Prognostic significance of indeterminate lung nodules in renal cell carcinoma

Many patients with renal cell carcinoma (RCC) are found to have lung nodules at the time of diagnosis. The significance of these nodules is unclear. This study sought to determine whether the presence of indeterminate lung nodules affects survival for patients with early-stage RCC.

A retrospective review was performed of patients with stages I to III RCC at an academic hospital who underwent nephrectomy between 2001 and 2006 and had baseline imaging available for review. Presence of lung nodule(s) was determined, along with patient and disease characteristics. The time from diagnosis to last known follow-up, metastasis, and death were determined. The study follow-up period extended to July 2012. Univariate and multivariate Cox proportional hazards models assessed disease-free and overall survival.

Of 548 patients, 240 met the inclusion criteria. Lung nodules were absent in 148 and present in 92 cases. Disease-free survival was associated with the presence of nodules (hazard ratio [HR] = 1.90; 95% CI: 1.04-3.46; P = 0.0362), tumor stage (stage II-HR = 5.61; 95% CI: 2.69-11.72; P<0.001 and stage III-HR = 2.49; 95% CI: 1.21-5.10; P = 0.0129) and tumor grade (HR = 2.43 for grades 3 or 4; 95% CI: 1.31-4.53; P = 0.005). The number and size of nodules were not associated with survival. Overall survival was associated with Charlson comorbidity score (HR = 1.30; 95% CI: 1.15-1.47; P<0.0001) and primary tumor size (HR = 1.29; 95% CI: 1.14-1.46; P<0.0001) but not the presence of lung nodules (HR = 1.73; 95% CI: 0.83-3.60; P = 0.1454).

The presence of indeterminate lung nodules had a negative effect on disease-free survival. Stage and grade were also significant. These findings underscore the importance of baseline imaging and vigilant surveillance of patients in whom nodules are identified.