When someone young and fit who doesn't smoke dies of lung cancer, it's natural that people start to wonder if there's any point in following all the health rules we're advised to follow.
Dana Reeve (right), the widow of actor Christopher Reeve who played Superman in the film series, was such a person. Just 44, she succumbed to aggressive lung cancer earlier this month, despite eating well, exercising regularly and, most importantly, never smoking.
This doesn't mean following good health rules is a waste of time. For most people, doing so means a longer and better quality of life. Statistics in Australia, the US and other developed countries show that the anti-tobacco message is finally getting through. It's not just to consumers, but to legislators, bosses, restaurant owners, transport owners, occupational health and safety managers - and there's now a drop in tobacco-related cancers.
But some people have been given bad tickets in the genetic lottery. For them, following the rules isn't enough, especially if their environment triggers their genetic tendency to form a particular cancer.
Childhood cancers are often a result of unfortunate genetic combinations, coupled with an environmental trigger.
In lung cancer too, there's a group of women, typically young (especially in Hong Kong), who develop a kind of cancer - adenocarcinoma of the lung - that isn't caused by smoking. Hong Kong has been the focus of much study into this type of cancer because we have one of the highest rates in the world.