Dietary intake of nitrate and nitrite and risk of renal cell carcinoma in the NIH-AARP Diet and Health Study.

BACKGROUND: Nitrate and nitrite are present in many foods and are precursors of N-nitroso compounds, known animal carcinogens and potential human carcinogens. We prospectively investigated the association between nitrate and nitrite intake from dietary sources and risk of renal cell carcinoma (RCC) overall and clear cell and papillary histological subtypes in the NIH-AARP Diet and Health Study. METHODS: Nitrate and nitrite intakes were estimated from a 124-item food frequency questionnaire. Over a mean follow-up of 9 years, we identified 1816 RCC cases (n=498, clear cell; n=115, papillary cell) among 491 841 participants. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Individuals in the highest quintile of nitrite intake from animal sources compared with those in the lowest quintile, had an increased risk of total RCC and clear cell subtype (HR=1.28, 95% CI, 1.10-1.49 and HR=1.68, 95% CI, 1.25-2.27, respectively). Nitrite from processed meats and other animal sources were associated with increased clear cell adenocarcinoma risk (HR=1.33, 95% CI, 1.01-1.76 and HR=1.78, 95% CI, 1.34-2.36, respectively). We found no association for nitrite intake from plant sources or nitrate intake overall. CONCLUSION: Our findings suggest that nitrite from animal sources may increase the risk of RCC, particularly clear cell adenocarcinomas.

Racial disparities in Hodgkin's lymphoma: a comprehensive population-based analysis.

BACKGROUND: Racial disparity has been investigated in a number of cancers; however, there remains a comparative paucity of data in Hodgkin's lymphoma (HL). PATIENTS AND METHODS: We examined time-, age-, and gender-specific incidence, disease characteristics, and survival across and within races for adolescent/adult HL (age 10-79 years) diagnosed during 1992-2007 in the SEER 13 registries. RESULTS: A total of 15 662 HL cases were identified [11,211 non-Hispanic whites, 2067 Hispanics, 1662 blacks, and 722 Asian/Pacific Islanders (A/PI)]. Similar to whites, A/PIs had bimodal age-specific incidence, while blacks and Hispanics did not. Further, HL was significantly more common in Hispanics versus whites age>65 years (7.0/1×10(6) versus 4.5/1×10(6), respectively, P<0.01). By place of birth, US-born Hispanics and A/PIs age 20-39 years had higher incidence of HL versus their foreign-born counterparts (P<0.05), however, rates converged age>40 years. Interestingly, from 1992-1997 to 2003-2007, A/PI incidence rates increased >50% (P<0.001). Moreover, this increase was restricted to US-born A/PI. We also identified a number of disease-related differences based on race. Finally, 5-, 10-, and 15-year overall survival rates were inferior for blacks and Hispanics compared with whites (P<0.005 and P<0.001, respectively) and A/PI (P<0.018 and P<0.001, respectively). These differences persisted on multivariate analysis. CONCLUSION: Collectively, we identified multiple racial disparities, including survival, in adolescent/adult HL.