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Some Details of Cancer
Somewhat Simplified

By Dr. Peter W. Kujtan, B.Sc., M.D., Ph.D.

Article printed on page 26 in the March 6, 2013 edition of The Mississauga News under the feature: Health & Beauty, Medicine Matters.
Portrait of Dr. Peter W. Kujtan, supplied 2005
Dr. Peter W. Kujtan

As much as we tend to forget it, life is a cycle which has a beginning, middle and end. Due to the advent of medical breakthroughs in our lifetime, we have been conditioned to think the rewards should be measured in quantity and not quality.

Cancer has been redefined over the years and is considered as much a vital part of evolution as a disease. Many patients suddenly find themselves unwilling students of this subject. Tumors are no more than a collection of cells on our bodies in areas where we don't normally expect them.

There are basically three types of tumors. Benign tumors are collections of cells that don't cause us any unusual consequences. Most skin moles are one example.

The second category of tumor is called malignant. It is thought to arise from mistakes during cell replication resulting in loss of some cell controls. The cells in these tumors continue to multiply and it expands not recognizing the "it's too crowded signal” from neighboring cells. Malignant tumors are therefore cancer, and can arise from most body tissues. Interestingly, some tissues like small intestine cells reproduce almost daily, yet we never see tumors forming in them. Others like brain cells don’t reproduce and we do see tumors, suggesting the controls are complex.

The third category of tumor is called metastatic. This category is similar to malignant cells with uncontrolled growth, but in addition, the cells can cleave off the main tumor, somehow cloak themselves to travel within our body unmolested by the generations of guard or immune cells. They tend to enter other body area and organs where they begin new growths. This can cause massive body malfunction and be lethal. We know that metastatic cells tend to have multiple different mutations in them, and differ from malignant cells. It is almost impossible to tell the kind of tumor by looking at it. We usually do a biopsy of a portion for analysis and study.

To understand how treatments work, it requires one to quickly acquire a knowledge of genetics. The reproduction of our body cells depends on the successful copy of our master manual. This process is more complex than previously thought. Groups of instructions called genes, tell the cell how to assemble various proteins used to build, splint and erase. If nothing else, it is wise to at least learn a little bit about three types of genes involved in cancer.

Suppressor genes tend to code for things with slow growth. Repair genes tend to repair mistakes made during copying of the master manual. You can imagine how this column may appear if I failed to use any punctuation. Oncogenes usually stimulate growth, and can speed it up unreasonably. Any given cell in our body can only reproduce so many times, which forms the basis of aging.

Our cells are also capable of suicide, called apoptosis, which is a last resort to save those around them. The interesting thing is that we all possess these genes in various forms. We also know that our hostile environments such as smoking, sun-tanning or certain chemical exposure cause more mutations to occur in various cells. Some argue that it is Mother Nature’s way of adapting to these hostilities. The problem stems from the apparent randomness with which this occurs leading to mistakes which when not repaired can lead to cancer. A healthy lifestyle truly is the key.


Related resources:

Cancer from Wikipedia.

Metastasis. YouTube video, 2:12 min. A 3D animation showing how cancer cells spread to other parts of the body.

Understanding Cancer (Cancer #1). YouTube video, 4:00 min.

Cancer Growth Animation. YouTube video, 1:21 min. Video demonstrates how cancer growth happens in human body.

Tumor from MedlinePlus. A tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign). In general, tumors occur when cells divide and grow excessively in the body. Normally, cell growth and division is strictly controlled. New cells are created to replace older ones or to perform new functions. Cells that are damaged or no longer needed die to make room for healthy replacements. If the balance of cell growth and death is disturbed, a tumor may form. Problems with the body's immune system can lead to tumors ...

Tumor from Wikipedia. "A tumor (American English) or tumour (British English) is commonly used as a synonym for a neoplasm (a solid or fluid-filled [cystic] lesion that may or may not be formed by an abnormal growth of neoplastic cells) that appears enlarged in size. Tumor is not synonymous with cancer. While cancer is by definition malignant, a tumor can be benign, pre-malignant, or malignant, or can represent a lesion without any cancerous potential whatsoever.

The terms 'mass' and 'nodule' are often used synonymously with 'tumor' ... The term tumour/tumor is derived from the Latin word for 'swelling' - tumor ... A neoplasm can be caused by an abnormal proliferation of tissues, which can be caused by genetic mutations ..."

Metastatic Cancer from National Cancer Institute. A metastatic cancer is a cancer that has spread from the place where it first started to another place in the body. The most common sites of cancer metastasis are the lungs, bones, and liver. Treatment for metastatic cancer usually depends on the type of cancer and the size, location, and number of metastatic tumors.

Metastatic Tumor from BoneTumor.org. Metastatic tumors are cancers that started in another location and spread to the bones. More than 90% of all these metastatic lesions in bone are caused by a small number of primary tumors, including breast, lung, kidney, prostate, and thyroid. Bone is the third most common site of metastatic disease. Carcinomas are much more likely to metastasize to bone than sarcomas ... The ribs, pelvis and spine are normally the first bones involved and distal bones are rarely affected. Metastases are established when a single tumor cell or a clump of cells gain access to the blood stream, reach the bone marrow through blood vessels ...

Metastatic cancer overview from Canadian Cancer Encyclopedia, Canadian Cancer Society. How cancer spreads. Where cancer can spread. Common sites of metastases. Why cancers spread. Signs and symptoms. Diagnosis. Staging. Prognosis and survival. Treatment. Supportive care. Clinical trials.

Metastatic Bone Disease from OrthoInfo, American Academy of Orthopaedic Surgeons (AAOS). Cancer that begins in an organ, such as the lungs, breast, or prostate, and then spreads to bone is called metastatic bone disease (MBD). More than 1.2 million new cancer cases are diagnosed each year. Approximately 50% of these tumors can spread (metastasize) to the skeleton. The most common cancers that arise from organs and spread to bone include: Breast, Lung, Thyroid, Kidney, Prostate.

After the lung and the liver, the skeleton is the most common site of spread of cancers that begin in organs. Metastases to the lung and liver are often not detected until late in the course of disease because patients experience no symptoms. In contrast, bone metastases are generally painful when they occur.

Cancer most commonly spreads to these sites in the skeleton: Spine, Pelvis, Ribs, Skull, Upper arm, Long bones of the leg ... Because MBD weakens the affected bones, people with the disease are prone to fractures. Broken bones caused by MBD are termed "pathological fractures."

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