Higher levels of microRNA-21 linked to better survival and lower risk of recurrence in colorectal cancer

In this study, researchers examined whether levels of a blood marker called microRNA-21 could help predict colorectal cancer (CRC) recurrences. Such information may help select which patients require more intensive follow-up after treatment.

MicroRNA consists of small pieces of RNA, a molecule that tells the body's cells how to make certain proteins. RNA is part of the genetic make-up of a cell. Different types of microRNA are linked to cancer, and either protect against cancer or help cancers grow. MicroRNA-21 is a type of microRNA that was found to be elevated in many CRC patients. Identifying how microRNA-21 is related to cancer outcomes could help doctors and patients make decisions about treatment.

Researchers looked at 102 patients with CRC who underwent surgery to remove their tumors. Blood was drawn from each patient, their microRNA-21 levels were measured and patients were monitored for 3 years.

There was no relationship between microRNA-21 levels and tumor stage or whether the tumors had spread to the lymph nodes. MicroRNA-21 was not found to be directly related to disease-free survival (DFS; how long patients survive without a CRC recurrence). However, patients with high levels of microRNA-21 were 50% more likely to survive beyond 3 years, and were 51% less likely to have a cancer recurrence. In addition to high microRNA-21 levels, 3 other factors were also linked to a better chance of survival and lower chance of recurrence: younger age, lower tumor stage, and lower CEA levels (carcinoembryonic antigen; another cancer marker in the blood).

Higher levels of microRNA-21 were linked to a lower risk of CRC recurrence and higher patient survival.

This study cannot prove that higher levels of microRNA-21 in the blood actually caused better survival and lower cancer recurrence. Other studies have reported opposite results (high microRNA-21 levels linked to poor survival and more cancer recurrence), so these results should be interpreted carefully until more studies are conducted.

You should talk to your doctor about using microRNA-21 levels as a tool to help predict CRC outcomes after surgery.