MYC gene amplification drives protein overexpression and its clinical prognostic value in prostate cancer: a study of 152 Chinese cases.

OBJECTIVES

To investigate the expression patterns of ERG, PTEN, and c-Myc proteins in prostate adenocarcinoma; analyze the status of the MYC gene; and evaluate their correlations with clinicopathologic parameters and patient prognosis.

METHODS

In this retrospective study, 152 prostate adenocarcinoma cases were analyzed. Immunohistochemistry was performed for ERG, PTEN, and c-Myc protein expression. Fluorescence in situ hybridization was used to assess ERG rearrangement, MYC gene breakage, and amplification. Statistical analyses were conducted to evaluate associations between molecular markers and clinicopathologic variables, as well as their impact on survival outcomes.

RESULTS

The positive expression rates for ERG, PTEN, and c-Myc high expression (immunoreactive score ≥5) were 9.9%, 86.8%, and 50%, respectively. The detection rate of MYC gene amplification was 27.6%. Both c-Myc high expression and MYC gene amplification were significantly associated with the high-grade group (defined as Grade Group ≥3 and/or with cribriform pattern), lymphovascular invasion, advanced T stage, metastasis, and poor prognosis, with gene amplification demonstrating higher prognostic specificity. ERG protein expression was significantly correlated with PTEN positivity, whereas no significant association was found between MYC gene amplification and ERG protein expression; only a nonsignificant mutually exclusive trend was observed.

CONCLUSIONS

c-Myc activation, particularly MYC gene amplification, is a key driver and specific biomarker for an aggressive phenotype and poor prognosis in prostate adenocarcinoma. Combined detection of ERG, PTEN, and c-Myc status contributes to refining risk stratification systems. The lack of significant association between MYC amplification and ERG expression suggests they may represent distinct oncogenic pathways, warranting further validation in large prospective studies.