suggests an Italian cohort study.
Investigators led by Davide Bimbatti, MD, of Azienda Ospedaliera Universitaria Integrata in Verona, Italy, retrospectively studied 52 patients with mRCC who started active surveillance as their initial strategy for disease management. They assessed three predictors of outcomes: International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk class, number of metastatic sites, and tumor burden.
Patients remained on active surveillance for a median of 18.3 months and had a median total overall survival of 80.1 months, according to study results published in Urologic Oncology. Fully 69.2% started first-line systemic therapy during a median follow-up of 38.5 months.
The only baseline factor predicting time on active surveillance was IMDC class (hazard ratio, 2.15; P = .011).
An increasing number of metastatic sites during active surveillance was associated with poorer total overall survival (HR, 2.86; P = .010) and a trend toward poorer postsurveillance overall survival (HR, 2.37; P = .060).
Increasing tumor burden, measured as the sum in millimeters of the longest tumor diameter of each measurable lesion, during active surveillance was associated with both poorer total overall survival (HR, 1.16; P = .024) and poorer postsurveillance overall survival (HR, 1.21; P = .004).
Finally, an IMDC class of good or intermediate versus poor at the start of systemic therapy was a favorable predictor (HR, 0.07; P = .010; and HR, 0.12; P = .044, respectively) and an increase in tumor burden was an unfavorable predictor (HR, 1.26; P = .005) of postsurveillance overall survival.
“Our study confirms that active surveillance is a safe option for certain patients, with a median time on surveillance of 1.5 years delaying the beginning of systemic therapies and avoiding drug-related toxicities, with a median overall survival greater than 6.5 years,” wrote Dr. Bimbatti and coinvestigators.
“During active surveillance, patients rarely show any deterioration of the IMDC prognostic class. Meanwhile, the tumor burden changes, more than the increase of metastatic sites, account for the heterogeneity of the disease and may help physicians to make decisions about the early termination of active surveillance and the start of systemic therapy,” they concluded.
SOURCE: Bimbatti D et al. Urol Oncol. 2018 Oct 6. doi: 10.1016/j.urolonc.2018.08.018.