About Prostate Cancer Research

One of the primary concerns about prostate cancer is that many men are subjected to treatment that isn’t necessary. Even though death rates have declined by 40 percent in the past two decades, screening is controversial because doctors cannot reliably identify which tumors will progress and which are low risk, and won’t be life-threatening. The problem is that this lack of knowledge leads to uncertainly and anxiety in both patients and their physicians, often resulting in low-risk, indolent types of prostate cancer being over-treated. Of course the anxiety can also impact negatively on patient health.  

Other Prostate Cancer Studies

Kenfield’s study is not the first to combine the effects of lifestyle, diet and exercise.

A 2007 study looked specifically at dietary and nutritional methods that could be used to slow the progression of prostate cancer in patients who opted not to have treatment. Researchers studied 23 men aged between 43 and 74 who had been diagnosed (via biopsy) with prostate cancer. They were put onto a modified Mediterranean diet and given a nutritional prostatitis supplement to take. The diet involved avoiding red meat, eggs and dairy food. Soy was also excluded from the diet and pasta was limited. They were encouraged to use virgin olive oil and to eat lots of fresh fruit and cruciferous vegetables (including broccoli, Brussels sprouts, cabbage, cauliflower and kohlrabi, all of which are brassicas) as well as Omega 3 fatty acids, fish, tomatoes and red wine. The supplement contained vitamins C, B6 and E as well as zinc and selenium, amino acids, and several herbs including Echinacea, gatlic, ginkgo biloba, stinging nettle, pumpkin seed, Saw palmetto, and Pygeum africanum.

Prostate-specific antigen (PSA) is a recognized marker of prostate cancer and so it was PSA that was used to validate the results of the study. Remarkably, 87 percent of the men were found to have a 58 percent reduction in PSA over a 13 to 84 month period.

Another study that involved men who had opted not to have treatment aimed to show how intense lifestyle changes – including a vegan diet and frequent exercise – could slow the growth of the cancer. After a year most of the participants had a slight drop in their PSA level.

Other studies have shown that drinking pomegranate juice or extract slow the cancer after radiation or surgery. Another showed flaxseed taken daily to have a similar effect.

Typically studies focus on different elements relating to prostate cancer, nutrition and lifestyle being one of these. Other specific topics include:

• Prevention with researchers looking for foods that may lower risks of prostate cancer. The lycopenes in tomatoes and isoflavones in soybeans are thought to be useful preventatives. Some vitamins are recommended (including C, B6 and E,) but research studies have reported contradictory results.
• Early detection to catch tumors before they cause health problems. It is currently thought that the Color Doppler Ultrasound might produce more accurate prostate biopsies.
• Diagnostic solutions that are more reliable than existing diagnoses.
• Treatments including surgery and radiation that is more effective than existing treatments and therapies. One of the newest treatments being used for early stage cancer is High-Intensity Focused Ultrasound (HIFU) that destroys cancer cells by heating them with ultrasonic beams.
• Staging that helps determine treatment options. This includes Enhanced MRI and the newer Positron-Emission Tomography (PET) scans.
• Therapies including hormones, chemotherapy drugs, and immunotherapy that relies on special vaccines. Currently a large study is looking at the use of PROSTVAC that contains a genetically modified virus that contains PSA. According to the American Cancer Society, early results are promising as the body’s immune system recognizes the virus and begins to destroy the cancer cells containing PSA.

In 2013, UCSF won a $9.5 million federal grant (for study over three years) aimed at transforming and revolutionizing prostate cancer treatment. There are at least 10 specialists in the team, including Kenfield. The principal investigator of this new study is Dr Peter R. Carroll, co-director of urologic cancer at UCSF’s Helen Diller Family Comprehensive Cancer Center and professor of the UCSF Department of Urology. The co-principal director is June M. Chan, who works closely with Kenfield.

Stacey Kenfield

A seasoned researcher, Dr Kenfield has worked in the field of cancer epidemiology for the past nine years. During this time, she was part of the HPFS team that was incorporated in the new study. She is particularly interested in the relationship between physical activity and prostate cancer survival, recurrence and mortality. She has co-authored 50 studies, and has been lead author of 11 of them. Most studies focused on cancer of some sort, primarily prostate cancer.