Researchers in Switzerland have found women may be more vulnerable to cancers caused by smoking than men.
Scientists from St Gallen Canton Hospital studied 683 lung cancer patients and found women were younger than men when they developed the disease even though they smoked, on average, significantly less.
Dr Martin Frueh said: "Our findings suggest that women may have an increased susceptibility to tobacco carcinogens."
The research, which has been presented at the first European Multidisciplinary Conference in Thoracic Oncology (EMCTO) in Lugano, Switzerland, also found that there is a growing awareness that smoking was riskier for women.
Dr Enriqueta Felip, from Val D'Hebron University Hospital in Barcelona, Spain, who co-chaired the meeting, said: "In the early 1900s lung cancer was reported to be rare in women, but since the 1960s it has progressively reached epidemic proportions, becoming the leading cause of cancer deaths among women in the United States."
However, previous research, which checked the progress of 640 patients who had surgery for lung cancer over a 10-year period, found that women were likely to live longer than men after having lung tumours removed.
Typical survival after surgery for men was 2.1 years, but 4.7 years for women.