Prognostic Impact of Lymphnode Metastases in Patients with Metastatic Renal Cell Carcinoma

BACKGROUND: Lymphnode metastases (LMN) in metastatic renal cell carcinoma (mRCC) has been associated with an unfavourable prognosis. However, the prognostic impact of LNM in mRCC in context of other solid organ metastases and throughout subsequent therapeutic lines is not well-defined. OBJECTIVE: This retrospective single-center analysis was designed to elucidate the impact of LNM in the context of other solid organ metastases and throughout subsequent therapeutic lines. METHODS: mRCC patients (pts) at our center were analysed (observation period, 04/00-03/16). Primary endpoint was overall survival (OS) and the impact of line of therapy as a co-variate. Pts were grouped into: with LNM [LNM(+)], without LNM [LNN(-)]. Subgroup analyses of LNM(+) was performed including the subgroup LNM(+) and other solid organ metastases [LNM(+) other] and LNM(+) without other solid organ metastases [LMN(+) only]. RESULTS: 383/401 mRCC pts were eligible. 318 (83.2%), 230 (60.1%) and 154 (40.5%) pts received 1stL, 2ndL and 3rdL medical treatment, respectively. In the overall population OS was 40.1 months (95% CI: 32.7-47.4), with superior OS in LNM(-) compared to LNM(+) pts (log rank, HR 1.7, 95%-CI 1.3-2.2, p < 0.001). This effect was maintained across lines of therapies. LNM(+) only had a similar risk of death as LNM(-) pts (HR 1.2, 95%-CI 0.8-2.0, p = 0.4), while the risk of death was significantly increased for LNM(+) other compared to LNM(-) (HR 1.9, 95%-CI 1.5-2.6, p <0.001). CONCLUSION: LNM(+) in mRCC is associated with a poor OS. However, impaired OS in LNM(+) might be associated with the presence of other solid organ metastases rather than with the existence of LNM alone. Further studies are warranted to support this hypothesis.