Impact factors of lymph node retrieval on survival in locally advanced rectal cancer with neoadjuvant therapy

BACKGROUND Conventional clinical guidelines recommend that at least 12 lymph nodes shouldbe removed during radical rectal cancer surgery to achieve accurate staging.Thecurrent application of neoadjuvant therapy has changed the number of lymphnode dissection.AIM To investigate factors affecting the number of lymph nodes dissected afterneoadjuvant chemoradiotherapy in locally advanced rectal cancer and to evaluatethe relationship of the total number of retrieved lymph nodes(TLN)with diseasefreesurvival(DFS)and overall survival(OS).METHODS A total of 231 patients with locally advanced rectal cancer from 2015 to 2017 wereincluded in this study.According to the American Joint Committee on Cancer(AJCC)/Union for International Cancer Control(UICC)tumor-node-metastasis(TNM)classification system and the NCCN guidelines for rectal cancer,thepatients were divided into two groups:group A(TLN≥12,n=177)and group B(TLN<12,n=54).Factors influencing lymph node retrieval were analyzed byunivariate and binary logistic regression analysis.DFS and OS were evaluated byKaplan-Meier curves and Cox regression models.RESULTS The median number of lymph nodes dissected was 18(range,12-45)in group A and 8(range,2-11)in group B.The lymph node ratio(number of positive lymphnodes/total number of lymph nodes)(P=0.039)and the interval betweenneoadjuvant therapy and radical surgery(P=0.002)were independent factors ofthe TLN.However,TLN was not associated with sex,age,ASA score,clinical T orN stage,pathological T stage,tumor response grade(Dworak),downstaging,pathological complete response,radiotherapy dose,preoperative concurrentchemotherapy regimen,tumor distance from anal verge,multivisceral resection,preoperative carcinoembryonic antigen level,perineural invasion,intravasculartumor embolus or degree of differentiation.The pathological T stage(P<0.001)and TLN(P<0.001)were independent factors of DFS,and pathological T stage(P=0.011)and perineural invasion(P=0.002)were independent factors of OS.Inaddition,the risk of distant recurrence was greater for TLN<12(P=0.009).CONCLUSION A shorter interval to surgery after neoadjuvant chemoradiotherapy for rectalcancer under indications may cause increased number of lymph nodes harvested.Tumor shrinkage and more extensive lymph node retrieval may lead to a morefavorable prognosis.

Comparison of lymph node number and prognosis in gastric cancer patients with perigastric lymph nodes retrieved by surgeons and pathologists

Objective： To compare the numbers of positive and total lymph nodes and prognosis in gastric cancer patients whose perigastric lymph node retrieval was performed by surgeons and pathologists. Methods： We conducted a retrospective analysis of clinical and follow-up data from 1,056 patients who underwent gastric cancer D2 radical lymph node resection between January 2008 and December 2010 in the Gastrointestinal Surgery Department of Yantai Yuhuangding Hospital. The follow-up ended in December 2015. Patients were divided into two groups according to the specialty of physicians who performed the postoperative perigastric lymph node retrieval： the surgeon group （475 cases） and the pathologist group （581 cases）. The numbers of positive and total perigastric lymph nodes and the 3- and 5-year survival were compared between gastric cancer patients in the two groups overall and stratified by TNM stage （AJCC 7th Edition）. Results： Overall, the numbers of positive and total lymph nodes were significantly higher in the surgeon group than in the pathologist group （6.53±4.07 vs. 4.09±3.70, P=0.021; 29.64±11.50 vs. 20.71±8.56, P〈0.001）. Further analysis showed that the total number of lymph nodes in stage Ⅰ patients （19.40±9.62 vs. 15.45±8.59, P=0.011） and the numbers of positive and total lymph nodes in stage Ⅱ（1.38±1.08 vs. 0.87±1.55, P=0.031; 25.35±10.80 vs. 16.75±8.56, P〈0.001） and stage Ⅲ patients （8.11±6.91 vs. 6.66±5.12, P=0.026; 32.34±12.55 vs. 25.45±8.31, P〈0.001） were significantly higher in the surgeon group than in the pathologist group. The survival analysis showed that the 3- and 5-year survival of stage Ⅱ and Ⅲ patients was significantly higher in the surgeon group than in the pathologist group （82.0% vs. 73.1%, 69.5% vs. 61.2%, P=0.038; 49.2% vs. 38.9%, 36.3% vs. 28.0%; P=0.045）. Conclusions： Compared with retrieval performed by pathologists, postoperative perigastrie lymph node retrieval performed by surgeons was associated with significant increase in the total lymph node number of stage Ⅰ patients, the numbers of positive and total lymph nodes of stageⅡ and Ⅲ patients, and the survival of stageⅡ and stage Ⅱ gastric cancer patients.

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.