Purpose
There is increasing evidence that altered microRNA expression is associated with tumor progression and survival in cancer patients. We tested if the expression of specific microRNAs was associated with prognosis and disease progression in early stage lung adenocarcinoma.
Experimental Design
The expression of miR-21, miR-17 and miR-155 was measured by quantitative RT-PCR in tissues from 317 non small cell lung cancer (NSCLC) patients that originated from Maryland, Norway and Japan. Kaplan Meier and Cox regression analysis evaluated associations of microRNA expression with cancer-specific mortality and disease free survival.
Results
Elevated miR-21 (hazard ratio [HR] 2.06, 1.13–3.75), miR-17 (HR 2.00, 1.10–3.61), miR-155 (HR 2.37, 1.27–4.42) was associated with worse cancer-specific mortality in the Maryland cohort. These were evaluated in two additional cohorts and only miR-21 was associated with worse cancer-specific mortality in the Norwegian cohort (HR 2.78, 1.22–6.31) and worse relapse free survival in the Japanese cohort (HR 2.82, 1.57–5.07). More advanced stage tumors expressed significantly higher levels of miR-21 compared to TNM stage I tumors. TNM stage I patients were evaluated separately and high levels of miR-21 was associated with worse cancer-specific mortality (HR 2.16, 1.11–4.21) and relapse-free survival (3.40, 1.57–7.36) independent of other clinical factors.
Conclusions and Summary
This is the first study to report that increased miR-21 expression is associated with disease progression and survival in stage I lung cancer. This suggests that expression of miR-21 may contribute to lung carcinogenesis and serve as a therapeutic target or early stage prognostic biomarker for lung adenocarcinoma.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.