Population-wide PSA screening: no reduction in deaths

Prostate cancer is exceedingly common, especially with age. It estimated from autopsy studies that one-third of men in their forties have prostate cancer, and by age 85, that figure increases to as high as 75%.1,2 However, most of these cases of prostate cancer are not actually life-threatening. U.S. The lifetime risk of a diagnosis is 15.9%, but the lifetime risk of death from prostate cancer is only 2.8%. Even without treatment, most prostate cancers are not deadly.2 Most men with prostate cancer die from other causes, not from prostate cancer.

Because of the low risk of death from prostate cancer, there is controversy regarding population-wide PSA screening of men without symptoms suggesting prostate cancer. There is no distinction by the PSA between disease that is likely or unlikely to progress to a life-threatening disease. So should all men be screened?

Blood in vials. Flickr: Kenny Holston 21

The most important question is this: Does screening reduce the risk of dying from prostate cancer?
The U.S. Preventive Services Task Force, an impartial agency that assesses scientific evidence on prevention and primary care, issued a statement in 2008 saying that they had found “insufficient evidence that screening for prostate cancer improved health outcomes” in men younger than 75. In men 75 or older, the USPSTF found that “the harms of screening and treatment outweigh any potential benefits.”3

New evidence that screening does not reduce death rates
A long-term study published in January 2012 has not found any decrease in prostate cancer deaths in men undergoing annual screening compared to a control group. The Prostate, Lung, Colorectal, and Ovarian cancer screening trial (PLCO trial) of over 76,000 men had published intermediate results after 10 years of follow up, and were not updating that study, extending to 13 years of follow up. The results were similar after 13 years: about 12% more cancers were diagnosed in the screening group, but death rates were not different between the two groups, suggesting that population-wide screening does not reduce the number of prostate cancer deaths.4

This report comes on the heels of a meta-analysis of PSA screening trials performed for the USPSTF in October 2011, which reported information from 5 trials (including the 10-year data from the PLCO trial). Collectively analyzing data from these trials, the authors concluded that PSA screening “results in small or no reduction in prostate cancer-specific mortality.”5

Could PSA screening be harmful?
Despite the above evidence, the idea of screening is still attractive – if you had prostate cancer, wouldn’t it be better to know it? Maybe not.

PSA screening is known to produce many false-positive results - about 70% of men who have elevated PSA levels do not actually have cancer.6 Certainly, psychological harms are inherent in false-positive results, although there is insufficient research to estimate the extent of this harm.5

Healthy men who undergo annual screening may expose themselves to unnecessary and potentially harmful treatments:

  • Prostate biopsy complications include fever, infection, bleeding, pain, and urinary difficulty in some men.
  • If an abnormal PSA followed by prostate biopsy does indeed detect cancer, 90% of men will be treated with surgery, radiation, or androgen deprivation therapy.
    • Up to 0.5% of men die within 1 month of prostate cancer surgery, and 0.6-3% have cardiovascular events. One to seven percent will have serious complications. Radiation and surgery have adverse effects including urinary continence and erectile dysfunction in 20-30% of men. Radiation is also associated with bowel dysfunction.2, 3
    • Androgen deprivation therapy for localized prostate cancer is associated with erectile dysfunction in about 40% of men. Additional serious harms have been reported in patients receiving androgen deprivation therapy for advanced prostate cancers, including increased risk of heart disease, diabetes and bone fractures.2,3,7

Since most cases of prostate cancer are not life-threatening, these procedures are often unnecessary.

The U.S. Preventive Services Task Force (USPSTF) is currently revising their screening recommendations.
As of now, a draft version of the new recommendations is available. In short:

“…the USPSTF now recommends against PSA-based screening for prostate cancer in all age groups.”2

For real protection against cancer, we must focus on prevention rather than relying on early detection. A diet based on beneficial plant foods with documented anti-cancer properties is much more reliable than PSA screening, and protects against heart disease, diabetes, and all cancers, not just prostate cancer. A healthful, plant-based diet is also effective at halting the progression of prostate cancer.8-11

To learn more about protecting yourself from prostate cancer, read my 10 strategies for preventing prostate cancer. Also, in my most recent book, Super Immunity, I discuss the latest scientific research on super foods that supercharge the immune system and fight cancer, and I explain how to put this knowledge into practice by following an anti-cancer eating style.

 

References:

 

1. Sakr WA, Haas GP, Cassin BF, et al: The frequency of carcinoma and intraepithelial neoplasia of the prostate in young male patients. J Urol 1993;150:379-385.
2. Screening for Prostate Cancer: U.S. Preventive Services Task Force Recommendation Statement DRAFT. U.S. Preventive Services Task Force; 2011.
3. Screening for Prostate Cancer: U.S. Preventive Services Task Force Recommendation Statement. 2008.
4. Andriole GL, Crawford ED, Grubb RL, 3rd, et al: Prostate Cancer Screening in the Randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial: Mortality Results after 13 Years of Follow-up. J Natl Cancer Inst 2012;104:125-132.
5. Chou R, Croswell JM, Dana T, et al: Screening for prostate cancer: a review of the evidence for the U.S. Preventive Services Task Force. Ann Intern Med 2011;155:762-771.
6. Esserman L, Shieh Y, Thompson I: Rethinking Screening for Breast Cancer and Prostate Cancer. JAMA: The Journal of the American Medical Association 2009;302:1685-1692.
7. Robinson D, Garmo H, Lindahl B, et al: Ischemic heart disease and stroke before and during endocrine treatment for prostate cancer in PCBaSe Sweden. Int J Cancer 2012;130:478-487.
8. Frattaroli J, Weidner G, Dnistrian AM, et al: Clinical events in prostate cancer lifestyle trial: results from two years of follow-up. Urology 2008;72:1319-1323.
9. Fuhrman J: Dr. Joel Fuhrman Case Study Series: Prostate Cancer.
10. Ornish D, Magbanua MJ, Weidner G, et al: Changes in prostate gene expression in men undergoing an intensive nutrition and lifestyle intervention. Proc Natl Acad Sci U S A 2008;105:8369-8374.
11. Ornish D, Weidner G, Fair WR, et al: Intensive lifestyle changes may affect the progression of prostate cancer. J Urol 2005;174:1065-1069; discussion 1069-1070.

 

Men with recurring prostate cancer not dying from prostate cancer

       Prostate cancer is the second most common cancer in men (second to skin cancer). It is well established that the death rate from prostate cancer is quite low:

  • Men in the U.S. have a 16% lifetime chance of being diagnosed with prostate cancer, but only a 3% chance of dying from it.[1]
  • The five-year and ten-year relative survival rates for prostate cancer are over 99% and 91%, respectively. [2]
  • The primary causes of death of men with prostate cancer are cardiovascular disease and other cancers.[3]

After treatment for prostate cancer (either radiation or prostatectomy), prostate-specific antigen (PSA) levels continue to be monitored. If PSA begins to increase, this is called “biochemical recurrence” (BCR) of prostate cancer.

Biochemical recurrence and mortality

A study in U.S. veterans attempted to figure out how biochemical recurrence affected risk of dying from prostate cancer. Six hundred twenty three men were followed for 15 years after being treated for prostate cancer. In this study, 37% of men who were treated with prostatectomy and 48% of men who were treated with radiation experienced BCR.

Overall, a total of 387 men had died within 15 years – 48 of these men died of prostate cancer, representing 12% of total deaths. For men who underwent prostatectomy and experienced BCR, the total rate of death within five years was 34%, and the rate of prostate cancer death was 3%. For radiation and BCR, death rate within five years was 35%, and prostate cancer death rate was 11%.[4, 5]

In short, the researchers came to the conclusion that the probability of dying from prostate cancer, even after biochemical recurrence, is relatively small. They mention that their findings are in agreement with the often quoted phrase “most men die with prostate cancer, not of it.”

Since BCR is defined as an increase in PSA following treatment, this data also suggests that PSA levels may not be an accurate predictor of risk after treatment. Further studies will likely examine this issue.

Routine PSA screening

Blood vials

Routine PSA screening is known by the scientific community not to be as accurate or valuable as the public is led to believe. About 70% of men with elevated PSA do not actually have cancer, and PSA screening is not thought by scientists to reduce prostate cancer-related deaths.[6-8] Richard J. Ablin, who originally discovered PSA in 1970, recently called PSA screening a “hugely expensive public health disaster” in a New York Times editorial. Dr. Ablin supports his assertion with these facts:

  • FDA approval of PSA tests occurred largely in response to a study that found that PSA screening was only able to detect 3.8% of cancers, and that blood PSA levels may be elevated due to a number of factors, such as drug use, infections, and benign prostatic hyperplasia (BPH).
  • The U.S. Preventive Services Task Force, the American College of Preventive Medicine, and the American Cancer Society do not recommend routine PSA screening. However, PSA screening is still routinely used.[1]

Men should not rely on PSA screening as a method of “early detection” to prevent prostate cancer. Rather they should avoid the cause of prostate cancer. Diets high in vegetables (especially cruciferous vegetables and tomato products) and fruit, and low in dairy products, meat, and processed foods, are known to be protective.[9-11] Living and eating healthfully protects against prostate cancer, as well as the other chronic diseases common to Americans (such as heart disease, strokes, and colon cancer) – the same diseases that kill most men with prostate cancer. For those who already have prostate cancer, a healthy, plant-based diet is effective at halting progression of the disease.[12-15]

 

References:

1. Ablin, R.J., The Great Prostate Mistake, in New York Times. 2010. p. 27.
2. American Cancer Society. What are the key statistics about prostate cancer? 06/30/2010 09/02/2010]; Available from: http://www.cancer.org/Cancer/ProstateCancer/DetailedGuide/prostate-cancer-key-statistics.
3. Ketchandji, M., et al., Cause of death in older men after the diagnosis of prostate cancer. J Am Geriatr Soc, 2009. 57(1): p. 24-30.
4. Uchio, E.M., et al., Impact of biochemical recurrence in prostate cancer among US veterans. Arch Intern Med, 2010. 170(15): p. 1390-5.
5. Harding, A. Even when prostate cancer returns, most survive. Reuters Health 08/25/10; Available from: http://www.reuters.com/article/idUSTRE67O4RR20100825?feedType=nl&feedName=ushealth1100.
6. Esserman, L., Y. Shieh, and I. Thompson, Rethinking Screening for Breast Cancer and Prostate Cancer. JAMA: The Journal of the American Medical Association, 2009. 302(15): p. 1685-1692.
7. Coldman, A.J., N. Phillips, and T.A. Pickles, Trends in prostate cancer incidence and mortality: an analysis of mortality change by screening intensity. CMAJ, 2003. 168(1): p. 31-5.
8. Andriole, G.L., et al., Mortality results from a randomized prostate-cancer screening trial. N Engl J Med, 2009. 360(13): p. 1310-9.
9. Steinbrecher, A., et al., Dietary glucosinolate intake and risk of prostate cancer in the EPIC-Heidelberg cohort study. Int J Cancer, 2009. 125(9): p. 2179-86.
10. van Breemen, R.B. and N. Pajkovic, Multitargeted therapy of cancer by lycopene. Cancer Lett, 2008. 269(2): p. 339-51.
11. Ma, R.W. and K. Chapman, A systematic review of the effect of diet in prostate cancer prevention and treatment. J Hum Nutr Diet, 2009. 22(3): p. 187-99; quiz 200-2.
12. Frattaroli, J., et al., Clinical events in prostate cancer lifestyle trial: results from two years of follow-up. Urology, 2008. 72(6): p. 1319-23.
13. Ornish, D., et al., Changes in prostate gene expression in men undergoing an intensive nutrition and lifestyle intervention. Proc Natl Acad Sci U S A, 2008. 105(24): p. 8369-74.
14. Ornish, D., et al., Intensive lifestyle changes may affect the progression of prostate cancer. J Urol, 2005. 174(3): p. 1065-9; discussion 1069-70.
15. Fuhrman, J., Dr. Joel Fuhrman Case Study Series: Prostate Cancer.

 

 

 

 

 

 

Prostate Cancer Over-Diagnosed - Lots of Money to Be Made

People are getting unnecessary medicals test that cost a ton of money? No, you don’t say! A new study in the Journal of the National Cancer Institute reveals large-scale screening for prostate cancer using the prostate-specific antigen, or PSA, test has resulted in mass over-diagnosis and over-treatment:

The death rate from prostate cancer has fallen in the United States, but not necessarily because of mass screening, study co-author Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Medical School's Institute for Health Policy and Clinical Practice contended. "There are a number of reasons why mortality might fall, but the most obvious is that we have better treatment," he said. "Even without early detection, I expect mortality would fall."

Results of a European study reported earlier this year indicated that "to save the life of one man, 50 must be over-diagnosed," he said.

Guidelines for screening for blood levels of PSA -- a protein produced by the prostate gland -- differ widely. The American Cancer Society does not recommend PSA screening. But, the society says a PSA test can be offered to men, starting at age 50, during a discussion with their physician. That discussion should also include an explanation of the potential benefits and limitations of such screening.

It all comes down to money! I asked Dr. Fuhrman about it and he said, “It’s true. Prostate cancer screening in general is flawed, but it is big business and the business of medicine trumps science because of the money to be made.” And Dr. Fuhrman insists the PSA test does not accurately detect cancer anyway.

An important thing to remember is prevention, prevention, prevention! Reports come out all the time highlighting the benefits of plant foods on prostate cancer prevention:

Image credit: Ranoush.

Pomegranates Slow Prostate Cancer

More good news for pomegranates! A new study in The Journal of Urology found pomegranate juice slows the doubling time of prostate specific antigen (PSA). PSA’s are used to track and diagnosis prostate cancer. For the study, participants, 48 men with rising PSA levels after surgery or radiotherapy, who drank one glass of pomegranate juice each day, had longer doubling times during a 56 month follow-up than men not drinking pomegranate juice; Nutra Ingredients investigates.

And last week, nutrients found pomegranates called polyphenols were shown to reduce cell inflammation, helping to prevent heart disease and diabetes. And other research revealed test subjects drinking pomegranate juice actually had better PSA scores.

In March, a report on fish linked omega-3 fatty acids with lower risk of prostate cancer. Dr. Fuhrman sells a DHA supplement that provides essential omega-3 fatty acids.

Image credit: нσвσ

Pomegranates Fight Cell Inflammation

A new study in Journal of Inflammation claims polyphenols, plant nutrients that reduce the risk of cardiovascular disease and cancer, contained in pomegranate extract inhibit the production of inflammatory compounds, potentially preventing chronic inflammation associated with heart disease, Alzheimer's, osteoporosis, diabetes and arthritis. For the study, scientists stimulated cells to prompt an inflammatory response and then incubated the cells with pomegranate. Results showed pomegranate extract decreased pro-inflammatory reaction; Bakery and Snacks investigates.

Pomegranates are the real deal. Dr. Fuhrman calls them potent disease-fighters, especially for prostate cancer. In 2006, a study revealed men drinking pomegranate juice had better PSA scores. And pomegranates have also been found to help prevent atherosclerosis and diabetes.

In related news, the term “antioxidants” is resonating with consumers and increasing their willingness to try products including them. Maybe that’s the why the pomegranate phone is so darn cool.

Image credit: John-Morgan

Health-Points: Friday 3.13.09

Image credit: The New York Times

Veggie Diets Slow Prostate Cancer

Last spring, researchers determined lowering cholesterol cuts risk of prostate cancer. And now, a new study in Urology claims a diet rich in vegetable protein and low in saturated fat, dairy products and animal protein, boosts prostate-specific antigen (PSA), a biological marker for prostate cancer, resulting in slower PSA-doubling time and better quality of life. Scientists examined 36 men with prostate cancer, placing some of them on a vegetable-based diet, resulting in these men reporting more indicators of increased quality of life; Reuters reports.

Fruits and vegetables are serious cancer fighters! Eating foods like watermelon, tomatoes, pomegranate, green vegetables, red peppers and berries halt the development of prostate cancer, unlike saturated fat which increases prostate cancer risk.

Oh, and Dr. Fuhrman points out that PSA testing does not accurately detect prostate cancer if you are over 60 years old. So start eating veggies now!

Image credit: akimera