Genetic profile and immunohistochemical study of clear cell renal carcinoma: Pathological-anatomical correlation and prognosis.

Introduction: Renal cell carcinoma (RCC) accounts for 2-3% of all tumors being the most frequent solid lesion in the kidney.

Objective: To determine what genetic alterations and immunohistochemical (IHC) of clear cell renal carcinoma (ccRCC) are associated with prognosis and tumor aggressiveness.

Patients And Methods: Experimental analytical study with 57 patients who underwent radical and partial nephrectomy between 2005 and 2011, all with diagnosis of ccRCC and minimum post-operative follow-up of 36 months. The pathological study included IHC determination of biomarkers associated (CAIX, CAM 5.2, CD10, c-erbB-2, EGFR, HIF-1a, Ki67, MDM2, PAX-2 y 8, p53, survivin and VEGFR 1 and 2). Genetic analysis was carried out using multiplex ligation-dependent probe amplification (MLPA). Clinical data were collected and summarized using an access-type database, adding genetic analysis and IHC data of each patient's tumor sample. IHC statistical analysis included Chi-square, Kruskal-Wallis and multivariate analysis. The genetic analysis was performed using multivariate logistic regression (normal/deletion-duplication). Significance level p<0.05.

Results: Pathologic stage was: pT1 (61.8%), pT2 (32.7%); pT3-T4 (5.4%); 16.3% were pN+ and 19.3% M1. 23.6% recurred being predominantly to distance in 83.3%. 27.3% of patients died (73.3% ccCCR). CAIX (Carbonic anhydrase IX) and tumor size were associated with worse Fuhrman grade (p = 0.035; p = 0.001 respectively). Deletion-duplication of genes increased the likelihood: of death (APC, Bcl-2 and CDKN2A by 11, 7 and 4 respectively and SMAD4 reduced the probability by 88%); tumor recurrence (CDKN2A by fifteen fold and VHL reduced the probability by 87%); pT greater than 2 (CCND2, MDM2 and WT1 multiplied by 6, 7 and 9); risk of N+ (CDK4 and EBF1 by 13); distant metastases (BRCA2 and DLEU1 by 5); Fuhrman grade ≥3 (BRCA1, BRCA2 and p53 by 40, 75 and 34 respectively, while that FHIT reduced by 96%). Deletion-duplication of CDK4 and DCC increased survival by a factor of 13 and 16, while that DLEU1 and RUNX1 decreased survival time by 80%.

Conclusion: CAIX and tumor size are associated with increased aggressiveness. The mutations to level 5q, 9p, 11p, 12, 13q, 17, 18q and 21q are associated with more aggressive tumors and with worse survival rate.