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- Wang, Yang, et al.
(author)
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Prognostic value of the extent of lymphadenectomy for esophageal cancer-specific survival among T1 patients
- 2021
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In: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 21:1
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Journal article (peer-reviewed)abstract
- Background: Clinically, there are no clear guidelines on the extent of lymphadenectomy in patients with T1 esophageal cancer. Studying the minimum number of lymph nodes for resection may increase cancer-specific survival.Methods: Patients who underwent esophagectomy and lymphadenectomy at T1 stage were selected from the Surveillance, Epidemiology and End Results Program (United States, 1998–2014). Maximally selected rank and Cox proportional hazard models were used to examine three variables: the number of lymph nodes examined, the number of negative lymph nodes and the lymph node ratio.Results: Approximately 18% had lymph node metastases, where the median values were 10, 10 and 0 for the number of lymph nodes examined, the number of negative lymph nodes and the lymph node ratio, respectively. All three examined variables were statistically associated with cancer-specific survival probability. Dividing patients into two groups shows a clear difference in cancer-specific survival compared to four or five groups for all three variables: there was a 29% decrease in the risk of death with the number of lymph nodes examined ≥14 vs < 14 (hazard ratio 0.71, 95% confidence interval: 0.57–0.89), a 35% decrease in the risk of death with the number of negative lymph nodes ≥13 vs < 13 (hazard ratio 0.65, 95% confidence interval: 0.52–0.81), and an increase of 1.21 times in the risk of death (hazard ratio 2.21, 95% confidence interval: 1.76–2.77) for the lymph node ratio > 0.05 vs ≤ 0.05.Conclusions: The extent of lymph node dissection is associated with cancer-specific survival, and the minimum number of lymph nodes that need to be removed is 14. The number of negative lymph nodes and the lymph node ratio also have prognostic value after lymphadenectomy among T1 stage patients.
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- Zhang, Xiangwei, et al.
(author)
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The Prognostic Value of Tumor Length for Cause-Specific Mortality in Resectable Esophageal Cancer.
- 2018
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In: Annals of Thoracic Surgery. - : Elsevier. - 0003-4975 .- 1552-6259. ; 106:4, s. 1038-1046
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Journal article (peer-reviewed)abstract
- BACKGROUND: The current esophageal cancer AJCC-TNM staging system may not capture the full prognostic implications of the primary tumor. A study is needed to explore the prognostic value of tumor size on esophageal cancer-specific mortality.METHODS: Patients who underwent surgical resection for non-metastatic esophageal cancer were selected from the Surveillance, Epidemiology and End Results Program database (United States, 1988 - 2014). Using statistics methods - maximally selected rank and two hazard models (Cox model and Fine-Gray model) - the optimum cutoff point for tumor length in each T classification was estimated and the prognostic value of tumor size on esophageal cancer-specific mortality was analyzed.RESULTS: 4,447 patients were identified. The median tumor size was significantly correlated with T classification, with the correlation coefficient of 0.43 (p < 0.001). Patients in the T1-T3 classifications who had larger tumor size showed a larger probability of cancer-specific mortality. The multivariate Cox model showed that tumor size was significantly associated with an increase in cancer-specific mortality in T1 (2.15, 95% CI [1.72, 2.69]) and T2 (1.31, 95% CI [1.06, 1.62]), but marginally significantly in T3 (1.12, 95% CI [1.00, 1.27]) and insignificantly in T4 classification (p > 0.1). Similar results were found using the multivariate Fine-Gray model.CONCLUSIONS: We have found that combining T classification with tumor size can increase the precision in identifying the high-risk groups in T1-T2 classification. Based on esophageal cancer-specific mortality our study is the first to explore the prognostic cutoff point of tumor size by T classification.
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- Wu, Lele, et al.
(author)
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Organic matter composition and stability in estuarine wetlands depending on soil salinity
- 2024
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In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 945
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Journal article (peer-reviewed)abstract
- Coastal wetlands are key players in mitigating global climate change by sequestering soil organic matter. Soil organic matter consists of less stable particulate organic matter (POM) and more stable mineral -associated organic matter (MAOM). The distribution and drivers of MAOM and POM in coastal wetlands have received little attention, despite the processes and mechanisms differ from that in the upland soils. We explored the distribution of POM and MAOM, their contributions to SOM, and the controlling factors along a salinity gradient in an estuarine wetland. In the estuarine wetland, POM C and N were influenced by soil depth and vegetation type, whereas MAOM C and N were influenced only by vegetation type. In the estuarine wetland, SOM was predominantly in the form of MAOM ( > 70 %) and increased with salinity (70 % -76 %), leading to long-term C sequestration. Both POM and MAOM increased with SOM, and the increase rate of POM was higher than that of MAOM. Aboveground plant biomass decreased with increasing salinity, resulted in a decrease in POM C (46 % - 81 %) and N (52 % -82 %) pools. As the mineral amount and activity, and microbial biomass decreased, the MAOM C (2.5 % -64 %) and N pool (8.6 % -59 %) decreased with salinity. When evaluating POM, the most influential factors were microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Key parameters, including MBC, DOC, soil salinity, soil water content, aboveground plant biomass, mineral content and activity, and bulk density, were identified as influencing factors for both MAOM abundance. Soil water content not only directly controlled MAOM, but together with salinity also indirectly regulated POM and MAOM by controlling microbial biomass and aboveground plant biomass. Our findings have important implications for improving the accumulation and increased stability of soil organic matter in coastal wetlands, considering the global sea level rise and increased frequency of inundation.
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4. |
- Wu, Yuntao, et al.
(author)
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Climatic controls on stable carbon and nitrogen isotope compositions of temperate grasslands in northern China
- 2023
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In: Plant and Soil. - : Springer. - 0032-079X .- 1573-5036. ; 491, s. 133-144
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Journal article (peer-reviewed)abstract
- Aims The natural abundances of stable carbon (C) and nitrogen (N) isotopes (delta C-13 and delta N-15) are extensively used to indicate the C and N biogeochemical cycles at large spatial scales. However, the spatial patterns of delta C-13 and delta N-15 in plant-soil systems of grasslands in northern China and their main driving factors across regional climatic gradient are still not well understood. Methods We measured plant and soil delta C-13 and delta N-15 compositions as well as their associated environmental factors across 2000 km climatic gradient (-0.2 to 9 degrees C; 152 to 502 mm) in grasslands of northern China. Results The soil delta C-13 and delta N-15 values in surface were lower than those in bottom for temperate typical steppe but had no significant differences for temperate meadow steppe and temperate desert steppe. Soil delta C-13 values declined with increasing soil organic carbon (SOC) but increased as mean annual temperature (MAT). These changes were attributed to the microbial decomposition rate. The delta N-15 values in soil and plant were negatively correlated with MAT and mean annual precipitation (MAP), which were mainly related to the low soil organic matter mineralization rate and the shift of dominant species from C-4 to C-3. Conclusions Our results indicate the spatial patterns and different influencing factors on delta C-13 and delta N-15 values along the climatic gradient in grasslands of northern China. The findings will provide scientific references for future research on the C and N biogeochemical cycles of temperate grasslands.
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- Zhang, Xiangwei, et al.
(author)
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The prognostic value of tumor length to resectable esophageal squamous cell carcinoma : a retrospective study
- 2017
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In: PeerJ. - : PeerJ. - 2167-8359. ; 5
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Journal article (peer-reviewed)abstract
- Background: The current TNM classification system does not consider tumor length for patients with esophageal carcinoma (EC). This study explored the effect of tumor length, in addition to tumor depth and lymph node involvement, on survival in patients with esophageal squamous cell carcinoma (ESCC).Methods: A total of 498 ESCC patients who underwent surgical resection as the primary treatment were selected in the retrospective study. Pathological details were collected, which included tumor type, TNM stage, differentiation. Other collected information were: the types of esophageal resection, ABO blood group, family history and demographic and lifestyle factors. A time-dependent receiver operating characteristic (ROC) curve and a regression tree for survival were used to identify the cut-off point of tumor length, which was 3 cm. Univariate and multivariate Cox proportional hazard regression models were used to identify the prognostic factors to ESCC.Results & Discussion: The 1-, 3-, 5-year overall survival rates were found to be 82.5%, 55.6%, and 35.1%, respectively. Patients who had larger tumor length (>3 cm) had a higher risk for death than the rest patients. From the univariate Cox proportional hazards regression model, the overall survival rate was significantly influenced by the depth of the tumor and lymph node involvement (either as dummy or continuous variables), Sex, and tumor length. Using these four variables in the multivariate Cox proportional hazard regression model, we found that the overall survival was significantly influenced by all variables except Sex. Therefore, in addition to the depth of the tumor and lymph node involvement (as either dummy or continuous variables), the tumor length is also an independent prognostic factor for ESCC. The overall survival rate was higher in a group with smaller tumor length (≤3 cm) than those patients with larger tumor length (>3 cm), no matter what the tumor stage was.Conclusion: The tumor length was found to be an important prognostic factor for ESCC patients without receiving neoadjuvant therapy. The modification of EC staging system may consider tumor length to better predict ESCC survival and identify higher risk patients for postoperative therapy.
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