Causes of cancer

I'm Dr. Mabel Ryder, an endocrinologist at Mayo Clinic. In this video, we'll cover the basics of thyroid cancer: What is it? Who gets it? The symptoms. Diagnosis and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available. What is the thyroid? This is a butterfly shaped gland that sits at the base of your neck. It's an important gland responsible for producing hormones that control a lot of vital functions in your body, such as your heart and your heart rate, your blood pressure, your body temperature, and your weight. When thyroid cells mutate, changes to their DNA cause them to grow and multiply. Where healthy cells typically die, these abnormal cells grow and grow and eventually form a tumor. Sometimes these cells invade nearby tissue, and can spread or metastasize to other parts of the body. There are several different kinds of thyroid cancer. Some grow slowly. Others can be more aggressive. Because we're able to detect small thyroid cancers with new technology, the rate of thyroid cancer incidence has gone up. However, most cancers are very treatable and the prognosis for most patients with thyroid cancer is excellent. There are other things that can increase your chances of developing thyroid cancer. Women are three times more likely to develop thyroid cancer. And exposure to high levels of radiation, for instance, radiation therapy to the head or neck for other cancers, can increase your r...

Overview Cancer refers to any one of a large number of diseases characterized by the development of abnormal cells that divide uncontrollably and have the ability to infiltrate and destroy normal body tissue. Cancer often has the ability to spread throughout your body. Cancer is the second-leading cause of death in the world. But survival rates are improving for many types of cancer, thanks to improvements in cancer screening, treatment and prevention. Symptoms Signs and symptoms caused by cancer will vary depending on what part of the body is affected. Some general signs and symptoms associated with, but not specific to, cancer, include: • Fatigue • Lump or area of thickening that can be felt under the skin • Weight changes, including unintended loss or gain • Skin changes, such as yellowing, darkening or redness of the skin, sores that won't heal, or changes to existing moles • Changes in bowel or bladder habits • Persistent cough or trouble breathing • Difficulty swallowing • Hoarseness • Persistent indigestion or discomfort after eating • Persistent, unexplained muscle or joint pain • Persistent, unexplained fevers or night sweats • Unexplained bleeding or bruising When to see a doctor Make an appointment with your doctor if you have any persistent signs or symptoms that concern you. If you don't have any signs or symptoms, but are worried about your risk of cancer, discuss your concerns with your doctor. Ask about which cancer screening tests and procedures are approp...

How do cancer cells come about? The body is made up from millions of tiny cells. Different parts of the body such as organs, bones, muscles, skin and blood are made up from different specialised cells. Most cells have a centre called a nucleus. The nucleus in each cell contains thousands of genes which are made up from a chemical called DNA. The genes are like codes which control the functions of the cell. For example, different genes control how the cell makes proteins, or hormones, or other chemicals. Certain genes control when the cell should multiply, and certain genes even control when the cell should die. Most types of cell in the body divide and multiply from time to time. As old cells wear out or become damaged, new cells are formed to replace them. Some cells normally multiply quickly. For example, you make millions of red blood cells each day as old ones become worn out and are broken down. Some cells do not multiply at all once they are mature - for example, brain cells. Normally, your body only makes the right number of cells that are needed. Sometimes a cell becomes abnormal. This occurs because one gene (or more) in the cell becomes damaged or altered. The abnormal cell may then divide into two, then four, then eight, and so on. Lots of abnormal cells may then develop from the original abnormal cell. These cells do not know when to stop multiplying. A group of abnormal cells may then form. If this group of cells gets bigger, it becomes a large clump of abnorm...

Your natural skin tone can affect the appearance of melanoma. If you have darker skin, look for the following: • A dark spot, growth, or darker patch of skin that is growing, bleeding, or changing in any way • A sore that won’t heal (or heals and returns) • A patch of skin that feels dry and rough • A dark line underneath or around a fingernail or toenail Merkel Cell Carcinoma • A new spot on your skin • Noticeable changes in the size, color, or shape of an existing sore or spot on your skin • A skin growth that resembles a wart • A painful or itchy spot on your skin that doesn't change • A nonhealing spot on your skin that bleeds or becomes crusty • A skin sore or growth that has a raised border and central crusting or bleeding • A red, scaly, or rough spot on your skin • A scar-like growth that lacks a well-defined border • A small, smooth, pale patches of skin • A small, pink, pearly skin bump • A waxy or pearly lump on your skin • A red patch or irritated area • A small, pink, pearly skin bump • A yellow or white scar-like area • A smooth growth with a dent or dimple in the middle • A bleeding or oozing score • A sore that crusts over with a scab • A is for asymmetry: Most melanomas are asymmetrical (two halves that are not the same). • B is for border: Melanoma borders tend to have notched or scalloped and poorly defined edges. • C is for color: Melanomas tend to be different shades of brown, tan, or black, or have areas of white, red, or blue. • D is for diameter or ...

There are a lot of rumors and myths about cancer that make it hard for people to know what’s true. Here are answers to some of the questions people ask about the causes of cancer. If you want to know more about how cancer starts and spreads, see What is a risk factor? A risk factor is something that raises the chance of getting a disease. Each cancer has its own risk factors. Having risk factors does not mean that someone will get cancer. Even when a person with a risk factor is found to have cancer, there’s no way to prove that the risk factor caused the cancer. Some risk factors, like a person’s age or gene damage, can’t be changed. But some risk factors can be controlled. Tobacco use, contact with secondhand smoke, being in the sun, excess body weight, not being active, drinking alcohol, and not eating a healthy diet are risk factors that can be managed. Other risk factors include getting certain viruses and contact with certain kinds of radiation or chemicals. Can injuries cause cancer? Falls, bruises, broken bones, or other such injuries do not cause cancer. Sometimes a person might visit a health care provider for an injury and cancer is found. But the injury did not cause the cancer; the cancer was already there. Can I bring cancer on myself? Your personality and emotions cannot cause cancer and will not affect the outcome of your cancer. Research shows that there is no connection between personality types or attitude and cancer occurrence or outcomes. Can stress ca...

Carcinoid Tumors This form of cancer starts in a type of cell that's found throughout the body, including the small intestine, called neuroendocrine cells. These cells make the hormones that are involved in digestion. A carcinoid tumor may start in these cells, though it is rare. This type of cancer is slow-growing. Gastrointestinal Stromal Tumor This type of cancer is not common. It begins in cells in the small intestine that are called interstitial cells of Cajal. These cells serve as a kind of traffic signal for the muscles in the digestive system (including the small intestine). Cancer can begin in these cells. Lymphoma This type of cancer starts in the lymph nodes. These nodes are part of the lymphatic system that runs throughout the body, including in the abdomen, and aids our immune system. Non-Hodgkin lymphoma is the type most often seen in the small intestine. This type of small intestine cancer is associated with celiac disease. • Age: This type of cancer is more likely to occur in people who are over the age of 65 years. • Alcohol use: A large analysis of several studies found that alcohol use might be a factor in the development of small intestine cancer. However, there might be nuances, with heavier drinking presumed to be associated. • Celiac disease: There is an increased risk of an intestinal cancer called enteropathy-associated T-cell lymphoma in people who live with celiac disease. It is thought that gluten causes inflammation in the intestine which, over...

Husband and wife Professor Simon Conn and Dr Vanessa Conn’s team at the Flinders Centre for Innovation in Cancer has been researching the role of circular RNAs in DNA damage and forming cancer genes. Credit: Flinders Foundation Australian cancer researchers have made an important new connection between a person's cancer risk and the functions of circular RNAs, a recently discovered family of genetic fragments present within our cells. A new Flinders University-led study published in Cancer Cell, finds that specific circular RNAs within many of us can stick to the DNA in our cells and cause DNA mutations which result in "While environmental and "This is the first example of a genetic molecule present within many of us which has the capacity to mutate our very own DNA and drive cancer from inside." "This opens the door to use these molecules as new therapeutic targets and markers of disease at a very early stage, when the likelihood of curing cancers is much higher." The research compared the neonatal blood tests or Guthrie cards of babies who went on to develop The findings suggest it is the abundance of the circular RNA molecules within certain individuals' cells which is a major determinant for why they develop these specific cancer-causing genes or oncogenes and other do not. "Circular RNAs can bind to DNA at many different locations across a range of cells. By binding to the DNA at specific sites, these circular RNAs cause a number of changes culminating in the breakage...

Lung cancer Lung cancer begins in the cells of your lungs. Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale. Lung cancer is the leading cause of cancer deaths worldwide. People who smoke have the greatest risk of lung cancer, though lung cancer can also occur in people who have never smoked. The risk of lung cancer increases with the length of time and number of cigarettes you've smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer. Symptoms Lung cancer typically doesn't cause signs and symptoms in its earliest stages. Signs and symptoms of lung cancer typically occur when the disease is advanced. Signs and symptoms of lung cancer may include: • A new cough that doesn't go away • Coughing up blood, even a small amount • Shortness of breath • Chest pain • Hoarseness • Losing weight without trying • Bone pain • Headache When to see a doctor Make an appointment with your doctor if you have any persistent signs or symptoms that worry you. If you smoke and have been unable to quit, make an appointment with your doctor. Your doctor can recommend strategies for quitting smoking, such as counseling, medications and nicotine replacement products. Causes Smoking causes the majority of lung cancers — both in smokers and in people exposed to secondhand smoke. But lung cancer...