Anne-Marie Baird, researcher of lung cancer at Trinity College in Dublin, is the target of different reactions from people when she talks about her profession. One of the most memorable things was when you heard from a participant in an academic conference: "Why waste your time researching this? They deserve it – and they're all going to die."
Lung cancer is the most common cancer worldwide, with 1.8 million newly diagnosed cases in 2012 (the latest available data). And 58% of new cases are in developing countries.
To make matters worse, in the last decades the patient's survival has not increased much. Between 1971 and 1972 the chance to survive 10 years after the diagnosis was only 3%. Between 2010 and 2011, only 5%.
In the same period, a woman with breast cancer nearly doubled her chances of living 10 years after diagnosis – from 40% to 78.5%.
A common opinion about lung cancer is that it is itself caused by smoking – and that the problem will eventually disappear when everyone leaves the smoking habit.
First, the cases of lung cancer do not occur anywhere in the world
First, cases of lung cancer do not occur anywhere in the world. ] The difference in gender is an obvious example. More men than women are still diagnosed with lung cancer – and in the US the risk is 1 in 15 throughout life, while that of women is 1 in 17. But while a recent American study showed that the level of cancer continues to decrease the lungs in men, the lungs in young women have increased. And on the whole, while the number of men diagnosed with lung cancer has decreased over the last two decades, it has increased by 27%.
Researchers do not know why. But there is research that suggests that women react differently to nicotine and that their DNA is more easily and deeper damaged by carcinogens.
Women's health risks can become apparent later because women have started smoking after men. Few women smoked in the US in the 1920s, for example. But when the custom began to be sold – and was seen – as a symbol of emancipation, the rates of female smokers increased. A study conducted in more than 100 countries has shown that the link between gender equality and rates for smokers persists.
"In countries where women have more empowerment, the number of women smoking is higher than that of men," write researchers Sara Hitchman and Geoffrey Fong
as a result, although men are 5 times more likely to smoke than women This is not true in many countries. In the US, 22% of men and 15% of women smoke; in Australia, 19% of men and 13% of women; in Brazil, 11% of women and 9% of men. And the younger you are, the smaller the gender difference. In youth groups between the ages of 13 and 15, 12% of girls smoke, compared to 15% of boys in the US.
"The empowerment of women has to continue", write Hitchman and Fong.
Although smoking causes about 85% of lung cancer problems – and the only great thing we can do to reduce the risk of lung cancer (and non-smoking – not smoking does not necessarily guarantee protection against the disease.
"Lung cancer at people who do not smoke are not trivial, "says Charles Swanton, chief medical officer of Cancer Research UK." In my experience, 5% to 10% of patients (from lung cancer) never smoked. "
This also seems to be different for women A study showed that one in five women who have had lung cancer has never smoked, among men, is one in 10. A study of lung cancer patients operated in the UK between 2008 and 2014 showed that 67% among women who had never smoked, were women.
Part of this inequality is probably related to the indirect exposure of women to smoke – passive smoking. If women have historically smoked, the chance that a non-smoking woman marries a smoking spouse is higher than the other way around.
To make matters worse, as the World Health Organization said, "Women and children often lack the power to negotiate smoke-free spaces, including in their homes." Secondhand smoke increases the likelihood that a non-smoker has 20-30% lung cancer and causes 430,000 deaths worldwide – 60% of them are women.
Domestic sex tasks may be relevant in some situations. The use of charcoal for cooking can be linked to lung cancer in non-smoking women in China and some used fuels in India may also increase the risk of lung cancer.
Meanwhile, the proportion of cancer patients has increased. lungs that they have never smoked are increasing. An American study showed that 17% of people with the most common form of lung cancer never smoked between 2011 and 2013, compared with 8.9% of people diagnosed between 1990 and 1995. In the UK, researchers pointed out that the proportion of non-smokers who underwent lung cancer surgery jumped from 13% to 28% between 2008 and 2014.
In Brazil, the National Cancer Institute (Inca) reports that there are 28,200 cases of lung cancer each year. Brazil and estimates that 10% is not caused by direct smoke. A study from 2017 showed that combustion in the Amazon produces smoke that can damage lung cells and cause cancer; the high pollution of cities also causes concern about their health risk for the lung.
It is important to remember that most patients with lung cancer are still smokers. But even small percentages have an impact: only 0.2% of non-smokers in the UK were diagnosed with lung cancer, but this refers to 1469 women who have never smoked the disease.
smoking is very different. Different genes have changed or mutated in both cases. For non-smokers, cancer is usually caused by changes in the EGFR gene – which can be controlled with new and effective medicines.
In general, cancer develops when the normal processes remain healthy and alive when making new cells. Carcinogenic chemicals, ultraviolet light and viruses can damage the DNA in cells and cause a carcinogenic problem. But in many cases there is no identifiable external risk – and this may be the case for some non-smokers who have lung cancer.