Cancer can be defined as uncontrolled division of a cell, where the cell becomes immortal and does not die. Cancer can also be defined as a collection of 250 or more variety of disease. It is the name given to a collection of related diseases.
“Cancer in itself is a broad term. It can be described as the disease that results when cellular changes cause the uncontrolled growth and division of cells. including – breast cancer, colon cancer, prostrate cancer and many other organs that have an uncontrolled growth of cells. Largely it can be divided into two categories – Solid and liquid cancer” Dr. Rahul Bhargava, Oncologist, Director and Head – Fortis Memorial research Institute. “Solid cancer forms tumors – abnormal mass of tissue. Examples of solid tumors are sarcomas, carcinomas, and lymphomas. Leukemia’s (blood cancer) generally does not form solid tumors and is an example of liquid cancer.”
Cancer can start almost anywhere in the human body. It is normal for human cells to grow and divide to form new cells when the body needs them. When cells grow old or become damaged, they die, and are replaced with new cells that are formed. When cancer develops, this orderly renewal of cell process breaks down. Cells become more and more abnormal, old or damaged cells survive when they should die, and new cells are formed when they are not needed. These extra cells can divide without stopping and may form growths called tumors – masses of tissue.
Types of Tumor
Cancerous tumors are malignant, they can spread into nearby tissues. In addition, as these tumors grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymphatic system and form new tumors far from the originally formed tumor. The benign tumors do not spread into nearby tissues despite being large sometimes. Once removed, they usually don’t grow back, whereas malignant tumors sometimes can.
What causes cancer?
Cancer is a complex group of diseases with many possible causes. There is no single cause to it, but interaction of many factors together that cause it. The factors involved may be genetic, environmental, or constitutional characteristics of the individual. It can be caused by certain changes in the genes which are the basic physical units of inheritance. Changes in the genetics that cause cancer can be inherited from our parents. They can also develop as a result of errors that occur as cells divide or due to damage to DNA caused by certain environmental exposures. Cancer-causing agents include substances, such as the chemicals in tobacco, radiation, such as ultraviolet rays from the sun. In simple words, one can either inherit cancer through genetics or develop it in his lifetime through carcinogens.
Each person’s cancer is a unique combination of genetic changes. Cancer cells have more genetic changes, such as mutations in DNA than normal cells even in the same tumour.
There is no single accurate test for cancer. The examination requires a thorough history and physical examination along with diagnostic testing. Diagnostic procedures for cancer may include imaging, laboratory tests, tumor biopsy, endoscopic examination, surgery, or genetic testing, blood tests, urinalysis, complete blood count, tumor markers, ultrasounds, X-ray, bone scans, lymph angiogram and many other procedures and lab tests.
Cancer treatment depends on the patients medical condition and the type of cancer. Common treatments involve chemotherapy and radiation therapy. Other methods include surgeries and biological therapies. Doctors also plan treatments based on several key factors, such as the type and stage of the cancer and the person’s age, health, and lifestyle.
Other treatments include – Combined modality therapy, Adjuvant therapy, Neoadjuvant therapy, radiation therapy, hormone therapy, blood and bone marrow transplant, biological therapy, immunotherapy.