Adjuvant treatment with the chemotherapy drug S-1 increased OS among Japanese patients with pancreatic cancer, according to results of a phase 3 trial presented at the Gastrointestinal Cancers Symposium.
Pancreatic cancer is the fourth leading cause of cancer-related death. Because the disease is typically discovered after it spreads beyond the pancreas, only 20% to 30% of patients are candidates for surgery.
Patients typically receive gemcitabine (Gemzar, Eli Lilly) following surgery. Previous studies have suggested that treatment with the oral fluoropyrimidine S-1 is associated with similar outcomes as gemcitabine among patients with inoperable cancer, according to background information provided by researchers.
Katsuhiko Uesaka, MD, medical deputy director at the Shizuoka Cancer Center Hospital in Shizuoka Prefecture, Japan, and colleagues compared the efficacy of S-1 as an adjuvant, single-agent chemotherapy with gemcitabine in Japanese patients with stage I-III pancreatic cancer.
The researchers randomly assigned 385 patients from 33 hospitals in Japan to postoperative treatment with gemcitabine (n=193) or S-1 (n=192) from April 2007 to June 2010.
An interim analysis of the study results showed patients assigned to S-1 had a 44% lower risk of death than patients assigned to gemcitabine.
Patients who received S-1 had higher rates of 2-year OS (70% vs. 53%) and 2-year relapse-free survival (49% vs. 29%) than patients who received gemcitabine.
“S-1 may be considered as the new standard treatment for Japanese pancreatic cancer patients,” Uesaka said during a press conference prior to the symposium. “Our survival data were much stronger than expected.”
S-1 currently is available in several Asian countries and most of Europe. It is not yet available in the United States. Gastrointestinal side effects — such as diarrhea — are most severe among white patients, and they must receive lower doses of the drug.
Consequently, findings in this study are not applicable to non-Asian populations, Uesaka and colleagues said.
For more information:
Uesaka K. Abstract #145. Presented at: Gastrointestinal Cancers Symposium; Jan. 24-26, 2013; San Francisco.
Disclosure: The researchers report honoraria and research funding from Eli Lilly and Taiho Pharmaceutical.