8p deletions in renal cell carcinoma are associated with unfavorable tumor features and poor overall survival.

BACKGROUND AND METHODS

8p deletions are common in renal cell carcinoma. To study their prognostic impact and association with kidney cancer phenotype, a tissue microarray with 1,809 cancers was analyzed by fluorescence in situ hybridization for 8p21 copy numbers.

RESULTS

One thousand four hundred and seventy four interpretable tumors showed substantial differences between renal cancer subtypes. That 8p deletion was only seen in 1 (0.5%) of 216 papillary carcinomas underscores the biologic uniqueness of papillary kidney cancer, which is also defined by a highly distinct morphology. 8p deletions were found in 13.2% of 976 clear cell carcinomas, 7.8% of 77 chromophobe carcinomas, 0.8% of 119 oncocytomas, but also in several rare tumor entities including 1 of 4 collecting duct cancers, 1 of 3 multilocular cystic clear cell renal cell neoplasm of low malignancy, 2 of 10 Xp11.2 translocation cancers, 3 of 18 not otherwise specified carcinomas, and 1 analyzed medullary carcinoma. In clear cell carcinomas, 8p deletions were significantly associated with higher International Society of Urologic Pathologists (ISUP) grading (P = 0.0014), Fuhrman (P = 0.0003) and Thoenes grade (P = 0.0033), advanced tumor stage (P = 0.0002), large tumor diameter (P = 0.0019), distant metastases (P = 0.0183), overall survival (P = 0.0394), and recurrence free survival (P < 0.0001). In multivariate analysis, the prognostic role of 8p deletions was not independent of established clinic-pathological parameters. In conclusion, 8p deletions are strongly linked to tumor aggressiveness in clear cell kidney cancer.

CONCLUSIONS

Because 8p deletions are easy to measure by fluorescence in situ hybridization, 8p deletion assessment, most likely in combination with other parameters, may have a role in future prognosis assessment in clear cell kidney cancer.