Tumours- What are they, Malignant vs Benign tumours, Stages & Risks
In simple terms, a tumour is a lump or tissue or mass resembling swelling. It is caused when cells don’t die when they should or divide more than they should. Not all tumours are cancerous, but if one appears, it is best that you consult a doctor.
If you have a healthy body, you will grow, divide, and replace other cells in the body. When the new cells are created, the old cells die. But, if you have cancer, new cells start to form, even though the body doesn’t need them. If it leads to the formation of a group of cells, the tumour can develop. Some tumours consist of noncancerous cells and are benign, others are malignant. Malignant tumours are cancerous where the cells can spread to other body parts.
Benign vs Malignant tumours
Benign tumours are the ones that don’t invade other body parts and remain in their primary location. They don’t spread to distant parts of local structures of the body. They have distinct borders and tend to grow slowly. In most cases, benign tumours are not problematic. However, if they become so large that they start compressing nearby structures, it can lead to pain and other medical complications. For instance, if a large benign tumour compresses the windpipe (trachea), it can lead to difficulty in breathing. In this case, it would warrant immediate surgical removal. In the case of a tumour in the brain, the limited space in the skull means that if there is a large growth inside the brain cavity, it can be fatal for you.
Also, benign tumours usually don’t recur after removal. Some of the most common benign tumour examples are lipomas in the skin and fibroids in the uterus. There are some types of benign tumours that can transform into malignant tumours. These should be monitored closely and removed surgically. An example of this is the colon polyps that can become malignant.
Malignant tumours are the type of tumours with cells that spread locally or to distant sites and grow uncontrollably. They are cancerous in nature and spread to distant sites through the lymphatic system or the bloodstream. This spread is known as Metastasis and it can occur in any body part. But, it is most commonly found in the lungs, liver, bone, and brain.
Stages of tumour development
Through a stepwise progression, a tumour grows from a single, genetically altered cell to a group of cells. The following stages of tumour development are applicable for solid tumours like sarcoma or carcinoma. Blood cell tumours have a similar process as well but since its cells are freely floating, they aren’t restricted to a single location in the body:
- Hyperplasia - In this stage, the altered cell starts to divide uncontrollably that leads to the creation of excess cells in the tissue region. These cells don’t have an abnormal appearance but are just excess in number.
- Dysplasia - If there are additional genetic changes to the hyperplastic cells, it can result in increasingly abnormal growth. The tissue and the cells won’t look normal anymore. The tissue and the cells might get disorganized.
- Carcinoma in situ (CIS) - Additional changes can make the tissues and cells even more abnormal. These cells will now spread over a larger area and the tissue region will primarily involve altered cells. At this stage, the cells often become more primitive in terms of their capabilities. For example, a liver cell that doesn’t make liver-specific proteins. In these cases, the cells are called anaplastic or de-differentiated. A key facet in the growth at this stage is that the cells are still within the initial location. They haven’t crossed the basal lamina yet and started invading other tissues. Cancers at this stage can be cured by surgery as the abnormal cells are still in one location. However, they do have the potential to be malignant growths and become invasive.
- Inactive Cancers - At this stage, the tumours have started invading surrounding tissues and spreading to areas other than the local tissue. These types of tumours are dangerous and responsible for deaths caused by cancer.
A risk factor for cancer is anything increasing your chance of getting cancer. However, most of these risk factors don’t cause cancer directly. You might have most of these risk factors and never develop cancer or you might have no known risk factor, and still develop one.
However, it is still important to know if you are at risk for cancer and discuss this with your doctor. They can help you make better lifestyle choices that improve your health. Also, with this information, the doctor can deduce if you should go for genetic testing and counselling.
Here are some of the general risk factors for cancer:
- Older age
- A family or personal history of cancer
- Specific chemicals
- Some viral infections like the Human Papillomavirus (HPV)
There are ways to avoid some of these risk factors by stopping risky behaviour. This includes using alcohol and tobacco and being overweight. Some of the risk factors can’t be avoided like getting older.
In most cases of benign tumours, you won’t need any treatment. The doctor might only suggest watchful waiting to ensure that it doesn’t cause any problems. However, if symptoms are becoming a problem, you might need treatment. One of the most common treatment options for benign tumours is surgery. The goal of the surgical procedure is to remove the tumour while ensuring that there is no damage to the surrounding tissues. A malignant tumour can spread fast and needs treatment to avoid it spreading to other body parts. If they are diagnosed early, the treatment will be surgery with possible radiotherapy or chemotherapy. However, once cancer has spread, the treatment might be systemic such as chemotherapy, targeted therapy or immunotherapy.
Reviewed by Dr. Suparna Rao, Consultant - Medical Oncology