Study Assesses Effect of Tomato Oil on Precancerous Prostate Changes
Lycopene, an antioxidant commonly found in tomatoes and tomato-based products, is perceived to reduce the risk of developing prostate cancer.
A new study at Northwestern University seeks to determine whether natural tomato oil with a high concentration of lycopene may reverse or delay progression of high-grade prostatic intraepithelial neoplasia (HGPIN), a condition in which abnormal cells form within the prostate. HGPIN is the strongest risk factor yet identified for the development of prostate cancer.
The study is headed by Peter H. Gann, MD, ScD, professor of preventive medicine at Northwestern University’s Feinberg School of Medicine and a member of the cancer epidemiology and prevention program at The Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
Lycopene has been found to have anti-tumor activity in a number of laboratory studies. Also, it has been used in a number of cancer studies in humans (for example, lung, stomach, and prostate cancers) that demonstrated a lower cancer rate in people with a high dietary intake of lycopene.
Research has shown a more than 20 percent reduced risk for developing prostate cancer in men who ate more cooked tomato products, such as tomato sauce. Additional studies showed that cooking tomatoes and eating them with oil substantially increases the bioavailability of lycopene.
The National Cancer Instituteâsponsored study at Northwestern will use tomato extract (literally, tomato oil) from non-genetically modified tomatoes raised in Israel and specially grown to be high in lycopene content.
Results of the study will be useful for clarifying the mechanisms of action of lycopene in the prostate, designing phase III clinical studies and, more generally, determining the chemopreventive potential of this relatively nontoxic dietary compound.
Prostate cancer is the most commonly diagnosed cancer among men in the United States, amounting to an expected 230,100 new cases and 29,900 deaths in 2004, according to the American Cancer Society.
“Prostate cancer is a rational target for chemoprevention because of its high public health burden and relatively slow growth rate,” Dr. Gann said.
“Although early surgical treatment of prostate cancer might be effective, it involves substantial discomfort. This, plus the wide variability in the biological behavior of prostate cancer, makes overtreatment a persistent and serious concern,” Dr. Gann said.
To qualify for the lycopene HGPIN study, participants must be age 40 and older; have had a biopsy indicating HGPIN without cancer within the last two years; be ambulatory, capable of self-care, and able to perform light or sedentary work; be willing to limit intake of lycopene-containing foods, as well as supplements containing lycopene during the study period; and have no prior cancer (except basal cell or squamous cell skin cancer) or complete remission for at least five years.
For information on the lycopene HGPIN study, call 312/908-8421.
(Reprinted from Northwestern University News Center.)
