Can a blood test predict if your colorectal cancer will spread?

This study looked at whether a blood test which measures plasma osteopontin (OPN) levels can predict the likely course of colorectal cancer.

The pronosis of colorectal cancer (CRC) following surgery remains poor. This is often due to the cancer spreading.
It is hoped that by finding a method of predicting or detecting cancer beginning to spread, survival rates can be improved.

OPN is a protein found in the blood that has roles in bone formation and inflammation. It is also associated with cell growth and invasion (early signs of cancer growth).

Biomarkers are naturally occurring body substances or measurements that are associated with a disease and often used for predicting the progression or outcome of a disease. Early research suggests OPN may be a useful biomarker for detecting the early spread of CRC. While levels of OPN before surgery have been shown to be useful, little research has been done on the usefulness of the levels after surgery.

83 patients  with CRC and 56 healthy patients were included in this study. The levels of OPN was measured in each patient prior to surgery and an average of 6 months following. The CRC patients were divided into early stage (stage 1 and 2) and advanced stage (stage 3 and 4). Patients were followed for an average of 30 months.

CRC patients with advanced stage disease had significantly higher levels of OPN (187.91ng/ml) compared to healthy patients (115.27 ng/ml). The difference was not as clear when the OPN levels in the early stage group (137 ng/ml) was compared with the healthy patients.

There was no difference in OPN levels prior to surgery between patients with and without cancer that would spread from its original site.  

In a subgroup of 89 CRC patients, 40 found their cancer had spread from its original site within 30 months of treatment. Post-operative levels of OPN were much higher in these patients (187 ng/ml) compared to those whose cancer did not spread (145.7 ng/ml).

Disease-free survival (DFS) is the length of time after primary treatment for a cancer ends that the patient survives without any signs or symptoms of that cancer. CRC patients who had a lower OPN level after surgery had a significantly longer DFS than those with a high OPN. This was only true when OPN levels were measured after surgery.

The authors concluced that a high OPN level after surgery was linked with the spread of CRC. They noted that this suggests that the level of OPN after surgery is a potentially useful biomarker for monitoring CRC patients after surgery.
 

This study should be repeated with a larger number of patient samples to confirm the results. 

Discuss biomarkers and measuring your OPN level with your doctor.