Post-surgery risk factors for recurrence in stage 2 and 3 colorectal cancer

This study investigated the risk factors for recurrence (when the cancer comes back) after surgery in patients with stage 2 and stage 3 colorectal cancer. Researchers suggested that high-risk patients can be identified by assessing tumor specific blood levels, tumor spread to the lymphatic system and infiltrative growth (IG; when the tumor has the capacity to spread to other parts of the body).

Approximately one-third of stage 2 and 3 colorectal cancer patients experience recurrences after surgery. Intensive follow-up of these patients was shown to be useful to detect recurrences early and to plan an effective treatment. It would be useful to have methods of identifying patients at high-risk of recurrence. Certain tumor specific blood factors such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9), tumor location, tumor size and IG could possibly be useful measures in the follow-up of these patients.

The objective of this study was to investigate the utility of the factors CEA, CA 19-9, tumor location, tumor size and IG at predicting recurrence after colorectal surgery.

This study included information about 386 patients with stage 2 (206) and stage 3 (180) colorectal cancer. These patients underwent surgery and were followed-up every 3 months for the first two years and every 3-6 months for the following 3 years.

For stage 2 patients the average follow-up period was 51 months. Among stage 2 patients, 13% experienced a recurrence after a follow-up of 14 months. Increased CA 19-9 blood levels were detected in only three stage 2 patients. Patients with lymphatic system involvement were 5.99 times more at risk of a worse recurrence-free survival (RFS; time from treatment to recurrence). Patients with tumors with IG were 4.02 times more at risk of a worse RFS.

The average follow-up time for stage 3 patients was 45 months. 26% of patients experienced recurrence after a follow-up period of 12.5 months. Pre and post-surgery levels of CEA and CA 19-9 were higher in patients with recurrences. Patients with increased pre-surgery levels of CEA were 3.22 times more at risk of a worse RFS. Patients with increased post-surgery levels of CA 19-9 were 5.08 times more at risk of a worse RFS. IG was associated with 3.19 times more risk of a worse RFS. 

Stage 3 patients with a tumor size of 50 mm or more and lymphatic involvment were also more at risk of a worse RFS. 

This study suggested that patients with a high risk of recurrence can be identified by measuring the blood levels of CEA and CA 19-9, tumor size, lymphatic involvement and IG.