IMDC score, metastatic sites predict survival in mRCC patients undergoing surveillance

Surveillance of favourable-risk patients with metastatic renal cell carcinoma (mRCC) using risk stratification based on the International mRCC Database Consortium (IMDC) and number of metastatic sites may be done following cytoreductive nephrectomy without initiating systemic therapy, suggests a recent study.

“This approach can delay patients’ exposure to the side effects of systemic therapy,” the authors said.

Among mRCC patients who underwent surveillance after cytoreductive nephrectomy, the median systemic therapy-free survival was 23.6 months (95 percent confidence interval [CI], 15.1‒40.6), while the intervention-free survival was 11.8 months (95 percent CI, 8.0‒18.4).

In addition, cancer-specific and overall survival were 54.2 months (95 percent CI, 46.2‒71.4) and 52.4 months (95 percent CI, 40.3‒66.8), respectively.

Notably, favourable-risk patients had longer systemic therapy-free survival (50.6 vs 11.1 months; p<0.01), [intervention-free] survival (25.2 vs 7.3 months; p<0.01), and cancer-specific survival (71.4 vs 46.2 months; p=0.02) than those with unfavourable risk.

This large single-institution study retrospectively analysed patients with mRCC who underwent cytoreductive nephrectomy followed by surveillance. The Kaplan‒Meier method with a log-rank test was used to assess the predictors of survival.

The authors then stratified patients based on IMDC and number of metastatic sites (Rini score), with IMDC score ≤1 and ≤2 metastatic organ sites considered favourable risk. Systemic therapy-free survival was the primary endpoint, while secondary ones included intervention-free survival, cancer-specific survival, and overall survival.