Login to Access Video or Poster Abstract: MP67-02
Sources of Funding: none

Introduction

Heterochromatin protein 1 gamma (HP1?) is a non-histone heterochromatic protein, which plays an important role in maintaining the stability of chromatin and embryonic development. Recently, HP1? has been implied to be involved in the development and progression of cancer. Here, we investgated the association of HP1? expression with oncologic outcome of patients with non-metastatic clear cell renal cell carcinoma (ccRCC).

Methods

In this retrospective study, we enrolled 721 patients with non-metastatic ccRCC performed partial or radical nephrectomy at two academic medical centers between 2005 and 2009. The first cohort with 521 patients was treated as training cohort and the other as validation cohort. Tissue microarrays (TMAs) were built on triplicate from formalin-fixed, paraffin embedded specimens. Immunohistochemistry (IHC) was performed and the association of HP1? expression with standard pathologic features and clinical outcomes were evaluated.

Results

High HP1? expression were remarkably correlated with shortened survival time (P = 0.001 and P < 0.001, respectively) and increased risk of recurrence (P = 0.037 and P = 0.001, respectively) in both cohorts. HP1? could also offer a better prognostic stratification based on traditional histologic factors. Furthermore, multivariate analyses confirmed HP1? to be an independent adverse prognostic factor for post-operative survival of patients. A predictive nomogram was generated based on identified independent risk factors to for a better prognosis of patients’ survival at 5 and 10 years.

Conclusions

HP1? expression emerges as an independent prognostic factor for non-metastatic ccRCC patients after surgical treatment

Funding

none