Tag: prostate

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Role of Calcium and Milk Products in Prostate Cancer

Dear Dr. B: We are in Arizona for the winter. My husband and I have always taken calcium and Vitamin D. There seems to be a lot of controversy here with several people who feel that calcium for men is putting them at high risk for prostate cancer.
Apparently this warning was on T.V. and in the newspapers. What is the truth, doctor?

Answer: Nobody knows exactly what causes prostate cancer. There are a variety of factors implicated in this process. There are some factors (diet and weight) you can change but others like age, ethnicity and family history cannot be changed.

As we know, prostate gland is present only in man. Any normal man can develop prostate cancer because normal men have male hormones (testosterone). Lack of testosterone due to any cause can reduce the risk of prostate cancer.

Age is an important factor. Prostate cancer is rare before the age of 45. As one gets older, the risk increases. Men of African or Caribbean ancestry have the highest risk.

What has race to do with prostate cancer? Scientists are not sure about that. There may be subtle genetic, dietary, environmental and hormonal differences. Another interesting fact is that dark skin absorbs less sunlight than light skin, which may contribute to the higher incidence of prostate cancer among men of African or Caribbean ancestry because of lack of vitamin D.

Family history is important. If your father or brother has had prostate cancer you are approximately two to two and half times more likely than the average man to be diagnosed with the disease during your lifetime. Having two first-degree relatives with prostate cancer increases your risk to about five to 10 times that of a man with no family history, and your risk soars to almost 100 per cent if three or more first-degree relatives have had prostate cancer.

Diet is linked to prostate cancer. A low fat diet may help prevent prostate cancer. Foods rich in saturated fats have been associated with increased risk of prostate cancer, possibly because they are metabolized into testosterone. Fish oils may protect against prostate cancer especially omega-3 fatty acids found in fatty fish like trout, anchovies, bluefish and white albacore tuna.

What about the role of milk, cheese and calcium? The American Cancer Society website article of 2001says, “Experts say excessive calcium intake may be unwise in light of recent studies showing that high amounts of the mineral may increase risk of prostate cancer.”

Here is a dilemma. There is a reasonable evidence to suggest that calcium may play an important role in the development of prostate cancer but evidence also shows calcium may lower the risk of colon cancer and age-related thinning of the bones.

The recommended daily allowance (RDA) of calcium is 1,000 mg per day for men and 1,500 mg for women. Important thing to remember is the words, “excessive calcium intake.” It is also critical to remember that this evidence is not conclusive. The word “may” is used quite often in this context.

You can have milk, cheese and other dairy products in moderation. An 8-ounce glass of milk contains about 300 mg of calcium, an ounce of cheese has about 200 mg, and a serving of yogurt has about 312 mg of calcium. Men should stay within 1000 mg of calcium per day. And don’t forget your vitamin D 1000 to 2000 IU per day especially in winter months. Vitamin D has an important role in preventing prostate cancer and other cancers.

A balanced diet, combined with regular exercise, is always a good idea.

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A man with benign enlarged prostate gland – What are the treatment options?

A man has symptomatic benign enlargement of the prostate gland. What are his treatment options?

“Prostatic disease eventually affects almost all men; benign prostatic hypertrophy or hyperplasia (BPH) is an inevitable part of aging,” says an article in the Canadian Medical Association Journal (CMAJ June 19, 2007).

Do we need to worry about prostatic hypertrophy or hyperplasia which in simple terms means prostatic enlargement? Sure, we have to worry. Who knows, it could be malignant. Although prostatic enlargement eventually affects almost all aging men, not all men suffer from prostatic cancer. The lifetime risk of diagnosis of prostatic cancer is 18 per cent and death from prostatic cancer is three per cent.

Enlarged prostate gland has several effects. These include difficulty with voiding urine and blood PSA levels may go up. Other complications are urinary retention, urinary bleeding, bladder stones, recurrent urinary tract infections and renal failure. These effects become progressively worse requiring frequent medical attention and rising PSA requires multiple tests to rule out prostate cancer.

About 20 years ago, the standard treatment for benign enlargement of prostate gland was surgery. Now, patients with mild symptoms do not need any treatment. Patients with moderate symptoms are treated with medications. These medications have shown to improve the flow of urine and improve the quality of life. Do these medications prevent complications of BPH? Studies have shown that this is possible.

The two major classes of drugs used to treat BPH are: a) alpha-blockers like doxazosin relax smooth muscle fibers of the bladder neck and prostate gland to reduce prostatic obstruction, b) five- – reductase inhibitors like finasteride decrease levels of testosterone in the prostatic gland itself but do not affect the systemic testosterone level. This leads to reduction of the prostate gland by 20-30 per cent.

With -blockers, patients experience relief of symptom within two weeks of starting the medication, compared with several months with finasteride. Researchers have found that doxazosin and finasteride slowed down the growth of BPH compared with placebo; the combination therapy was significantly more effective than either drug alone.

The CMAJ article says that the Medical Therapy of Prostatic Symptoms study showed that:
-BPH is a progressive disease
-progression can be prevented by medical therapy
-patients at risk for progression can be readily identified by PSA level, prostatic volume and symptom severity
-and the combination of finasteride and doxazosin is more effective than either alone in preventing progression, particularly in high-risk groups.

Are there any side-effects to these medications?

The article says that clinically significant side effects, mainly postural hypotension (low blood pressure), were infrequent and they led to cessation of therapy in 18–27 per cent of the men involved in the study. Side effects that occurred were minor and related mainly to sexual function.

Patients treated with finasteride had significant benefit with improvement in urinary symptoms. There was also an added advantage in that the finasteride-treated patients saw reduction in the overall risk of prostate cancer by 25 per cent – a rate almost unheard of in the field of cancer prevention, says the CMAJ article. The authors of the article say, “Because PSA levels are reduced in men with BPH who are taking finasteride, rising PSA findings are more likely to be caused by prostate cancer. Taking this drug may therefore provide a diagnostic advantage as well.”

The article poses the question: Should selected patients now be offered finasteride to lower their risk of developing prostate cancer and BPH progression?

“The answer, based on these trials, is unequivocally yes,” conclude the authors of the CMAJ article.

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Did you know…

Did you know the death rate for breast cancer for Canadian women has dropped by 25 per cent since 1986?

A Canadian Cancer Society special report in Canadian Statistics 2007 says increased participation in organized breast screening programs (particularly by women aged 50 to 69) has led to earlier detection and made it more likely that patients who have breast cancer receive successful treatment (CMAJ June 19, 2007).

The national recommendation is that organized breast cancer screening programs actively screen women aged 50 to 69 every two years. Organized screening programs began in British Columbia in 1988 and have since expanded to include all provinces, the Yukon and the Northwest Territories.

If you are under 50 years of age or 70 and over then discuss your risks and screening program with your physician.

The screening program includes mammogram, clinical examination of your breasts by your physician every two years and monthly breast self-examination.

Did you know that early diagnosis and treatment of prostate cancer was first suggested a century ago?

Although prostate-specific antigen (PSA) blood test has been widely used in North America to detect early prostate cancer, it is still unknown whether PSA screening significantly reduces mortality from prostate cancer.

Actually PSA measurements reflect cancer risk, with the risks of cancer and of aggressive cancer increasing with the level of PSA (CMAJ June 19, 2007). Besides PSA blood level, your physician will look at other risk factors before he can advise you on further management. Other risk factors are: family history of prostate cancer, digital rectal examination findings, age, ethnicity and history of previous biopsy with a negative result.

Since PSA test is not a perfect test for detecting early prostate cancer, you should discuss with your doctor the risks and benefits of ordering such a test. PSA blood test for screening is not recommended by the Canadian Task Force on Preventive Health Care as there is insufficient evidence to promote it for screening for early detection of prostate cancer. Canadian Urological Association and Prostate Cancer Alliance have recommended that it be performed only after detailed discussion of the pros and cons between doctor and patient.

What is interesting is that recent nationwide survey indicated that almost half of Canadian men over 50 years of age reported receiving PSA screening during their lifetime. PSA blood test and digital rectal examination have become part of annual physical examination for men over 50 by their family physician and 72 per cent of these men had these tests in the last one year (CMAJ).

Prostate cancer is thought to be the disease of older men. But autopsy studies have found that 27 per cent of men in their 30s and 34 per cent of men in their 40s have histological evidence of the disease (not necessarily clinically known disease). The current lifetime risk of disease diagnosis is 18 per cent and lifetime risk of dying from prostate cancer is three per cent.

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Prostate Cancer Tests


Dear Dr. B: Can you please tell me about the new test under development for early detection of prostate cancer?

Answer: I received this question from a friend whose style of writing and sense of humour I enjoy. The e-mail contained a comment on my last column on aspirin and colon cancer and the photograph accompanying the article showing a flexible sigmoidoscope. Here in part is what my friend said:

‘Imaginative photo. We amateurs still squirm about such “personal” things and, I’m sure, men more than women, are real wimps about poking around the body. Of course, to a medical person it is a smart surgical instrument used in an everyday procedure. To a patient it is perceived as a fire hose up the whazoo… Just the other day I was discussing, in a casual conversation, the old finger-vs.-PSA test… Today, through bleary eyes, I read a piece in the Globe about new research and new tests under development. I know you’ve hit this before. But it might be worth a visit to this subject again some time.’

My friend is right. It is time to revisit the subject because prostate cancer is the most frequent cancer and the second leading cause of death from cancer in men, exceeded only by lung cancer. In our region, 80 to 90 new cases of prostate cancers are diagnosed each year. And each year 10 to 15 patients die of the disease.

The walnut size prostate gland lies below the urinary bladder in front of the lowest inch of the rectum, through which it can readily be felt on digital rectal examination. The gland has an important role in the proper flow of urine. It also provides the proteins and ions that form the bulk of the semen. In conjunction with other smaller glands in the vicinity, the prostate gland produces secretions that serve to lubricate the reproductive system and provide a vehicle for storage and passage of sperms.

Once upon a time, “the old finger” i.e. digital rectal examination (DRE) was the only crude way to pick up early prostate cancer. Although DRE has a cancer detection rate of only 0.8 to 7.2 percent, it remains an important test that can be done easily in a doctor’s office. It also checks for anal and rectal tumours.

Then came the PSA blood test. PSA was expected to replace the embarrassing and uncomfortable DRE. And it was promoted as an ideal test for screening and early detection of prostate cancer. But this hope has not materialized.

Now a group of researchers from the University of Michigan Medical School are working on a test which would use the body’s own immune system to detect prostate cancer early. That makes sense as the immune system, in response to cancer, releases thousands of chemicals into the bloodstream to destroy the tumor.

The new blood test looks for 22 of these chemicals that specifically fight prostate cancer. The preliminary report indicates that these chemicals are more reliable than PSA in detecting prostate cancer. But the bad news is that it will be several years before this test is perfected and marketed for everyday use.

In the meantime, we have to rely on “the old finger” and PSA test. Findings from a new national research study released recently by the Prostate Cancer Research Foundation of Canada (PCRF) found very few Canadian men are willing to discuss prostate cancer and PSA test with their family doctors. PCRF has launched a campaign with a slogan “Don’t Get Scared. Get Tested.” More information can be found on PCRF website, www.prostatecancer.ca.

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