Impact of the number of lymph nodes retrieved on outcome in patients with muscle invasive bladder cancer.

We postulate that the number of lymph nodes examined in cystectomy specimens can have an impact on the outcome of patients with bladder cancer. We analyzed data on 322 patients with muscle invasive bladder cancer who underwent radical cystectomy and bilateral pelvic lymphadenectomy. We evaluated the associations of the number of lymph nodes identified by the pathologist in the surgical specimen with the local recurrence rate and survival outcome. Patients were divided into groups by lymph node status and the distribution of the number of lymph nodes examined. In stages pN0 and pN+ cases improved survival was associated with a greater number of lymph nodes examined. We determined that at least nine lymph nodes should be studied to define lymph node status accurately. These results indicate that surgical resection and pathological assessment of an adequate number of lymph nodes in cystectomy specimens increases the likelihood of proper staging and impacts patient outcome. Such information is important not only for the therapy and prognosis of individuals, but also for identifying those who may benefit from adjuvant chemotherapy.