Nutrition Counseling Among Men Undergoing Genetic Counseling for Prostate Cancer
By Michelle Perron
An exploratory analysis of men with prostate cancer or at risk for prostate cancer identified a need to supplement patient genetic education and counseling with the basics of healthy eating.
“We identified some unique signals about dietary patterns,” explained Veda N. Giri, MD, Associate Professor in Medical Oncology and Cancer Biology and Director of Cancer Risk Assessment and Clinical Cancer Genetics at Sidney Kimmel Cancer Center at Jefferson Health in Philadelphia.
Multiple sources report that an estimated 5-10 percent of all prostate cancers are considered hereditary. This exploratory analysis was part of Genetic Evaluation of Men (GEM), a prospective research registry and genetic testing cohort study led by Sidney Kimmel Cancer Center (SKCC). The goal of GEM is to collect personal medical and cancer history data, family cancer data, exposure history, and biospecimens to support research focused on optimal genetic testing and counseling strategies for men with prostate cancer.
In an interview with Oncology Times, Giri explained that the exploratory analysis focused on dietary practices was the first of its kind involving men with suspected genetic risk for prostate cancer. The research was presented at the American Society of Clinical Oncology 2018 conference and the abstract was published in the Journal of Clinical Oncology (2018;36[15 Suppl]:1519).
The research was conducted at SKCC and Fox Chase Cancer Center, also in Philadelphia. It involved more than 300 men receiving genetic counseling related to a prostate cancer diagnosis or an identified risk for prostate cancer. Genetic counseling provides a unique opportunity to promote a healthy lifestyle, yet this practice is understudied in men, the authors wrote.
GEM participants completed a structured lifestyle questionnaire that asked about dietary behaviors. Specifically, the questionnaire asked the men to identify the frequency with which they consumed six types of foods: cruciferous vegetables; salted or smoked meats; and foods rich in vitamin C, vitamin A, vitamin D, and lycopene. Additionally, the questionnaire asked the men to identify their daily servings from specific food groups: red meat; seafood; chicken; legumes or other protein sources; vegetables; fruits; grain; milk products; and foods high in saturated fat. The survey also asked about alcohol intake. The researchers compared the data gathered from the completed questionnaires to the U.S. Department of Agriculture’s Food Patterns recommendations for cancer survivors.
The study sample consisted of 320 men; 239 had been diagnosed with prostate cancer and 81 were considered at risk for prostate cancer. Of these 320 men, 269 (84%) were overweight or obese according to CDC guidelines (BMI of 25 or higher). Specific findings about dietary habits included the following:
Men with aggressive prostate cancer reported eating more red meat compared to men with less aggressive prostate cancers.
The consumption of vitamin C once or twice per week was significantly lower among men with aggressive prostate cancer.
A higher percentage of men with aggressive prostate cancer and higher body weight reported that they did not meet recommended guidelines for vegetable intake.
Researchers assessed distributions of dietary consumption according to prostate cancer status, aggressiveness (Gleason >7, T3, or metastatic disease), family history, and BMI with Chi-Square contingency analyses and adjusted residuals.
Perspective & Future Direction
In this sample of men receiving genetic counseling for inherited prostate cancer, specific dietary patterns were associated with aggressive prostate cancer, and a high proportion of them were overweight or obese.
“We were surprised by these findings,” Giri said. “Although these are motivated men who are proactive enough to assess what led to the development their prostate cancer, 84 percent are overweight or obese.”
The finding about red meat consumption is particularly concerning, Giri noted. “The men with more aggressive cancer reported eating more red meat than those with less aggressive cancers. This needs attention from a prostate cancer risk and overall health perspective.”
The American Cancer Society states that, although the exact role of diet in prostate cancer is not clear, men who eat significant amounts of red meat or high-fat dairy products appear to have a slightly higher chance of developing prostate cancer. However, these men also tend to eat fewer fruits and vegetables—a conclusion that is supported by the new GEM analysis.
“We need to discuss diet more often with men who have prostate cancer, from the time of diagnosis all the way through treatment and in the genetic testing setting,” Giri said. “We believe it’s probably not being discussed to a significant extent at the present time.”
Up next for Giri and her team at SKCC is a targeted analysis of physical activity among patients receiving genetic counseling for prostate cancer. “We need to look at activity patterns as another area to address for modifications,” she said. “Eventually we want to get to developing interventions to target diet and lifestyle in men who have prostate cancer or are at risk for it, to identify the most effective methods. It’s likely going to take a large trial to make this determination.”
Giri said she hopes the oncology community will gain more awareness and understanding of the impact of nutrition and physical activity practices on men with prostate cancer.
“This cancer, when diagnosed in the early stages, is curable, and there is a large population of survivors,” Giri emphasized. “Dietary modification and lifestyle modification are important issues for these men. We need to pay attention not only to outcomes from prostate cancer treatment, but also to overall health.”