But the study, published online in the International Journal of Cancer, doesn't claim bread causes kidney cancer.
The researchers included Francesca Bravi, MD, of the Istituto di Ricerche Farmacologiche "Mario Negri" in Milan.
Between 1992 and 2004, Bravi's team interviewed 767 patients with renal cell carcinoma at Italian hospitals. They also interviewed 1,534 patients without kidney cancer.
Patients completed surveys about their diets during the previous two years. The questions covered 78 foods and beverages.
The findings show renal cell carcinoma patients were more likely than those without kidney cancer to have the highest intake of bread, and, to a lesser extent, pasta and rice.
People without renal cell carcinoma were more likely to eat the greatest amount of vegetables, poultry, and processed meats.
The researchers found no association between renal cell carcinoma and coffee, tea, soups, eggs, red meat, fish, cheese, potatoes, fruit, desserts, or sugars.
The results take into account other factors, such as family history of kidney cancer, smoking, and alcohol use.
However, the study doesn't prove any particular dietary pattern causes or prevents renal cell carcinoma.
Doctors are often unable to explain exactly why one person gets cancer and another doesn't.
The researchers speculate that "a diet rich in refined cereals and poor in vegetables may have an unfavorable role on RCC [renal cell carcinoma]."
SOURCES: Bravi, F. International Journal of Cancer, Oct. 20, 2006; online edition. News release, John Wiley & Sons, Inc.
By Miranda Hitti
Reviewed by Louise Chang