Chromosome 9p deletions are an independent predictor of tumor progression following nephrectomy in patients with localized clear cell renal cell carcinoma.

Objectives: Chromosome 9p deletions have been observed in 14% to 36% of patients with clear cell renal cell carcinoma (ccRCC) and are associated with advanced-stage tumors. We evaluated whether chromosome 9p deletions are an independent predictor of worse outcomes in patients with localized ccRCC.

Materials And Methods: In this retrospective study, tumor samples from 94 patients with ccRCC NX-0 M0 who underwent radical nephrectomy or conservative renal surgery were analyzed using a fluorescence in situ hybridization technique.

Results: The median follow-up period was 11.7 years, and 9p deletions were identified in 15% of cases. The cancer-specific survival rate estimated at 5 and 10 years was 99% and 96%, respectively, for patients without such chromosomal losses and 71% and 57% in patients with a loss of 9p (P<0.001). Chromosome 9p deletions were an independent prognostic factor in a multivariate analysis, increasing the risk of death due to disease by 28-fold (95% CI: 5-155, P<0.001). In patients with a low risk of progression, i.e., a low Stage, Size, Grade, and Necrosis score (0-2), low risk according to the University of California at Los Angeles Integrated Staging System, and low risk according to the pathological triad used at University of Sao Paulo, tumors with 9p deletions were significantly associated with a poorer cancer-specific survival at 10 years: 70%, 67%, and 67% vs. 98%, 97%, and 98%, respectively, in patients without 9p deletions.

Conclusion: Chromosome 9p deletions independently establish a poorer prognosis for patients with localized ccRCC, providing further relevant clinical information that may improve the predictive ability of the main prognostic systems currently in use.