Enzyme Predicts Whether Patients Will Do Better or Worse With Chemotherapy

Swedish researchers report that following colorectal cancer surgery, measurement of the tumor's thymidylate synthase (TS) level may help predict which patients will benefit -- and which may do worse -- if they have follow-up chemotherapy.

Dr. David Edler reported in the Journal of Clinical Oncology on a study of 442 patients who underwent surgery alone for colorectal cancer, and 420 who received the widely used chemotherapy drug 5-FU following their cancer surgery.

About one-third of the patients whose tumors had the highest TS level of TS had "a significantly longer disease-free survival if they were treated with (chemotherapy) compared with surgery alone," the researchers reported.

But 28 percent of the patients who had low TS levels actually seemed "to have a worse outcome when treated with adjuvant chemotherapy," the researchers found.

"The study indicates that patients with high TS levels may benefit from adjuvant 5-FU–based chemotherapy," the researchers concluded.

Other sources: Journal of Clinical Oncology