Dietary fat intake and risk of epithelial ovarian cancer by tumour histology.
BACKGROUND
Studies of fat intake and epithelial ovarian cancer (EOC) risk have reported inconsistent findings, hence we hypothesised that associations may vary by histologic subtype.


METHODS
We evaluated fat intake in a New England case-control study including 1872 cases and 1978 population-based controls (1992-2008). Epithelial ovarian cancer risk factors and diet were assessed using a food frequency questionnaire at enrolment. Logistic regression was used to estimate associations between fat intake and EOC risk and polytomous logistic regression was used to test whether associations varied by histologic subtype.


RESULTS
We observed a decreased risk of EOC when comparing the highest vs lowest quartiles of intake of omega-3 (odds ratio (OR)=0.79, 95% confidence interval (CI) 0.66-0.96, P-trend=0.01) and omega-6 (OR=0.77, 95% CI 0.64-0.94, P-trend=0.02) and an increased risk with high consumption of trans fat (OR=1.30, 95% CI 1.08-1.57, P-trend=0.002). There was no significant heterogeneity by tumour histologic subtype; however, we observed a strong decreased risk for endometrioid invasive tumours with high intake of omega-3 (quartile (Q) 4 vs Q1, OR=0.58, 95% CI 0.41-0.82, P-trend=0.003).


CONCLUSIONS
These findings suggest that higher intake of omega-3 may be protective for EOC overall and endometrioid tumours in particular, whereas greater consumption of trans fat may increase risk of EOC overall.
1] Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA [2] Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics and Gynecology, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA [3] Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London W2 1PG, UK.
M A
MA
Merritt
1] Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA [2] Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics and Gynecology, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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Cramer
1] Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA [2] Division of Reproductive Medicine, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA [3] Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA.
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SA
Missmer
Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics and Gynecology, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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Vitonis
Department of Community and Family Medicine, Dartmouth Medical School, Geisel School of Medicine at Dartmouth, One Medical Center Drive, HB 7926, Lebanon, NH 03756, USA.
L J
LJ
Titus
1] Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA [2] Obstetrics and Gynecology Epidemiology Center, Department of Obstetrics and Gynecology, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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Terry
D000077216:Carcinoma, Ovarian Epithelial; D016022:Case-Control Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D004435:Eating; D015525:Fatty Acids, Omega-3 / Q000378:metabolism; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000196:embryology* / Q000378:metabolism / Q000473:pathology; D009511:New England; D010051:Ovarian Neoplasms / Q000196:embryology* / Q000378:metabolism / Q000473:pathology; D012306:Risk; D012307:Risk Factors
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3