Correlation of miR-34a with the invasiveness and prognosis of breast cancer / 中华普通外科杂志

ABSTRACT

Objective To investigate the potential role of miR-34a on breast cancer recurrence and prognosis.Methods In this study,88 breast cancer patients underwent mastectomy with detailed clinical follow-up information.Extracting RNA from the formalin-fixed paraffin embedded samples,miR-34a levels were quantified by quantitative real-time polymerase chain reaction (qRT-PCR).miR-34a levels among clinico-pathological variables were accessed by Mann Whitney-U test.RFS and OS survival curves were derived from Kaplan-Meier estimates and the curves were compared by Log-rank tests.All statistical tests were two-sided.Results Significantly lower miR-34a level was found in tumor tissue compared to paired normal tissue (P =0.000).A potential relationship between miR-34a levels and existing clinico-pathological parameters of breast cancer,such as menstrual status,tumor size,nodal involvement,stage of disease,hormone receptor status,HER2 status,or tumor subtype was investigated.No statistically significant difference were identified for these features (P ＞ 0.05).miR-34a level was significant lower among G3 group than G1 + 2 group (P =0.024).Down-regulated miR-34a level was observed in breast cancer with later relapse compared to patients without relapse (P =0.008).When considering 2-△Ct =0.117 (median level)as cut-off value,patients with miR-34a up-regulation showed a positive association towards a longer survival,either RFS(P=0.026,Log-rank test) or OS(P =0.019,Log-rank test).Conclusions miR-34a,as a tumor suppressor,promotes differentiation and contributes to relapse when down-regulated.miR-34a has the potential as prognostic factor for breast cancer.