Effect of the number of positive lymph nodes and lymph node ratio on prognosis of patients after resection of pancreatic adenocarcinoma

BACKGROUND： The prognostic factors related to lymph node involvement [lymph node status, the number of positive lymph nodes, lymph node ratio （LNR）] and the number of nodes evaluated in patients with pancreatic adenocarcinoma after pancreatectomy are poorly defined. METHODS： A total of 167 patients who had undergone resection of pancreatic adenocarcinoma from February 2010 to August 2011 were included in this study. Histological examination was performed to evaluate the tumor differentiation and lymph node involvement. Univariate and multivariate analyses were made to determine the relationship between the variables related to nodal involvement and the number of nodes and survival. RESULTS： The median number of total nodes examined was 10 （range 0-44） for the entire cohort. The median number of total nodes examined in node-negative （pN0） patients was similar to that in node-positive （pN1） patients. Patients with pN1 diseases had significantly worse survival than those with pN0 ones （P=0.000）. Patients with three or more positive nodes had a poorer prognosis compared with those with the negative nodes （P=0.000）. The prognosis of the patients with negative nodes was similar to that of those with one to two positive nodes （P=0.114）. The median survival of patients with an LNR ≥0.4 was shorter than that of patients with an LNR 〈0.4 in the pN1 cohort （P=0.014）. No significance was found between the number of total nodes examined and the prognosis, regardless of the cutoff of 10 or 12 and in the entire cohort or the pN0 and pN1 groups. Based on the multivariate analysis of the entire cohort and the pN1 group, the nodal status, the number of positive nodes and the LNR were all associated with survival. CONCLUSIONS： In addition to the nodal status, the number of positive nodes and the LNR can serve as comprehensive factors for the evaluation of nodal involvement. This approach may be more effective for predicting the survival of patients with pancreatic adenocarcinoma after pancreatectomy.

Prognostic significance of the number of pelvic lymph nodes removed in patients with early cervical cancer

Objective The aim of this research was to study the prognostic significance of the number of pelvic lymph nodes removed in patients with early cervical cancer.Methods We searched the Pub Med database using the terms "cervical cancer" and "lymph nodes" or "lymphadenectomy". Studies on the association between number of lymph nodes removed and prognosis or survival were identified. We retrospectively studied the relevant research.Results Ten retrospective studies were included. Two studies indicated that the number of lymph nodes had no association with prognosis whereas three studies found a positive relationship. Five studies indicated some factors that could influence the relationship between number of lymph nodes and prognosis.Conclusion The number of lymph nodes removed may positively influence the prognosis of patients with cervical cancer. Some factors may influence the relationship between the extent of lymph nodes removed and patient prognosis. Additional multicenter, prospective studies with large samples are required to confirm the study findings.

Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer

BACKGROUND The prognostic value of quantitative assessments of the number of retrieved lymph nodes(RLNs)in gastric cancer(GC)patients needs further study.AIM To discuss how to obtain a more accurate count of metastatic lymph nodes(MLNs)based on RLNs in different pT stages and then to evaluate patient prognosis.METHODS This study retrospectively analyzed patients who underwent GC radical surgery and D2/D2+LN dissection at the Cancer Hospital of Harbin Medical University from January 2011 to May 2017.Locally weighted smoothing was used to analyze the relationship between RLNs and the number of MLNs.Restricted cubic splines were used to analyze the relationship between RLNs and hazard ratios(HRs),and X-tile was used to determine the optimal cutoff value for RLNs.Patient survival was analyzed with the Kaplan-Meier method and log-rank test.Finally,HRs and 95%confidence intervals were calculated using Cox proportional hazards models to analyze independent risk factors associated with patient outcomes.RESULTS A total of 4968 patients were included in the training cohort,and 11154 patients were included in the validation cohort.The smooth curve showed that the number of MLNs increased with an increasing number of RLNs,and a nonlinear relationship between RLNs and HRs was observed.X-tile analysis showed that the optimal number of RLNs for pT1-pT4 stage GC patients was 26,31,39,and 45,respectively.A greater number of RLNs can reduce the risk of death in patients with pT1,pT2,and pT4 stage cancers but may not reduce the risk of death in patients with pT3 stage cancer.Multivariate analysis showed that RLNs were an independent risk factor associated with the prognosis of patients with pT1-pT4 stage cancer(P=0.044,P=0.037,P=0.003,P<0.001).CONCLUSION A greater number of RLNs may not benefit the survival of patients with pT3 stage disease but can benefit the survival of patients with pT1,pT2,and pT4 stage disease.For the pT1,pT2,and pT4 stages,it is recommended to retrieve 26,31 and 45 LNs,respectively.

Does lymph node dissection improve the prognosis of patients with colorectal cancer?

The number of lymph nodes(LNs)dissected during surgery has become an interesting topic.Simple intuition always leads us to believe that dissecting more LNs will result in more accurate pathological staging and assurance of surgical quality.However,when the number of LNs dissected reaches a certain threshold,the patient’s prognosis does not continue to improve as the number of dissected nodes increases.Instead,an increase in the number of dissected LNs may be accompanied by a higher incidence of complications.Currently,there are only less than 40%of colorectal cancer patients undergoing adequate LN evaluation.Therefore,obtaining a sufficient number of LNs in clinical practice is extremely challenging.How to further address the insufficiency of LN dissection due to various reasons,which results in concerns of surgeons about patient prognosis,is currently a critical focus.

The value of the lymph node ratio and total number of lymph nodes examined for resected pancreatic signet ring cell carcinoma:a retrospective cohort study

Background:Pancreatic signet ring cell carcinoma(SRCC)is an exceedingly rare histological subtype of pancreatic cancer.Previous studies have focused on the trends of incidence and independent predictors of pancreatic SRCC.Our objectives of the study were to analyze the prognostic value of the lymph node ratio(LNR)and to explore the minimal number of lymph nodes examined to accurately evaluate the N stage in resected pancreatic SRCC.Method:We analyzed 120 patients diagnosed from January 1,1990,to December 31,2016,constituted the study cohort from the Surveillance,Epidemiology,and End Results(SEER)registry.We calculated the overall survival(OS)of these patients by using a Kaplan–Meier analysis.The Kaplan–Meier analysis was used to analyze the influence of various factors on the prognosis of patients in the univariate analysis.The multivariate Cox analysis were applied to find independent prognostic factors of patients with pancreatic SRCC.Receiver-operating characteristic curve(ROC)analysis to investigate the discriminatory ability of the total number of lymph nodes examined(TNLE)relative to whether lymph node metastasis was present.Results:The median number of lymph nodes examined among 120 patients with resected pancreatic SRCC was 14(interquartile range:6.25–20.0).According to the univariate analysis of OS,age,grade,chemotherapy,LNR,and TNLE were significantly different(P<.05).We demonstrated the prognostic benefit of chemotherapy in resected pancreatic SRCC,whereas radiotherapy was not associated with improved survival.The multivariate survival analysis showed that LNR and grade were independent prognostic indicators after pancreatic SRCC resection for OS.TNLE≥8 showed the highest discriminatory power for evaluating lymph node metastasis(Area under curve(AUC):0.656,95%confidence interval:0.564–0.741,Youden index:0.2533,sensitivity:78.67%,specificity:46.67%,P=.003).Conclusion:Our study indicated that the LNR was a valuable independent prognostic factor for resected pancreatic SRCC.Regional lymphadenectomy of at least 8 lymph nodes was necessary to accurately stage patients.An adequate number of lymph nodes examined are necessary for clinicians to accurately predict the significance of the LNR in resected pancreatic SRCC.

Robustness analysis of interdependent PV grids and communication network based on complex network

Currently,the photovoltaic（ PV） cloud network is an important research point in energy Internet. From the perspective of the robustness analysis of PV cloud network,traditional robustness index,the relative size of the giant connected component before and after the cascading,which is focused on the giant component,is not appropriate for the distributed PV network because of the big difference between PV generators and large power grid. In this paper,a new index is proposed,the minimum removed nodes number（ MRNN）,which can make the entire system collapse,to evaluate the robustness of PV cloud network system. Simulation results show that MRNN can clearly indicate the system robustness under different parameters.