Igor Akushevich of Duke University in Durham, N.C., said the primary purpose of the study was to develop an approach to estimate the contributions of measurable risk factors to cancer risk among the elderly.

"So far, we have not come to the stage where we are able to make specific recommendations regarding risk factors," Akushevich said in a statement. "However, we can confirm several of them which are known. As expected, we see associations of cigarette smoking with lung cancer."

The researchers said they were surprised at some of the findings. Cancer risk was not associated with alcohol consumption, as reported in other studies. A possible explanation may be that those age 65 or older tend to drink moderately.

"Other interesting associations are increased risk of breast cancer for those women afraid to go to the doctor to investigate health problems and a decreased risk of breast and lung cancers for those who never lose their temper," Akushevich said.

Light physical activities decrease risk of cancer and moderate activities decrease the risks, but the picture for vigorous exercise is contradictory, the study said.

The findings were presented at the American Association for Cancer Research's International Conference on Frontiers in Cancer Prevention Research.