Adult Urology Oncology: Adrenal/Renal/Upper Tract/Bladder The Chromophobe Tumor Grading System is the Preferred Grading Scheme for Chromophobe Renal Cell Carcinoma David S. Finley,* Brian Shuch, Jonathan W. Said, Gretchen Galliano, Robin A. Jeffries, Abdelmonem A. Afifi, Brandon Castor, Clara Magyar, Ardavan Sadaat, Fairooz F. Kabbinavar, Arie S. Belldegrun and Allan J. Pantuck From the Institute of Urologic Oncology (DSF, BS, AS, FFK, ASB, AJP) and Department of Pathology (JWS, GG, BC, CM), David Geffen School of Medicine and Department of Biostatistics, School of Public Health (RAJ, AAA), University of California-Los Angeles, Los Angeles, California Abbreviations and Acronyms CRCC = chromophobe renal cell carcinoma CTG = chromophobe tumor grade ECOG = Eastern Cooperative Oncology Group FNG = Fuhrman nuclear grade OS = overall survival RCC = renal cell carcinoma RFS = recurrence-free survival Submitted for publication April 5, 2011. Study received institutional review board ap- proval. * Correspondence: Institute of Urologic Oncol- ogy, David Geffen School of Medicine at UCLA, 924 Westwood Blvd., Suite 1050, Los Angeles, California 90095, (telephone: 310-206-1434; FAX: 310-794-3513; e-mail: finds7@gmail.com). For another article on a related topic see page 2419. Purpose: The prognostic usefulness of the Fuhrman nuclear grading system has been questioned for chromophobe renal cell carcinoma due to its frequent nuclear and nucleolar pleomorphism. Chromophobe tumor grade, a novel 3-tier tumor grading system based on geographic nuclear crowding and anaplasia, was re- cently reported to be superior to the Fuhrman system. We compared the 2 scoring systems in a large sporadic chromophobe renal cell carcinoma cohort to deter- mine which grading scheme provides the most predictive assessment of clinical risk. Materials and Methods: We identified a total of 84 cases of sporadic chromo- phobe renal cell carcinoma in 82 patients from a total of 2,634 cases (3.2%) spanning 1989 to 2010. A subset of 11 tumors had secondary areas of sarcomatoid transformation. All cases were reviewed for Fuhrman nuclear grade and chro- mophobe tumor grade according to published parameters by an expert genitouri- nary pathologist blinded to clinicopathological information. Results: The distribution of Fuhrman nuclear grades 1 to 4 was 0%, 52.4%, 32.9% and 14.7% of cases, and the distribution of chromophobe tumor grades 1 to 3 was 48.8%, 36.5% and 14.7%, respectively. Metastasis developed in 20 patients (24.4%). Survival analysis revealed statistically significant differences in recur- rence-free survival when adjusted for chromophobe tumor grade and Fuhrman nuclear grade. Chromophobe tumor grade showed a slightly higher AUC for recurrence-free survival and overall survival than the Fuhrman nuclear grading system. Neither chromophobe tumor grade nor Fuhrman nuclear grade was retained as an independent predictor of outcome in multivariate modeling when patients with sarcomatoid lesions were excluded. Conclusions: Chromophobe tumor grade effectively stratifies patients with chro- mophobe renal cell carcinoma across all grading levels. Since it does not rely on nuclear features, it avoids the hazard of overestimating the malignant potential of chromophobe renal cell carcinoma. Overall chromophobe tumor grade has higher predictive accuracy than the Fuhrman nuclear grading system. Key Words: kidney; carcinoma, renal cell; neoplasm metastasis; anaplasia; prognosis EACH year more than 50,000 RCC cases are diagnosed in the United States. 1 Of the major RCC subtypes sporadic CRCC accounts for approx- imately 5% to 10% of the total num- ber. 2–5 Certain clinicopathological 2168 www.jurology.com 0022-5347/11/1866-2168/0 Vol. 186, 2168-2174, December 2011 THE JOURNAL OF UROLOGY ® Printed in U.S.A. © 2011 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH,INC. DOI:10.1016/j.juro.2011.07.068