The Differences Between Normal And Cancer Cells

Cancer cells are very different from normal cells. Among the main differences are:

• Normal cells grow in a controlled manner while cancer cells grow uncontrollably.
• Normal cells respond to signals that cause them to stop dividing or to naturally die. Cancer cells ignore such signals.
• Normal cells do not travel around the body. Cancer cells do.
• Normal cells do invade other parts of the body. Cancer cells do.
• Unlike normal cells, cancer cells cause the blood vessels to grow toward tumours, thereby supplying them with the nutrients they need to grow.
• Cancer cells hide from the immune system so the body cannot get rid of abnormal or damaged cells.
• Cancer cells may also trick the immune system into treating them as normal cells so that instead of attacking the cancer, the immune system protects it.
• Cancer cells use different kinds of nutrients as compared to normal cells which often enables the cancer to spread rapidly.

Not All Tissue Changes Are Cancer

As mentioned in Part 1 of this blog, abnormal cells may join together to form tissue known as tumours. Some of these changes may, in time, turn cancerous, but it is important to note that not all tissue changes are cancer. Among the types of tissue changes that are not generally cancerous are:

• Hyperplasia: This is a condition where the cells' multiplication is faster than normal and an excessive cell build-up occurs. However, these cells are normal and not cancerous.
• Dysplasia: This is an advanced form of hyperplasia where the excess cells may look abnormal. In such cases the tissue is not cancerous but the chance of the disease developing is greater. An oncologist will decide if treatment is required or not.
• Carcinoma in situ: This is a more advanced type of dysplasia where the possibility of abnormal cell development is high, but since the cells do not invade adjacent tissue as cancer does, it is not cancer but needs to be carefully monitored.

Types Of Cancer

Cancer can take many forms – there are over 100 different forms of the disease. The name given to a type of cancer is usually that of the organ or tissue where it first formed. In other words, cancer that starts in the brain is brain cancer and cancer that starts in the lungs is lung cancer. In some cases, cancer may be defined by the type of cell where the disease began such as epithelial cell or squamous cell cancer.

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Also Read: Understanding Cancer – The First Step In Dealing With It – Part 1

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Among the most common forms of the disease are:

• Carcinomas: This is the most common type of cancer. It consists of abnormal epithelial cells which cover the outer and inner surfaces of the body. There are several subcategories of this type of cancer, including:
  1. Adenocarcinoma is a form of cancer that begins in the epithelial cells that produce mucus or fluids. Cancer of the prostate, breast and colon are of this type.
  2. Basal cell carcinoma this cancer starts in the outer layer of the skin.
  3. Squamous cell carcinoma forms under the outer layer of the skin and in organs like the stomach, lungs, bladder, intestines and kidneys.
  4. Transitional cell carcinoma begins in the lining of organs like the ureters, bladder, some parts of the kidneys, etc.
• Sarcomas: This type of cancer forms in the soft tissue of the body including blood vessels, lymph vessels, fat, muscles, tendons and ligaments, and the bones. The most common types of soft tissue sarcoma are dermatofibrosarcoma protuberans, Kaposi sarcoma, leiomyosarcoma, malignant fibrous histiocytoma and liposarcoma. Osteosarcoma is the most common form of bone cancer.
• Lymphoma: Lymphocytes are disease-fighting white blood cells that are essential to the immune system. When abnormal lymphocytes build up in the lymphatic system, and often in other parts of the body also, it is known as lymphoma.
• Leukaemia: This type of cancer begins in the bone marrow where red blood cells are produced. In this form of the disease, no solid tumour is produced and instead large volumes of abnormal white blood cells build up in the bone marrow and blood, forcing out the red blood cells. The low number of red blood cells reduces the volume of oxygen carried to the tissues leading to tissue damage, increased risk of infections and uncontrolled bleeding. Chronic leukaemia develops slowly and the acute form of the disease develops rapidly.
• Melanoma: The skin, and to some extent the eyes, have cells called melanocytes that produce pigments that give colour to the skin and eyes. When the cells develop abnormally, melanoma of skin/eye cancer forms.
• Brain and spinal cord tumours: As with other forms of cancer, when abnormal cell development occurs in the brain and/or spinal cord, a tumour develops which may be benign or malignant.

While these are the most common forms or places for cancer to develop, other parts of the body and other organs are also susceptible to tumour formation.

While cancer is a serious disease, there is no need to fear it. Instead, be on guard against it. The key to effective treatment of cancer is early detection and diagnosis. Regular health checkups and cancer screenings play a critical role in this. Going to a leading hospital that offers a range of health checkup programs designed to meet varying needs and a specialized oncology department is the best way to protect yourself against the disease and if it should strike, to successfully fight against it.

Cancer takes a huge physical, mental, emotional and spiritual toll on a patient. Having the right support and the will to overcome the disease is a major step in defeating the disease.

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