14 DAY TRIAL // The weak sex...
Indeed, in the case of many cancers, women have been observed to display a lower resistance than men. But when the patients are older than 60, the differences in the cancer survival rates vanish. This fact made some researchers suspect that female sex hormones, before reaching the age of 60, can be linked to this enhanced resistance of women to cancer.
"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 of thoracic oncology program at the Cardinal Bernardin Cancer Center, Loyola University Health System, Maywood, Illinois.
Previous researches concluded that women better survive to sex-related shifts in drug metabolism due to estrogen (the main female sex hormone) levels.
"In the modern chemotherapy era, a detailed analysis of this issue had not been undertaken until now," said Albain, also professor at the division of hematology/oncology, department of medicine, Loyola University Chicago Stritch School of Medicine, Maywood.
In the new approach, the Southwest Oncology Group (SWOG) Committee on Special Populations and the SWOG Lung Committee investigated data on 1,334 patients (36 % women) from six consecutive Phase II or III advanced stage non-small cell lung carcinoma (the most common type of lung cancer) clinical trials. It resulted clearly that median one- and two-year survivals were much better for women compared with men.
At one year, 46 percent of women survived, compared to 35 percent of men who survived and at two years 19 percent of women could be compared to 13 percent in men.
"Women with advanced lung cancer lived longer than men. However the survival benefit is for women age 60 or older. Age 60 is the cutoff point," said Albain.
The average survival for women older than 60 was 11 months; while for men of the same age it was 8 months.
"Women had a 14 % reduced risk of death," said Albain, who also serves as vice president, National Lung Cancer Partnership, a national research advocacy organization.
There was no major difference in patient and disease traits (maximum toxicity grade, number of toxicities or specific toxicity types) by sex under 60, except for weight loss. The data enhanced the hypothesis that estrogen levels could be blamed.
"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.