The role of lymph node dissection in the management of urothelial carcinoma of the upper urinary tract.

Urothelial carcinoma of the upper urinary tract (UCUUT) is a disease with poor prognosis and a high incidence of lymphatic metastasis at 30-40%. Lymphadenectomy may be a possible surgical strategy to control the spread of lymphatic cancer, but its therapeutic benefit in UCUUT has remained controversial in contrast to bladder cancer in which consensus has been almost reached with respect to the necessity of extended lymphadenectomy. We hypothesized that radical lymphadenectomy may also be important for UCUUT since UCUUT is histologically similar to bladder cancer. One of the major reasons for uncertainty about whether lymphadenectomy has any therapeutic value may have resulted from an incomplete understanding of the regional nodes. Thus, we started our analyses by clarifying this issue, and found that the primary sites of lymphatic metastases encompassed a relatively wide area, especially on the right side, when compared with the conventional recognition. We further reported complete lymphadenectomy in which all regional sites which were dissected appeared to provide a survival benefit for patients with UCUUT at an advanced stage. To date, several studies from the other institutes have added supportive evidence for the therapeutic role of lymphadenectomy. Although there are several points to be determined such as the extent of the template, the minimum number of lymph nodes removed, or the candidate for lymphadenectomy, performing lymphadenectomy is unlikely to have a negative effect on the patient. In the future, we expect that controlled prospective studies will further clarify the potential role of lymphadenectomy in UCUUT.