By Maggie Fox
Washington - Older women with lung cancer live longer than men the same age, US researchers reported on Saturday, and said their finding suggests that estrogen might affect chemotherapy.
The study found that women aged over 60 who have advanced lung cancer lived a median of 11 months, compared to just eight months for men.
"I get amazed with my older woman patients. They tend to do better. They tend to have less side effects than my 45-year-olds," said Dr Kathy Albain of the Cardinal Bernardin Cancer Centre at Loyola University in Maywood, Illinois.
A study of more than 1 300 patients showed that women over the age of 60 had a 14 percent reduced risk of death from advanced non-small cell lung cancer compared to men over two years, Albain told a meeting of the American Society of Clinical Oncology in Chicago.
At one year, 35 percent of the men were still alive compared to 46 percent of women. After two years, 13 percent of men were alive compared to 19 percent of the women.
"It appears very possible from supporting data that we have that higher estrogen levels interact with chemotherapy drugs," Albain said in a telephone interview.
That, combined with evidence from other studies, suggests estrogen may play a role, Albain said. It may be a case of the less estrogen the better, compared to what a patient's body once produced.
Other studies have shown that men with higher estrogen levels fare worse when treated for cancer, Albain said. Although estrogen is known as the "female" hormone, men's bodies produce estrogen too, although in smaller amounts.
It must have something to do with an individual's normal levels of estrogen, Albain said. "We are going the study the biology of this," she said.
A woman's estrogen levels drop after menopause, which occurs at an average age of 51. It will be important to study the effects of hormone replacement therapy on lung cancer treatment, Albain said.
Right now, the study is good news for older women diagnosed with lung cancer, however, Albain said.
"The tendency is to take an older woman and say, 'There, there, you have lung cancer and there is nothing we can do'," she said. "There still tends to be nihilism out there."
But in fact, chemotherapy can make lung cancer patients live longer and more comfortable lives, even if they cannot be cured, Albain said.
"If estrogen levels interact with the efficacy of certain chemotherapy drugs or some other, as-yet-undefined factor, we can utilise this knowledge to design new therapies," Albain added.
Last year, lung cancer was diagnosed in more than 174 000 Americans and killed more than 160 000. It kills 1.3 million people globally every year.