Risk Factors for Ipsilateral Adrenal Involvement in Renal Cell Carcinoma

Objectives We retrospectively review patients treated for renal cell carcinoma at 19 institutes in collaboration with the Japanese Society of Renal Cancer, to clarify the risk factors for ipsilateral adrenal involvement (IADI). Methods The clinicopathologic factors of the 30 patients with IADI were compared with those of the 926 control patients without IADI, and independent predictors for IADI were identified by multivariate analysis. Results Preoperative computed tomography (CT) could detect 83.3% of the instances of synchronous ipsilateral adrenal metastasis. Patients with IADI had significantly larger primary tumors, higher pT stages and histologic grades, and higher percentages of upper pole involvement, microvascular invasion, spindle-cell-type tumors, lymph node metastasis (LNM), and distant metastasis (DM) outside the ipsilateral adrenal gland (IAd) than in control patients. Multivariate logistic regression analysis of clinical factors revealed that tumor size greater than 5.5 cm, pT stage of 3 or higher, LNM, and DM outside IAd, but not upper pole involvement, were significant predictors of IADI. Conclusions Tumor size greater than 5.5 cm, clinical T stage of 3 or higher (tumor for which pT stage of 3 or higher is suspected), LNM, and DM outside IAd seemed to be important preoperative indicators of IADI. These factors and CT findings would be useful preoperative indicators for ipsilateral adrenalectomy. Moreover, patients with renal cell carcinoma who have normal adrenal on CT, have a T1 tumor extending less than 5.5 cm, and have neither LNM nor DM are good candidates for adrenal-sparing nephrectomy.