On-target Toxicities Predictive of Survival in Metastatic Renal Cell Carcinoma (mRCC) Treated With Sunitinib: A Multicenter Retrospective Study

BACKGROUND

Preliminary studies suggested that selected drug-related toxicities of sunitinib may correlate with a better prognosis.

PATIENTS AND METHODS

From January 2006 through December 2015, we retrospectively analyzed data of 145 patients with metastatic renal cell carcinoma treated with sunitinib as a first-line therapy in 7 different Italian oncology departments. Hypertension, hypothyroidism, thrombocytopenia, neutropenia, and anemia were evaluated. Overall survival (OS) and progression-free survival (PFS) were calculated. OS and PFS were compared in patients who developed and who did not develop a drug-related toxicity. A multivariate analysis using the Cox regression model was performed.

RESULTS

We evaluated 145 patients (92 males; median age, 70 years); 105 (62.4%) patients experienced at least 1 toxicity: 66 (45.5%) patients developed hypothyroidism, 41 (28.3%) thrombocytopenia, 39 (26.9%) hypertension that required medical therapy, 22 (15.2%) anemia, and 11 (7.6%) neutropenia. The median PFS of patients who developed hypertension was 12 months (95% confidence interval [CI], 9-21 months) versus 9 months (95% CI, 7-12 months) in patients who did not develop toxicity; the median OS was 36 months (95% CI, 22 months to not reached) versus 26 months (95% CI, 18-34 months). For neutropenia, the median PFS was 17.5 months (95% CI, 9-65 months) versus 10 months (95% CI, 8-12 months); the median OS was 23 months (95% CI, 13 months to not reached) versus 28 months (95% CI, 22-35 months). At univariate and multivariate analysis, we observed a protective effect of hypertension and neutropenia on tumor progression (hazard ratio, 0.47; 95% CI, 0.28-0.78 and hazard ratio, 0.26; 95% CI, 0.09-0.76, respectively).

CONCLUSIONS

Many patients developed toxicities during treatment with sunitinib; hypertension and neutropenia were related to longer PFS in our cohort.