Clear Cell Renal Cell Carcinoma: Associations Between CT Features and Patient Survival

The objective of this study was to investigate associations between CT features and survival in patients with clear cell renal cell carcinoma (ccRCC).

The study included 763 patients with histopathologically confirmed ccRCC who underwent preoperative contrast-enhanced CT between 1999 and 2011. Imaging features, both qualitative (cystic tumor, necrosis, tumor contact with renal sinus, renal vein invasion, peritumoral stranding, and peritumoral neovascularity) and quantitative (maximal tumor diameter and distance from the tumor to the renal sinus), were evaluated. Univariate and multivariable Cox regressions were used to assess associations of imaging features with disease-specific survival (DSS) and disease-specific progression-free survival (PFS).

Greater tumor size and the presence of renal vein invasion on CT were associated with decreased DSS and disease-specific PFS (p < 0.05), and the presence of extensive necrosis (more than two-thirds of the tumor volume) was associated with decreased disease-specific PFS (p < 0.05); this association remained statistically significant when we controlled for pathologic tumor stage. In contrast, no disease-specific death or progression was seen in patients with purely cystic tumors. Greater distance between the tumor and the renal sinus was not statistically significantly associated with longer survival.

In patients with ccRCC, observation of extensive necrosis on CT was statistically significantly associated with decreased disease-specific PFS, whereas greater tumor size and the presence of renal vein invasion on CT were statistically significantly associated with decreased DSS and disease-specific PFS. No disease progression was observed in tumors with a cystic appearance. Therefore, selected CT features could potentially aid in risk assessment for and counseling of patients with ccRCC and could provide prognostic information beyond the established tumor staging system.