Does removing main lymph nodes improve colon cancer patient survival?

This study investigated whether surgical removal of the main lymph nodes improves the survival of patients with surgically curable colon cancer.

Surgical removal of lymph nodes is classified depending on the extent of lymph node removal. D2 dissections involve removal of the lymph nodes beside the colon and intermediate nodes (located along vessels that drain to main lymph nodes). D3 dissection includes the nodes removed for D2 dissections as well as removal of main lymph nodes located at the base of supplying arteries.

For patients with localized colorectal cancer, removal of the affected bowel and the surrounding lymph nodes is the accepted surgical treatment. However, whether D3 dissection further improves the chance of survival is not clear. 

This study examined data for 6580 patients who had D3 node dissection and surgery and 3518 patients who had D2 node dissection and surgery for T3 (the cancer has grown into the outer layers of the colon) or T4 (the cancer has grown through the outermost layer of the colon and may have spread to nearby tissues) colon cancer. Of the total number of patients, 3425 patients who underwent D2 node dissection were compared to 3425 patients who underwent D3 node dissection.

Patients who underwent the D3 node dissection had higher overall survival than patients who underwent D2 dissection. The risk of death decreased by 19% for patients who underwent D3 dissection.

The authors concluded that D3 lymph node dissection improved the chance of survival for patients with T3 or T4 colon cancer.