Tag: Cancer

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Prostate Cancer

Dear Dr. B: What is PSA? I believe this a blood test to check for prostate cancer. If this is true then why is my family doctor reluctant to order one for me? Can you please tell me more about this test, who should get it and how often? Yours, worried Mr. P

Dear Mr. P: PSA stands for Prostate-Specific Antigen. Yes, this test is now widely used for early detection of prostate cancer and to follow the progress of patients who have had prostate cancer.

Prostate cancer is now the most commonly diagnosed cancer in Canadian men and second most common cause of death from cancer in men. Prostate gland is present only in men at the junction of the urinary bladder and the urethra. PSA was thought to be produced and secreted solely by the cells of the prostate gland. But this is not true anymore. PSA is also found in breast cancer and other cancers.

Once upon a time, digital rectal examination was the only crude way to pick up early prostate cancer. Then came PSA blood test. PSA was expected to replace the embarrassing and uncomfortable digital rectal examination. And it was promoted as an ideal test for screening and early detection of prostate cancer. But this hope has not materialised. And the controversy continues.

In a recent edition of the Canadian Medical Association Journal, there are two commentaries on this issue. One is written by two family physicians and the other one by a urologist.

The family physicians feel that PSA testing in men over 70 should be avoided. They restrict the use of PSA screening to men between 50 and 70 years of age unless they are at higher risk (e.g. black American men and those with a family history), in which case screening is initiated at 40.

How often the test should be ordered?

According to the family physicians, the literature survey suggests that PSA should be ordered anywhere from every 2 years to every 5 years. Normal value should be less than 4 ng/mL. Another report suggests that men with PSA results of 4ng/mL and below should be tested every 6 months for at least 3 consecutive tests.

Currently, these family physicians recommend PSA every year for eligible patients but feel that screening every 5 years is a reasonable alternative.

The urologist’s commentary agrees that PSA testing for all men between 50 and 70 is a good idea. But PSA screening every 5 years may be inadequate. The urologist feels that yearly testing is reasonable unless the PSA level is below 1 ng/mL, in which case testing every 2 years is acceptable.

In about 20 percent of patients with normal PSA results, diagnoses of prostate cancer will be missed, which supports the idea that digital rectal examination is an important additional diagnostic tool. But digital rectal examination on its own will miss a substantial numbers of prostate cancers.

The urologist feels that the upper limit of normal (4ng/mL) may be too high and it would be prudent for family physicians to refer patients to a urologist if the PSA result is above 2.5-3.0 ng/mL.

So, Mr. P, have I confused you? If yes, then you are now on par with other doctors! The last word on this subject is yet to come. But I hope this information will help you put your doctor’s advice in proper perspective.

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Diet and Cancer

“Doc, one more column on nutrition and I will throw up!” says Dave.

“Dr. B, just ignore him. Tell me, how can good nutrition prevent cancer?” asks Susan.

Susan, this question has been bothering me too. So, let us see if there is any scientific literature to prove that good nutrition can prevent cancer.

Here are two articles. First one, a review article titled “Diet and the prevention of cancer” in the British Medical Journal. Second one, “Diet and cancer” in the Encyclopaedia Britannica. This is what they have to say.

There are three ways in which a person’s usual diet may lead to cancer: (1) A cancer producing substance, in food or drink, can come in contact with the lining of the mouth, throat, oesophagus, stomach, intestines, liver, or urinary bladder and trigger changes leading to cancer. (2) A person is little overfed or a little underfed may influence the incidence of hormone-dependent cancers in the breast, uterus or prostate by altering the hormone secretion or metabolism. (3) Some nutrients may influence the susceptibility of other sites to cancer producing substances.

It has been estimated that diet may be responsible for around 38 percent of cancer deaths. About 80 percent of cancers of the large bowel, breast and prostate may be related to diet. One of the articles says: While there is strong but indirect epidemiological evidence that most of the common cancers could be made less common by suitable modifications of food habits, there is still no precise and reliable evidence as to exactly what dietary changes would be of major importance.

For people like you and me this creates a significant dilemma. We need to know exactly what to eat and what to avoid to prevent cancer. Just like the “heart smart” diets where we know the type of foods that will keep our heart and blood vessels healthy.

Colon and rectal cancer is one for which the evidence that diet is involved is probably strongest. Constipation is known to be a risk factor because of the increased time the cancer inducing substances in the stool spend against the lining of the colon and rectum. Increased intake of fibre and vegetables can hasten the transit time and reduce the risk.

Red meat , processed meat, and canned meat increase the risk of colon and rectal cancer.

When it comes to breast cancer, overweight postmenopausal women have up to a twofold greater risk. In premenopausal women, the effect of weight is inconsistent. Meat and alcohol are associated with increased risk. Low intake of vegetables and fibre may have the same effect.

Other cancers where nutrition is important are: cancer of the prostate, stomach, oesophagus, pancreas, lung, and uterus. The common theme is – excessive use of cigarettes, alcohol, meat, and fat. Not enough intake of fruits, vegetables, fibre, and certain types of vitamins.

Role of vitamins in cancer is controversial. Some experts believe that caution should be used with high doses of purified supplements of vitamins and minerals. But all experts believe that vegetables and fruits have strong protective effect and red meat and processed meat is linked to high risk of many cancers.

So next time you buy a burger, don’t ask: Where is the beef?


This series of articles explore the health problems of Dave and his family. They are composite characters of a typical family with health problems.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!

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Ovarian and Uterine Cancer

“Dr. B, can we discuss early detection and prevention of cancers of the ovary and uterus?”

Sure, Susan. I will give you some information today and you discuss this further with your family doctor and/or gynecologist. Remember cancer of the uterus can be either in its body (endometrial) or in its opening (cervix).

In 1993, 606 Alberta women were diagnosed with invasive (beyond the superficial layer) cancers of the female genital organs: endometrial 256, ovary 203, cervix 122 and others 25. This does not include 1517 women who were diagnosed with in-situ (confined to the superficial layer) cancers of the cervix.

“What symptoms would I have if I had cancer of the ovary or uterus?”

Susan, unfortunately the early symptoms are none or very vague. Early diagnosis of ovarian cancer is more a matter of chance. Irregular vaginal bleeding may be the only early sign of uterine cancer. Hence, most of the gynecological cancers are picked up at a late stage. Of course, the Pap smear has completely changed the outcome of cervical cancers.

“Doctor, are there any risk factors which I should be aware of?”

Susan, for ovarian cancer, the risk factors are age (steady rise up to age 80) and family history. For endometrial cancer – age, obesity and estrogen therapy are major risk factors. For cervical cancer, the risk factors are well recognized. These are: some types of sexually transmitted disease(s), early age at first intercourse, and having multiple sexual partners.

“Doctor, what about screening tests?”

Susan, for ovarian and endometrial cancers, there are no recommendation for screening. But for cervical cancer, Pap smear is highly recommended. In U.S., this has reduced the incidence and death rate by 70 percent in the last 40 years.

Invasive cervical cancer is usually diagnosed between the ages of 45 and 50. But the average age of women with carcinoma in-situ is between 25 and 30 with evidence of increase in younger women. This could be related to risky health practices, such as experimenting with new ideas, relationships and activities during adolescence which may have long term adverse consequences.

“Dr. B, final question! How often should a woman get a Pap smear?”

Susan, for those who are not at high risk, first Pap smear should be done soon after the age of 18 or once the woman is sexually active. If this is normal and the one after a year is also normal then repeat after every three years until age 70.

It is very important for every woman to discuss her risk factors with her family doctor and/or gynecologist. Recommendations may vary. Any unexpected vaginal bleeding should be reported to your doctor to see if further investigation is required.

“Thank you, doctor,” Susan said as she got ready to leave my office. She continues to strive for good health for herself and her family. I admire her dedication.

(This series of articles explore the health problems of Dave and his family. They are composite characters of a typical family with health problems)

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!

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Pancreatic Cancer

“Doc, few days ago, my neighbor’s wife, Yazmin, died of pancreatic cancer at the age of 59. Her husband, Yusuf, is devastated. He feels guilty. He thinks he could have done more to save her.”

Dave looks upset. I know when something is bothering him because normally he would say: What’s up doc? Busy today?

“Dave, here is some information which may help.”

Pancreatic cancer is the fifth leading cause of cancer death in North America. In 1992, 214 Albertans died of the disease (males 114, females 100). In 1993, 216 new cases were diagnosed in this province (males 98, females 118).

The prognosis is dismal. The overall 5 year survival rate is less than 2 percent, the worst of any cancer. Only 20 percent of the patients will be diagnosed at stage where surgery may offer hope.

The surgery is extensive with significant complications. Even those who survive the ordeal, the 5 year prognosis may not be better than 25 percent.

“Doc, why is it difficult to make an early diagnoses?”

Two main reasons: first, the pancreas is a long, narrow, transverse, deep seated organ behind the stomach in the upper abdomen; second, the initial symptoms are none or very vague. By the time ultrasound or CAT scan picks it up, it is too late.

Dave is surprised to hear that. He tells me about the difficulties Yusuf and Yazmin have overcome over the past 25 years. They had arrived penniless as refugees from Uganda with six children: the youngest, triplets, were about a year old.

Yusuf is a good watch repairer. After moving from few unsatisfactory jobs, he opened his own business: a jewelry shop. Yazmin did the “salesmanship” and Yusuf repaired watches. They were happy.

As parents, they had their share of problems raising children. Their oldest daughter has multiple sclerosis. Now, Yusuf has to deal with the tragedy of losing his wife.

Dave was almost in tears. “Doc, what causes pancreatic cancer?”

The precise cause is unknown. Smoking and chronic inflammation are suspected in the causation of the disease. An estimated 5-10 percent of pancreatic cancers are inherited and additional 10-20 percent may have other significant genetic influence (Current Oncology-July 1998).

“Doc, thanks for listening. I will go and see Yusuf. See if I can help him with the information I have.”

Good luck, Dave.

(This series of articles explore the health problems of Dave and his family. They are composite characters of a typical family with health problems)

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!