], 1.02 to 1.13) and a history of acute kidney injury (AKI) within 100 days after transplantation (HR, 6.30; 95% CI, 2.21 to 17.9) were significant risk factors for CKD. Conditioning regimen, stem cell source, or the presence of acute/chronic GVHD was not significantly associated with CKD in this study. Patients with CKD had a lower overall survival rate (HR, 4.11; 95% CI, 1.3 to 13.0) than patients without CKD. Careful monitoring of renal function is required for long-term survivors after allo-HSCT, especially in patients who have experienced AKI and in older patients.

Predictive models for conversion of prediabetes to diabetes

AIM

To clarify the natural course of prediabetes and develop predictive models for conversion to diabetes.

METHODS

A retrospective longitudinal study of 2105 adults with prediabetes was carried out with a mean observation period of 4.7years. Models were developed using multivariate logistic regression analysis and verified by 10-fold cross-validation. The relationship between [final BMI minus baseline BMI] (δBMI) and incident diabetes was analyzed post hoc by comparing the diabetes conversion rate for low (< -0.31kg/m²) and high δBMI (≥ -0.31kg/m²) subjects after matching the two groups for the covariates.

RESULTS

Diabetes developed in 252 (2.5%/year), and positive family history, male sex, higher systolic blood pressure, plasma glucose (fasting and 1h- and 2h-values during 75g OGTT), hemoglobin A1c (HbA1c) and alanine aminotransferase were significant, independent predictors for the conversion. By using a risk score (RS) that took account of all these variables, incident diabetes was predicted with an area under the ROC curve (95% CI) of 0.80 (0.70-0.87) and a specificity of prediction of 61.8% at 80% sensitivity. On division of the participants into high- (n=248), intermediate- (n=336) and low-risk (n=1521) populations, the conversion rates were 40.1%, 18.5% and 5.9%, respectively. The conversion rate was lower in subjects with low than high δBMI (9.2% vs 14.4%, p=0.003).

CONCLUSIONS

Prediabetes conversion to diabetes could be predicted with accuracy, and weight reduction during the observation was associated with lowered conversion rate.