DNA Repair System Affects Colon Cancer Recurrence and Survival

Extract

Colorectal cancer patients with defects in mismatch repair--one of the body’s systems for repairing DNA damage—have lower recurrence rates and better survival rates than patients without such defects, according to a study published online May 19 ^th in the Journal of the National Cancer Institute.

About 15% of colorectal cancers are associated with mismatch repair defects. Some defects are caused by the inherited gene mutations found in Lynch syndrome and others occur by chance, or “sporadically.” But it has never been clear whether mismatch repair defects are linked to cancer recurrence rates, time-to-recurrence and site of recurrence and whether such defects influence response to chemotherapy.

To explore these questions, Frank A. Sinicrope, M.D., of the Mayo Clinic in Rochester, Minn., and colleagues analyzed data from more than 2,000 clinical trial patients who had been treated after surgery with chemotherapy that included 5-fluorouracil (5-FU), a standard drug used in colorectal cancer. All patients had stage II or III colon cancer.