Now they're just messing with our minds...

From The Times of India:

Researchers have suggested that quitting smoking suddenly could be an early symptom of lung cancer for longtime smokers.

"It is widely known that many lung cancer patients have stopped smoking before diagnosis. This observation is often dismissed, by saying that these patients must have quit because of symptoms of their cancer," said Barbara Campling of the Thomas Jefferson University in Philadelphia.

"However, we found that the majority of lung cancer patients who stopped smoking before diagnosis quit before the onset of symptoms. Furthermore, they often quit with no difficulty, despite multiple previous unsuccessful quit attempts. This has led us to speculate that, in some cases, spontaneous smoking cessation may be an early symptom of lung cancer," said Campling.

Ho hum. There was a theory doing the rounds that smoking somehow simultaneously causes and suppresses cancer, so once you've started, you're better off if you just keep going - as evidenced by the fact that a lot of people who quit then develop lung cancer. This 'research' turns that logic neatly on its head.