Variable 18F-fluorodeoxyglucose uptake in gastric cancer is associated with different levels of GLUT-1 expression

Diagnostic performance of F-18 FDG PET or PET/CT for detection of recurrent gastric cancer: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis investigated the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or PET/computed tomography (PET/CT) for the detection of disease recurrence after curative resection of gastric cancer.

METHODS

The PubMed and Embase databases, from the earliest available date of indexing through November 30, 2019, were searched for studies evaluating the diagnostic performance of F-18 FDG PET or PET/CT to detect recurrent disease after gastric cancer surgery.

RESULTS

Across 17 studies (1,732 patients), the pooled sensitivity for F-18 FDG PET or PET/CT was 0.82 (95% confidence interval [CI], 0.74-0.88) with heterogeneity of I2=76.5 (p<0.001), and the specificity was 0.86 (95% CI, 0.78-0.91) with heterogeneity of I2=94.2 (p<0.001). Likelihood ratio (LR) tests gave an overall positive LR of 6.0 (95% CI, 3.6-9.7) and negative LR of 0.2 (95% CI, 0.14-0.31). The pooled diagnostic odds ratio was 29 (95% CI, 13-63). The summary receiver operating characteristic curve indicates that the area under the curve was 0.91 (95% CI, 0.88-0.93).

CONCLUSION

The current meta-analysis showed good sensitivity and specificity of F-18 FDG PET or PET/CT for detecting recurrent disease after curative resection of gastric cancer despite heterogeneity in ethnicity, recurrence rate, histology, and interpretation method.

A novel association between Bmi-1 protein expression and the SUVmax obtained by 18F-FDG PET/CT in patients with gastric adenocarcinoma

This study aimed to examine B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) in gastric adenocarcinoma (GAC) and its association with the maximal standard uptake value (SUVmax) of preoperative fluorine-18-fludeoosyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT). Clinicopathological data were retrospectively collected from 60 primary GAC patients. The Bmi-1 protein expression in GAC and adjacent noncancerous tissues was examined by immunohistochemistry and western blot analysis. Pearson's correlation analysis was conducted to assess the correlation between Bmi-1 expression and the SUVmax. The Bmi-1 protein levels were significantly greater in GAC versus noncancerous tissues, and higher Bmi-1 was significantly correlated with a lower degree of tumor differentiation, higher tumor stages, more lymph node metastasis, and depth of invasion. The SUVmax value was significantly correlated with the T stage, N stage, and clinical stage, but not with age, gender, tumor size, histological differentiation degree, or Lauren classification. Moreover, a significant positive correlation between Bmi-1 and SUVmax was observed in GAC tissues. In conclusion, our findings demonstrate a novel correlation between Bmi-1 and preoperative SUVmax in GAC patients who did not receive radiotherapy, chemotherapy, or targeted treatment before surgery, and both are positively correlated with unfavorable prognostic factors and a higher grade of malignancy.

Natural compounds targeting glycolysis as promising therapeutics for gastric cancer: A review

Gastric cancer, a common malignant disease, seriously endangers human health and life. The high mortality rate due to gastric cancer can be attributed to a lack of effective therapeutic drugs. Cancer cells utilize the glycolytic pathway to produce energy even under aerobic conditions, commonly referred to as the Warburg effect, which is a characteristic of gastric cancer. The identification of new targets based on the glycolytic pathway for the treatment of gastric cancer is a viable option, and accumulating evidence has shown that phytochemicals have extensive anti-glycolytic properties. We reviewed the effects and mechanisms of action of phytochemicals on aerobic glycolysis in gastric cancer cells. Phytochemicals can effectively inhibit aerobic glycolysis in gastric cancer cells, suppress cell proliferation and migration, and promote apoptosis, via the PI3K/Akt, c-Myc, p53, and other signaling pathways. These pathways affect the expressions of HIF-1α, HK2, LDH, and other glycolysis-related proteins. This review further assesses the potential of using plant-derived compounds for the treatment of gastric cancer and sheds insight into the development of new drugs.

PET/CT for Predicting Occult Lymph Node Metastasis in Gastric Cancer

A portion of gastric cancer patients with negative lymph node metastasis at an early stage eventually die from tumor recurrence or advanced metastasis. Occult lymph node metastasis (OLNM] is a potential risk factor for the recurrence and metastasis in these patients, and it is highly important for clinical prognosis. Positron emission tomography (PET)/computed tomography (CT) is used to assess lymph node metastasis in gastric cancer due to its advantages in anatomical and functional imaging and non-invasive nature. Among the major metabolic parameters of PET, the maximum standardized uptake value (SUVmax) is commonly used for examining lymph node status. However, SUVmax is susceptible to interference by a variety of factors. In recent years, the exploration of new PET metabolic parameters, new PET imaging agents and radiomics, has become an active research topic. This paper aims to explore the feasibility and predict the effectiveness of using PET/CT to detect OLNM. The current landscape and future trends of primary metabolic parameters and new imaging agents of PET are reviewed. For gastric cancer patients, the possibility to detect OLNM non-invasively will help guide surgeons to choose the appropriate lymph node dissection area, thereby reducing unnecessary dissections and providing more reasonable, personalized and comprehensive treatments.

Evaluation of the 18F-FDG-PET/CT uptake association with pathological and immunohistochemistry features in esophagogastric adenocarcinoma

BACKGROUND

The present study aimed to analyze the association between 18F-fluorodeoxyglucose (FDG) uptake and histologic panel in esophagogastric adenocarcinoma.

METHODS

We retrospectively enrolled 26 patients with histologically confirmed esophageal, gastroesophageal junction and gastric adenocarcinoma that have been submitted to pretreatment FDG-PET/CT. We collected the cancer tissue sample of each patient and performed immunohistochemical analyses of the glucose transport protein 1 (GLUT-1), Ki-67, cysteine aspartate-specific proteinases (Caspase)-3 and hexokinase-1, and evaluated the association of these parameters with FDG uptake. The FDG uptake was measured by tumor standardized uptake value (SUV), metabolic tumor volume (MTV), and Total Lesion Glycolysis (TLG). Besides, we analyzed the association of FDG uptake and tumor location, Lauren's histologic subtype, grade of cellular differentiation and intratumoral inflammatory infiltrate.

RESULTS

We found a positive association between GLUT-1 with SUV and TLG, Caspase-3 and SUV and inflammation grade with SUV.

CONCLUSION

Tumor inflammation infiltrate, GLUT-1 and Caspase-3 correlated with 18F-FDG uptake in PET/CT in esophagogastric adenocarcinoma. These findings may help understand the pathologic PET/CT significance in cancer. Understanding the meaning of the 18F-FDG uptake in the field of tumor histologic and immunohistochemistry features is essential to allow the evolution of PET/CT application in esophageal and gastric carcinomas.

Gallium-68-labeled fibroblast activation protein inhibitor PET in gastrointestinal cancer: insights into diagnosis and management

PURPOSE

Gallium-68-labeled fibroblast activation protein inhibitor (⁶⁸Ga-FAPI) is an emerging promising tumor tracer. This study aims to evaluate the diagnostic efficiency of ⁶⁸Ga-FAPI PET in gastrointestinal cancer, and to determine its potential impact on clinical management.

METHODS

Patients with malignancies were prospectively enrolled in a clinical trial to evaluate the diagnostic value of ⁶⁸Ga-FAPI PET. One hundred twenty patients with gastrointestinal malignancies (121 ⁶⁸Ga-FAPI PET scans) between June 2020 and May 2021 were retrospectively analyzed. Initial staging of untreated patients and restaging of treated patients were evaluated. The treatment scheme promoted by imaging was determined according to NCCN guidelines. Final diagnosis and treatment reference standards were determined by a dedicated multidisciplinary team. The diagnostic performance and treatment guidance of ⁶⁸Ga-FAPI PET were compared with those of conventional imaging (CI) and ¹⁸F-FDG PET.

RESULTS

The diagnostic accuracy of ⁶⁸Ga-FAPI PET was much higher than that of CI and ¹⁸F-FDG PET (95.0% vs. 65.1% and 69.0%, respectively, both p < 0.001). ⁶⁸Ga-FAPI PET revised diagnosis in 30.3% and 26.2% of patients compared with CI and ¹⁸F-FDG PET. The accordance rate of ⁶⁸Ga-FAPI PET-guided treatment in comparison with the reference standard was significantly higher than that of CI and ¹⁸F-FDG PET (96.7% vs. 75.2% and 76.2%, respectively, both p < 0.001). ⁶⁸Ga-FAPI PET changed treatment in 22.9% and 23.8% of patients compared with CI and ¹⁸F-FDG PET.

CONCLUSIONS

⁶⁸Ga-FAPI PET showed remarkable diagnostic performance in gastrointestinal cancer, resulting in more accurate staging and guidance for timely treatment revision, thereby having a critical impact on clinical management.

TRIAL REGISTRATION

NCT04554719. Registered September 8, 2020-retrospectively registered, http://clinicaltrails.gov/show/NCT04554719.

Bmi-1 directly upregulates glucose transporter 1 in human gastric adenocarcinoma

This study aimed to investigate whether and how Moloney murine leukemia virus integration site 1 (Bmi-1) plays a role in the regulation of glucose transporter 1 (GLUT1) in gastric adenocarcinoma (GAC). GAC and matched noncancerous tissues were obtained from GAC patients who underwent surgical treatment at the China-Japan Union Hospital, Jilin University (Changchun, Jilin, China). The human GAC cell line AGS and the gastric epithelial cell line GES-1 were used for in vitro studies. BALB/c nude mice were used for in vivo studies. The Bmi-1 and GLUT1 protein levels were significantly greater in human tissues from GAC patients and AGS cells in comparison with controls. Silencing of Bmi-1 resulted in significant decrease in glucose uptake, lactate levels, and GLUT1 expression. In vivo¹⁸F-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) imaging studies indicated that the nude mice bearing xenografts of AGS cells treated with Bmi-1-specific small interfering RNA (siRNA) had a significantly lower maximum standardized uptake value (SUV_max) in comparison with the control mice. Thus, Bmi-1 directly upregulates GLUT1 gene expression, through which it is involved in enhancing glucose uptake in GAC. The results also provide scientific evidence for ¹⁸F-FDG PET/CT imaging to evaluate Bmi-1 and glucose uptake in GAC.

SIGNALING PATHWAYS THAT DRIVE 18F-FDG ACCUMULATION IN CANCER

2-¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) measures glucose consumption and is an integral part of cancer management. Most cancer types upregulate their glucose consumption, yielding elevated ¹⁸F-FDG PET accumulation in those cancer cells. The biochemical pathway through which ¹⁸F-FDG accumulates in cancer cells is well-established. However, beyond well-known regulators such as c-Myc, PI3K/Akt, and HIF1α, the proteins and signaling pathways that cancer cells modulate to activate the facilitated glucose transporters (GLUTs) and hexokinase enzymes that drive elevated ¹⁸F-FDG accumulation are less well-understood. Understanding these signaling pathways could yield additional biological insights from ¹⁸F-FDG PET scans and could suggest new uses of ¹⁸F-FDG PET in the management of cancer. Work over the past five years, building on studies from years prior, has identified new proteins and signaling pathways that drive glucose consumption in cancer. Here we review these recent studies and discuss current limitations to our understanding of glucose consumption in cancer.

Relationship between total lesion glycolysis of primary lesions based on 18F-FDG PET/CT and lymph node metastasis in gastric adenocarcinoma: a cross-sectional preliminary study

OBJECTIVES

We explored the relationship between lymph node metastasis (LNM) and total lesion glycolysis (TLG) of primary lesions determined by 18fluoro-2-deoxyglucose PET/computed tomography (18F-FDG PET/CT) in patients with gastric adenocarcinoma, and evaluated the independent effect of this association.

METHODS

This retrospective study included 106 gastric adenocarcinoma patients who were examined by preoperative 18F-FDG PET/CT imaging between April 2016 and April 2020. We measured TLG of primary gastric lesions and evaluated its association with LNM. Multivariate logistic regression and a two-piece-wise linear regression were performed to evaluate the relationship between TLG of primary lesions and LNM.

RESULTS

Of the 106 patients, 75 cases (71%) had LNM and 31 cases (29%) did not have LNM. Univariate analyses revealed that a per-SD increase in TLG was independently associated with LNM [odds ratio (OR) = 2.37; 95% confidence interval (CI), 1.42-3.98; P = 0.0010]. After full adjustment of confounding factors, multivariate analyses exhibited that TLG of primary lesions was still significantly associated with LNM (OR per-SD: 2.20; 95% CI, 1.16-4.19; P = 0.0164). Generalized additive model indicated a nonlinear relationship and saturation effect between TLG of primary lesions and LNM. When TLG of primary lesions was <23.2, TLG was significantly correlated with LNM (OR = 1.26; 95% CI, 1.07-1.48; P = 0.0053), whereas when TLG of primary lesions was ≥ 23.2, the probability of LNM was greater than 60%, gradually reached saturation effect, as high as 80% or more.

CONCLUSIONS

In this preliminary study, there were saturation and segmentation effects between TLG of primary lesions determined by preoperative 18F-FDG PET/CT and LNM. When TLG of primary lesions was ≥ 23.2, the probability of LNM was greater than 60%, gradually reached saturation effect, as high as 80% or more. TLG of primary lesions is helpful in the preoperative diagnosis of LNM in patients with gastric adenocarcinoma.

18F-FDG PET and PET/CT for the evaluation of gastric signet ring cell carcinoma: a systematic review

BACKGROUND

In the last years, 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) has demonstrated its utility for the evaluation of gastric cancer; however, considering some histotypes such as gastric signet ring cell carcinoma (GSRCC) the results are limited. The aim of this review is to analyze the diagnostic performance of 18F-FDG PET and PET/CT for the assessment of GSRCC.

METHODS

A wide literature search of the PubMed/MEDLINE, Scopus, Embase and Cochrane library databases was made to find relevant published articles about the diagnostic performance of 18F-FDG PET or PET/CT for the evaluation of GSRCC.

RESULTS

The comprehensive computer literature search revealed 179 articles. On reviewing the titles and abstracts, 162 articles were excluded because the reported data were not within the field of interest. Nine studies were included in the review and references were also screened for additional articles. Finally, 26 articles were selected and retrieved in full-text version.

CONCLUSION

Despite some limitations affect our review, GSRCC seems to have low 18F-FDG uptake, and therefore 18F-FDG PET or PET/CT reveals impaired sensitivity for its evaluation. However, a correlation between 18F-FDG uptake and some clinico-pathologic features (such as stage, depth of invasion, size and presence of nodal metastasis) has been demonstrated. Besides, a possible prognostic role of PET/CT features is starting to emerge.

18F-fluorodeoxyglucose uptake in advanced gastric cancer correlates with histopathological subtypes and volume of tumor stroma

PURPOSE

The aim of this study was to investigate the correlation between preoperative ¹⁸F-fluorodeoxyglucose (FDG) uptake and histological subtypes, amount of tumor stroma in advanced gastric cancer (GC), and clinical outcomes.

METHODS

We evaluated 56 patients (male/female, 42:14; mean age, 69 years) with advanced GC who underwent surgical resection at our institution and positron emission tomography-computed tomography with 18F-FDG prior to surgery. We used the maximum standardized uptake value (SUVmax) of the tumor and the tumor-to-liver ratio (TLR) of the SUVmax for the analysis. The SUVmax and TLR correlated with histological subtypes, immunohistochemistry (IHC) for CD34, and recurrence-free survival (RFS). Tumor stroma in GC was evaluated by CD34 expression. GCs were classified according to the Lauren and World Health Organization (WHO) classifications.

RESULTS

The average FDG uptakes (SUVmax) were 4.17% and 14.04% in diffuse and intestinal type GCs, respectively, according to the Lauren classification, and 4.17%, 13.87%, 7.70%, 9.71%, and 19.45% in the poorly cohesive, tubular, mucinous, and papillary adenocarcinomas, respectively, according to the WHO classification. The FDG uptake in diffuse type was significantly lower than that in the intestinal type (p = 0.000). The SUVmax and TLR of the CD34(+) group (mean SUVmax, 5.50; TLR, 1.56) were significantly lower than those of the CD34(-) group (mean SUVmax, 14.09; TLR, 4.09). RFS was not associated with TLR or CD34 expression.

CONCLUSION

GC, which has abundant tumor stroma characterized by high CD34 expression on IHC, shows low FDG uptake.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers

BACKGROUND

F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis.

OBJECTIVE

This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC.

METHODS

We measured the preoperative maximum standardized uptake value (SUV_max) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUV_max cut-off values of ≥ 2.8.

RESULTS

Regarding the prognosis of patients with resectable BTC, a LN SUV_max ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUV_max < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group.

CONCLUSION

High LN SUV_max was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

Positron Emission Tomographic Imaging of Tumor Cell Death Using Zirconium-89-Labeled APOMAB® Following Cisplatin Chemotherapy in Lung and Ovarian Cancer Xenograft Models

PURPOSE

Early detection of tumor treatment responses represents an unmet clinical need with no approved noninvasive methods. DAB4, or its chimeric derivative, chDAB4 (APOMAB®) is an antibody that targets the Lupus associated antigen (La/SSB). La/SSB is over-expressed in malignancy and selectively targeted by chDAB4 in cancer cells dying from DNA-damaging treatment. Therefore, chDAB4 is a unique diagnostic tool that detects dead cancer cells and thus could distinguish between treatment responsive and nonresponsive patients.

PROCEDURES

In clinically relevant tumor models, mice bearing subcutaneous xenografts of human ovarian or lung cancer cell lines or intraperitoneal ovarian cancer xenografts were untreated or given chemotherapy followed 24h later by chDAB4 radiolabeled with [⁸⁹Zr]Zr^IV. Tumor responses were monitored using bioluminescence imaging and caliper measurements. [⁸⁹Zr]Zr-chDAB4 uptake in tumor and normal tissues was measured using an Albira SI Positron-Emission Tomography (PET) imager and its biodistribution was measured using a Hidex gamma-counter.

RESULTS

Tumor uptake of [⁸⁹Zr]Zr-chDAB4 was detected in untreated mice, and uptake significantly increased in both human lung and ovarian tumors after chemotherapy, but not in normal tissues.

CONCLUSION

Given that tumors, rather than normal tissues, were targeted after chemotherapy, these results support the clinical development of chDAB4 as a radiodiagnostic imaging agent and as a potential predictive marker of treatment response.

Obesity and Energy Substrate Transporters in Ovarian Cancer-Review

Ovarian cancer is the seventh most common cancer in women. It is characterized by a high mortality rate because of its aggressiveness and advanced stage at the time of diagnosis. It is a nonhomogenous group of neoplasms and, of which the molecular basics are still being investigated. Nowadays, the golden standard in the treatment is debulking cytoreductive surgery combined with platinum-based chemotherapy. We have presented the interactions and the resulting perspectives between fatty acid transporters, glucose transporters and ovarian cancer cells. Studies have shown the association between a lipid-rich environment and cancer progression, which suggests the use of correspondent transporter inhibitors as promising chemotherapeutic agents. This review summarizes preclinical and clinical studies highlighting the role of fatty acid transport proteins and glucose transporters in development, growth, metastasizing and its potential use in targeted therapies of ovarian cancer.

Potential Role of Glucose Transporter-1 Expression in Gastric Cancer: A Meta-Analysis and Systematic Review

Background:

Glucose transporter-1 (GLUT-1) has been differentially expressed in various malignancies including gastric cancer (GC). Several previous meta-analyses of GLUT-1 have some significant limitations, such as researching the association between GLUT-1 and various cancer types with no specificity, not studying clinicopathological parameters with GLUT-1, existing conspicuous heterogeneity and so forth. Therefore, we performed a meta-analysis to evaluate the association between GLUT-1 expression and survival of gastric cancer patients, as well as clinicopathological characteristics.

Methods:

We systematically searched PubMed, Embase, Web of Science and China National Knowledge Infrastructure for relevant studies in accordance with the applicable criteria up to Aug 2017. Hazard ratios (HRs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were used as the effective measures.

Results:

A total of 13 studies involving 1972 patients were included in this meta-analysis. The results demonstrated that there was a significant association between GLUT-1 expression and overall survival (OS) (HR=1.45, 95% CI=1.13–1.87) or disease-free survival (DFS) (HR=2.18, 95% CI=1.46–3.25). Moreover, GLUT-1 expression was significantly correlated with worse tumor nodes metastases (TNM) stage (OR=0.34, 95% CI=0.28–0.43), presence of lymph node metastasis (OR=2.88, 95% CI=1.34–6.19), intestinal type of Lauren classification (OR=3.84, 95% CI=2.57–5.74) and invasion of serosa (OR=0.25, 95% CI=0.18–0.35).

Conclusion:

Our meta-analysis showed that GLUT-1 was significantly correlated with poor OS and DFS in gastric cancer. Additionally, GLUT-1 was also a potential prognostic indicator of aggressive clinicopathological parameters in gastric cancer.

Total Lesion Glycolysis Assessment Identifies a Patient Fraction With a High Cure Rate Among Esophageal Adenocarcinoma Patients Treated With Definitive Chemoradiation

OBJECTIVE

We aimed to determine whether tumor metabolism could be prognostic of cure in L-EAC patients who receive definitive chemoradiation.

SUMMARY BACKGROUND DATA

Patients with inoperable localized esophageal adenocarcinoma (L-EAC) often receive definitive chemoradiation; however, biomarkers and/or imaging variables to prognosticate cure are missing.

METHODS

Two hundred sixty-six patients with L-EAC who had chemoradiation but not surgery were analyzed from the prospectively maintained EAC databases in the Department of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center (Texas, USA) between March 2002 and April 2015. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) from the positron emission tomography data were evaluated.

RESULTS

Of 266 patients, 253 (95%) were men; the median age was 67 years (range 20-91 yrs) and 153 had poorly differentiated L-EAC. The median SUVmax was 10.3 (range 0-87) and the median TLG was 85.7 (range 0-3227). Both SUVmax and TLG were higher among those with: tumors >5 cm in length, high clinical stage, and high tumor and node categories by TNM staging (all P < 0.0001). Of 234 patients evaluable for cure, 60 (25.6%) achieved cure. In the multivariable logistic regression model, low TLG (but not low SUVmax) was associated with cure (continuous TLG value: odds ratio 0.70, 95% confidence interval (CI) 0.54-0.92). TLG was quantified into 4 quartile categorical variables; first quartile (Q1; <32), second quartile (Q2; 32.0-85.6), third quartile (Q3; 85.6-228.4), and fourth quartile (Q4; >228.4); the cure rate was only 10.3% in Q4 and 5.1% in Q3 but increased to 28.8% in Q2, and 58.6% in Q1. The cross-validation resulted in an average accuracy of prediction score of 0.81 (95% CI, 0.75-0.86).

CONCLUSIONS

In this cross-validated model, 59% of patients in the 1st quartile were cured following definitive chemoradiation. Baseline TLG could be pursued as one of the tools for esophageal preservation.

Low metabolic activity in primary gastric adenocarcinoma is associated with resistance to chemoradiation and the presence of signet ring cells

PURPOSES

Preoperative chemoradiation is a potential treatment option for localized gastric adenocarcinoma (GAC). Currently, the response to chemoradiation cannot be predicted. We analyzed the pretreatment maximum standardized uptake value (SUV_max) and total lesion glycolysis (TLG) on positron emission tomography/computed tomography as potential predictors of the response to chemoradiation.

METHODS

We analyzed the SUV_max and TLG data from 59 GAC patients who received preoperative chemoradiation. We used logistic regression models to predict a pathologic complete response (pCR) and Kaplan-Meier curves to determine overall survival among patients with high and low SUV_max or TLG.

RESULTS

Twenty-nine patients (49%) had Siewert type III adenocarcinoma and 30 (51%) had tumors located in the lower stomach. Forty-one patients had poorly differentiated GAC, and 26 had signet ring cells. The median SUV_max was 7.3 (0-28.2) and the median TLG was 56.6 (0-1881.5). Patients with signet ring cells had a low pCR rate, as well as a low SUV_max and TLG. In the multivariable logistic regression model, high SUV_max was a predictor of pCR (odds ratio = 11.1, 95% confidence interval = 2.12-50.0, p = 0.004). Overall survival was not associated with the SUV_max (log-rank p = 0.69) or TLG (log-rank p = 0.85) CONCLUSION: A high SUV_max was associated with sensitivity to chemoradiation and pCR in GAC, and signet ring cells seemed to confer resistance.

Glucose Transporter-1 (GLUT-1) Expression is Associated with Tumor Size and Poor Prognosis in Locally Advanced Gastric Cancer

Background

The clinicopathological parameters associated with glucose transporter-1 (GLUT-1) expression in advanced gastric cancer are still controversial. This study aimed to determine the clinicopathological parameters and prognosis associated with GLUT-1 expression in advanced gastric cancer.

Material/Methods

The GLUT-1 expression level of 234 consecutive gastric cancer samples was detected by immunohistochemical staining and evaluated by semiquantitative analysis. The clinicopathological data and expression level of GLUT-1 of enrolled patients were retrospectively analyzed with univariate and multivariate analyses.

Results

Tumor size, depth of invasion, and Lauren classification were independent factors related to GLUT-1 expression (P<0.05). Within advanced gastric cancer, tumor size and Lauren type were independent factors associated with GLUT-1 (P=0.011, P<0.001, respectively). The mean survival time of GLUT-1-positive patients with stage M0 advanced gastric cancer who had undergone radical gastrectomy was shorter than that of GLUT-1-negative patients (61.26±6.12 versus 80.88±7.38, P=0.044). GLUT-1 was an independent prognosis factor in locally advanced gastric cancer patients who had undergone radical gastrectomy (hazard ratio [HR] 1.769, P=0.046). The mean survival time of adjuvant chemotherapy was significantly better than no adjuvant chemotherapy in the GLUT-1-positive group (71.10±6.88 versus 24.65±8.69, P<0.001) and in the GLUT-1 negative group (87.48±7.99 versus 49.39±11.71, P<0.001).

Conclusions

Tumor size and Lauren type independently affected GLUT-1 expression in advanced gastric cancer. GLUT-1 was not only related to poor prognosis but also predicted to be a metabolic biomarker for intestinal type in locally advanced gastric cancer. The relationship among GLUT-1, hepatic metastasis and chemotherapy regimens, and mechanism of chemotherapy responses related to GLUT-1 should be further investigated.

Small early gastric cancer with synchronous bone metastasis: A case report

Bone metastasis during the early stages of gastric cancer is rare, and synchronous bone metastasis is even less common. The present report outlines a case of a small early gastric cancer, which was detected due to bone metastasis. A 63-year-old man was referred to Fukuyama Medical Center with back pain and anorexia of 2 weeks' evolution. MRI revealed multiple metastatic lesions in the thoracic and spinal bone. Fluorodeoxyglucose positron emission tomography revealed focal uptake in the lesser curvature of the stomach and in the spinal bone, pelvic and thigh bone, but uptake was not detected in the stomach. Esophagogastroduodenoscopy revealed a 10 mm slightly elevated lesion with a central depression in the middle-third of the stomach. Endoscopic ultrasonography confirmed that the tumor was confined to the mucosa. A biopsy specimen acquired from the gastric lesion indicated signet-ring cell carcinoma, and the specimen acquired from the lumbar spine revealed cell aggregation such as that found in signet-ring cell carcinoma. The patient received first-line chemotherapy with S-1 and cisplatin, and second-line chemotherapy with nab-paclitaxel. However, the patient died 120 days after consultation at Fukuyama Medical Center.

Establishment of a [18F]-FDG-PET/MRI Imaging Protocol for Gastric Cancer PDX as a Preclinical Research Tool

Purpose

The utility of 18-fluordesoxyglucose positron emission tomography ([¹⁸F]-FDG-PET) combined with computer tomography or magnetic resonance imaging (MRI) in gastric cancer remains controversial and a rationale for patient selection is desired. This study aims to establish a preclinical patient-derived xenograft (PDX) based [¹⁸F]-FDG-PET/MRI protocol for gastric cancer and compare different PDX models regarding tumor growth and FDG uptake.

Materials and Methods

Female BALB/c nu/nu mice were implanted orthotopically and subcutaneously with gastric cancer PDX. [¹⁸F]-FDG-PET/MRI scanning protocol evaluation included different tumor sizes, FDG doses, scanning intervals, and organ-specific uptake. FDG avidity of similar PDX cases were compared between ortho- and heterotopic tumor implantation methods. Microscopic and immunohistochemical investigations were performed to confirm tumor growth and correlate the glycolysis markers glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) with FDG uptake.

Results

Organ-specific uptake analysis showed specific FDG avidity of the tumor tissue. Standard scanning protocol was determined to include 150 μCi FDG injection dose and scanning after one hour. Comparison of heterotopic and orthotopic implanted mice revealed a long growth interval for orthotopic models with a high uptake in similar PDX tissues. The H-score of GLUT1 and HK2 expression in tumor cells correlated with the measured maximal standardized uptake value values (GLUT1: Pearson r=0.743, P=0.009; HK2: Pearson r=0.605, P=0.049).

Conclusions

This preclinical gastric cancer PDX based [¹⁸F]-FDG-PET/MRI protocol reveals tumor specific FDG uptake and shows correlation to glucose metabolic proteins. Our findings provide a PET/MRI PDX model that can be applicable for translational gastric cancer research.

Pattern of use of positron emission tomography/computed tomography (PET/CT) scan in non-colorectal gastrointestinal cancers at KFSHRC, Riyadh, Saudi Arabia

Background

Positron emission tomography/computed tomography (PET/CT) scan is useful if clinically indicated. It is not for conventional routine use due to its high cost. Moreover, it can be confusing if ordered in non-indicated conditions. We evaluate if the pattern of PET/CT ordered in gastrointestinal cancers (non-colorectal origin) has followed evidence-based guidelines and whether it helped in the improvement of patient’s outcome. This study included non-colorectal gastrointestinal cancer patients from 2007 to 2008 who had one or more PET/CT scans done during their management. In each case, data collected revealed whether PET/CT affected the management or the stage or not. Patients were identified through the hospital tumor registry software CNExT (C/NET Solutions, Berkeley, CA). Tabulation and statistical data analysis were done using JMP-SAS statistical software application (version 9.4: SAS Institute, Cary, NC, USA). The scan report quality and use indications were outlined.

Results

Seventy-seven patients were identified, with 107 PET/CT scans done. Their median age is 59 (21–86) years. Males were 45 (58.5%). Tumor origin was 46.8% esophageal and gastroesophageal junction cancer, 15.6% gastric cancer, 11.7% pancreatic cancer, 11.7% hepatobiliary tumors, 10.4% neuroendocrine tumors, 2.6 % gastrointestinal stromal tumors, and 1.3% small bowel cancer. Indications of the PET/CT were as follows: staging in 59.8%, follow-up after finishing treatment in 14.9%, restaging at relapse in 8.4%, assessing response after/during treatment in 3.7%, follow-up of previous PET/CT in 12.1%, and others in 0.9%. PET/CT changed the stage in 19.6% and affected the management plan in 11.2% only. Fifty-two scans needed pathological pursuit as decided by investigators; of them, PET/CT for the lesions that could have changed the stage reported indeterminate/equivocal results in 32 (29.9%) of all scans. The pathological pursuit for the equivocal lesions on PET/CT scans was done in only 12 of 52 (23.1%) scans.

Conclusions

Local guidelines for ordering PET/CT scan are suggested because overuse was documented, and an evidence-based approach should be respected before its use.

Prognostic Value of Metabolic Information in Advanced Gastric Cancer Using Preoperative 18F-FDG PET/CT

Purpose

This study evaluated the usefulness of semiquantitative and volumetric PET parameters for predicting prognosis in patients with advanced gastric cancer (AGC).

Methods

We enrolled 213 patients who underwent ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) prior to curative surgery for AGC. Maximum standardized uptake value (SUVmax) and tumor-to-liver uptake ratio (TLR) were measured in all patients. Metabolic tumor volume (MTV) and total lesion glycolysis were measured in volume-measurable patients. For further quantification of FDG uptake, we developed PET prognostic scores by combining SUVmax and MTV (1: low SUVmax/low MTV; 2: high SUVmax/low MTV; 3: high SUVmax/high MTV). Comparison of PET parameters between recurrence and non-recurrence groups was performed. Univariate and multivariate analyses for recurrence-free survival (RFS) and overall survival (OS) were subsequently performed.

Results

The recurrence rate was 32.4% (69/213 patients). Mean SUVmax and mean MTV of the recurrence group were significantly higher than those of the non-recurrence group (p = 0.026 and p = 0.025). TLR showed marginal significance (p = 0.051). In multivariate analysis for RFS including all patients, SUVmax (p = 0.022), TLR (p = 0.010), and PET score (p = 0.003) were independent prognostic factors. In post hoc analysis of PET score, significant differences in RFS were observed between PET scores 2 and 3 as well as scores 1 and 3. No significant difference in RFS was observed between scores 1 and 2. Only PET score was statistically significant for OS in univariate analysis. None of the PET parameters were statistically significant for OS in multivariate analysis.

Conclusion

High SUVmax and high MTV of the primary tumor suggest a high risk of recurrence for AGC patients. Even if SUVmax is similar, the prognosis may vary depending on MTV. Combining PET parameters results in a better prediction for prognosis.

Clinicopathologic parameters associated with the FDG-avidity in staging of early gastric cancer using 18F-FDG PET

This study investigated the clinicopathologic factors associated with 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) uptake of early gastric cancer (EGC) and used them to design a clinical scoring method to predict FDG-avidity of EGC.Two hundred twenty-nine retrospectively enrolled patients underwent preoperative F-FDG positron emission tomography/computed tomography (PET/CT). Histologic information was obtained by gastrectomy (n = 195) or endoscopic mucosal dissection (n = 34). The association between clinicopathologic factors and F-FDG uptake by the primary tumor was determined. The results were used to develop a clinical scoring method.F-FDG uptake was detected in 49 (17.5%) patients. According to univariate analysis, location, gross type, World Health Organization classification, Lauren classification, size, depth of invasion, and lymphatic invasion were significant variables affecting F-FDG uptake (all P < .05). According to multivariate analysis, location (lower 3rd, P = .035), gross type (0-I, 0-IIa, P < .001), size (≥2.5 cm, P = .026), and depth of invasion (submucosa, P = .007) were significantly associated with FDG-avidity. A clinical scoring system, ranged from 0 to 4, was developed by giving one score to 4 independent variables. A cut-off value of 2.5 showed good prediction of FDG-avidity in EGCs, with a sensitivity and specificity of 65.0% and 85.2%, respectively.F-FDG uptake by EGC depends on location, gross type, size, and depth of invasion of the primary tumor. A clinical scoring system based on clinicopathologic variables can predict the FDG-avidity of primary tumors in patients with EGC.

Roles of GLUT-1 and HK-II expression in the biological behavior of head and neck cancer

The Warburg effect plays an important role in the proliferation and invasion of malignant tumors. Glucose transporter 1 and hexokinase II are two key energy transporters involved in mediating the Warburg effect. This review will analyze the mechanisms of these two markers in their effects on the biological behavior of head and neck cancer.

Long non-coding RNA-NEF targets glucose transportation to inhibit the proliferation of non-small-cell lung cancer cells

Long non-coding RNA (lncRNA)-NEF is a newly discovered lncRNA, which exhibits an inhibitory function on the metastasis of hepatocellular carcinoma, while its involvement in other types of malignancy are unknown. In the present study, tumor and adjacent healthy tissues were obtained from patients with non-small-cell lung cancer (NSCLC), and blood was obtained from patients with NSCLC and healthy individuals. Expression levels of lncRNA-NEF in tumor tissue samples, healthy tissue samples and serum were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic curve analysis and survival curve analysis were performed to evaluate the diagnostic and prognostic value of serum lncRNA-NEF for NSCLC. The effects of lncRNA-NEF overexpression in NSCLC cell lines on tumor cell proliferation, glucose uptake, glucose transporter 1 (GLUT1) protein expression and mRNA expression were investigated by Cell Counting kit-8 assay, glucose uptake assay, western blot analysis and RT-qPCR, respectively. It was identified that lncRNA-NEF was downregulated in NSCLC tissues, compared with healthy controls, and the serum level of lncRNA-NEF was negatively associated with primary tumor stage. Therefore, serum lncRNA-NEF may be a sensitive diagnostic and prognostic marker for NSCLC. Overexpression of lncRNA-NEF inhibited NSCLC cell proliferation and glucose uptake, and downregulated GLUT1 expression. Therefore, it can be concluded that lncRNA-NEF can target glucose transportation to inhibit the proliferation of NSCLC cells.

The clinical implications of FDG-PET/CT differ according to histology in advanced gastric cancer

BACKGROUND

The prognostic impact of preoperative 18F-FDG PET/CT in advanced gastric cancer (AGC) remains a matter of debate. This study aims to evaluate the prognostic impact of SUVmax in preoperative 18F-FDG PET/CT of AGC according to histologic subtype, with a focus on the differences between tubular adenocarcinoma and signet ring cell (SRC) carcinoma.

METHODS

As a discovery set, a total of 727 AGC patients from prospective database were analyzed according to histologic subtype with Cox proportional hazard model and p-spline curves. In addition, another 173 patients from an independent institution was assessed as an external validation set.

RESULTS

In multivariate analysis, high SUVmax in preoperative 18F-FDG PET/CT of AGC was negatively correlated with disease-free survival (DFS) and overall survival (OS) in patients with diffuse type (DFS: HR 2.17, P < 0.001; OS: HR 2.47, P < 0.001) or SRC histology (DFS: HR 2.26, P = 0.005; OS: HR 2.61, P = 0.003). This negative prognostic impact was not observed in patients with intestinal type or well or moderately differentiated histology. These findings have been consistently confirmed in a validation set. The p-spline curves also showed a gradual increase in log HR as SUVmax rises only for SRC histology and for diffuse-type AGC. Finally, a novel predictive model for recurrence of AGC with diffuse type or SRC histology was generated and validated based on the preoperative SUVmax.

CONCLUSIONS

Preoperative high SUVmax of AGC is a poor prognostic factor in those with diffuse type or SRC histology. This study is the first to demonstrate the differential prognostic impact of preoperative PET/CT SUVmax in AGC according to histologic subtype and provide a clue to explain previous discrepancies in the prognostic impact of preoperative PET/CT in AGC. Prospective studies are required to validate the role of preoperative SUVmax in AGC.

Cancer of the gastroesophageal junction: a diagnosis, classification, and management review

Management of gastroesophageal junction (GEJ) adenocarcinoma is a controversial topic. The rising incidence of this cancer requires a clear consensus to ensure proper management. Application of oncological principles for tumors of the esophagus or stomach is not possible because of comparative differences in the biology of GEJ adenocarcinoma, leading to different therapeutic options. Staging work-up with endoscopy, endosonography, and PET is essential to inform the choice of neoadjuvant treatment and surgical approach to GEJ adenocarcinoma. Surgery remains the only curative treatment and should be undertaken in specialized centers.

Prognostic value of metabolic parameters on preoperative 18F-fluorodeoxyglucose positron emission tomography/ computed tomography in patients with stage III gastric cancer

This study investigated the prognostic value of metabolic parameters determined by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with stage III gastric cancer. Patients with pre-operative PET/CT and confirmed stage III after curative surgical resection were retrospectively enrolled. Parameters evaluated from pre-operative PET/CTwere maximum standardized uptake value (SUV_max) and peak SUV (SUV_peak) of primary tumor, SUV_max or SUV_peak of tumor to liver ratio (TLR_max and TLR_peak). Volumetric parameters, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were also evaluated. These PET/CT parameters were compared with the overall survival (OS) and recurrence-free survival (RFS). From total of 133 consecutive patients, tumor recurrence was found in 54 patients (40.6%) and 53 died during the follow-up period (median, 43 mo; range 5-62). In univariate analysis, SUV_max, SUV_peak, TLR_max and TLR_peak were significantly associated with the OS and RFS. In multivariate analysis, high TLR_max and TLR_peak were significantly unfavorable prognostic factors for RFS (both P<0.05) even after adjusting for age, depth of tumor invasion, lymph node metastasis, and chemotherapy. MTV and TLG showed no statistically significant correlation with outcome. In conclusion, glucose metabolism of primary tumor measured by pre-operative PET/CT provides prognostic information, especially for recurrence, in stage III gastric cancer.

The prognostic value of volume-based parameters using 18F-FDG PET/CT in gastric cancer according to HER2 status

BACKGROUND

We aimed to find the clinical value of metastatic tumor burden evaluated with F18-FDG PET/CT in gastric cancer patients, considering the human epidermal growth factor receptor 2 (HER2) status.

METHODS

We retrospectively reviewed 124 patients with locally advanced or metastatic gastric cancer at Yonsei Cancer Center between January 2006 and December 2014 who had undergone baseline FDG PET/CT before first-line chemotherapy. We measured the maximum standardized uptake value from the primary tumor (SUV_max) and whole-body (WB) PET/CT parameters, including WB SUV_max, WB SUV_mean, WB metabolic tumor volume (WB MTV), and WB total lesion glycolysis (WB TLG), in all metabolically active metastatic lesions (SUV threshold ≥2.5 or 40% isocontour for ≤2.5), and we determined their association with patient survival outcomes.

RESULTS

SUV_max was higher in HER2-positive gastric cancers (median 12.1, range 3.4-34.6) compared to HER-2 negative (7.4, 1.6-39.1, P < 0.001). Among all patients, WB TLG > 600, which is indicative of a high metastatic tumor burden, showed worse progression-free survival (PFS) [hazard ratio (HR), 2.003; 95% CI, 1.300-3.086; P = 0.002] and overall survival (OS) (HR, 3.001; 95% CI, 1.950-4.618; P < 0.001) than did WB TLG ≤ 600. Among HER2-positive gastric cancer patients treated with trastuzumab, higher metabolic tumor burden predicted worse OS, but not PFS.

CONCLUSIONS

HER2-positive gastric cancers had higher SUV_max compared to HER2-negative gastric cancers. In both HER2-negative patients and -positive patients receiving trastuzumab, FDG PET/CT volume-based parameters may have a role in further stratifying the prognosis of stage IV gastric cancer.

Predictive value of glucose transporter-1 and glucose transporter-3 for survival of cancer patients: A meta-analysis

Background and Objective

The role of glucose transporters in cancers remains contradictory. We conducted a systematic review and meta-analysis to assess the association between overall survival and glucose transporter s (GLUTs) 1 and 3 to find an accurate prognostic biomarker.

Methods

We systematically searched the PubMed, EMbase and Medline databases for relevant published studies that were consistent with the eligible criteria up to January 2016, and calculated pooled estimated hazard ratios of GLUT-1 and -3′s expressions in different cancer types and ethnic populations. Random-effects models were used to assess estimates from studies with significant heterogeneities.

Results

Overall, 12 studies concerning GLUT 1 and 2 studies concerning GLUT 3, which involved 2008 participants when combined, were included in this analysis. We found that overexpression of GLUTs were significantly correlated to poorer survival rates (HR=1.63, 95%CI=1.09-2.44 and HR=1.89, 95%CI=1.28-2.81). In the subgroup analysis, the GLUT 1 up-regulation was correlated with negative overall survival in pancreatic cancer and gastric cancer and with better overall survival in colorectal cancer. In addition, overexpression of GLUT 1 was associated with a poorer prognosis in the Asian population, while no significance was found in the non-Asian subgroup. However, limitations do exist, which could be handled better.

Conclusions

A combination of GLUTs 1 and 3 might help predict malignancy of cancers and direct effective cancer therapy.

PFKFB3 was overexpressed in gastric cancer patients and promoted the proliferation and migration of gastric cancer cells

OBJECTIVE

Gastric cancer is one of the most common cancers worldwide, and the prognosis is still very poor due to the lack of specific and sensitive biomarkers. Aerobic glycolysis is one of the critical hallmarks of gastric cancer cells, and several glycolytic enzymes are highly expressed in gastric cancer patients. However, the expression and clinical significances of phosphofructokinase-2/fructose-2,6-bisphosphatase3 (PFKFB3, one of the glycolytic enzymes) in a large sample of gastric cancer patients remain unclear.

METHODS

The expression of PFKFB3 was detected in 134 gastric cancer patients by qRT-PCR, immunohistochemistry, and western blot analyses. The correlation between PFKFB3 expression and clinicopathological factors was analyzed by χ 2 test. In addition, we also analyzed whether the knockdown of PFKFB3 by siRNAs could inhibit the ability of gastric cancer cells (MGC-803 and AGS) to proliferate and migrate by MTT analysis and transwell analyses.

RESULTS

PFKFB3 was highly expressed in 81.3% (109/134) of gastric cancer patients. The overexpression of PFKFB3 was associated with lymph node metastasis (P = 0.045) and TNM stage (P = 0.033). Knockdown of PFKFB3 by siRNAs significantly inhibited the proliferation and migration abilities of gastric cancer cells.

CONCLUSION

Our data suggest that PFKFB3 might be a potential biomarker for gastric cancer and anti-neoplastic targeting gene.

Preoperative staging of nodal status in gastric cancer

An accurate preoperative staging of nodal status is crucial in gastric cancer, because it has a great impact on prognosis and therapeutic decision-making. Different staging methods have been evaluated for gastric cancer in order to predict nodal involvement. So far, no technique could meet the necessary requirements, which include a high detection rate of infiltrated lymph nodes and a low frequency of false-positive results. This article summarizes different staging methods used to assess lymph node status in patients with gastric cancer, evaluates the evidence, and proposes to establish new methods.

Glucose transporters 1, 3, 6, and 10 are expressed in gastric cancer and glucose transporter 3 is associated with UICC stage and survival

BACKGROUND

Due to proliferation and increased metabolism, cancer cells have high glucose requirements. The glucose uptake of cells is influenced by a group of membrane proteins denoted the glucose transporter family (Glut-1 to -12). Whereas increased expression and a negative correlation with survival have been described for Glut-1 in several types of cancer, the impact of other glucose transporters on tumor biology is widely unknown.

METHODS

In this retrospective study, gastric cancer specimens of 150 patients who underwent total gastrectomy between 2005 and 2010 were stained for Glut-1, -3, -6, and -10 by immunohistochemistry. Expression of Glut-1, -3, -6, and 10 was correlated to prognosis as well as clinical and pathological parameters.

RESULTS

Glut-1, Glut-3, Glut-6, and Glut-10 were expressed in 22.0, 66.0, 38.0, and 43.3 % of the analyzed samples. Whereas Glut-1, -6, and -10 did not show a correlation with prognosis, positive staining for Glut-3 was associated with higher UICC stage and inferior prognosis. The mean overall survival was 38.6 months for Glut-3 positive patients, as compared to 51.2 months for Glut-3 negative patients (p < 0.05). Coexpression of two or more of the analyzed glucose transporters was correlated to inferior prognosis. Glut-3 and UICC stage were significant prognostic factors in multivariate analysis.

CONCLUSIONS

All of the analyzed glucose transporters were expressed in a significant proportion of the gastric cancer samples. Glut-3 was associated with higher UICC stage and inferior prognosis. These findings are relevant to therapeutic approaches that target glucose metabolism as well as to imaging using radioactively labeled glucose.

Predictive Role of the Number of 18F-FDG-Positive Lymph Nodes Detected by PET/CT for Pre-Treatment Evaluation of Locally Advanced Gastric Cancer

OBJECTIVES

The aim of this study was to investigate the predictive value of the numbers of metabolically positive lymph nodes (MPLN) detected by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in patients with locally advanced gastric cancer (LAGC).

METHODS

We retrospectively analyzed the records of 50 patients with LAGC (stage T2-T4) who had undergone pre-operative PET/CT examination and laparotomy (total gastrectomy, n = 11; subtotal gastrectomy, n = 13; distal gastrectomy, n = 22; and bypass with gastrojejunstomy, n = 4). The numbers of MPLN were determined by combining visual observations with semi-quantitative measurements of the maximized standardized uptake value (SUVmax). Performance was investigated in terms of predicting post-surgical overall survival (OS).

RESULTS

The median post-surgical OS was 32.57 months (range 3.0-94 months). The numbers of MPLN were moderately correlated with the numbers of histological positive LN (r = 0.694, p = 0.001). In univariate analyses, the numbers of MPLN (≤ 2 vs. ≥3), PET/CT LN (positivity vs. negativity), SUVmax of LN (< 2.8 vs. ≥ 2.8), TNM stage (I, II vs. III, IV), and surgery type (R0 vs. non-R0) were significantly associated with OS. In multivariate analysis, surgery type (R0 vs. non-R0) and numbers of MPLN (≤ 2 vs. ≥ 3) were both independent factors for poor OS.

CONCLUSIONS

This explored study indicates that the number of MPLN could provide additional information for LAGC prognosis. Patients with MPLNs ≥ 3 may be at the risk of the more bad outcomes, and the further clinical trials are needed.

FLT-PET/CT diagnosis of primary and metastatic nodal lesions of gastric cancer: comparison with FDG-PET/CT

PURPOSE

To examine the diagnostic performance of (18)F-fluorothymidine (FLT)-PET/CT of primary and metastatic nodal lesions of gastric cancer by comparing with (18)F-fluorodeoxyglucose (FDG)-PET/CT.

METHODS

The enrolled study population comprised 17 patients with 17 newly diagnosed gastric cancers who underwent surgery of the primary lesion and regional nodes after both FDG- and FLT-PET/CT scans. Visual detectability of the primary gastric lesions was correlated with pathological factors using the Fisher exact or Mann-Whitney U test. The sensitivity, specificity, and accuracy in detecting nodal lesions were compared between both PET/CT scans using the McNemar exact or χ (2) test.

RESULTS

Fourteen of 17 (82.4%) primary cancers were visualized by both FDG- and FLT-PET/CT scans. Although FDG or FLT visibility was not significantly associated with tumor size (p = 0.16) or histological type (p = 1.00), the 3 nonvisible lesions were pathologically early (T1) cancers. The sensitivity, specificity, and accuracy for detecting nodal metastasis were 44.8% (13/29), 98.7% (164/166), and 90.8% (177/195) for FDG-PET/CT, and 31.0% (9/29), 100% (166/166), and 89.7% (175/195) for FLT-PET/CT, respectively. No significant difference was found between the two scans in sensitivity (p = 0.13), specificity (p = 0.48), or accuracy (p = 1.00).

CONCLUSION

FLT-PET/CT may have the same diagnostic value as FDG-PET/CT for detection of primary and nodal lesions of gastric cancer.

Expression and clinical significance of glucose transporter-1 in pancreatic cancer

Increasing evidence has demonstrated that malignant cells exhibit increased glucose uptake, which facilitates survival and growth in a hypoxic environment. The glucose transporter-1 (GLUT-1) is overexpressed in a variety of malignant tumors. However, the association between GLUT-1 expression and clinicopathological factors, ¹⁸F-fluorodeoxyglucose uptake and tumor proliferation in pancreatic cancer has not been investigated to date. In the present study, the expression of GLUT-1 in 53 pancreatic cancer tissues was analyzed, which revealed that GLUT-1 was overexpressed in pancreatic tissue and correlated with poor prognosis and clinicopathological characteristics, including increased tumor size, clinical stage and lymph node metastasis, maximum standardized uptake value (SUV_max) and Ki-67 expression. The receiver operating characteristic curve analysis indicated that a cut-off SUV_max value of 4.830 was associated with optimal sensitivity (88%) and specificity (71.4%) for the detection of strong positive GLUT-1 expression. In addition, as the expression of GLUT-1 was found to correlate with Ki-67 expression, GLUT-1 may exhibit a significant effect on cell proliferation in pancreatic cancer. Overall, these findings indicate that GLUT-1 may represent a prognostic indicator, and a potential therapeutic target for pancreatic cancer.

Metabolic landscape of advanced gastric cancer according to HER2 and its prognostic implications

BACKGROUND

In advanced gastric cancer (AGC), HER2 is a validated therapeutic target. However, the metabolic landscape of AGC based on HER2 status has not been reported. Furthermore, the prognostic value of HER2 in AGC is under debate. The purpose of this study was to determine the metabolic landscape and prognosis on the basis of HER2 status in AGC.

METHODS

We analyzed 866 AGC patients treated with palliative chemotherapy and whose HER2 status was evaluated. HER2 positivity was defined as HER2 IHC 3+ or HER2/CEP17 ratio ≥2. Among them, 363 patients were evaluated with (18)F FDG-PET before chemotherapy. We analyzed mSUV (maximal standardized uptake value) according to HER2 status and clinical outcomes.

RESULTS

Among 866 patients, 225 (26.0 %) had HER2+ GC. The mSUV of HER2+ GC was significantly higher than that of HER2- GC (12.6 vs. 8.7, p < 0.001). Increased HER2 IHC positivity was correlated with increased mSUV (IHC-: 8.1, IHC 1+: 8.2, 2+: 11.4, 3+: 13.2, p < 0.001). Excluding HER2+ patients who received HER2-targeting agents, OS of patients was not different by HER2 status (12.5 vs. 11.9 months, p = 0.688). However, according to tumor metabolism, patients with higher mSUV showed worse OS regardless of HER2 positivity (mSUV < 12.8:14.8, ≥12.8:8.6 months, p < 0.001).

CONCLUSION

Tumor metabolism of AGC adversely influenced OS under treatment with cytotoxic chemotherapy. Tumor metabolism was higher in HER2+ AGC than HER2-. However, HER2 was not a prognostic factor in patients who received chemotherapy without HER2-targeting agents.

Glucose metabolism in gastric cancer: The cutting-edge

Glucose metabolism in gastric cancer cells differs from that of normal epithelial cells. Upregulated aerobic glycolysis (Warburg effect) in gastric cancer meeting the demands of cell proliferation is associated with genetic mutations, epigenetic modification and proteomic alteration. Understanding the mechanisms of aerobic glycolysis may contribute to our knowledge of gastric carcinogenesis. Metabolomic studies offer novel, convenient and practical tools in the search for new biomarkers for early detection, diagnosis, prognosis, and chemosensitivity prediction of gastric cancer. Interfering with the process of glycolysis in cancer cells may provide a new and promising therapeutic strategy for gastric cancer. In this article, we present a brief review of recent studies of glucose metabolism in gastric cancer, with primary focus on the clinical applications of new biomarkers and their potential therapeutic role in gastric cancer.

Polymeric Micelle Platform for Multimodal Tomographic Imaging to Detect Scirrhous Gastric Cancer

Scirrhous gastric cancer (SGC) is a recalcitrant tumor, which is among the most lethal cancers. A critical issue for the improvement of SGC prognosis is the lack of an effective imaging method for accurate detection and diagnosis. Because combined nuclear medicine imaging with magnetic resonance imaging (MRI) has the ability to detect cancer with high sensitivity, and quantitation and spatial resolution, it has potential to overcome the issues with SGC detection. Herein, we designed and synthesized a new block copolymer poly(ethylene glycol)-b-poly(γ-benzyl l-glutamate) linked with a chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA-PEG-b-PBLG) to provide a platform for multimodal tomographic imaging. We then successfully prepared DOTA-functionalized polymeric micelles (DOTA/m) measuring 30 nm in diameter, which is an appropriate size to penetrate deeply into tumors with thick fibrosis, including SGC. ¹¹¹In-labeled DOTA/m highly accumulated in Colon-26 tumors (mouse colon cancer with hyperpermeability), but also in OCUM-2 M LN tumors (SGC with hypopermeability), clearly depicting both tumors by single photon emission computed tomography (SPECT). Gd-labeled DOTA/m clearly visualized OCUM-2 M LN tumors by MRI with high spatial resolution. Moreover, ¹¹¹In/Gd-labeled micelles, as well as the mixture of ¹¹¹In- and Gd-labeled DOTA/m demonstrated the capability of this system for selective multimodal SPECT/MR imaging of SCG. Our findings support ¹¹¹In/Gd-DOTA-labeled micelles as a clinical translationable modality for multimodal tomographic imaging capable of detecting SGC.

Initial Standardized Uptake Value of Positron Emission Tomography Influences the Prognosis of Patients with Localized Gastric Adenocarcinoma Treated Preoperatively

BACKGROUND

In patients with localized gastric adenocarcinoma (LGAC) who receive preoperative therapy, tools to predict response or prognosticate outcome before therapy are lacking. We used initial standardized uptake value (iSUV) of positron emission tomography (PET) to evaluate its association with overall survival (OS).

METHODS

We identified 60 patients with confirmed LGAC who were treated with preoperative chemoradiation and had a baseline PET in addition to other routine staging. Fisher's exact test and Wilcoxon's rank sum test were used to determine the association between iSUV and other variables, and the log-rank test and Cox proportional hazards model were used for survival analysis.

RESULTS

The median iSUV was 6 (range, 0-28). The presence of signet ring cells in pretreatment biopsies correlated highly with low iSUV (≤ 6; p = 0.0017). Patients with a high iSUV (> 6) had a longer OS compared to those with a low iSUV (≤ 6; p = 0.0344). iSUV was not an independent predictor (p = 0.12); however, the risk of death was reduced for patients with an iSUV > 6 (hazard ratio = 0.26).

CONCLUSION

Our novel findings show that among LGAC patients treated with preoperative chemoradiation and surgery, those with a high iSUV have longer OS than patients with a low iSUV. iSUV appears to have a predictive role in patients with LGAC when treated with preoperative chemoradiation.

Preoperative Standardized Uptake Value of Metastatic Lymph Nodes Measured by 18F-FDG PET/CT Improves the Prediction of Prognosis in Gastric Cancer

This study assessed whether preoperative maximum standardized uptake value (SUVmax) of metastatic lymph nodes (LNs) measured by F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-FDG PET/CT) could improve the prediction of prognosis in gastric cancer.One hundred fifty-one patients with gastric cancer and pathologically confirmed LN involvement who had undergone preoperative F-FDG PET/CT prior to curative surgical resection were retrospectively enrolled. To obtain nodal SUVmax, a transaxial image representing the highest F-FDG uptake was carefully selected, and a region of interest was manually drawn on the highest F-FDG accumulating LN. Conventional prognostic parameters and PET findings (primary tumor and nodal SUVmax) were analyzed for prediction of recurrence-free survival (RFS) and overall survival (OS). Furthermore, prognostic accuracy of survival models was assessed using c-statistics.Of the 151 patients, 38 (25%) experienced recurrence and 34 (23%) died during follow-up (median follow-up, 48 months; range, 5-74 months). Twenty-seven patients (18%) showed positive F-FDG nodal uptake (range, 2.0-22.6). In these 27 patients, a receiver-operating characteristic curve demonstrated a nodal SUVmax of 2.8 to be the optimal cutoff for predicting RFS and OS. The univariate and multivariate analyses showed that nodal SUVmax (hazard ratio [HR] = 2.71, P < 0.0001), pathologic N (pN) stage (HR = 2.58, P = 0.0058), and pathologic T (pT) stage (HR = 1.77, P = 0.0191) were independent prognostic factors for RFS. Also, nodal SUVmax (HR = 2.80, P < 0.0001) and pN stage (HR = 2.28, P = 0.0222) were independent prognostic factors for OS. A predictive survival model incorporating conventional risk factors (pT/pN stage) gave a c-statistic of 0.833 for RFS and 0.827 for OS, whereas a model combination of nodal SUVmax with pT/pN stage gave a c-statistic of 0.871 for RFS (P = 0.0355) and 0.877 for OS (P = 0.0313).Nodal SUVmax measured by preoperative F-FDG PET/CT is an independent prognostic factor for RFS and OS. Combining nodal SUVmax with pT/pN staging can improve survival prediction precision in patients with gastric cancer.

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

PET/Computed Tomography in the Diagnosis and Staging of Gastric Cancers

Although there has been a reduction of the incidence and mortality of gastric cancer, it remains among the commonest causes of cancer-related death. Accurate staging and evaluation of treatment response are vital for management. PET is used to complement anatomic imaging in cancer management. PET/computed tomography (CT) has demonstrated its potential value for preoperative staging, evaluation of response to therapy, and detection of recurrence. Not all types of gastric cancers have a high affinity for fluorodeoxyglucose. PET/CT in the evaluation and staging of gastric cancer is not established, but studies indicate that there may be an evolving role for this imaging modality.

Improving patient selection for 18F-FDG PET scanning in the staging of gastric cancer

Standard pretreatment staging for gastric cancer includes CT of the chest, abdomen, and pelvis; gastroscopy; and laparoscopy. Although (18)F-PET combined with CT has proven to be a useful staging tool in many cancers, some gastric cancers are not (18)F-FDG-avid and its clinical value is still debatable.

METHODS

Gastric cancer patients who underwent staging (18)F-FDG PET scans from 2002 to 2013 at the Peter MacCallum Cancer Center were retrospectively analyzed, and a systematic review was also conducted using PubMed between 2000 to March 2014 to investigate clinicopathologic parameters associated with (18)F-FDG avidity. A pretreatment PET scoring system was developed from predictors of (18)F-FDG avidity.

RESULTS

Both the retrospective analysis of the patients and the systematic literature review showed similar significant predictors of (18)F-FDG avidity, including large tumor size, non-signet ring cell carcinoma type, and glucose transporter 1-positive expression on immunohistochemistry. A PET scoring system was developed from these clinicopathologic parameters that allowed (18)F-FDG-avid tumors to be detected with a sensitivity of 85% and a specificity of 71%.

CONCLUSION

A pretreatment PET scoring system can assist in the selection of patients with gastric adenocarcinoma when staging (18)F-FDG PET is being considered.

Nanoparticle-based targeted therapeutics in head-and-neck cancer

Head-and-neck cancer is a major form of the disease worldwide. Treatment consists of surgery, radiation therapy and chemotherapy, but these have not resulted in improved survival rates over the past few decades. Versatile nanoparticles, with selective tumor targeting, are considered to have the potential to improve these poor outcomes. Application of nanoparticle-based targeted therapeutics has extended into many areas, including gene silencing, chemotherapeutic drug delivery, radiosensitization, photothermal therapy, and has shown much promise. In this review, we discuss recent advances in the field of nanoparticle-mediated targeted therapeutics for head-and-neck cancer, with an emphasis on the description of targeting points, including future perspectives.

Performance of (18)F-FDG PET/CT as a postoperative surveillance imaging modality for asymptomatic advanced gastric cancer patients

OBJECTIVE

The purpose of this study was to investigate the diagnostic performance of postoperative fluorine-18 fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) as a surveillance modality for advanced gastric cancer patients who were asymptomatic and negative by conventional follow-up.

METHODS

We retrospectively collected 46 advanced gastric cancer patients who received approximately 1-year-postoperative (18)F-FDG PET/CT surveillance following curative resection (mean age 60.6 ± 11.5 years). (18)F-FDG PET/CT was interpreted by nuclear medicine physicians who were blind to the clinical information. Final confirmation was determined by clinical follow-up using tumor markers, conventional CT scan, upper gastrointestinal endoscopy and with/without subsequent histopathologic diagnosis.

RESULTS

Four patients developed recurrence (8.7 %; 1 local and 3 distant recurrences). For local recurrence, (18)F-FDG PET/CT found four hypermetabolic lesions and one was local recurrence. For distant recurrence, seven hypermetabolic lesions were found in six patients and true-positive was three lesions. False-positive cases were mainly turned out to be physiologic small bowel uptake. Regardless of the recurrence site, the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-FDG PET/CT were 100 % (4/4, 95 % confidence interval (CI) 39.6-100 %), 88.1 % (37/42, 95 % CI 73.6-95.5 %), 44.4 % (4/9, 95 % CI 15.3-77.3 %) and 100 % (37/37, 95 % CI 88.3-100 %), respectively in the patient-based analysis.

CONCLUSION

Our study showed good specificity of postoperative surveillance (18)F-FDG PET/CT for detecting recurrence. Careful caution should be made for interpreting some false-positive hypermetabolic lesions in postoperative (18)F-FDG PET/CT, especially at the local anastomosis site.

In vivo near-infrared fluorescence imaging of apoptosis using histone H1-targeting peptide probe after anti-cancer treatment with cisplatin and cetuximab for early decision on tumor response

Early decision on tumor response after anti-cancer treatment is still an unmet medical need. Here we investigated whether in vivo imaging of apoptosis using linear and cyclic (disulfide-bonded) form of ApoPep-1, a peptide that recognizes histone H1 exposed on apoptotic cells, at an early stage after treatment could predict tumor response to the treatment later. Treatment of stomach tumor cells with cistplatin or cetuximab alone induced apoptosis, while combination of cisplatin plus cetuximab more efficiently induced apoptosis, as detected by binding with linear and cyclic form of ApoPep-1. However, the differences between the single agent and combination treatment were more remarkable as detected with the cyclic form compared to the linear form. In tumor-bearing mice, apoptosis imaging was performed 1 week and 2 weeks after the initiation of treatment, while tumor volumes and weights were measured 3 weeks after the treatment. In vivo fluorescence imaging signals obtained by the uptake of ApoPep-1 to tumor was most remarkable in the group injected with cyclic form of ApoPep-1 at 1 week after combined treatment with cisplatin plus cetuximab. Correlation analysis revealed that imaging signals by cyclic ApoPep-1 at 1 week after treatment with cisplatin plus cetuximab in combination were most closely related with tumor volume changes (r2 = 0.934). These results demonstrate that in vivo apoptosis imaging using Apopep-1, especially cyclic ApoPep-1, is a sensitive and predictive tool for early decision on stomach tumor response after anti-cancer treatment.