Factors influencing adrenal metastasis in renal cell carcinoma

We determine the incidence and characteristics of adrenal involvement in localized and advanced renal cell carcinoma, and evaluate the role of adrenalectomy as part of radical nephrectomy.

From 1993 to 1999, 210 patients with renal cell carcinoma (RCC), (139 men and 71 women, mean age 60.8 years, range 12-96) underwent radical nephrectomy with associated adrenalectomy. Patients were divided into two subgroups of 106 with localized (stage T1-2 tumor, groupl) and 104 with advanced (stage T3-4N01M01, group2) renal cell carcinoma. A retrospective review of preoperative computerized tomography (CT) of the abdomen was performed. Radiographic findings were subsequently compared to postoperative histopathological results to assess the predictive value of tumor characteristics and imaging in determining adrenal metastasis.

Of the 210 patients, 15 (7.1%) had adrenal involvement. Tumor stage correlated with probability of adrenal spread, with T3-4 and T1-2 accounting for 13.4% and 0.9% of cases, respectively (p < 0.001). Upper pole intrarenal RCC most likely to spread was local extension to the adrenal gland, representing 53.3% of adrenal involvement. In contrast, multifocal, lower pole and mid region RCC tumors metastasized hematogenously, representing 21.4%, 7%, and 14% of adrenal metastasis, respectively. The relationship between intrarenal tumor size (mean 7.8 cm, range 4 to 21) and adrenal involvement was not statistically significant. Preoperative CT demonstrated 97.7% specificity, 98.4% negative predictive value, 87% sensitivity and 80% positive value for adrenal involvement by RCC.

Ipsilateral adrenalectomy should only be performed if a lesion is seen preoperatively on CT scan or if gross disease is seen at the time of nephrectomy. The prognosis is poor for RCC with ipsilateral involvement even with complete removal. Because of this poor prognosis we believe that adrenal involvement should constitute a separate stage category.