7 facts about Malignancy
1. Definition
Malignancy is a life-threatening progressive condition.Malignant Cancer means unwanted, uncontrolled growth of cells which are structurally and functionally different from their parent cells.
2. What goes wrong?
The DNA present in the nucleus of all the cells in the body is the source of 'genetic-control' over the structure and function of each cell. When, due to some reason, the DNA is repeatedly damaged, it might undergo mutation (change) and and that 'genetic-control' is lost. Hence, the cells start dividing in a haphazard manner, only to produce more abnormal cells. This abnormal cell mass is what we call 'tumor'. It has the potential to damage to the surrounding tissues and organs, creating a 'micro-environment' of its own.
3. Proto-oncogenes and Tumor-suppressor genes.
4. What is the difference between normal cells and cancer cells?
Normally, all the cells stop dividing in the absence of the growth signals, after the 'stop' process.
Whereas, the cancer cells lack the 'stop' process. Because, the Proto-oncogenes undergo mutation (change) and promote cell growth when not necessary. They are then called Onco-genes. Moreover, the Tumor-suppressor genes get deactivated and more so, promoting cell growth that might invade other parts of the body (metastasis).
Moreover , the malignant cells have different characteristics than the normal cells-
5. What is the difference between malignancy and infection?
Infection is caused by invasion of foreign micro-organisms in the body.
Malignancy involves abnormally mutated own body cells, and not foreign cells.
Body's immune system fights the foreign invasion in case of infection.
Body's immune system does not recognize or register cancer cells as foreign, and hence does not keep it in check.
6. Why do many cancers occur in old age?
This happens because, the longer we live, the higher is the chance of DNA getting exposed to damaging substances and carcinogens. Moreover, the body's capacity to regenerate lost tissue and repair errors is diminished in old age.
7. Why are the most common cancers, so common?
The most common cancers are Breast cancer and Ovarian cancer in women, Prostate cancer in men.
Also, cancers of skin, blood cells, lining of bowel, and lungs are some more common ones.
The reason why these are more common is related to the rate of division of cells, and need of replacing tissues. The cells in blood, inner lining of lungs, bowels and on the skin are constantly replaced more than other parts of the body.Hence the chances of mutation are higher.Even in case of growing children, the bone cells are constantly under change and growth, increasing their chances of having bone cancers.
In case of women, the breast tissues and the ovarian cells are constantly under some hormonal regulation.They undergo constant changes, which puts them at higher risk.
In case of men, as they grow old, the prostate undergoes slow and constant changes due to hormones which again increases the risk of mutation.
Hence, these cancer are more common than others.
Also read-
What are Benign Tumors?
What is Malignancy?
5 reasons why you should study Oncology.
What is psycho-oncology?
12 causes of cancer.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
1. Definition
Malignancy is a life-threatening progressive condition.Malignant Cancer means unwanted, uncontrolled growth of cells which are structurally and functionally different from their parent cells.
2. What goes wrong?
The DNA present in the nucleus of all the cells in the body is the source of 'genetic-control' over the structure and function of each cell. When, due to some reason, the DNA is repeatedly damaged, it might undergo mutation (change) and and that 'genetic-control' is lost. Hence, the cells start dividing in a haphazard manner, only to produce more abnormal cells. This abnormal cell mass is what we call 'tumor'. It has the potential to damage to the surrounding tissues and organs, creating a 'micro-environment' of its own.
3. Proto-oncogenes and Tumor-suppressor genes.
 |
| G1, S, M, G2 are the phases of a cell cycle which are regulated by the genes, mutation of which causes formation of tumor. |
All the cells in the body divide. Some more than others, as some cells in the body have to be constantly replaced. So, this division process is almost always under control. Let's refer to it as the 'start' and 'stop' process. These are governed by two different set of genes-the growth promoters or Proto-oncogenes and the growth suppressor or Tumor-suppressor genes. The Proto-oncogenes get activated when they receive growth signals, and the cells then divide.When it is needed to stop. the 'tumor-suppressor' genes regulate the stopping process.As seen in the above diagram, these genes regulate the cell cycle.
4. What is the difference between normal cells and cancer cells?
Normally, all the cells stop dividing in the absence of the growth signals, after the 'stop' process.
Whereas, the cancer cells lack the 'stop' process. Because, the Proto-oncogenes undergo mutation (change) and promote cell growth when not necessary. They are then called Onco-genes. Moreover, the Tumor-suppressor genes get deactivated and more so, promoting cell growth that might invade other parts of the body (metastasis).
Moreover , the malignant cells have different characteristics than the normal cells-
| the image shows difference between normal and cancerous cell division. (image courtesy:national cancer institute) |
- they divide from a single cell, and then the cloning of abnormal cells begin
- the cells become anaplastic, and more grade of anaplasty means more dangerous malignancy
- their nucleus is larger, irregular in shape and darker than normal
- the cytoplasm or cell mass is smaller and irregular
- they possess different staining properties or pleomorphism.
5. What is the difference between malignancy and infection?
Infection is caused by invasion of foreign micro-organisms in the body.
Malignancy involves abnormally mutated own body cells, and not foreign cells.
Body's immune system fights the foreign invasion in case of infection.
Body's immune system does not recognize or register cancer cells as foreign, and hence does not keep it in check.
6. Why do many cancers occur in old age?
This happens because, the longer we live, the higher is the chance of DNA getting exposed to damaging substances and carcinogens. Moreover, the body's capacity to regenerate lost tissue and repair errors is diminished in old age.
7. Why are the most common cancers, so common?
The most common cancers are Breast cancer and Ovarian cancer in women, Prostate cancer in men.
Also, cancers of skin, blood cells, lining of bowel, and lungs are some more common ones.
The reason why these are more common is related to the rate of division of cells, and need of replacing tissues. The cells in blood, inner lining of lungs, bowels and on the skin are constantly replaced more than other parts of the body.Hence the chances of mutation are higher.Even in case of growing children, the bone cells are constantly under change and growth, increasing their chances of having bone cancers.
In case of women, the breast tissues and the ovarian cells are constantly under some hormonal regulation.They undergo constant changes, which puts them at higher risk.
In case of men, as they grow old, the prostate undergoes slow and constant changes due to hormones which again increases the risk of mutation.
Hence, these cancer are more common than others.
Also read-
What are Benign Tumors?
What is Malignancy?
5 reasons why you should study Oncology.
What is psycho-oncology?
12 causes of cancer.
Cancer and surgery.
What is Radiation oncology?
What is Cancer-related fatigue?
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