ADJUVANT XELOX FOR GASTRIC CANCER

After surgery for advanced gastric cancer, treatment with capecitabine and oxaliplatin (XELOX) cuts the risk for death by 34% over 5 years, compared with surgery alone, according to new data from the Capecitabine and Oxaliplatin Adjuvant Study in Stomach Cancer (CLASSIC) study.

"Since adjuvant XELOX after D2 gastrectomy improves disease-free and overall survival, compared with surgery alone, adjuvant XELOX should be considered as a standard treatment for patients with stage II/III gastric cancer," lead author Sung Hoon Noh, MD, PhD, from the Department of Surgery at Yonsei University College of Medicine in Seoul, South Korea, told Medscape Medical News.

The multinational open-label randomized phase 3 CLASSIC trial was conducted in China, South Korea, and Taiwan. Patients with stage II to IIIB gastric cancer who had undergone curative D2 gastrectomy were assigned to adjuvant XELOX for 8 cycles or surgery alone. The XELOX regimen consisted of oral capecitabine (1000 mg/m² twice daily on days 1 to 14 of each cycle) plus intravenous oxaliplatin (130 mg/m² on day 1 of each cycle) for 6 months.

New 5-Year Data

In the 3-year CLASSIC data, disease-free survival (the primary end point) was better with XELOX than with surgery alone (74% vs 59%; hazard ratio [HR], 0.56; P < .0001), as reported by Medscape Medical News.

Dr. Noh presented the 5-year CLASSIC results last week at the 2013 European Society for Medical Oncology (ESMO) World Congress on Gastrointestinal Cancer in Barcelona, Spain.

At the clinical data cutoff date of November 2012, 103 (20%) patients treated with XELOX and 141 (27%) treated with surgery alone had died, which represents a 34% reduction in the risk for death with XELOX, compared with surgery alone (HR, 0.66; 95% confidence interval [CI], 0.51 - 0.85; P = .0015 by stratified Cox regression analysis).

In addition, the 5-year overall survival rate was better with XELOX than with surgery alone (78% vs 69%; P = .0029, log-rank test unstratified).

In the analysis of disease-free survival, 139 (26.7%) patients treated with XELOX and 203 (39.4%) treated with surgery alone had relapsed, developed a new gastric cancer, or died, which represents a 42% reduction in the risk for an event with XELOX (HR, 0.58; 95% CI, 0.47 - 0.72; P < .0001 by stratified Cox regression analysis).

The 5-year disease-free survival rate was 68% with XELOX and 53% without (P < .0001, log-rank test unstratified).

Succeeding Where Others Failed

"Surgery is the most important modality in gastric cancer treatment, and it was considered that gastric cancer could be cured with surgery alone if the surgery is proper (D2 gastrectomy)," Dr. Noh toldMedscape Medical News. "However, whether the surgery is enough in advanced disease is controversial."

"The new CLASSIC data clearly show that a XELOX regimen administered after surgery prolongs the lives of patients with gastric cancer," he said.

Adjuvant XELOX after curative D2 gastrectomy "should be considered as a standard treatment option for patients with operable gastric cancer," the study team concludes.

ESMO spokesperson Andrés Cervantes, MD, PhD, professor of medicine at the University of Valencia in Spain, noted that "many trials reporting the effect of postoperative chemotherapy after gastrectomy for gastric cancer patients have failed to find a significant benefit in survival."

Dr. Cervantes, who was not involved in the study, said these new findings are important because they represent mature survival data from a "well-designed trial."

"Having a positive study in this setting with drugs that are available in any country in Europe, or even worldwide, is definitely important," he added.

2013 European Society for Medical Oncology (ESMO) World Congress on Gastrointestinal Cancer: Abstract O-0007. Presented July 4, 2013.