Hyuck Jae Choi

Diagnostic performance of computer tomography, magnetic resonance imaging, and positron emission tomography or positron emission tomography/computer tomography for detection of metastatic lymph nodes in patients with cervical cancer : Meta-analysis

We performed a meta‐analysis to compare diagnostic performances of computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET or PET/CT), for detection of metastatic lymph nodes in patients with cervical cancer. We searched MEDLINE (PubMed), EMBASE and the Cochrane Review database in December 2007. All articles were independently reviewed and selected by three evaluators. We estimated a summary receiver operating characteristic (sROC) curve. The area under the curve (AUC), Q*, and pooled weighted estimates of sensitivity and specificity for each modality by patient‐based and region‐ or node‐based data analyses and conducted pair‐wise comparisons between modalities using the two‐sample Z‐test. Forty‐one of 768 initially identified studies were included in the meta‐analysis. In a patient‐based data analysis, PET or PET/CT showed the highest pooled sensitivity (82%) and specificity (95%), while CT showed 50% and 92%; and MRI, 56% and 91%, respectively. The AUC (0.9641) and Q* (0.9106) of PET or PET/CT were significantly higher than those of MRI (AUC = 0.8270; Q* = 0.7599), both P < 0.001. In region‐ or node‐based data analysis, sensitivities of CT (52%) and PET or PET/CT (54%) were higher than that of MRI (38%), P < 0.02 and P < 0.001, respectively, while specificities of MRI (97%) and PET or PET/CT (97%) were higher than that of CT (92%), both P < 0.001. The AUC and Q* showed no significant difference among CT, MRI, and PET or PET/CT. PET or PET/CT had an overall higher diagnostic performance than did CT or MRI in detecting metastatic lymph nodes in patients with cervical cancer. (Cancer Sci 2010)

Effects of antioxidant supplements on cancer prevention: meta-analysis of randomized controlled trials

BACKGROUND This meta-analysis aimed to investigate the effect of antioxidant supplements on the primary and secondary prevention of cancer as reported by randomized controlled trials. METHODS We searched Medline (PubMed), Excerpta Medica database, and the Cochrane Review in October 2007. RESULTS Among 3327 articles searched, 31 articles on 22 randomized controlled trials, which included 161 045 total subjects, 88 610 in antioxidant supplement groups and 72 435 in placebo or no-intervention groups, were included in the final analyses. In a fixed-effects meta-analysis of all 22 trials, antioxidant supplements were found to have no preventive effect on cancer [relative risk (RR) 0.99; 95% confidence interval (CI) 0.96-1.03). Similar findings were observed in 12 studies on primary prevention trials (RR 1.00; 95% CI 0.97-1.04) and in nine studies on secondary prevention trials (RR 0.97; 95% CI 0.83-1.13). Further, subgroup analyses revealed no preventive effect on cancer according to type of antioxidant, type of cancer, or the methodological quality of the studies. On the other hand, the use of antioxidant supplements significantly increased the risk of bladder cancer (RR 1.52; 95% CI 1.06-2.17) in a subgroup meta-analysis of four trials. CONCLUSIONS The meta-analysis of randomized controlled trials indicated that there is no clinical evidence to support an overall primary and secondary preventive effect of antioxidant supplements on cancer. The effects of antioxidant supplements on human health, particularly in relation to cancer, should not be overemphasized because the use of those might be harmful for some cancer.

Additional value of MR/PET fusion compared with PET/CT in the detection of lymph node metastases in cervical cancer patients

We evaluated the additional diagnostic value of magnetic resonance/positron emission tomography (MR/PET) fusion in the detection of metastatic lymph nodes in cervical cancer patients. Seventy nine patients with FIGO stage IB-IVA cervical cancer who had undergone both magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) before lymphadenectomy were included in this study. Image analysis was first performed with PET/CT images only. A second analysis was then performed with MR/PET fused images that focused on the additional information obtained from the MR images. Lymphadenectomy involved removing all visible lymph nodes in the surgical field. To enable nodal group-specific comparisons, para-aortic and pelvic lymph nodes were divided into seven nodal groups: para-aortic, both common iliac, both external iliac and both internal iliac/obturator areas. Histopathological evaluation of lymph nodes has been the diagnostic standard. The value of the additional information from the MR images was evaluated by means of receiver operating characteristic (ROC) analysis. Fused MR/PET rendered readers to detect six more metastatic lymph node groups. The sensitivity and specificity of PET/CT and fused MR/PET were 44.1%, 93.9% and 54.2%, 92.7% respectively. The ROC analysis demonstrated a higher diagnostic performance of fused MR/PET compared to PET/CT alone for detecting lymph node metastases (p=0.0259). The findings of this study demonstrate the additional diagnostic value of fused MR/PET images compared with PET/CT in the detection of metastatic lymph nodes in patients with uterine cervical cancer.

Preoperative Magnetic Resonance Imaging Staging of Uterine Cervical Carcinoma: Results of Prospective Study

Objective To determine the accuracy of the preoperative staging of uterine cervical cancer by magnetic resonance (MR) imaging in 115 patients in a prospective study. Methods A prospective study was performed in 115 patients who underwent MR imaging at 1.5 T before surgery or biopsy. Histopathologic findings were correlated with MR imaging results for all patients. Results The accuracy of preoperative tumor staging by MR imaging in the 115 patients was 77%. In terms of the evaluation of parametrial status, this study had an accuracy of 94% and a sensitivity of 38%. The accuracy and sensitivity of MR imaging for vaginal invasion were 81% and 87%, respectively. In terms of lymph node metastasis, this study had an accuracy of 97% and a sensitivity of 36%. Conclusion Magnetic resonance imaging has high accuracy in the preoperative staging of uterine cervical cancer.

MRI for Pretreatment Lymph Node Staging in Uterine Cervical Cancer

OBJECTIVE The purpose of this article is to assess the accuracy of MRI in detecting pelvic and paraaortic lymph node metastasis from uterine cervical cancer using various imaging criteria. CONCLUSION Although MRI analysis resulted in relatively low sensitivity, size and margin (spiculated or lobulated) were useful criteria for predicting lymph node metastasis from cervical cancer.

Green tea consumption and risk of stomach cancer: A meta‐analysis of epidemiologic studies

This meta‐analysis investigated the quantitative association between the consumption of green tea and the risk of stomach cancer in epidemiologic studies using crude data and adjusted data. We searched MEDLINE, EMBASE and the Cochrane Review in August 2007. All the articles searched were independently reviewed and selected by 3 evaluators according to predetermined criteria. A total of 13 epidemiologic studies were included. When all the case–control and cohort studies were pooled, the relative risks (RR) of stomach cancer for the highest level of green tea consumption when compared with the lowest level of consumption were shown to be 1.10 (95% confidence interval (CI), 0.92–1.32) using the crude data and 0.82 (95% CI, 0.70–0.96) using the adjusted data. In the meta‐analyses of case–control studies, no significant association was seen between green tea consumption and stomach cancer using the crude data (RR, 0.79; 95% CI, 0.58–1.07), but green tea was shown to have a preventive effect on stomach cancer using the adjusted data (RR, 0.73; 95% CI, 0.64–0.83). In the meta‐analyses of the recent cohort studies, the highest green tea consumption was shown to significantly increase stomach cancer risk using the crude data (RR, 1.59; 95% CI, 1.16–2.18), but no significant association between them was seen when using the adjusted data (RR, 1.04; 95% CI, 0.93–1.17). Unlike the case–control studies, no preventive effect on stomach cancer was seen for the highest green tea consumption in the meta‐analysis of the recent cohort studies. Further clinical trials are needed.

Pretreatment assessment of tumor enhancement on contrast-enhanced computed tomography as a potential predictor of treatment outcome in metastatic renal cell carcinoma patients receiving antiangiogenic therapy.

Tumor vascularity is a potential predictor of treatment outcomes in metastatic renal cell carcinoma (mRCC), and contrast enhancement of tumors in computed tomography (CT) is correlated significantly with microvessel density. In this study, the authors investigated whether tumor enhancement in contrast‐enhanced CT (CECT) is useful for predicting outcomes in patients with mRCC who are receiving antiangiogenic therapy.

Soy intake and risk of endocrine-related gynaecological cancer: a meta-analysis.

Background  Epidemiology studies have reported associations between soy intake and the risk of endocrine‐related gynaecological cancers. However, to date there have been no quantitative meta‐analyses reported regarding this topic.

Insulin-degrading enzyme secretion from astrocytes is mediated by an autophagy-based unconventional secretory pathway in Alzheimer disease

ABSTRACT The secretion of proteins that lack a signal sequence to the extracellular milieu is regulated by their transition through the unconventional secretory pathway. IDE (insulin-degrading enzyme) is one of the major proteases of amyloid beta peptide (Aβ), a presumed causative molecule in Alzheimer disease (AD) pathogenesis. IDE acts in the extracellular space despite having no signal sequence, but the underlying mechanism of IDE secretion extracellularly is still unknown. In this study, we found that IDE levels were reduced in the cerebrospinal fluid (CSF) of patients with AD and in pathology-bearing AD-model mice. Since astrocytes are the main cell types for IDE secretion, astrocytes were treated with Aβ. Aβ increased the IDE levels in a time- and concentration-dependent manner. Moreover, IDE secretion was associated with an autophagy-based unconventional secretory pathway, and depended on the activity of RAB8A and GORASP (Golgi reassembly stacking protein). Finally, mice with global haploinsufficiency of an essential autophagy gene, showed decreased IDE levels in the CSF in response to an intracerebroventricular (i.c.v.) injection of Aβ. These results indicate that IDE is secreted from astrocytes through an autophagy-based unconventional secretory pathway in AD conditions, and that the regulation of autophagy is a potential therapeutic target in addressing Aβ pathology.

Value of T2-weighted MR imaging in differentiating low-fat renal angiomyolipomas from other renal tumors.

Backgound Accurate preoperative diagnosis of fat scanty angiomyolipomas is an important clinical issue. By evaluating the low signal intensity of angiomyolipomas in MR T2-weighted images the diagnostic accuracy can be elevated. Purpose To retrospectively assess the usefulness of T2-weighted MR imaging for differentiating low-fat angiomyolipomas (AMLs) from other renal tumors. Material and Methods We retrospectively evaluated 71 patients with surgically proven renal masses (10 AMLs, 57 renal cell carcinomas [RCCs], and four oncocytomas), all of which showed no visible fat as well as gradual enhancement patterns on contrast-enhanced CT. Signal intensity was measured in each renal mass and in the spleen on T2-weighted images, and each signal intensity ratio (SIR) was calculated; SIR values were then compared in the AML and non-AML groups. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of the two parameters for differentiating the two groups. Results The SIR values (77 ± 24% vs. 162 ± 79%, p = 0.002) were significantly lower in the AML than in the non-AML group. The area under the ROC curve was 0.926 for SIR. The sensitivity and specificity in the diagnosis of AMLs were 90% and 90.2%, using SIR cut-off of 92.5%. Conclusion Signal intensity measurements on T2-weighted MR images can differentiate AML from non-AML in the kidney.