Lymph node dissection has two potential roles: staging and/or a therapeutic effect. Genitourinary malignancies such as testis and penile cancers have an established survival benefit of lymph node dissection, whereas the role of LND for RCC is much more controversial. Dr. Gershman stated that the biologic plausibility of LND for M0 patents is the potential curative nature for pN1 RCC. In the M1 patient, cytoreduction of tumor burden may reduce tumor immunosuppression and improve response to systemic therapy.
EORTC 30881 randomized 732 patients with cT1-3N0M0 to radical nephrectomy with or without lymph node dissection. Only 4% of these patients were pN1. No improvement in progression free or overall survival was noted. Observational studies of M0-1 patients at average risk support EORTC 30881 data. A recent Bhindi et al BJUI publication was a meta-analysis of 7 studies which demonstrated no improvement in survival for patients who receive LND in M0, M1, and M0-1 cohorts.
A 2017 analysis evaluated almost 1800 patients with a propensity score adjustment treated at a single center with radical nephrectomy for M0 RCC from 1990-2010, 35% of which underwent LND (6.2% were pN1). Again, no differences were seen in cancer specific or overall survival. A total of 3 studies have evaluated the role of LND in cN1 RCC patients. The 2 most contemporary publications show no improvement in cancer outcomes with LND.
A study by Ristau et al evaluated 1943 patients from the ASSURE trial (36.1% underwent LND). High risk patients were defined as pT1bN0 G3-4, >pT2N0, or pTanyN+. No benefit in LND was seen in overall or cancer specific survival. A secondary analysis of patients from EORTC 30881 with cT3N0M0 subgroup treated with radical nephrectomy +/- LND were evaluated in an intention to treat analysis. Similarly, no benefit in LND was identified.
Dr. Gershman summarized the studies he discussed with this excellent chart:
In the absence of level 1 evidence, Dr. Gershman suggested we must rely on collective observational data. Although it appears that LND is not therapeutic, it still is likely prognostic. pN1 patients may consider adjuvant therapy while cN1 patients may benefit from clinical trials (neoadjuvant therapy). Multiple studies have demonstrated that LND does not increase morbidity rates compared to radical nephrectomy alone.
In conclusion N1 disease independently prognostic for both M0 and M1 RCC. Staging role is important with emerging paradigms of multimodal management.
Presented by: Boris Gershman, MD Rhode Island Hospital and The Miriam Hospital, Warren Alpert Medical School of Brown University
Written by: David B. Cahn, DO, MBS @dbcahn, Fox Chase Cancer Center, Philadelphia, PA at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA