Jasmeet K. Gill

The association of mammographic density with ductal carcinoma in situ of the breast: the Multiethnic Cohort.

IntroductionIt is well established that women with high mammographic density are at greater risk for breast cancer than are women with low breast density. However, little research has been done on mammographic density and ductal carcinoma in situ (DCIS) of the breast, which is thought to be a precursor lesion to some invasive breast cancers.MethodWe conducted a nested case-control study within the Multiethnic Cohort, and compared the mammographic densities of 482 patients with invasive breast cancer and 119 with breast DCIS cases versus those of 667 cancer-free control subjects. A reader blinded to disease status performed computer-assisted density assessment. For women with more than one mammogram, mean density values were computed. Polytomous logistic regression models were used to compute adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for two measurements of mammographic density: percentage density and dense area.ResultsMammographic density was associated with invasive breast cancer and breast DCIS. For the highest category of percentage breast density (≥50%) as compared with the lowest (<10%), the OR was 3.58 (95% CI 2.26–5.66) for invasive breast cancer and 2.86 (1.38–5.94) for breast DCIS. Similarly, for the highest category of dense area (≥45 cm2) as compared with the lowest (<15 cm2), the OR was 2.92 (95% CI 2.01–4.25) for invasive breast cancer and 2.59 (1.39–4.82) for breast DCIS. Trend tests were significant for invasive breast cancer (P for trend < 0.0001) and breast DCIS (P for trend < 0.001) for both percentage density and dense area.ConclusionThe similar strength of association for mammographic density with breast DCIS and invasive breast cancer supports the hypothesis that both diseases may have a common etiology.

Dietary Patterns and the Risk of Non-Hodgkin Lymphoma: The Multiethnic Cohort

We examined dietary patterns and the risk of non-Hodgkin lymphoma (NHL) in the Multiethnic Cohort, which includes more than 215,000 Caucasians, African-Americans, Japanese-Americans, Native Hawaiians, and Latinos aged 45–75 at baseline. All subjects completed a validated food-frequency questionnaire. After a median follow-up time of 10 years, we identified 939 incident NHL cases through linkages with tumor registries. Three patterns, “Vegetables,”“Fruit and Milk,” and “Fat and Meat,” were analyzed using Cox regression. None of the patterns was significantly associated with the risk of NHL in the total population. However, the Vegetables pattern was inversely related to risk in Caucasian women with a hazard ratio of 0.56 (Ptrend = 0.04), and the Fat and Meat pattern was associated with a fivefold higher risk of follicular lymphoma in men (Ptrend = 0.03). The lack of significant results in men and women indicates a limited role of diet in NHL etiology, but dietary patterns might have ethnic- and subgroup-specific effects on NHL.