People with cancer are at increased risk of developing another cancer later, a recent study confirms.
The risk is particularly high for cancers caused by smoking and obesity.
The data are based on registry data from 1.5 million cancer patients who fell ill between 1992 and 2011.
Of the patients, 160,000 developed new cancer and 89,000 died of cancer during an average of seven years of follow-up.
Patients with laryngeal or bladder cancer were at greatest risk for new cancer, but most other cancers were at risk.
Patients with laryngeal cancer were about twice as likely to develop another cancer and four times more likely to die of cancer than the rest of the population.
In people with bladder cancer, the risks were twice and almost five times higher than in the rest of the population.
The risks of illness varied, but most of the risks were due to cancers associated with smoking and obesity.
One-third of new cancers were lung cancers.
The results corroborate evidence of an increased risk of cancer patients also developing other cancers and suggest that the risks are related, at least in part, to preventable risk factors.
Quitting smoking and reducing obesity would be key ways to reduce the risk of disease.
The study was published in the Journal of the American Medical Association (JAMA).