Influence of Clinical Risk Factors on Outcomes in Men with Stage I Non-Seminomatous Germ Cell Tumor Undergoing Robot-Assisted Retroperitoneal Lymph Node Dissection

Background: We recently published our multi-institutional experience performing primary robot-assisted retroperitoneal lymph node dissection (RA-RPLND) for men with non-seminomatous germ cell tumor (NSGCT). We concluded that primary RA-RPLND for NSGCT can be performed safely with low complication rates, acceptable early oncologic outcomes, and lower overall theoretical chemotherapy burden. In this commentary, we explore outcomes in clinical stage I patients stratified by clinical risk factors (RF) and estimate reductions in chemotherapy burden. Methods: In our original study, we included clinical stage I and highly select clinical stage II patients. Clinical risk factors were defined as lymphovascular invasion (LVI) and/or predominance of embryonal carcinoma (EC) (>40%) in the orchiectomy specimen. Results: 72% (28/39) of stage I patients that underwent RA-RPLND could be classified as belonging to the RF+ group (Figure 1). Among the RF+ group, 36% (10/28) had both LVI and EC (LVI+EC+). Of the LVI+EC+ patients, 70% had positive nodes (N+), whereas the rate was much lower in the LVI only (LVI+EC-) and EC only (LVI-EC+) groups (17% for both). Primary RA-RPLND allowed for accurate pathologic staging and avoidance of chemotherapy in the 90% and 64% of pN0 patients in the RF-and RF+ groups, respectively. Overall node positive rates were 36% and 9% for men with and without clinical risk factors, respectively. The majority of these node positive patients had pN1 disease and were thus candidates for post RPLND surveillance, thus reducing therapeutic burden and exposure to long-term toxicity. Conclusion : Primary RA-RPLND can be safely performed with low complication rates and acceptable short term oncologic outcomes. Assessing clinical risk factors when deciding on treatment may further improve outcomes by helping to identify clinical stage I patients who are more likely to be stage II and thus benefit most from adjuvant treatment with RPLND.