Abstract: PD53-03
Sources of Funding: None

Introduction

For patients undergoing post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND), the dual goals are to maximize therapeutic efficacy while minimizing morbidity. A prior institutional study showed > 40 lymph nodes (LN) improves the diagnostic efficacy of the operation. Our study evaluates the prognostic significance of LN yield at time of PC-RPLND using the National Cancer Database (NCDB).

Methods

NCDB was used to identify patients who underwent PC-RPLND for non-seminomatous germ cell tumour (NSGCT) from 2004-2013. To ensure proper sequencing of chemotherapy and RPLND, only patients with Stage III NSGCT were included. Patients were stratified by ≤ 20, 21-40, and > 40 LN examined. A multivariable Cox proportional hazards model was constructed to evaluate the association of LN yield at PC-RPLND with overall survival (OS).

Results

A total of 645 patients underwent PC-RPLND for Stage III NSGCT. Patients with > 40 LN, were more likely to have private insurance than those with 21-40 or ≤ 20 (77% vs 74% vs 64%, p = 0.014), pure embryonal (18% vs 15% vs 15%) or teratoma (13.7% vs 12.5% vs 5.8%) histology. On univariate analysis, insurance status (p = 0.015), M1b stage (p = 0.006), positive LN status (p = 0.018), LN metastasis size (<2cm, p = 0.017 & 2-5cm, p = 0.021) and LN count, both as a continuous (p = <0.001) and categorical (p = 0.015) variable, predicted OS (Table 1). Five-year OS was 96% for the > 40 LN group, compared to 91% and 77% for the 21- 40 and ≤ 20 LN groups (Figure 1). Risk-adjusted multivariable Cox model showed an 83% reduction in hazard of death for patients with > 40 LN examined (hazard ratio [HR] 0.17; 95% CI, 0.04- 0.71) (Table 1).

Conclusions

The results from our study demonstrate LN yield appears to be an independent predictor of OS in patients undergoing PC-RPLND. These results suggest that the removal and review of more than 40 LN improves the therapeutic efficacy of PC-RPLND for NSGCT.

Funding

None