Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study

1. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Suzanne M. Dolwick Grieb, MSPH: University of Florida (UF) Ryan P. Theis, MPH: UF Deborah Burr, Ph.D.: UF Dan Benardot, Ph.D., R.D.: Georgia State University Tariq Siddiqui, M.D.: UF Nabih R. Asal, Ph.D.: UF JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

2. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Background • The American Cancer Society projects that 54,390 new kidney and pelvis cancer cases will be diagnosed in the U.S. in 2008.1 Renal cell carcinoma (RCC) accounts for approximately 85% of all malignant neoplasms of the kidneys in the U.S.2 • RCC has continued to rise in incidence among both men and women over the past three decades.2 • Only 2% of RCC cases can be attributed to genetic predisposition, suggesting that the secular trends are largely environmental in etiology.2 • Research regarding the role of diet and nutrition on RCC risk has considered individual nutrients (decompositional approach) and food types and patterns (integrative approach), although these reports have been inconclusive 1. American Cancer Society. Cancer Facts and Figures 2008. Atlanta: American Cancer Society, 2008. 2. Lipworth L, Tarone RE, McLaughlin JK. The epidemiology of renal cell carcinoma. J Urol. 2006;176(6):2353-2358. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

3. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Purpose The current project reports findings from a population-based case-control study of RCC in Florida and Georgia and considers the role of diet on RCC risk. Specifically, an integrative approach is used, focusing on the role of food items and food groups on RCC. Dairy, fruits, vegetables, grains and meat items are considered. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

4. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Sample • Cases included 335 Florida and Georgia residents who were diagnosed with histologically confirmed renal cell carcinoma between January 1, 2000 and December 31, 2004, identified through hospital records and the Florida Cancer Data System. Response rate = 69% • Controls were frequency-matched to cases by age (+/- 5 years), sex and race and included 337 persons with no history of kidney disease, identified from the general population using random-digit dialing. Response rate = 42%. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

5. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Data Collection • All subjects were interviewed on their history of medical, environmental and behavioral risk factors using an epidemiological questionnaire. • Dietary intake was assessed using the 70-item Block 2000 Brief Food Questionnaire (BFQ), which assesses past nutritional intake for a single year period. • Controls answered the BFQ for the previous year. If a case had not altered their diet significantly since diagnosis, the BFQ was answered for the previous year. If the cases had altered their diet, they were asked to respond to the BFQ for the year prior to diagnosis JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

6. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Data Analysis • Comparisons of means and proportions between cases and controls employed the t-test and chi-squared test respectively. • Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for each risk and protective factor evaluated. All analyses were controlled for age, gender, race, income, body mass index (BMI) and pack-years of smoking. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

7. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Adjusted odds ratio (AOR)a for renal cell carcinoma by consumption frequency of different food groups *P < 0.05 AORs based on 4th quartile of consumption compared to 1st quartile of consumption Adjusted Odds Ratio a Estimates from unconditional logistic regression, controlled for age at interview, gender, race, income, body mass index and pack- years of smoking JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

8. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Selected adjusted odds ratio (AOR)a for renal cell carcinoma by consumption of different foods *P < 0.05 AORs based on consumption of food item 5 or more times a week compared to less than once a week Adjusted Odds Ratio a Estimates from unconditional logistic regression, controlled for age at interview, gender, race, income, body mass index and pack- years of smoking JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

9. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Selected adjusted odds ratio (AOR)a for renal cell carcinoma by consumption of different foods *P < 0.05 AORs based on consumption of food item 3 or more times a week compared to less than once a week Adjusted Odds Ratio a Estimates from unconditional logistic regression, controlled for age at interview, gender, race, income, body mass index and pack- years of smoking JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

10. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Conclusions • Results support previous observations regarding dietary links to renal cell carcinoma (RCC). • Despite national recommendations to increase citrus fruit intake to reduce risk of all cancers, neither fruits in general nor citrus fruits in particular were associated with RCC risk in this observational, case-control study. Apple/pear intake, was associated with reduced risk of RCC among men only. • The association between RCC and white bread among women may be related to it’s high glycemic index rating. Food with high glycemic index ratings have been implicated in other cancers. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).

11. Food Groups and Renal Cell Carcinoma: Results from a Case-Control Study Conclusions • Dairy consumption among women significantly increased the risk of RCC in the current study. This finding remains controversial in the literature. • Potentially protective benefits of tomato intake, particularly among men, and increased risk of higher intakes of white bread, fried potatoes, and dairy among women require further study. • More data are needed to specify amounts, frequency and influence of other diet behaviors. JOURNAL OF THEAMERICAN DIETETICASSOCIATION Dolwick Grieb S, et al. J Am Diet Assoc. 2009; 109 (Apr).