Sarcomatoid Features in mRCC Predict Worse Survival After Cytoreductive Nephrectomy

Patients who have metastatic renal cell carcinoma with sarcomatoid differentiation in the primary tumor have a 35% increased risk for death following cytoreductive nephrectomy, study found.

Sarcomatoid features in the tumors of patients with metastatic renal cell carcinoma (mRCC) are associated with higher mortality rates among those receiving upfront cytoreductive nephrectomy (CN), new findings presented at the European Association of Urology 2020 virtual congress suggest.

The findings are from a study of 617 patients with mRCC who underwent CN with or without metastasectomy. Investigators stratified patients according to the presence of sarcomatoid features (SF) in the final specimen.

Of the 617 patients, 118 (19.1%) had sarcomatoid features in the final specimen, Michele Marchioni, MD, of SS Annunziata Hospital in Chieti, Italy, and colleagues reported. The median involvement of the sarcomatoid component was 35%. A significantly higher proportion of patients with than without SF were classified as having a poor prognosis based on Heng’s criteria (44.9% vs 33.3%). Patients with SF more frequently harbored locally advanced disease (pT3-4 stage tumors: 88.1% vs 73.7%) and pN1 tumors (28.80% vs 18.22%), according to the investigators.

The cohort had a median follow-up of 55.1 months. A total of 395 patients (64%) died. The median overall survival was significant shorter for patients with SF (13.1 vs 17.9 months). Patients with SF had a significant 35% increased risk for death even after accounting for Heng’s risk group, type of surgery and pT and pN stage.

In addition, among patients with SF, mortality rates among those with SF involvement greater than 35% and greater than 50% were similar to those with SF involvement less than 35% and less than 50%, respectively.

The results suggest that all patients with SF in the primary tumor “should be carefully followed independently of percentage of sarcomatoid differentiation,” Dr Marchioni and colleagues concluded.