New European research has revealed some of the key risk factors for lung cancer, finding that it is not only heavy smokers who have more chance of developing the disease.
Carried out by researchers from the University of Crete, Greece and the Norwegian University of Science and Technology, Norway, together the team looked at survey responses from 65,000 Norwegians aged between 20 and 100 to identify the strongest risk factors.
From their sample, the researchers found that 94 percent of the patients diagnosed with lung cancer were smokers or ex-smokers.
In addition, 21 percent of the lung cancer cases occurred in those under the age of 55, and 36 percent of cases occurred in those who had smoked less than 20 cigarettes a day for less than 20 years, suggesting that it is not just older heavy smokers who are at risk.
The researchers then used the results to pinpoint which individuals among smokers and ex-smokers are more likely to develop lung cancer.
Five contributing risk factors for lung cancer are already well known, including increasing age, pack-years (based on how many years you’ve smoked 20 cigarettes daily), how many cigarettes you’ve smoked daily (a few cigarettes a day for many years is more harmful than many cigarettes for a few years), how long it’s been since you quit smoking (the risk decreases over time), and body mass index (the lower the BMI the higher the risk).
The team also found two new factors, including a periodical daily cough and how many hours a day you’re exposed to smoke indoors, both of which increase the risk of lung cancer.
The next step was to use these seven factors to see if lung cancer could be predicted without the need of a CT scan, an expensive screening method for lung cancer which exposes patients to small doses of radiation, which over time can be harmful.
The researchers found that in a sample of 45,000 individuals who had all answered the same questionnaires and been followed for up to 20 years, they could predict with nearly 88 percent accuracy who would develop lung cancer first.
“The method can reduce the number of people exposed to radiation from unnecessary CT scans, and maximise identification of persons with true risk,” says Oluf Dimitri Røe, one of the studies authors. “It is also the first model that can accurately predict lung cancer in light smokers, younger people, and people who quit smoking many years before.”
The researchers also created a risk calculator using the seven factors, named the HUNT Lung Cancer Risk Model, which allows those concerned to calculate their own personal risk of developing lung cancer within 6 years and within 16 years. The calculator is available to use online.
The results can be found published online in The Lancet-affiliated journal EBioMedicine.