Should direct ipsilateral adrenal invasion from renal cell carcinoma be classified as pT3a?

PURPOSE The 2002 American Joint Committee on Cancer primary tumor classification for renal cell carcinoma (RCC) defines a tumor as pT3a if it invades the perinephric or renal sinus fat or directly invades the ipsilateral adrenal gland. In the current study we evaluated the association of direct ipsilateral adrenal invasion with outcome to determine if reclassification of these tumors as pT4 would improve the accuracy of the current tumor classification. MATERIALS AND METHODS We studied 424 patients who underwent nephrectomy and adrenalectomy for unilateral, sporadic, pT3 or pT4 RCC between 1970 and 2000 at the Mayo Clinic. Cancer specific survival was estimated using the Kaplan-Meier method. RESULTS Cancer specific survival for the 22 patients with pT3a or pT3b tumors that directly invaded the ipsilateral adrenal gland was significantly worse compared with that of patients with pT3a (p <0.001) or pT3b (p = 0.011) disease that did not invade the adrenal gland. There was no significant difference in the 5-year cancer specific survival between the patients with pT3a or pT3b tumors that directly invaded the ipsilateral adrenal gland and patients with pT4 tumors (cancer specific survival rates of 20% and 14%, respectively, p = 0.490). CONCLUSIONS Although rare, RCC with direct ipsilateral adrenal invasion behaves more aggressively than tumors involving perinephric or renal sinus fat. We believe that RCC tumors with direct adrenal invasion should be classified as pT4.