| IntroductionBladder cancer has become a worldwide problem threatening human health.Radical cystectomy(RC)combined with pelvic lymph node dissection is the gold standard for the treatment of high-risk non-muscle invasive and muscle invasive bladder cancer.At present,the prognostic factors of bladder cancer are as follows:tumor stage,grade,age,physical condition,adjuvant therapy.There is still controversy about the effect of the number of lymph node dissection and lymph node positivity on the prognosis of bladder cancer.ObjectiveAn overview of the therapies of bladder cancer.We conducted the first meta-analysis to clarify the potential associations of lymph node positivity and the outcomes of bladder cancer treated with RC on the basis of findings from all published epidemiological studies.Additionally,we conducted the first meta-analysis to clarify the potential association between the number of dissected lymph nodes and the outcomes of bladder cancer treated with RC,on the basis of findings from all published epidemiological studies.Methods1.Review the treatment of bladder cancerSummarize the treatment of bladder cancer by searching the related literature.2.The associations of lymph node positivity with the outcomes of bladder cancer treated with radical cystectomy:a meta-analysisPubMed,Web of Science,and the Cochrane Library were searched to identify potentially relevant published literature up to July 2016.The primary search terms included the following items:’radical cystectomy’,or ’bladder cancer’,or’transitional cell carcinoma’,or ’urinary bladder neoplasms’;’lymphadenectomy’,or’lymph node positivity’,or ’lymph node involvement’,or ’lymph node metastasis’,or’lymph node dissection’,or’lymph node excision’,or ’lymph node removed’;’outcome’,or ’survival’,or ’mortality’,or ’recurrence’.Meta-analysis was performed using STATA Statistical Software(version 12.0,Stata Corp.,College Station,TX,USA).We assessed publication bias using funnel plots coupled with Begg’s and Egger’s tests.Moreover,sensitivity analyses were performed to clarify whether the results were influenced due to someone study by omitting one study at a time.3.A greater number of dissected lymph nodes is associated with more favorable outcomes in bladder cancer treated by radical cystectomy:a meta-analysisA systematic literature search was performed in PubMed,Embase and the Cochrane Library to identify the eligible studies published from the inception of the databases to April 2016.The primary search string included the following items:’radical cystectomy’,or ’bladder cancer’,or ’transitional cell carcinoma’,or ’urinary bladder neoplasms’;’lymphadenectomy’,or ’lymph node dissection’,or ’lymph node excision’,or ’lymph node removed’;’outcome’,or ’survival’,or ’mortality’,or’recurrence’.All statistical analyses were conducted using STATA 12.0(StataCorp LP,College Station,TX,USA).Furthermore,Egger’s test and Begg’s method were applied to evaluate the possible bias,combined with a visual inspection of the funnel plot.Moreover,sensitivity analyses were performed to clarify whether the results were influenced due to someone study by omitting one study at a time.Results1.The associations of lymph node positivity with the outcomes of bladder cancer treated with radical cystectomy:a meta-analysisFinally,a total of 24 studies including 17452 cases were chosen for the meta-analysis,which were retrospective cohort designed and published between 2004 and 2015.7 studies including 9947 cases reported the relationships between lymph node positivity and overall mortality of bladder cancer treated by RC.The increased risk was observed in the meta-analysis between the two.The summary relative risk estimates(SRRE)for overall mortality was 2.05(95%CI,1.34-2.76),suggesting that lymph node positivity was an indicator of poor prognosis for bladder cancer after RC.9 studies including 4082 cases assessed the associations of lymph node positivity with recurrence of bladder cancer after RC.The summary relative risk estimates(SRRE)were statistically significant for recurrence(SRRE 2.07;95%CI,1.79-2.35).Lymph node positivity was associated with worse cancer-specific mortality of bladder cancer after summarizing 14 studies on cancer-specific mortality.The summary relative risk estimates(SRRE)was 1.87(95%CI 1.43-2.30).No statistical evidence of publication bias was found by the Begg’s or Egger’s tests.We did not find any single study would affect the overall result by sensitivity analyses.2.A greater number of dissected lymph nodes is associated with more favorable outcomes in bladder cancer treated by radical cystectomy:a meta-analysisFinally,a total of 25 studies including 41,400 cases were chosen for the meta-analysis,which were retrospective cohort designed and published between 2003 and 2015.The pooled results for the OS of bladder cancer patients using a random-effects model based on 13 studies,with a sample size of 34,128 individuals.An inverse association was identified between the highest vs.the lowest category of LND and the OS rates of bladder cancer patients treated with RC[summary relative risk estimate(SRRE)=0.72;95%CI,0.64-0.80)].The outcomes of bladder cancer were presented as CSS in 14 studies with a total of 12,518 bladder cancer patients.A decreased risk,corresponding to a higher CSS rate of bladder cancer patients was found in the patients in whom a greater number of nodes were removed during RC(SRRE=0.66;95%CI,0.54-0.80).The association between the number of dissected nodes and the RFS of bladder cancer patients following RC was reported in 9 studies,including 4,387 bladder cancer patients.The summarized result of these studies indicated that a significant inverse association was observed between the highest vs.the lowest category of LND and the RFS of bladder cancer following RC,with an SRRE of 0.64(95%CI,0.50-0.82).No statistical evidence of publication bias was indicated by the Begg’s test and the Egger’s test.We did not find any single study would affect the overall result by sensitivity analyses.Conclusions1.The gold standard for the treatment of high-risk non muscle invasive bladder cancer and muscle invasive bladder cancer is radical cystectomy and pelvic lymphadenectomy.2.The results of this study showed that lymph node positivity reduced OS,RFS and CSS in patients undergoing radical cystectomy.3.Overall,bladdercancer patients with the highest category of LND had 28%,34%and 36%reducedrisks,corresponding to overall survival,cancer-specific survival and recurrence-free survival,respectively,compared with patients with the lowest category of LND. |
PDF Full Text Request