Tumor is a mass of tissues which proliferate rapidly, spread throughout the body and may eventually cause death of the host [1]. Chemotherapy is an effective treatment against various types of cancer either singly or in combination with surgery and/or radiotherapy. The present study is aimed at to evaluate the methanolic extract of plumbago zeylanica against dalton's ascitic lymphoma.
Answers
Explanation:
Cells become abnormal if their DNA – and therefore their "knowledge" – becomes damaged. As long as there are very few abnormal cells and they are kept under control by our immune system, they will not harm us. It is only when these cells start to divide uncontrollably, forming lumps or growths, that we have one of the more than 200 diseases called cancer. Growths like this are called tumors. The main differences between malignant (cancerous) and benign (non-cancerous) tumors are that malignant ones can
spread into the surrounding tissue,
destroy the surrounding tissue, and
cause other tumors to develop.
Malignant tumors can be life-threatening. But there are also some kinds of cancer that develop so slowly in older people that they do not lead to any problems in their lifetime.
Benign tumors usually do not cause much damage and are not normally life-threatening. But there is no guarantee: benign growths can become dangerous if they grow a lot, or they might become malignant after a certain amount of time.
If cancer cells start replicating, they do not behave like normal cells. For example, they do not know when to stop replicating and when to die. And they do not always stick together, so they might break away and move through the vascular or lymphatic system and start growing somewhere else in the body.
When a malignant tumor is contained within one area and has not spread to the surrounding tissue, like the one in the picture above, the medical term is “carcinoma in situ.” If this tumor does not keep growing, that means it is just lying there quietly (“dormant cancer cells”). It is not likely to cause harm unless it starts growing.
To keep growing, these tumors start to create their own blood vessels to supply them with the extra oxygen, glucose and hormones they need to survive and keep getting bigger. That process of developing a blood supply system is called angiogenesis (the growth of new blood vessels). Once a tumor does this, it can start to invade the surrounding tissue. This is called an invasive cancer, and you can see what that looks like below.
Active cancer cells can enter the bloodstream or lymphatic system and move to other parts of the body to start the process of forming a tumor all over again somewhere else (metastatic or secondary cancer).
Cancer therapy aims to remove tumors or limit their growth
There are many different types of cancer treatments that all try to remove the malignant tumor, or at least limit the growth and spread of the cancer. Some cancers can be removed by surgery. Drugs (chemotherapy) or various types of radiotherapy are also sometimes used to shrink tumors before surgery. Chemotherapy and/or radiotherapy might be used after surgery too, to destroy leftover cancer cells and prevent the cancer from growing back (recurrence).
If the tumor cannot be removed by surgery, medication and/or radiotherapy may be used. The exact treatment depends on various things, like the type of tumor and the stage of the disease.
Cancer drugs work in different ways. Some aim to interfere with the cancer growth process by stopping the development of blood vessels that feed the tumor, for example. Other drugs specifically aim to stop the cancer cells replicating or reacting to hormones. Researchers are always trying to find new ways to limit the growth and spread of cancer cells.