Oleanolic acid suppresses the proliferation of lung carcinoma cells by miR-122/Cyclin G1/MEF2D axis.

Oleanolic acid (OA) is a natural compound from plants with anti-tumor activities. However, the mechanism of the inhibitory effect of OA on cell cycle progression has not been completely explored. We employed several lung carcinoma cell lines to investigate the cell cycle-related molecular pathway affected by OA. The data revealed that OA suppressed the proliferation of lung cancer cells in both dose- and time-dependent manners, along with an increase in miR-122 abundance. The suppression of miR-122 abolished the effect of OA on lung cancer cells. CCNG1 and MEF2D, two putative miR-122 targets, were found to be downregulated by OA treatment. Restoring their expression counteracted the effect of OA on lung carcinoma cells. OA was further shown to induce the expression of miR-122-regulating transcriptional factors in lung cancer cells. Collectively, OA induced cell cycle arrest in lung cancer cells through miR-122/Cyclin G1/MEF2D pathway. This finding may contribute to the understanding of the molecular mechanism of OA's anti-tumor activity.

The correlation of bone morphogenetic protein 2 with poor prognosis in glioma patients.

Glioma is the most common type of human intracranial cancers and has poor prognosis. Bone morphogenetic protein 2 (BMP2) plays important roles in cancer cell signalings (Vecht et al. Oncologist 19:751-9, 2014). Here, we aimed to investigate the correlation of BMP2 with patient prognosis as well as pathological indicators. Immunohistochemistry was used to test BMP2 proteins in 45 gliomas of distinct malignancy grade, and Kaplan-Meier survival analysis was performed to assess prognostic significance. BMP2 protein was also detected in cell lines by Western blot. We observed that BMP2 protein was stained in 44.4% (20 out of 45) of all glioma tissues, including 32.1% of low-grade (I + II) gliomas and 52.9% of high-grade (III + IV) gliomas. Grade IV gliomas potently expressed BMP2 proteins. Western blot showed BMP2 protein expressed in cell lines NHA, A172, T98G, U87, and U251. In addition, BMP2 expression was significantly associated with WHO grade (p = 0.024). According to log-rank test and Cox regression model, BMP2 can be suggested as an independent prognostic factor, apart from WHO grade. Taken together, BMP2 is differently highly expressed in different grades of gliomas and correlated to WHO grade. BMP2 also independently indicates poor prognosis in old glioma patients, which is indicative of an effectively therapeutic target.

Cell surface nucleolin is crucial in the activation of the CXCL12/CXCR4 signaling pathway.

Recently, CXCL12-CXCR4 has been focused on therapeutic strategies for papillary thyroid carcinoma (PTC) and other cancers. At the same time, cell surface nucleolin is also over-expressed in PTC and others. Interestingly, a few reports suggest that either CXCR4 or cell surface nucleolin is a co-receptor for HIV-1 entry into CD4+ T cells, which indicates that there is a relationship between CXCR4 and nucleolin. In this study, antibody and siRNA were used to identify effects of cell surface nucleolin and CXCR4 on cell signaling; soft-agar colony formation assay and Transwell assay were used to determine roles of nucleolin and CXCR4 in cell proliferation and migration. Importantly, co-immunoprecipitation was used to demonstrate the relationship between CXCR4 and nucleolin. Results showed CXCR4 and nucleolin were co-expressed in PTC cell line K1, B-CPAP, and TPC-1. Either cell surface nucleolin or CXCR4 was necessary to prompt extracellular signal-regulated kinase phosphorylation. When blocked, CXCR4 or nucleolin can significantly affect TPC-1 proliferation and migration (p < 0.01). Co-immunoprecipitation analysis identified that nucleolin can bind and interact with CXCR4 to activate CXCR4 signaling. This study suggests that nucleolin is crucial in the activation of CXCR4 signaling, which affects cell growth, migration, and invasiveness. Further, nucleolin may interact with other receptors. Our study also offers new ideas for cancer therapy.

Isolation, identification and characterization of an algicidal bacterium from Lake Taihu and preliminary studies on its algicidal compounds.

In an effort to identify a bio-agent capable of controlling cyanobacterial blooms, we isolated a bacterial strain, A27, which exhibited strong algicidal activity against the dominant bloom-forming species of Microcystis aeruginosa in Lake Taihu. Based on 16S rRNA gene sequence analysis, this strain belongs to the genus Exiguobacterium. This is the first report of an algicidal bacterial strain belonging to the genus Exiguobacterium. Strain A27 exhibited algicidal activity against a broad range of cyanobacteria, but elicited little or no algicidal activity against the two green algal strains tested. The algicidal activity of strain A27 was shown to be dependent on the density of the bacteria and to have a threshold density of 1.5x10(6) CFU/mL. Our data also showed that the algicidal activity of strain A27 depended on different growth stages of Microcystis aeruginosa (exponential approximately lag phase > early stationary) rather than that of the bacterium itself. Our results also suggested the algicidal activity of strain A27 occurred via the production of extracellular algicidal compounds. Investigation of the algicidal compounds revealed that there were at least two different algicidal compounds produced by strain A27. These results indicated that strain A27 has great potential for use in the control of outbreaks of cyanobacterial blooms in Lake Taihu.

Sulfate-reducing bacteria in leachate-polluted aquifers along the shore of the East China Sea.

The diversity of sulfate-reducing bacteria (SRB) in the aquifer underlying the Laogang Landfill along the shore of the East China Sea was investigated. The DNA extracted from 15 groundwater samples was subjected to PCR amplification of the dissimilatory sulfite reductase (dsr) gene. Full-length dsrAB amplicons (approximately 1.9 kb) were then used to construct 4 clone libraries, while the dsrB amplicons (approximately 350 bp) were used for denaturing gradient gel electrophoresis (DGGE) analysis. The clones in the 4 libraries covered all cultured SRB lineages, as well as a deeply branching clade not affiliated with any cultured SRB. In addition, nearly 80% of the 388 clones in the 4 libraries were similar to sequences of the Deltaproteobacteria, Desulfobacteriaceae, Desulfovibrionales, Syntrophaceae, and Desulfobulbaceae. Furthermore, a wide variety of marine SRB was detected, which indicated that seawater has infiltrated the aquifer. Indeed, the DGGE profiles revealed obvious variations in SRB diversity among the 15 samples, which clustered in accordance with the sulfate concentration of the samples ([SO4(2-)]). Moreover, the sulfate concentrations and SRB diversity along the leachate plume did not show regular variation, which suggests the impact of both groundwater flow and seawater intrusion.

Value of PET/CT versus enhanced CT for locoregional lymph nodes in non-small cell lung cancer.

PURPOSE: To compare the diagnostic efficacies of integrated (18)F FDG PET/CT images and contrast-enhanced helical CT images in locoregional lymph node metastasis in the patients with non-small cell lung cancer (NSCLC). METHODS: From June 2005 to June 2007, 122 potentially operable patients with proven or suspected non-small cell lung cancer underwent integrated PET/CT and contrast-enhanced CT scans followed by surgical nodal staging. The results of reviewing PET/CT and enhanced CT images for the locoregional lymph node metastasis were compared in relation to pathologic findings. RESULTS: Preoperative nodal staging was compared with postoperative histopathological staging, 80% (98 of 122) of patients correctly staged, 13% (16 of 122) of patients were overstaged, and 7% (8 of 122) were understaged by PET/CT, while those values for CT were 56% (68 of 122), 26% (32 of 122), and 18% (22 of 122), respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT for lymph nodes were 86%, 85%, 85%, 64%, 95%, respectively; compared with 69%, 71%, 70%, 43%, 88% for CT (P=0.000, 0.000, 0.000, 0.001, 0.001, respectively). 81% false-negative interpretations and 72% false-positive interpretations on CT were corrected by PET/CT. 57% false-negative interpretations and 45% false-positive interpretations on PET/CT were corrected by CT. 6 % (9 of 153) positive lymph nodes and 8% (40 of 486) negative nodes at pathology were incorrectly diagnosed both by PET/CT and CT. CONCLUSION: Integrated PET/CT improves the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value than enhanced CT in the assessment of locoregional lymph nodes, and provides more efficient and accurate data of nodal staging, with a better effect on diagnosis and therapy in non-small cell lung cancer.

Investigation of total bacterial and ammonia-oxidizing bacterial community composition in a full-scale aerated submerged biofilm reactor for drinking water pretreatment in China.

The community composition of total bacteria and ammonia-oxidizing bacteria in a full-scale aerated submerged biofilm reactor for drinking water pretreatment was characterized by analysis of 16S rRNA gene and the functional gene amoA, respectively. Sampling was performed in February and in July. 16S rRNA gene clone libraries revealed 13 bacterial divisions. At both sampling dates, the majority of clone sequences were related to the Alpha- and Betaproteobacteria. A minor proportion belonged to the following groups: Gammaproteobacteria, Deltaproteobacteria, Nitrospira, Firmicutes, Acidobacteria, Verrucomicrobia, Actinobacteria, Planctomycetes, Chloroflexi, Gemmatimonadetes and the Cytophaga-Flavobacterium-Bacteroides group. Some sequences related to bacteria owning high potential metabolic capacities were detected in both samples, such as Rhodobacter-like rRNA gene sequences. Surveys of cloned amoA genes from the two biofilm samples revealed ammonia-oxidizing bacterial sequences affiliated with the Nitrosomonas oligotropha lineage, Nitrosomonas communis lineage. An unknown Nitrosomonas group of amoA gene sequences was also detected.

Molecular analysis of microbial community in a groundwater sample polluted by landfill leachate and seawater.

Seashore landfill aquifers are environments of special physicochemical conditions (high organic load and high salinity), and microbes in leachate-polluted aquifers play a significant role for intrinsic bioremediation. In order to characterize microbial diversity and look for clues on the relationship between microbial community structure and hydrochemistry, a culture-independent examination of a typical groundwater sample obtained from a seashore landfill was conducted by sequence analysis of 16S rDNA clone library. Two sets of universal 16S rDNA primers were used to amplify DNA extracted from the groundwater so that problems arising from primer efficiency and specificity could be reduced. Of 74 clones randomly selected from the libraries, 30 contained unique sequences whose analysis showed that the majority of them belonged to bacteria (95.9%), with Proteobacteria (63.5%) being the dominant division. One archaeal sequence and one eukaryotic sequence were found as well. Bacterial sequences belonging to the following phylogenic groups were identified: Bacteroidetes (20.3%), beta, gamma, delta and epsilon-subdivisions of Proteobacteria (47.3%, 9.5%, 5.4% and 1.3%, respectively), Firmicutes (1.4%), Actinobacteria (2.7%), Cyanobacteria (2.7%). The percentages of Proteobacteria and Bacteroides in seawater were greater than those in the groundwater from a non-seashore landfill, indicating a possible influence of seawater. Quite a few sequences had close relatives in marine or hypersaline environments. Many sequences showed affiliations with microbes involved in anaerobic fermentation. The remarkable abundance of sequences related to (per)chlorate-reducing bacteria (ClRB) in the groundwater was significant and worthy of further study.

Variations of dominant microbial populations in groundwater in response to the leachate from Laogang Landfill.

Temporal changes of dominant microbial populations in groundwater in response to the leachate from Shanghai Laogang Landfill were investigated. Concentrations of dissolved redox-relevant species in groundwater suggested that the dominating redox process had changed from denitrification to methane-production/sulfate-reduction due to landfilling. Dominant microbial populations were determined using restriction fragment length polymorphism( RFLP) analyses of 16S rRNA gene libraries, which were further studied by sequencing and phylogenetic analyses. The results indicated that obvious shifts of dominant microbial populations had occurred in groundwater in response to the pollution of leachate. The closest relatives of some dominant clones are accordant with the dominating redox processes determined by hydrochemical analyses, based on the GenBank's indications on the ability to perform redox reactions.

Growth responses of Picea mongolica seedlings to defoliation rate.

Picea mongolica W. D. Xu. is an endemic species in China. The spruce forest is only found in semi-arid habitat in Inner Mongolia Autonomous Region of China. Based on the simulative defoliation experiment, it was proved that Picea mongolica seedlings had the compensatory and overcompensatory effects under the certain defoliation rate. The results of variance analysis on growth indexes showed that in PM I (natural regeneration seedlings under Picea mongolica forest), the differences of H1 (height in June 23) and H2 (height in September 3) were extremely significant, and the difference of D(diameter at the breast height) were not significant. In PM II (artificial regeneration seedlings under Betula platyphylla Suk. forest), the difference of H1 was significant, the difference of H2 was not significant, and the difference of D was extremely significant. The regression equations were established and the compensatory and overcompensatory points were obtained. In PM I, the compensatory points of H1, H2, and D were 0.7628, 0.7436, 0.5725, and the overcompensatory points were 0.6056, 0.5802 and 0.2909 respectively. In PM II, the compensatory points of H,, H2, and D are 0.5012, 0.3421, 0.2488, and the overcompensatory points are 0.4137, 0.2633 and 0.0747 respectively. These results suggested that the induction of compensatory growth mechanisms in spruce seedlings required a threshold level of defoliation, and the insects in Picea mongolica forest could be controlled in a certain degree.

The association between preoperative serum C-reactive protein and hepatocellular carcinoma recurrence in patients with chronic hepatitis B virus (HBV) infection--a retrospective study.

The prognosis of the patients with hepatocellular carcinoma (HCC) recurrence following curative hepatectomy is usually dismal. Whether preoperative serum C-reactive protein (CRP) can predict the recurrence of HCC in patients with chronic HBV infection is not clear. Total 232 patients with chronic HBV infection were included in this retrospective study. We investigated the association between detailed preoperative serum CRP levels and early (≤ 2 year) and late (> 2 year) HCC recurrence following curative hepatectomy. After adjusting for potential confounders, we found a saturation effect for preoperative serum CRP of 2.1 mg/dl existed for early HCC recurrence (ER). The incidence of ER increased with preoperative serum CRP less than 2.1 mg/dl (OR = 3.5, 95% CI 1.6-7.6, P = 0.001), and higher preoperative serum CRP (>2.1 mg/dl) did not increase the incidence of ER (OR = 0.8, 95% CI 0.2-2.7, P = 0.703). Whereas there is a linear relationship between preoperative serum CRP and late HCC recurrence (LR) (OR = 0.2, 95% CI, 0.1- 0.4) (OR = 1.8, 95% CI, 1.2-2.5, P = 0.002). In addition, the optimal cutoff point for serum CRP level was 1.5 mg/dl, instead of 1.0 mg/dl, in predicting both ER and LR. Patients with higher preoperative serum CRP level (>1.5 mg/dl) had lower recurrence free survival rates and overall survival rates (P<0.01). These results suggest that preoperative serum CRP played different roles on ER and LR following curative hepatectomy, thus further predicting the prognosis in patients with chronic HBV infection.

The Tumor-immune Index is Correlated With the Prognosis of Patients After Curative Resection for Nonsmall Cell Lung Cancer.

We developed a novel tumor-immune index (TII) based on carcinoembryonic antigen levels, lymphocyte counts, and platelet counts, and explored its prognostic value in nonsmall cell lung cancer (NSCLC).The prognostic value of the TII was evaluated based on a retrospective study of 205 patients with early NSCLC, who underwent resection in the whole year of 2006, and validated in another group of 228 patients enrolled in the next year of 2007. The optimal cut-off point for the TII was 578 × 10(-9), and this value was used to stratify patients with NSCLC into low TII (≤ 578 × 10(-9)) and high TII (>578 × 10(-9)) groups. Univariate and multivariate analyses revealed that high TII was an independent predictor for overall survival and recurrence-free survival in both the training and validation cohorts. The areas under the curve of the TII for survival and recurrence were significantly larger than those for tumor, node, metastasis (TNM) stage and carcinoembryonic antigen. In the subgroup analysis, the TII was also significantly correlated with overall survival (P = 0.001, P = 0.009, and P = 0.007 in the TNM I, II, and IIIa subgroups, respectively) and recurrence-free survival (P < 0.001, P = 0.006, and P = 0.014 in the TNM I, II, and IIIa subgroups, respectively). Similarly, for patients with N2-positive tumors, the overall survival and recurrence-free survival rates for patients in the high TII group were also significantly lower than the respective values for patients in the low TII group (P = 0.026 and P = 0.007, respectively). The TII can be used to distinguish patients with similar pathologies and stages into high and low-risk categories based on the probability of recurrence according to a convenient blood-based test.

The Clinical Utility of Matrix Metalloproteinase 9 in Evaluating Pathological Grade and Prognosis of Glioma Patients: A Meta-Analysis.

In the recent years, matrix metalloproteinase 9 (MMP-9) has been focused on as an indicator of glioma grade and prognosis, especially in China. However, all results resulted in many conflicts. So, it is necessary to conduct a meta-analysis to secure a convincing correlation between MMP-9 and grade and prognosis. Eligible studies were included via multiple searches, and then odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were estimated. Funnel plots were available for evaluation of publication bias. In addition, heterogeneity and sensitivity were also analyzed. In the present meta-analysis, 23 articles were allowed for inclusion with total 1,635 patients. Coincidentally, all studies were conducted in Chinese populations. High MMP-9 expression in gliomas was closely associated with high WHO grade (III+IV) (n = 22, OR = 5.25, 95% CI = 4.09-6.73; p = 0.000), while MMP-9 expression did not correlate to age (n = 4, OR = 1.02, 95 % CI = 0.67-1.54; p = 0.929) and gender (n = 5, OR = 0.91, 95% CI = 0.63-1.33; p = 0.632). Besides, overall survival analysis from two articles revealed MMP-9 expression significantly predicted 5-year-OS (HR = 6.44, 95% CI = 3.88-10.70; p = 0.000) in glioma patients. No heterogeneity and publication bias were observed across all studies. To conclude, this meta-analysis suggests MMP-9 is potently associated with high grade and poor 5 years prognosis, and MMP-9 test of glioma tissues should be established in department of pathology as a routine in clinical practice.

Outcomes for jejunal interposition reconstruction compared with Roux-en-Y anastomosis: A meta-analysis.

AIM: To compare the clinical outcomes between jejunal interposition reconstruction and Roux-en-Y anastomosis after total gastrostomy in patients with gastric cancer. METHODS: A systematic literature search was conducted by two independent researchers on PubMed, EMBASE, the Cochrane Library, Google Scholar, and other English literature databases, as well as the Chinese Academic Journal, Chinese Biomedical Literature Database, and other Chinese literature databases using "Gastrostomy", "Roux-en-Y", and "Interposition" as keywords. Data extraction and verification were performed on the literature included in this study. RevMan 5.2 software was used for data processing. A fixed-effects model was applied in the absence of heterogeneity between studies. A random effects model was applied in the presence of heterogeneity between studies. RESULTS: Ten studies with a total of 762 gastric cancer patients who underwent total gastrostomy were included in this study. Among them, 357 received jejunal interposition reconstruction after total gastrostomy, and 405 received Roux-en-Y anastomosis. Compared with Roux-en-Y anastomosis, jejunal interposition reconstruction significantly decreased the incidence of dumping syndrome (OR = 0.18, 95%CI: 0.10-0.31; P < 0.001), increased the prognostic nutritional index [weighted mean difference (WMD) = 6.02, 95%CI: 1.82-10.22; P < 0.001], and improved the degree of postoperative weight loss [WMD = 2.47, 95%CI: -3.19-(-1.75); P < 0.001]. However, there is no statistically significant difference in operative time, hospital stay, or incidence of reflux esophagitis. CONCLUSION: Compared with Roux-en-Y anastomosis, patients who underwent jejunal interposition reconstruction after total gastrostomy had a lower risk of postoperative long-term complications and improved life quality.

The Clinical Implications of Transforming Growth Factor Beta in Pathological Grade and Prognosis of Glioma Patients: A Meta-Analysis.

The transforming growth factor beta (TGF-ß) pathway plays a key role in oncogenesis of advanced cancers. However, the effects of TGF-ß pathway on gliomas are still controversial. So, it is essential to conduct a meta-analysis to determine their correlations. Eligible studies were included, and then odds ratios (ORs), standard mean differences (SMDs), and hazard ratios (HRs) with 95 % confidence intervals (95% CIs) were estimated. Funnel plots were available for evaluation of publication bias. In this meta-analysis, all 14 eligible studies involving 875 patients were included and conducted in China. Six studies with dichotomous data revealed altered TGF-ß expression in glioma tissues was closely associated with high WHO grade (III + IV) (OR 4.39, 95% CI 2.90-6.63; p = 0.000), meanwhile, seven studies with continuous data also demonstrated TGF-ß expression intensity extremely related to high grade (SMD -2.44, 95% CI -2.71, -2.16; p = 0.000). To our interest, TGF-ß expression was associated with old age (OR 0.59, 95% CI 0.36-0.93; p = 0.025) rather than gender (OR 1.04, 95% CI 0.64-1.67; p = 0.884). Besides, TGF-ß expression significantly correlated to 3-year-OS (n = 2; HR 2.53, 95% CI 1.18-5.41; p = 0.017) rather than 5-year-OS (n = 1; HR 1.04, 95% CI 0.66-1.64; p = 0.872) in glioma patients. No heterogeneity and publication bias were observed across all studies. Taken together, the present meta-analysis testifies TGF-ß is potently associated with high grade and poor 3 years prognosis, and TGF-ß test combined with survivin [1 Mol Neurobiol] and MMP9 [2 Mol Neurobiol] in glioma tissues should be clinically recommended as criteria of glioma grade in department of pathology.

[Bronchial and pulmonary arterial sleeve resection and reconstruction in the treatment of central NSCLC].

OBJECTIVE: To evaluate the indications and surgical procedure of bronchial and pulmonary artery sleeve resection for patients with centrally located non-small cell lung cancer, and how to prevent complications. METHODS: From July 1989 to Aug 2000, 32 cases of central NSCLC were treated with bronchial and pulmonary arterial sleeve resection and reconstruction. The results were retrospectively analyzed. RESULTS: The complication rate was 25.0% (8/32), the mortality rate in 30-day postoperation was 6.3% (2/32), the overall 1-, 3- and 5-year survival rate was 82.8% (24/29), 50.0% (11/22) and 33.3% (4/12), respectively. CONCLUSION: Bronchial and pulmonary arterial sleeve resection and reconstruction in the treatment of patients with central NSCLC can not only maximize preservation of functional pulmonary parenchyma and improve patients, quality of life, but also provide an opportunity for those patients with poor pulmonary function to receive surgical resection of the tumor.

The vertical distribution of bacterial and archaeal communities in the water and sediment of Lake Taihu.

This study was conducted to characterize the vertical distribution of bacterial and archaeal communities in the water and sediment of Lake Taihu, which underwent a change in trophic status from oligotrophic to hypertrophic in last half of the 20th century. The results revealed that the bacterial communities in different layers of sediment sample were very similar, and were related to Alpha-, Beta-, Gamma- and Deltaproteobacteria, Nitrospira, Bacteroidetes, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Chlorobi, Actinobacteria and Acidobacteria. In contrast, the archaeal communities varied greatly with depth. The archaeal communities were primarily related to Euryarchaeota and Crenarchaeota, with methanogenic Archaea accounting for approximately 2-35% of the total Archaea. Additionally, sequences related to putative ammonia-oxidizing Archaea and ammonia-oxidizing Bacteria were detected in different layers of sediment samples. The abundance of Archaea, Bacteria, methanogenic Archaea and Nitrospira was further characterized by real-time PCR.

Using 18F-fluorodeoxyglucose positron emission tomography to estimate the length of gross tumor in patients with squamous cell carcinoma of the esophagus.

PURPOSE: To determine the optimal method of using (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) to estimate gross tumor length in esophageal carcinoma. METHODS AND MATERIALS: Thirty-six patients with esophageal squamous cell carcinoma treated with radical surgery were enrolled. Gross tumor volumes (GTVs) were delineated using three different methods: visual interpretation, standardized uptake value (SUV) 2.5, and 40% of maximum standard uptake value (SUV(max)) on FDG-PET imaging. The length of tumors on PET scan were measured and recorded as Length(vis), Length(2.5), and Length(40), respectively, and compared with the length of gross tumor in the resected specimen (Length(gross)). All PET data were reviewed again postoperatively, and the GTV was delineated using various percentages of SUV(max). The optimal-threshold SUV was generated when the length of PET matched the Length(gross). RESULTS: The mean (+/-SD) Length(gross) was 5.48 +/- 1.98 cm. The mean Length(vis), Length(2.5), and Length(40) were 5.18 +/- 1.93 cm, 5.49 +/- 1.79 cm, and 4.34 +/- 1.54 cm, respectively. The mean Length(vis) (p = 0.123) and Length(2.5) (p = 0.957) were not significantly different from Length(gross), and Length(2.5) seems more approximate to Length(gross.) The mean Length(40) was significantly shorter than Length(gross) (p < 0.001). The mean optimal threshold was 23.81% +/- 11.29% for all tumors, and it was 19.78% +/- 8.59%, 30.92% +/- 12.28% for tumors >/=5 cm, and <5 cm, respectively (p = 0.009). The correlation coefficients of the optimal threshold were -0.802 and -0.561 with SUV(max) and Length(gross), respectively. CONCLUSIONS: The optimal PET method to estimate the length of gross tumor varies with tumor length and SUV(max); an SUV cutoff of 2.5 provided the closest estimation in this study.