Blood Test May Improve Treatment in Stage 2 Colon Cancer Patients

Elevated protein levels may indicate a need for both chemotherapy and surgery for colon cancer.

A blood test that measures carcinoembryonic antigens (CEA) can improve treatment in more than 1 of 6 patients with stage 2 colon cancer, a new Mayo Clinic study suggests.

In a study published in the Journal of Gastrointestinal Surgery, investigators used data from the National Cancer Database of 40,844 patients to examine the benefits of a simple blood test that measures CEA proteins in stage 2 colon cancer.

The results from the blood test administered prior to treatment could change the classification for 17% of patients with stage 2 colon cancer from average to high risk, according to the study. This change could alter the course of future treatment.

“The decision to give a patient chemotherapy after surgery is not a light one, and physicians must weigh the risk and benefits,” said senior author Kellie Mathis, MD, a Mayo Clinic colon and rectal surgeon. “We are currently using the blood test to help make these difficult decisions, and we suggest other physicians do the same.”

Although the blood test has been on the market for decades, it is not widely used.

“There is no good reason for a physician to omit this blood test, and more work needs to be done to ensure that all patients receive it,” Dr Mathis said.

For patients who do receive the blood test, it is often performed post-surgery to monitor the cancer’s development. The authors noted that early consideration for measuring protein levels could be warranted.

Additional findings revealed that patients with stage 2 cancer who had elevated protein levels and underwent surgery, but not chemotherapy, had a 5-year survival rate of 66%, and 76% rate for those without elevated levels.

Having both chemotherapy and surgery increased survival for patients with elevated protein levels compared with those who only underwent surgery, the authors noted.

“If a patient with a new diagnosis of stage 2 colon cancer has an elevated carcinoembryonic antigen level, physicians should consider chemotherapy in addition to surgery,” Dr Mathis concluded.