Difference in F-18 FDG Uptake After Esophagogastroduodenoscopy and Colonoscopy in Healthy Sedated Subjects.

PURPOSE: We aimed to evaluate the difference in fluorodeoxyglucose (FDG) uptake in sedated healthy subjects after they underwent esophagogastroduodenoscopy (EGD) and colonoscopy procedures. METHODS: The endoscopy group (n = 29) included healthy subjects who underwent screening via F-18 FDG positron emission tomography/computed tomography (PET/CT) after an EGD and/or colonoscopy under sedation on the same day. The control group (n = 35) included healthy subjects who underwent screening via PET/CT only. FDG uptake in the tongue, uvula, epiglottis, vocal cords, esophagus, stomach, duodenum, liver, cecum, colon, anus, and muscle were compared between the two groups. RESULTS: Maximum standardized uptake value (SUVmax) in the tongue, pharynx, larynx, and esophagus did not significantly differ between the endoscopy and control groups. In contrast, mean SUVmax in the whole stomach was 18 % higher in the endoscopy group than in the control group (SUVmax: 2.96 vs. 2.51, P = 0.010). In the lower gastrointestinal track, SUVmax from the cecum to the rectum was not significantly different between the two groups, whereas SUVmax in the anus was 20 % higher in the endoscopy group than in the control group (SUVmax: 4.21 vs. 3.50, P = 0.002). SUVmax in the liver and muscle was not significantly different between the two groups. Mean volume of the stomach and mean cross section of the colon was significantly higher in the endoscopy group than in the control group (stomach: 313.28 cm3 vs. 209.93 cm3, P < 0.001, colon: 8.82 cm2 vs. 5.98 cm2, P = 0.001). CONCLUSIONS: EGD and colonoscopy under sedation does not lead to significant differences in SUVmax in most parts of the body. Only gastric FDG uptake in the EGD subjects and anal FDG uptake in the colonoscopy subjects was higher than uptake in those regions in the control subjects.

Promoter methylation status of the FHIT gene and Fhit expression: association with HER2/neu status in breast cancer patients.

Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of several tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other types of cancer, and loss of Fhit expression has been observed in breast cancer. The aim of the present study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene correlates with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status. Pyrosequencing of bisulfite-treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples. We examined the expression of Fhit using tissue microarrays by immunohistochemical staining. FHIT methylation was detected in 96.7% and the positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancer, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. No significant correlation between methylation of the FHIT gene and its expression was observed in the present study. Our results suggest that loss of Fhit expression in breast cancer is associated with poor prognostic features, and it is also relevant to the results in HER2-negative breast cancer. Further studies with larger sample sizes and longer follow-up are required to clarify the predictive and prognostic value of Fhit expression and the FHIT gene methylation status in breast cancer.

Low methylation levels of the SFRP1 gene are associated with the basal-like subtype of breast cancer.

Epigenetic analyses have shown that aberrant DNA methylation signatures are associated with breast cancer molecular subtypes. In this study, we analyzed the methylation status of breast cancer-related genes in relation to the molecular subtypes and investigated whether the basal-like subtype displays distinct methylation profiles. By using pyrosequencing, we analyzed the DNA methylation status of 5 candidate genes in 60 breast cancer samples. We compared the methylation frequency across the molecular subtypes and analyzed the correlation between methylation levels and clinicopathological characteristics. A total of 59 cases displayed aberrant methylation. Amplification during polymerase chain reaction analysis failed in 1 case. The median methylation levels of the secreted frizzled-related protein 1 (SFRP1) gene were significantly lower in the basal-like subtype compared to the luminal A, luminal B and human epidermal growth factor receptor 2 (HER2) subtypes. Cadherin 13 (H-cadherin; CDH13) methylation levels were significantly higher in the HER2 tumors compared to the luminal A and basal-like subtypes. A comparison of the methylation status with clinicopathological characteristics revealed that the expression of bcl-2, progesterone receptor and epidermal growth factor receptor were associated with SFRP1 gene methylation status. Our results indicate that the basal-like subtype is associated with low methylation levels of the SFRP1 gene, suggesting that the methylation levels of specific breast cancer genes may potentially serve as epigenetic biomarkers and prognostic factors.