Death rates from lung cancer are higher among men who have never smoked than women who have never smoked, says new research published in this week's PLoS Medicine. The research also reports that among lifelong nonsmokers, African Americans and Asians living in Asia (but not in the USA) have higher death rates from lung cancer than people of European descent.
In an international collaboration, Michael Thun (American Cancer Society, Atlanta USA) and colleagues synthesized data from 13 large cohort studies, representing about 2 million people, and 22 cancer registries from ten countries. Thun and colleagues have assembled the largest overview to date of the incidence and mortality associated with lung cancer among self reported never smokers. They report that their synthesis does not support previous research that suggests lung cancer risk among never smokers is increasing or that women have higher incidence rates than men.
The researchers undertook the study to better understand the factors other than active smoking that influence risk of lung cancer, as well as the gender, racial, and geographic disparities in incidence and mortality. According to the World Health Organization, every year more than 1.4 million people worldwide die from lung cancer, which is the leading cause of cancer death. Up to 90% of lung cancer deaths are caused by exposure to cigarette smoke and, on average, current smokers are 15 times more likely to die from lung cancer than lifelong nonsmokers (never smokers).
Source: Public Library of Science