Adding oxaliplatin to adjuvant 5FU improves survival of patients with stage III colon cancer

Stage III colon cancer patients in the general population who receive adjuvant treatment for the disease have an improved rate of survival when oxaliplatin is added to 5-fluorouracil (5FU), according to a study published Jan. 20 in the Journal of the National Cancer Institute.

Colon cancer is a leading global cause of both illness and death; with an estimated 101,340 cases among Americans in 2011. Roughly one third of diagnoses are stage III or node-positive disease. In randomized clinical trials (RCTs), adding oxaliplatin to adjuvant 5FU is known to improve outcomes of patients with stage III colon cancer. But the effect of this combined therapy outside RCTs is unknown. In addition, fewer than 2% of patients with the cancer enroll in RCTs, and participants are known to be generally younger, healthier and less racially diverse than the overall cancer patient population.

In order to determine the effects of combined therapy in stage III colon cancer patients in the general population, Hanna K. Sanoff M.D., and assistant professor of Medicine, Hematology and Oncology at the University of Virginia School of Medicine and colleagues, gathered data from patients using the Surveillance, Epidemiology, and End Results registry linked to Medicare claims (SEER-Medicare), among other cancer registries. All patients had stage III colon cancer, received chemotherapy within 120 days of surgery, and were age 75 years or younger. Overall survival (OS) was then compared between patients treated with combined therapy and standard chemotherapy.

The researchers found that adding oxaliplatin to adjuvant therapies for stage III colon cancer in patients of the general cancer population was just as effective as in patients from RCTs. The addition of oxaliplatin showed improved survival across various practice settings, including those with older and minority patients as well as patients with greater comorbidity. "Physicians and patients should be reassured from our findings that oxaliplatin is associated with marginally but consistently superior survival for patients diagnosed before age 75 years in community settings," the authors write. They feel that now that combined therapy has proven efficacious in the general population, it is important to home in on high -risk subgroups such as patients over age 75, racially diverse minorities, and those with co morbid conditions.