Adding the chemotherapy drug gemcitabine (Gemzar) to cisplatin chemotherapy and radiation therapy extends overall survival among women with locally advanced cervical cancer, despite increased but tolerable toxicities, according to study results presented Sunday at the 2009 American Society of Clinical Oncology (ASCO) meeting in Orlando, Fla.
The findings are the first to show that adding gemcitabine to cisplatin chemotherapy slows cancer growth and improves survival, suggesting that "this regimen may become a standard of care for patients in developing countries where cervical cancer screening programs are deficient or not available," explained lead author Alfonso Duenas-Gonzalez, MD, PhD, a cancer researcher at the National Cancer Institute of Mexico and the Instituto of Biomedical Research UNAM.
About 70 percent of women with cervical cancer are diagnosed with locally advanced disease and require chemotherapy and radiation, he said.
From May 2002 to March 2004, Duenas-Gonzalez and colleagues enrolled 515 patients to compared progression-free survival and overall survival. In one arm, 259 women randomly assigned to receive standard therapy, cisplatin and external-beam radiation therapy plus gemcitabine, and in another arm, 256 women who received the standard therapy alone. The primary endpoint was progression-free survival at three years, compared between arms using Kaplan-Meier methods and a Z-statistic.
The trial was conducted among women in Argentina, Bosnia/Herzegovina, India, Mexico, Pakistan, Panama, Peru and Thailand, where these treatments are common and readily accessible to patients.
After a median follow-up of three years, progression-free survival was 74 percent in the gemcitabine group, compared with 65 percent in the standard therapy group; 78 percent of women in the gemcitabine group were alive compared with 69 percent who received standard therapy alone. In the first arm, two patients died due to causes probably related to treatment compared with zero patients in the second arm, according to the authors.
The researchers also reported that the incidence of side effects was three times greater in the gemcitabine group, with low blood cell counts and gastrointestinal problems being the most common toxicities observed, though these side effects were generally tolerable.