A study has shown for the first time that giving two chemotherapy drugs to women with advanced endometrial cancer after surgery reduced the risk of recurrence by 29% and extended survival by 32% compared with women who received whole abdominal irradiation.
The findings could improve the care for the 15% to 20% of patients with endometrial cancer who have advanced disease.
The study is published in the Journal of Clinical Oncology.
Endometrial cancer is the most common gynecologic cancer in the United States the American Cancer Society estimates that in 2005, 40,880 women will be diagnosed with the disease, and 7,310 will die.
" For the first time, adjuvant chemotherapy has been shown to extend survival in patients with advanced endometrial cancer," said the study's lead author, Marcus E. Randall, director of the Leo W. Jenkins Cancer Center at East Carolina University in Greenville, North Carolina. " These findings were surprising, given that previous studies showed that single chemotherapy agents do not have a significant impact on the disease."
Researchers from the Gynecologic Oncology Group ( GOG ) compared the rate of recurrence and overall survival between 194 women with advanced endometrial cancer who received chemotherapy with the drugs Doxorubicin and Cisplatin over a period of five months and 202 women who received radiation therapy to the entire abdomen over a period of approximately 1.5 months.
Patients were enrolled in the trial from 1992 until 2001.
Researchers followed patients for a median of just over six years, and used a statistical model to estimate five-year recurrence and survival rates.
After five years, 50% of patients who received chemotherapy were estimated to be free of disease compared with 38% of those who received whole abdominal irradiation.
Moreover, 55% of patients who received chemotherapy were estimated to be alive after five years, compared with 42% of patients in the radiation therapy group.
However, serious adverse side effects were more common in the chemotherapy group.
The most common serious side effects included reduced blood cell counts and problems with the digestive and nervous systems, liver, and heart.
Treatment-related deaths were also twice as common in the chemotherapy group ( 4%, vs. 2% of radiation patients ).
Another GOG study is underway to see if the chemotherapy drugs Carboplatin and Paclitaxel will be as effective, but with fewer serious side effects.
A less toxic regimen could help a greater number of patients with advanced disease, many of whom are elderly or have other illnesses that might prohibit the use of the aggressive chemotherapy regimen.
In addition, another GOG study evaluated the use of combination chemotherapy after "involved field" radiation therapy ( radiation to less than the whole abodomen ) to see if these patients might benefit more than those who receive either treatment alone.
" This study represents a major advance in the treatment of advanced endometrial cancer," noted Gini F. Fleming, director of the Medical Oncology Gynecologic and Breast Cancer Programs at the University of Chicago." Future trials need to address treatment of earlier-stage disease, optimization of chemotherapy regimen, integration of radiotherapy, and application of newer targeted agents."
Source: American Society of Clinical Oncology, 2005