What are tumors?
Tumors are a group of abnormal cells that grow to form lumps or growths. Depending on their type, different tumors grow and behave differently.
The different types of tumors are:
These tumors are non-cancerous. They are rarely life threatening or lead to serious issues, unless they grow in a vital organ or grow large enough to press on and disrupt nearby tissues. Benign tumors grow slowly and do not spread to other parts of the body. Once removed through surgery, these tumors rarely grow back. Except for rare cases, benign tumors are non-cancerous.
Precancerous or premalignant cells are those abnormal cells that have the potential to develop into cancer. As these cells grow and divide, they become more and more abnormal, till they turn into cancer. Precancerous changes may vary in their type of abnormality:
- Hyperplasia – This refers to an abnormal increase in the number of cells. While some hyperplasias are precancerous, most are not.
- Atypia (atypical) – These cells look slightly abnormal under the microscope, and are usually a result of changes caused by healing and inflammation rather than precancerous change. They go back to normal once inflammation reduces or healing is complete.
- Metaplasia – Though these cells look normal, they are not the usual type of cells found in that tissue or area of the body.
- Dysplasia – These cells develop abnormally, and are abnormal in appearance and organization. These cells are almost always precancerous.
These tumors are cancerous. Cancer cells may develop from one abnormal cell in the tissue; they have a larger nucleus, and look, behave, grow differently from the normal tissue cells. Malignant tumors grow in an uncontrolled fashion and may invade surrounding tissues, blood vessels or lymphatic system, in which case they can become life threatening. Cancer that spreads to a new part of the body from its original location is called metastatic cancer.
How are tumors named?
Tumors are commonly named after their place of origin. For example, breast cancer or lung cancer. Cancer of plasma cells is referred to multiple myeloma, of lymph nodes as lymphoma and of white blood cells as leukaemia. Some cancers are also named after the person who described them, like the Hodgkin lymphoma.
What is the cause of a tumor?
In normal conditions, cell growth and division is strictly controlled. New cells are created to replace the old ones. A tumor develops when a cell starts dividing abnormally and growing excessively due to excessive growth receptors on the cell surface because of the mutations in DNA. Common causes that disrupt the cell balance and lead to tumors are:
- Tobacco (oral cancer)
- Excess alcohol
- Excessive sunlight exposure (melanoma)
- Viruses (cervical cancer, hepatocellular carcinoma)
- Chemicals and Toxins
Some tumors affect one gender more than the other, while some are more common in children or elderly. Others may be related to environment, family history or diet.
What one needs to know about symptoms or signs?
Symptoms depend on the type and location of the tumor (shortness of breath, coughing in lung cancer), while some tumors (like pancreatic cancer) may not cause any symptoms till the condition reaches advanced stages.
Which specialist should be consulted?
People who experience symptoms of a tumor or feel a general sense of illness over long periods must consult their family physician, who will refer them to an oncologist, a doctor who specialises in treating cancer.
What are the screening tests and investigations done to confirm or rule out cancer?
Some tumors like those of the skin are easily visible, but most cannot b seen during a physical exam, as they are deep inside the body. The doctor may suggest the following tests for confirming diagnosis, depending on the area of concern:
- Biopsy – A piece of tissue is removed and examined under the microscope for determining a tumor and its status (benign or malignant).
- x-ray and other radiological tests
- Enzymes and Function tests
- Tumor markers
- Imaging tests – A CT or MRI scan can help determine the exact location of tumor and its extent of spread. Positron emission tomography (PET) is also used for certain tumor types.
What are the treatment options for tumor?
Treatment depends on the type of tumor, its state (benign or malignant), and location. Benign tumors are easy to treat – some are removed because of their location and their effect on surrounding, normal tissue. A malignant or cancerous tumor is treated through the following:
- Surgery (for cancers in one location, or cancers spread to nearby lymph nodes)
- Combination of the above methods
What are the known complications?
A tumor may affect the functioning of the organ it is present in. Metastasis or spread of a tumor to other body parts also makes the treatment difficult.
How can the disorder be prevented from happening or recurring?
The risk of malignant tumors can be reduced by:
- Practising a healthy diet
- Including exercise in daily routine; maintaining healthy weight
- Limiting consumption of alcohol
- Limiting exposure to radiation or toxic chemicals
- Avoiding smoking or tobacco
- Reducing exposure to sun