In 2013, over 20,000 women in the United States will be diagnosed with ovarian cancer and over 14,000 will die of the disease. Only half of women diagnosed with ovarian cancer will live 5 years after their diagnosis. This is partly because it is very difficult to detect ovarian cancer early, making prevention of this deadly disease especially important. Unfortunately, at this time, there are few ways for women to reduce their risk. Our goal is to determine if certain dietary factors may alter risk of ovarian cancer.
In this project we propose to look at the amount and type of fat a woman eats and her cholesterol levels, since these factors can be changed to reduce risk. A diet high in saturated fat, from foods like red meat, and trans fat, found in partially hydrogenated oils like margarine, increases women’s LDL or “bad” cholesterol levels. But, a diet high in unsaturated fats, such as those found in vegetable oils, seafood, and nuts, decreases LDL cholesterol levels and increases HDL or “good” cholesterol levels. Fat intake and cholesterol levels may not only impact the risk of diseases like heart disease, but may also influence ovarian cancer risk. We will use questionnaire data and blood cholesterol measurements from women participating in the Nurses’ Health Studies. These two on-going studies have almost 238,000 women who have been participating for 20-30 years. We will use this information to examine if bad fat increases ovarian cancer risk and good fat decreases risk. Our study is unique because we have asked about dietary fat intake at several points throughout a woman’s life, including during high school as well as premenopausal and postmenopausal years. We will also measure total, HDL, and LDL cholesterol levels in blood among a subset of women to see if cholesterol levels are associated with ovarian cancer risk.
Although ovarian cancer is usually thought of as one disease, there are several different types, including some tumors which express the estrogen receptor (ER). Fat and cholesterol also can increase estrogen levels and thus may increase risk of tumors that express ER. A strength of our study is that we have collected tumor samples from ovarian cancer patients, and can determine if their tumors express ER. Studies of diet are critical to learning what women can do to decrease their ovarian cancer risk. Our goal is to examine if dietary fat and cholesterol levels are associated with ovarian cancer risk. Not only could this improve prevention recommendations, but it may reduce the number of women affected by this deadly disease.
Megan Rice, Sc.D. is currently a research fellow working with Dr. Shelley Tworoger at the Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School. Her research focuses on the epidemiology of ovarian cancer with an emphasis on preventive factors. Dr. Rice is investigating the association between dietary fat, circulating cholesterol, and ovarian cancer risk and whether these associations vary by histologic subtype and estrogen/progesterone receptor expression in the tumor. Dr. Rice obtained her Doctor of Science from the Department of Epidemiology at the Harvard School of Public Health, her MPH in Epidemiology/Biostatistics from the UC Berkeley School of Public Health, and her BA and MA from Stanford University.