Thirty-three percent of all breast cancer cases in industrialized Western nations could be prevented if women decreased their food intake and exercised more often, according to researchers at a recent conference held in Barcelona, Spain.
Breast cancer is the leading cancer among women. In the United States, there were more than 190,000 new cases and 40,000 deaths, in 2009 alone. European women experienced almost 421,000 new cases and nearly 90,000 deaths in 2008, the most recent data available.
A 2006 study conducted in the UK found that obese women have a 60 percent increased risk of developing breast cancer, compared to women with normal weight.
"What can be achieved with screening has been achieved. We can't do much more," Carlo La Vecchia, chairman of the Epidemiology Department at the University of Milan, said in an interview. "It's time to move on to other things."
La Vecchia spoke Thursday at a European breast cancer conference in Barcelona. He noted information from the International Agency for Research on Cancer, which estimates that 25 to 30 per cent of breast cancer cases could be avoided if women were thinner and exercised more. The agency is part of the World Health Organization.
Better treatments, early diagnosis and mammogram screenings have dramatically slowed breast cancer, but experts said the focus should now shift to changing behaviors such as diet and physical activity.
"What can be achieved with screening has been achieved. We can't do much more," Carlo La Vecchia, head of epidemiology at the University of Milan, said in an interview. "It's time to move on to other things."
His remarks are in accord with new advice that lifestyle modifications, including smoking cessation, diet, sun exposure and exercise, play a major role in the risk of developing several cancers.
Harvard University professor, Dr. Michelle Holmes of Harvard University, studies lifestyle factors and cancer, remarked that people might mistakenly think their chances of getting cancer depend more on their genes than their lifestyle. Genes are not the determining factor in the development of cancer. Environmental exposure and lifestyle play a much more important role.
Our genes have been around for thousands upon thousands of years, but cancer rates rapidly changed during the 20th century, especially the last fifty years, in terms of increasing.
Estrogen supports the growth of many breast cancers. It is a hormone produced in fat tissue. Experts suspect that more weight a woman has causes increased estrogen production, which supports breast cancer development. Even in slim women, experts believe exercise can help reduce the cancer risk by converting more fat into muscle.
Europa Donna, a breast cancer support group’s spokeswoman, Karen Benn, remarked it is impossible to ignore the increasingly stronger links between lifestyle and breast cancer.
"If we know there are healthier choices, we can't not recommend them just because people might misinterpret the advice and feel guilty," she said. "If we are going to prevent breast cancer, then this message needs to get out, particularly to younger women."
Breast cancer rates experienced a sharp decline, when women discontinued hormone replacement therapy, when it was linked to breast cancer. Experts said a similar reduction may occur if women ate healthier and exercised more. Breast cancer rates rose continuously during the last 2 decades of the 20th century, as did a rise in obesity and the use of estrogen based hormones following menopause.
Dr. Holmes, also remarked that dietary changes is much easier to manager, than other breast cancer risk factors.
La Vecchia said countries like Italy and France - where obesity rates have been stable for the past two decades - show that weight can be controlled at a population level.
"It's hard to lose weight, but it's not impossible," he said. "The potential benefit of preventing cancer is worth it."
Source: International Agency for Research on Cancer: http://www.iarc.fr/