Background and objective: Clinical significance and indication for lymphadenectomy (LND) in renal cancer are controversial. In this study, we investigated renal cancer patients to clarify practical indications for LND.
Materials and methods: We retrospectively investigated lymph node metastasis in 238 renal cancer patients nephrectomized between September 1987 and November 1996 at Niigata University and related hospitals, especially concerning distant metastasis and clinical (pre- and/or intra-operative) diagnosis for lymph adenopathy, which could be detected before histopathological examination. Survival curves were drawn according to Kaplan-Meier's method, and statistic analyses were performed with chi-square test (or Fisher's exact test), Cox's multivariate proportional hazard test, Log-Rank test and t-test.
Results: One hundred and eighty seven of 238 patients (78.6%) were lymphadenectomized, and in another five patients lymph node dissection was incomplete. Eighteen of 192 patients (9.4%) were revealed to have positive nodes (pN+), which were frequently accompanied with advanced stage, distant metastasis, high grade, large tumor and poor survival compared to pN0. Clinical diagnosis for lymph node metastasis showed 57% of positive predictive value (13 of 23 patients which were expected to have positive nodes (cN+)). All of three false negative cases (2.1% of 142 cN0) had large tumor. cN+ and pN+ were frequently accompanied with increased CRP and/or fever up. Interferon-alpha was effective for two patients to suppress enlargement of newly appeared lymph adenopathy, and not effective for other seven patients with residual or recurrent nodes.
Conclusion: pN+ was frequently accompanied with advanced stage and poor prognosis, which suggested diagnostic and prognostic significance of LND. It was considered that therapeutic LND is indicated for the patients with enlarged lymph nodes or large tumor without distant metastases, and for the patients with both enlarged lymph nodes and distant metastases which seem to be slowly progressing and probably curable.