Cancer how does it start

Doctors are beginning to offer treatment options based on the genetic changes occurring in a specific tumor. Genomic tumor assessment may result in a more personalized approach to cancer treatment. Chat live now or call us Make a difference in the fight against cancer by donating to cancer research. Call us anytime. What is cancer? What are the most common forms of cancer?

There are five main categories of cancer: Carcinomas begin in the skin or tissues that line the internal organs. Sarcomas develop in the bone, cartilage, fat, muscle or other connective tissues.

Leukemia begins in the blood and bone marrow. Lymphomas start in the immune system. Central nervous system cancers develop in the brain and spinal cord. How is cancer treated? The three main treatments are: Surgery : directly removing the tumor Chemotherapy : using chemicals to kill cancer cells Radiation therapy : using X-rays to kill cancer cells The same cancer type in one individual is very different from that cancer in another individual.

What is oncology? What can you do to manage the side effects of cancer treatment? Moreover, metastatic cancer cells and cells of the original cancer usually have some molecular features in common, such as the presence of specific chromosome changes.

In some cases, treatment may help prolong the lives of people with metastatic cancer. In other cases, the primary goal of treatment for metastatic cancer is to control the growth of the cancer or to relieve symptoms it is causing. Metastatic tumors can cause severe damage to how the body functions, and most people who die of cancer die of metastatic disease. Some tissue changes may develop into cancer if they are not treated, however.

Here are some examples of tissue changes that are not cancer but, in some cases, are monitored because they could become cancer:. Normal cells may become cancer cells.

Before cancer cells form in tissues of the body, the cells go through abnormal changes called hyperplasia and dysplasia. In hyperplasia, there is an increase in the number of cells in an organ or tissue that appear normal under a microscope. In dysplasia, the cells look abnormal under a microscope but are not cancer.

Hyperplasia and dysplasia may or may not become cancer. There are more than types of cancer. Types of cancer are usually named for the organs or tissues where the cancers form. For example, lung cancer starts in the lung, and brain cancer starts in the brain. Cancers also may be described by the type of cell that formed them, such as an epithelial cell or a squamous cell. We also have information on childhood cancers and cancers in adolescents and young adults.

Carcinomas are the most common type of cancer. They are formed by epithelial cells, which are the cells that cover the inside and outside surfaces of the body. There are many types of epithelial cells, which often have a column-like shape when viewed under a microscope. Carcinomas that begin in different epithelial cell types have specific names:. Adenocarcinoma is a cancer that forms in epithelial cells that produce fluids or mucus. Tissues with this type of epithelial cell are sometimes called glandular tissues.

Most cancers of the breast, colon, and prostate are adenocarcinomas. Squamous cell carcinoma is a cancer that forms in squamous cells, which are epithelial cells that lie just beneath the outer surface of the skin. Squamous cells also line many other organs, including the stomach, intestines, lungs, bladder, and kidneys.

Squamous cells look flat, like fish scales, when viewed under a microscope. Squamous cell carcinomas are sometimes called epidermoid carcinomas. Transitional cell carcinoma is a cancer that forms in a type of epithelial tissue called transitional epithelium, or urothelium. This tissue, which is made up of many layers of epithelial cells that can get bigger and smaller, is found in the linings of the bladder, ureters, and part of the kidneys renal pelvis , and a few other organs.

Some cancers of the bladder, ureters, and kidneys are transitional cell carcinomas. Soft tissue sarcoma forms in soft tissues of the body, including muscle, tendons, fat, blood vessels, lymph vessels, nerves, and tissue around joints. Sarcomas are cancers that form in bone and soft tissues, including muscle, fat, blood vessels, lymph vessels , and fibrous tissue such as tendons and ligaments.

Osteosarcoma is the most common cancer of bone. The most common types of soft tissue sarcoma are leiomyosarcoma , Kaposi sarcoma , malignant fibrous histiocytoma , liposarcoma , and dermatofibrosarcoma protuberans. Our page on soft tissue sarcoma has more information. Cancers that begin in the blood-forming tissue of the bone marrow are called leukemias. These cancers do not form solid tumors.

Instead, large numbers of abnormal white blood cells leukemia cells and leukemic blast cells build up in the blood and bone marrow, crowding out normal blood cells. The low level of normal blood cells can make it harder for the body to get oxygen to its tissues, control bleeding, or fight infections. There are four common types of leukemia, which are grouped based on how quickly the disease gets worse acute or chronic and on the type of blood cell the cancer starts in lymphoblastic or myeloid.

Acute forms of leukemia grow quickly and chronic forms grow more slowly. Our page on leukemia has more information. Lymphoma is cancer that begins in lymphocytes T cells or B cells. These are disease-fighting white blood cells that are part of the immune system.

In lymphoma, abnormal lymphocytes build up in lymph nodes and lymph vessels, as well as in other organs of the body. Hodgkin lymphoma — People with this disease have abnormal lymphocytes that are called Reed-Sternberg cells.

These cells usually form from B cells. Non-Hodgkin lymphoma — This is a large group of cancers that start in lymphocytes. The cancers can grow quickly or slowly and can form from B cells or T cells. Our page on lymphoma has more information. Multiple myeloma is cancer that begins in plasma cells , another type of immune cell. The abnormal plasma cells, called myeloma cells, build up in the bone marrow and form tumors in bones all through the body. Multiple myeloma is also called plasma cell myeloma and Kahler disease.

Our page on multiple myeloma and other plasma cell neoplasms has more information. Melanoma is cancer that begins in cells that become melanocytes, which are specialized cells that make melanin the pigment that gives skin its color. Most melanomas form on the skin, but melanomas can also form in other pigmented tissues, such as the eye. Our pages on skin cancer and intraocular melanoma have more information. There are different types of brain and spinal cord tumors.

These tumors are named based on the type of cell in which they formed and where the tumor first formed in the central nervous system. For example, an astrocytic tumor begins in star-shaped brain cells called astrocytes , which help keep nerve cells healthy. Brain tumors can be benign not cancer or malignant cancer. Our pages on brain and spinal cord tumors in adults and brain and spinal cord tumors in children have more information.

Germ cell tumors are a type of tumor that begins in the cells that give rise to sperm or eggs. These tumors can occur almost anywhere in the body and can be either benign or malignant.

Neuroendocrine tumors form from cells that release hormones into the blood in response to a signal from the nervous system. These tumors, which may make higher-than-normal amounts of hormones, can cause many different symptoms. Neuroendocrine tumors may be benign or malignant.

Our definition of neuroendocrine tumors has more information. Carcinoid tumors are a type of neuroendocrine tumor. They are slow-growing tumors that are usually found in the gastrointestinal system most often in the rectum and small intestine. Carcinoid tumors may spread to the liver or other sites in the body, and they may secrete substances such as serotonin or prostaglandins, causing carcinoid syndrome.

Our page on gastrointestinal carcinoid tumors has more information. Menu Contact Dictionary Search. Understanding Cancer. What Is Cancer? Cancer Statistics. Cancer Disparities. Cancer Causes and Prevention. Risk Factors. Cancer Prevention Overview.

Changes to your body's normal processes or unusual, unexplained symptoms can sometimes be an early sign of cancer. But in many cases your symptoms will not be related to cancer and will be caused by other, non-cancerous health conditions. Read more about the signs and symptoms of cancer. It's important to get help from a GP if you have symptoms that you're worried about. Find out about using the NHS during coronavirus. Making some simple changes to your lifestyle can significantly reduce your risk of developing cancer.

The Macmillan Cancer Support website has more information about how a healthy lifestyle can help reduce your chances of developing cancer. Surgery is the first treatment to try for most types of cancer, as solid tumours can usually be surgically removed. Accurately diagnosing cancer can take weeks or months. As cancer often develops slowly over several years, waiting for a few weeks will not usually impact on the effectiveness of treatment.

You should not have to wait more than 2 weeks to see a specialist if your GP suspects you have cancer and urgently refers you. In cases where cancer has been confirmed, you should not have to wait more than 31 days from the decision to treat to the start of treatment.

NHS England has more detailed statistics on cancer waiting times.