MicroRNA Expression Predicts Survival in HCC Patients

Hepatocellular carcinoma, or HCC, is a common type of liver cancer. It occurs more often in men than in women, and men tend to develop a more aggressive form of the disease. Differences in tumor biology and/or in the tumor microenvironment, the noncancerous tissue surrounding a tumor, may play a role.

A team led by Xin Wei Wang, Ph.D., chief of the liver carcinogenesis section at the National Cancer Institute's (NCI's) Center for Cancer Research (Bethesda, MD, USA) measured levels of microRNAs associated with both cancerous and normal tissue in men and women. They analyzed microRNA expression profiles from 241 surgery patients. They first compared microRNA profiles of normal liver tissue, and then compared microRNAs in men and women. Several microRNAs were identified that were expressed more abundantly in normal female liver tissue. One of these, miR-26, was highly abundant and showed the greatest difference between the sexes, so it was chosen for further analysis.

Overall, male and female patients who had low levels of miR-26 did not live as long as patients who had higher expression levels of this microRNA. There was about a four-year difference in survival between the patient groups.

In a separate study, the team investigated whether miR-26 status influenced sensitivity to interferon therapy. Among patients who had received interferon therapy as part of their cancer treatment, those with low tumor levels of miR-26 (indicative of a poor prognosis) benefited most from receiving adjuvant interferon therapy. These patients survived at least 7.7 years longer than patients with low tumor levels of mi-R-26 that did not receive interferon therapy. In contrast, patients whose tumors had normal levels of miR-26 did not benefit from interferon.

The findings indicate that miR-26 status in tumors may help both to determine prognosis for patients with HCC and to select patients who might benefit from treatment with interferon. The study appeared in the October 8, 2009, issue of The New England Journal of Medicine.

All patients included in the study underwent surgery between 1999 and 2003 at the Liver Cancer Institute of Fudan University (Shanghai, China) and at the University of Hong Kong Medical Center (Hong Kong SAR, China). Most of the patients were hepatitis B virus-positive Chinese HCC patients. More work will be needed to evaluate the association of miR-26 status with outcomes in non-Asian HCC patients. Dr. Wang's team is planning a prospective trial to further determine the benefit of interferon therapy in HCC patients who have tumors with low levels of miR-26.

The findings indicate that miR-26 status in tumors may help both to determine prognosis for patients with HCC and to select patients who might benefit from treatment with interferon.

Related Links:
National Cancer Institute's (NCI's) Center for Cancer Research
Liver Cancer Institute of Fudan University
University of Hong Kong Medical Center