Background: Kidney cancers account for almost 2% of all cancers worldwide, with 150,000 new cases and 78,000 deaths from the disease occurring annually. An increase in the incidence of kidney neoplasm in western countries was noticed in the past few years. Between 1988 and 1992, the incidence of renal cancer per 100,000 person-year among males in USA, Norway, and France was 34.1, 9.00, and 16.10, respectively. Among females in the same countries, it was 5.70, 5.00, and 7.30, respectively. Although several individual case-control studies examined the association of meat intake and renal cancer risk, the results were inconsistent because of the insufficient statistical power of the individual studies. Therefore, the following meta-analysis was designed to help in clarifying the association.
Methods: Electronic search of MEDLINE, OVID, and PUBMED databases which have articles published between (1966 and 2006) was conducted to select studies for this meta-analysis.
Statistical analysis: Fixed and random-effects meta-analytical techniques were used to estimate the overall association between meat consumption and kidney cancer.
Results: Thirteen case-control studies were found. This meta-analysis supported a positive relationship between meat consumption and risk of renal cancer. Summary results indicated that there was from 20% to 22% higher risk of renal cancer among those in the highest relative to the lowest category of poultry and processed meat consumption. Consumption of all meat and red meat was associated with 27% and 30% higher risk, respectively. The increased risks were statistically significant.
Conclusions: Increased consumption of all meat, red meat, poultry, and processed meat is associated with an increase risk of kidney cancer. Reduction of meat consumption is an important approach to decreasing the incidence of kidney cancer in the general population.