Several different modalities are utilized in the treatment and manageent of cancer. The major approaches include chemotherapy, radiotherapy and surgery, all of which are beneficial to varying degrees in different types and stages of cancer. However, these treatments also have a host of adverse effects which every cancer patient should be aware about. Nevertheless, it should not detract a person with cancer from seeking medical assistance and following the advice of the oncologist.
What is cancer chemotherapy?
Chemotherapy is the use of drugs to destroy cancer cells. It is the major tool for medical management of cancer (malignant tumors) and is not used for benign tumors. These chemicals are often highly toxic to cells, and therefore also known cytotoxic drugs. Chemotherapy is usually a systemic approach meaning that it can affect the entire body while other cancer treatments like surgery or radiation therapy are a local approach.
What is a tumor?
Definition of a Tumor
A tumor basically means a swelling. The medical definition of a tumor as a swelling or a lesion which results from the abnormal growth of cells that persists even after the initiating stimulus has been removed. A tumor can be benign or malignant based on the behavior of the cells that make up the tumor.
Radiation therapy, or radiotherapy, is the application of high-energy radiation for therapeutic or palliative use – to treat disease, delay the progression of the disease or provide symptomatic relief. It is widely used in the treatment of cancer. Radiation is administered in the form of X-rays, gamma rays, or charged particles (like proton, electron) to kill cancer cells and shrink tumors.
Effect of Radiation on Cancer Cells
How does radiation therapy kill cancer cells?
Radiation therapy kills cancer cells by inflicting damage to its genetic material, the DNA. Radiation in the form of proton and neutrons cause direct DNA damage by ionization, while x-rays and gamma rays can damage DNA indirectly, by creating free radicals within the cells. A cell rich in free radical scavengers like glutathione are less affected by x-rays or gamma rays compared to the charged particle based radiation.