In addition, researchers at the the Aichi Cancer Center and Nagoya University Graduate School of Medicine said those with tooth loss have a 68 percent increased risk of developing head and neck cancer and a 54 percent greater chance of developing lung cancer. The rate of cancer increases proportionally to the number of lost teeth, the researchers said.

"Tooth loss is a common consequence of chronic bacterial infection and may, therefore, serve as a surrogate for chronic infection and inflammation, which in turn may be important to the pathogenesis of cancer," lead study author Akio Hiraki of the Aichi Cancer Center, in Nagoya, Japan, said in a statement.

However, the researchers point out cancer patient tooth loss may simply reflect unhealthy behaviors contributing to cancer risk. People with lost teeth may not be able to eat a healthy diet because diet is also a factor in cancer development.

The researchers compared the rates of 14 different cancers and rates of tooth loss in 5,240 cancer patients in Japan to 10,480 matched cancer-free participants.

The findings were published in the journal Cancer Epidemiology, Biomarkers and Prevention.