Prolactin and Risk of Epithelial Ovarian Cancer.

BACKGROUND: Prolactin is synthesized in the ovaries and may play a role in ovarian cancer etiology. One prior prospective study observed a suggestive positive association between prolactin levels and risk of ovarian cancer. METHODS: We conducted a pooled case-control study of 703 cases and 864 matched controls nested within five prospective cohorts. We used unconditional logistic regression to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between prolactin and ovarian cancer risk. We examined heterogeneity by menopausal status at blood collection, body mass index (BMI), age, and histotype. RESULTS: Among women with known menopausal status, we observed a positive trend in the association between prolactin and ovarian cancer risk (P trend = 0.045; OR, quartile 4 vs. 1 = 1.34; 95% CI = 0.97-1.85), but no significant association was observed for premenopausal or postmenopausal women individually (corresponding OR = 1.38; 95% CI = 0.74-2.58; P trend = 0.32 and OR = 1.41; 95% CI = 0.93-2.13; P trend = 0.08, respectively; P heterogeneity = 0.91). In stratified analyses, we observed a positive association between prolactin and risk for women with BMI ≥ 25 kg/m2, but not BMI < 25 kg/m2 (corresponding OR = 2.68; 95% CI = 1.56-4.59; P trend < 0.01 and OR = 0.90; 95% CI = 0.58-1.40; P trend = 0.98, respectively; P heterogeneity < 0.01). Associations did not vary by age, postmenopausal hormone therapy use, histotype, or time between blood draw and diagnosis. CONCLUSIONS: We found a trend between higher prolactin levels and increased ovarian cancer risk, especially among women with a BMI ≥ 25 kg/m2. IMPACT: This work supports a previous study linking higher prolactin with ovarian carcinogenesis in a high adiposity setting. Future work is needed to understand the mechanism underlying this association.

Cereal alkylresorcinols are absorbed by humans.

Currently there is no biomarker to link consumption of whole grain cereals and their observed health benefits. A candidate for a biomarker of whole grain wheat and rye intake is a class of phenolic lipids, the alkylresorcinols (AR). Studies to determine the uptake of AR in humans were carried out with a low fiber diet based on white wheat bread (AR free) and a high fiber diet based on rye bran-enriched bread (AR rich). For each diet, two meal frequencies were used: nibbling (7 small meals/d) and ordinary (3 large meals/d). Ten human ileostomy-operated subjects started with the AR-free diet for 2 wk, wk 1 on either nibbling or ordinary and wk 2 on the other meal frequency in a crossover design, followed by a 1-wk washout period, before the AR-rich diet performed as the AR-free diet. Food and ileostomy samples were analyzed for AR. Approximately 40% of AR were recovered in effluent from the small intestine, indicating that 60% of AR are taken up from or converted in the small intestine (ileal digestibility) with no difference between nibbling and ordinary meal frequencies. AR absorbed by humans may be of importance as bioactive compounds, or as a biomarker of whole grain wheat and rye intake.