Neoadjuvant Capecitabine Equivalent to 5-FU for Rectal Cancer

SAN FRANCISCO—Oral capecitabine plus neoadjuvant radiation offers equivalent outcomes and toxicity profiles compared to 5-fluorouracil (5-FU) plus radiation for patients with stage 2 or 3 rectal cancer, reported authors of a four-arm phase 3 clinical trial presented at the 2014 Gastrointestinal Cancers Symposium.

Adding oxaliplatin to either combination did not further improve outcomes but was associated with additional treatment toxicity, the authors noted.

“Doctors should feel reassured that they are not giving less effective therapy if they prescribe capecitabine,” said lead study author Carmen Joseph Allegra, MD, professor of medicine at the University of Florida in Gainesville, FL.

Oral capecitabine is “certainly far more convenient for patients” than 5-FU infusion, Dr. Allegra noted.

“It means taking pills twice a day, rather than undergoing surgery to place an intravenous port and then wearing a pump on their belt for 5 weeks,” he said.

Between 2004 and 2010, a total of 1,608 patients were randomly assigned to receive 5 weeks of radiotherapy plus intravenous 5-FU (225 mg/m² 5 days per week); 5-FU plus oxaliplatin (50 mg/m² per week); oral capecitabine (825 mg/m² twice daily 5 days per week); or capecitabine plus oxaliplatin. After undergoing the assigned treatment for 5 weeks, patients underwent tumor resection.

“There were no significant differences in local-regional [L-R] tumor control, DFS [disease-free survival] or OS [overall survival] between regimens for either the 5-FU-[capecitabine] (L-R, P = 0.98) or the [oxaliplatin]-none (L-R, P = 0.70),” Dr. Allegra reported.

Oxaliplatin was associated with increased rates of grade 3/4 diarrhea (P < 0.00001).

Early-stage rectal cancer is curable with combination neoadjuvant chemotherapy, radiotherapy, surgery, and postoperative chemotherapy, Dr. Allegra noted. 5-FU and capecitabine are radiosensitizers, improving rectal tumor responses to irradiation.

The 2014 Gastrointestinal Cancers Symposium is sponsored by the American Gastroenterological Association (AGA) Institute, the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), and the Society of Surgical Oncology (SSO).