Does Estrogen Influence Efficacy of Chemotherapy Drugs?
Women with advanced lung cancer survive longer than men if they are age 60 or older, but researchers no found difference by sex among people younger than 60, a finding that may point the way to improved treatment, according to a study released today at the American Society of Clinical Oncology (ASCO) annual meeting.
"If estrogen levels interact with the efficacy of certain chemotherapy drugs or some other, as-yet-undefined factor, we can utilize this knowledge to design new therapies," said lead study author Dr. Kathy S. Albain, director, thoracic oncology program at the Cardinal Bernardin Cancer Center, Loyola University Health System, Maywood, Ill.
Earlier studies suggested that women have better survival than men, possibly due to sex-related changes in drug metabolism based on estrogen levels.
"In the modern chemotherapy era, a detailed analysis of this issue had not been undertaken until now," said Albain, professor, division of hematology/oncology, department of medicine, Loyola University Chicago Stritch School of Medicine, Maywood, Ill.
For the study, the Southwest Oncology Group (SWOG) Committee on Special Populations and the SWOG Lung Committee analyzed data on 1,334 patients (36 percent women) from six consecutive Phase II or III advanced stage non-small cell lung carcinoma (NSCLC) clinical trials.
NSCLC is the most common form of lung cancer.
Results of the study, "Toxicity and survival by sex in patients with advanced non-small cell lung carcinoma (NSCLC) on modern Southwest Oncology Group (SWOG) trials," shows that median one- and two-year survivals were significantly better for women compared with men. At one year, 35 percent of men survived; 13 percent survived at two years. In contrast, 46 percent of women survived one year and 19 percent survived two years.
"Women with advanced lung cancer lived longer than men," said Albain. "However the survival benefit is for women age 60 or older. Age 60 is the cutoff point.
Albain reported the median survival for women age 60 or older was 11 months; for men it was 8 months.
Survival was similar by sex among people under age 60.
"Women had a 14 percent reduced risk of death," said Albain, who also serves as vice president, National Lung Cancer Partnership, a national research advocacy organization.
Researchers found no major difference in patient and disease characteristics by sex, except for weight loss. In addition there was no difference in maximum toxicity grade, number of toxicities or specific toxicity types.
Albain also showed supporting data for the hypothesis that estrogen levels may be part of the explanation. "In women treated with standard chemotherapy on three studies, independent of our database, the survival improvement occurs in those with lower estrogen levels," she said.
At Loyola, Albain is director, breast clinical research program; and co-director, the multidisciplinary breast oncology center at the Cardinal Bernardin Cancer Center.
Co-authors of the study include Joseph Unger, Southwest Oncology Group Statistical Center, Seattle; Carolyn C. Gotay, Ph.D, University of Hawaii Cancer Center, Honolulu; Dr. Angela M. Davies and Dr. David R. Gandara, University of California Davis Cancer Center, Sacramento; Dr. Martin Edelman, University of Maryland Greenebaum Cancer Center, Baltimore.
In addition, co-authors include Dr. Roy S. Herbst, M.D. Anderson Cancer Center, Houston; Dr. Karen Kelly, Kansas Masonic Cancer Research Institute, Kansas City, Kan.; Dr. Steve Williamson, University of Kansas Medical Center, Kansas City; and Dr. Antoinette J. Wozniak, Wayne State University Karmanos Cancer Institute, Detroit. Visit www.LoyolaMedicine.org for more information. To make an appointment with Albain, call (888) LUHS-888.