Wednesday 23 March 2011

Health Note Series

Cancer Prevention (For medical students)
We still don't know all of the factors involved in the causes of cancer. Of course you need to avoid the known carcinogens. Until we fully understand the causes of cancer, it is difficult to completely prevent it. That is especially so for prostate cancer.
A dietary study of 47,000 men over a six year period, done at Harvard, was published in the Dec. 1995 Journal of the National Institute. It showed that men who eat at least ten servings a week of tomatoes or tomato based foods such as pizza and spaghetti sauce were 45% less likely to develop prostate cancer. According to this study, most Italian men should have less prostate cancer.
Some studies have linked high animal fats to breast and prostate cancer.
Testosterone levels may also be suspect in the cause of prostate cancer. The oriental men usually have a fairly low level compared to Caucasians. Black men usually have a very high level. We know that prostate cancer is dependent on testosterone. If a male is castrated early in life, he will never have prostate cancer or benign prostatic hyperplasia (BPH). One of the most effective treatments for prostate cancer that has metastasized is castration. (A more euphemistic term is orchiectomy, but it means the same thing.) A less harsh treatment is to use drugs that chemically counteract androgenic hormones to bring them down to castrate level. These drugs are usually very expensive compared to orchiectomy. But most men had rather hold onto their balls because they represent manhood. Even if the testicles are nothing but a useless ornament that no one will ever see, they still want to keep them. Besides, maybe they will get lucky and their cancer will go into remission. Or someone will come up with a miracle cure.
A low level of zinc has also been cited as a possible cause of prostate cancer. Dr. L. C. Clark did a study that indicated that 200 µg or selenium per day could help prevent prostate cancer.
Testosterone levels are involved in prostate cancer. I have no idea what my level was in earlier years but at 70 years old my testosterone level was measured at 290 ng/100 ml. At age 72 it was 640 ng/100 ml. There is a lot of variation in testosterone levels, by age and even daily. The highest levels are usually in the morning.
On average, testosterone levels change with age. The highest level is from about 15 years old up to 30 years old, then it starts dropping. The levels may range from 400 ng/100 ml (nanograms per milliliter) up to 1 100 ng/1 00 ml at age 30. At age 70 it may range from 200 ng/100 ml up to about 600 ng/100 ml.
Prostate cancer is related to testosterone but it seems strange that more men get the cancer when they are older and the testosterone levels are normally decreasing. It would appear that a study should be done to determine if there is a correlation between testosterone levels and prostate cancer.
Frederica Perea, who wrote the Scientific American article mentioned above, is studying new methods of early detection of certain cancers. She looks at the genes and can detect differences that may predispose the person to cancer long before it becomes evident. But several questions have been raised similar to those raised by HIV testing for AIDS. What happens if a person is told that they have a high risk of developing cancel and he tries to buy health insurance? What happens to his employment? What will be the rules of privacy? What happens to his state of mind if he is told that he will die an early death because of cancer?
We are all different. I was a Doctor of Chiropractic. I believed in diet and nutrition. I never abused my boa, and was always well and healthy. I have taken vitamins with all of the trace elements every day for most of my adult life. I have a weight problem, so I have avoided eating fats and red meat for most of my adult life. According to the suspected causes of prostate cancer, 1 should not have got it. But again, we don't know all of the causes. And, also again, we are all different. Also remember, the first rule regarding cancer is that there are no rules.
Had I not taken care of my body, I might have gotten prostate cancer 20 years earlier.
Alternative Medicine
A word of caution. As I mentioned above, I am a strong believer in vitamins and minerals. But there are many "alternative medicine" type organizations who promote worthless products as a cure all for everything from ingrown toenails to cancer. Usually these products have not been tested or scientifically proven to have any value. The products usually come with several testimonies and perhaps endorsements from unethical doctors. These companies prey especially on cancer victims knowing that they will try anything to fight their disease. If you must use these unproven products, continue taking any prescribed medications and treatments. Do not ever rely on the unproven products unless you are participating in a scientific test.
How We Start Life
We first start life as a single cell that results from the uniting of a single sperm from the father and an egg from the mother. Neither the sperm nor the egg is a complete cell by itself. Every cell in our body has 46 chromosomes except the sperm and egg which has 23 chromosomes each. When the sperm and egg unite to form a complete cell, they will have 46 chromosomes. (Different animals and plants may have a different number of chromosomes.) The chromosomes contain the genetic materiel, inherited from each of your parents, that determines who you are and what you are.
Once the sperm and egg have united, almost immediately the single cell begins to divide and multiply. It divides into two complete cells, these two become four, the four become eight. Soon the single cell that resulted from the union of the sperm and egg becomes an embryo that has millions of cells.
To give you an idea of now cells multiply here is an old problem. It asked, "Which would you choose, to be given one million dollars outright, or to be given a single penny, then have it doubled each day for 30 days?" Without doing the simple math, many people would say they would rather have the million dollars. But if you are given one penny on the first day, then two on the second day, four on the third, and continue to double the amount each day, on the 30th day the single penny doubled each day would amount to $5,368,709.12. On the 31st day the amount would be $10,737,418.24.
The cells in the embryo may double and multiply even more often than once a day, so it is easy to understand how one cell can quickly develop into trillions. But the fast growing cells in the developing embryo are strictly regulated and controlled. After the baby is born, the cells continue to rapidly grow and multiply until the person reaches adulthood when normal growth is stopped and cells will only be produced to repair or replace damaged or worn out tissues. At this time the body will be made up of the several trillion cells.
Differentiation
The body is made up of several different cells, organs and tissues. All of these different cells are derived from the single cell that resulted from the fertilized egg. As the embryo grows and develops, the cells change, or differentiate, into whatever cell type is needed for a particular tissue or organ. (It is interesting to note that some plants and lower animals retain a large amount of undifferentiated cells throughout life. There are so many undifferentiated cells in some plants, such as the geranium, that all you need is a small piece of a branch to grow or clone a complete new plant. Some lizards can lose a part of their tail or a foot to a predator and the tail or foot will eventually regrow from embryonic type undifferentiated cells. If we could find out how the lower animals do this perhaps humans could do it. Studies are being done using human embryonic tissues, even though some people are protesting such studies.)
When a cancer develops, it may have several different types of cells. Some of the cancer cells may be very similar to the original prostate or whatever type of tissue it derived from. These cells would be called well differentiated. Some of the cells within the tumor may not have any resemblance at all to the original cells. These would be called poorly differentiated or undifferentiated. Between these two extremes might be some moderately differentiated cells. The process of cells becoming poorly differentiated or undifferentiated is sometimes called differentiation.
Most prostate cancers may have a mix of many different stages of differentiation. The Gleason Score for staging prostate cancer is based on the mix of the differentiation of the cells.
Ordinarily, those tumors with a large number of poorly differentiated cells are the more aggressive and dangerous. They grow faster and metastasize early. They usually have a worse prognosis than the well differentiated type tumors. But this is not always the case. There are no hard and fast rules that are etched in stone when it comes to cancer. Again, the only rule regarding cancer is that there are no rules. There are exceptions and sometimes the poorly differentiated tumor may grow no faster than a tumor that is well differentiated. And sometimes the well differentiated may become aggressive and fast growing.

Question:.    How Cancer Spreads?
Whenever cancer starts to spread, some of the metastatic cells are often stopped temporarily by lymph nodes. But the cancer cells usually don't cause enough alarm to cause the lymph nodes to stop them completely. The nodes may become overwhelmed and the cancer cells may proceed on their way to set up new colonies or tumors. In prostate cancer, quite often the new tumors are formed in the bones of the spine.
When a radical prostatectomy is performed, ordinarily, the lymph glands are examined first for cancerous cells. A microscopic examination of the lymph nodes can often reveal whether a cancer has metastasized. Sometimes a laparoscopic examination will be done before the operation. Or the surgeon will take out the lymph nodes and have a pathologist examine them immediately. If any cancer cells are found in the lymph nodes, it means that the cancer has already spread. In this case, it usually doesn't help to remove the prostate. Like the old saying, it's not much use locking the barn door after the horse has escaped. Most doctors will sew the patient back up and start him on other therapy.
How Cancer Survives
The cancer cells can spread by way of the lymph system and blood system and the several nerves that enter and leave the prostate. Reverse transcriptase polymerase chain reaction (RTPCR) is a fairly new test that can detect cancer cells in the blood stream. At the present time when cancer is diagnosed we have no way of knowing whether it has already metastasized. Once the cancer has spread, it does no good to remove the prostate. In fact it is a major operation that is traumatic and may cause more damage than good. Because we can't recognize early metastatic disease, many men are operated on needlessly. Some of these men may appear to have been cured, but within five years, metastatic cancer may become evident in up to 20 percent or more of men who thought they were cured.
Just being able to find a cancer cell in the blood stream is no guarantee that it will be able to find a suitable place to settle down, establish a colony and grow new blood vessels.
When cancer cells begin to proliferate, they must have lots of food and nutrition. To get it requires extra blood and lymph vessels. It is believed that tumors produce a substance called angiogenic factors, (Angeion is Greek meaning vessel), that causes the body to create the extra blood and lymph vessels.
For every chemical, drug or hormone that causes an action, there is usually one that causes an opposite reaction. Scientists are trying to find and identify the tumor angiogenic factors. If these factors can be identified, isolated and chemically analyzed, then perhaps a method can be devised that would inhibit the production of the angiogenic factors. Without these factors, the cancer cells would be denied a blood supply and nutrition and would thus die.
A man who has a degree in agriculture happened to read about angiogenesis. He had done some study of fish. He wrote a book called Sharks Don't Get Cancer. He claimed that the cartilage in sharks prevents them from getting cancer. He theorized that the shark cartilage could prevent cancer. (And almost every other kind of disease known to man.) He took dried shark cartilage, ground it into a powder form, mixed it with water in a food blender, then gave it to men as an enema. Women were given the standard rectal enema and the solution was also placed in their vagina. He said in the book that the enemas were necessary because oral doses of shark cartilage would be destroyed by the digestive enzymes. But it is highly doubtful that the large molecules and particles of the ground up shark cartilage could be absorbed through the lower intestine or through the walls of the vagina.
The fact that the cartilage would be broken down and digested if taken orally did not stop several companies from manufacturing and promoting an oral capsule. Mike Wallace of the CBS 60 Minutes did a segment on Mark Lane, the author of the book. Thousands of people rushed out to buy the book and the capsules of Cartilade shark cartilage.
The October 1993 issue of the Scientific American had an article that said that sharks do get cancer. They also said that you might as well eat pig's knuckles as to take the Cartilade. There is no scientific evidence whatsoever that shark cartilage can cure anything.
We are pretty sure that taking shark cartilage cannot hurt you, except in your pocketbook. It is quite expensive. The danger lies in that people may rely on this quackery and abandon their proven drugs and treatments.
When people have cancer, they will try anything to save their lives. There are many quacks and disreputable people who will seek out cancer victims and take advantage of them.
Oncogenes
There are about 100,000 genes in the chromosomes of each cell. The genes are carried in the DNA and are the blue print of all the characteristics that were inherited from the parents. The genes determine the eye color, the person's size and shape and all of the characteristics of a person. Some studies have indicated that a few of these genes, about 100 or so, are oncogenes, or genes that can cause cancer.
The cells of our body normally reproduce or split exactly in half when it is necessary to replace or repair nearby cells or tissues. When oncogenes are "hit" bye carcinogen, then reproduces, resulting new cells may be abnormal cancer cells. Some studies seem to indicate that it may take two or more hits to the oncogenes from carcinogens to cause cancer.

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