Define cancer

Key facts • Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020, or nearly one in six deaths. • The most common cancers are breast, lung, colon and rectum and prostate cancers. • Around one-third of deaths from cancer are due to tobacco use, high body mass index, alcohol consumption, low fruit and vegetable intake, and lack of physical activity. • Cancer-causing infections, such as human papillomavirus (HPV) and hepatitis, are responsible for approximately 30% of cancer cases in low- and lower-middle-income countries. • Many cancers can be cured if detected early and treated effectively. Overview Cancer is a generic term for a large group of diseases that can affect any part of the body. Other terms used are malignant tumours and neoplasms. One defining feature of cancer is the rapid creation of abnormal cells that grow beyond their usual boundaries, and which can then invade adjoining parts of the body and spread to other organs; the latter process is referred to as metastasis. Widespread metastases are the primary cause of death from cancer. The problem Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020 (1). The most common in 2020 (in terms of new cases of cancer) were: • breast (2.26 million cases); • lung (2.21 million cases); • colon and rectum (1.93 million cases); • prostate (1.41 million cases); • skin (non-melanoma) (1.20 million cases); and • stomach (1.09 million cases). The mo...

Another hallmark of cancer cells is their "replicative immortality," a fancy term for the fact that they can divide many more times than a normal cell of the body. In general, human cells can go through only about 40-60 rounds of division before they lose the capacity to divide, "grow old," and eventually die 3 ^3 3 cubed . Cancer cells are also different from normal cells in other ways that aren’t directly cell cycle-related. These differences help them grow, divide, and form tumors. For instance, cancer cells gain the ability to migrate to other parts of the body, a process called metastasis, and to promote growth of new blood vessels, a process called angiogenesis (which gives tumor cells a source of oxygen and nutrients). Cancer cells also fail to undergo programmed cell death, or apoptosis, under conditions when normal cells would (e.g., due to DNA damage). In addition, emerging research shows that cancer cells may undergo metabolic changes that support increased cell growth and division 5 ^5 5 start superscript, 5, end superscript . Cells have many different mechanisms to restrict cell division, repair DNA damage, and prevent the development of cancer. Because of this, it’s thought that cancer develops in a multi-step process, in which multiple mechanisms must fail before a critical mass is reached and cells become cancerous. Specifically, most cancers arise as cells acquire a series of mutations (changes in DNA) that make them divide more quickly, escape internal an...

Cancer survivors are people who have had cancer and are still alive, whether or not they still have this condition. Being a cancer survivor can lead to challenges but there are many support groups available to provide help. Improvements in treatment and early detection mean more people are surviving cancer. As of The Some of the general public may use this term to refer to someone who has either lived an amount of time after a cancer diagnosis or those who no longer have cancer. Cancer survivors face numerous challenges. Read on to learn more about cancer survivorship, the challenges a person may face, and where to find support. Share on Pinterest Thomas Pickard/Stocksy The The Cancer is not a straightforward condition. Some people may live many years without symptoms, whereas others may go into remission and then develop symptoms again. An anecdotal definition of cancer survivorship may be a person who has survived the active stages of cancer. However, healthcare professionals use the term Cancer can affect many aspects of a person’s health and well-being. However, there is not a singular experience of cancer survivorship. People may feel a range of emotions and may require more or less help with medical conditions and life changes. Both cancer and cancer treatment may cause several health changes and impact a person’s daily life. Health changes Cancer survivors may experience health changes • Heart conditions: People may have a higher risk of having congenital heart fail...

Cancer is a scary word. Almost everyone knows someone who got very sick or died from cancer. Most of the time, cancer affects older people. Not many kids get cancer, but when they do, very often it can be treated and cured. What Is Cancer? Cancer is actually a group of many related diseases that all have to do with cells. Cells are the very small units that make up all living things, including the human body. There are billions of cells in each person's body. Cancer happens when cells that are not normal grow and spread very fast. Normal body cells grow and divide and know to stop growing. Over time, they also die. Unlike these normal cells, cancer cells just continue to grow and divide out of control and don't die when they're supposed to. Cancer cells usually group or clump together to form tumors (say: TOO-mers). A growing tumor becomes a lump of cancer cells that can destroy the normal cells around the tumor and damage the body's healthy tissues. This can make someone very sick. Sometimes cancer cells break away from the original tumor and travel to other areas of the body, where they keep growing and can go on to form new tumors. This is how cancer spreads. The spread of a tumor to a new place in the body is called metastasis (say: meh-TASS-tuh-sis). p Causes of Cancer You probably know a kid who had chickenpox — maybe even you. But you probably don't know any kids who've had cancer. If you packed a large football stadium with kids, probably only one child in that sta...

Medical researchers use knockout cells to study how genes function and how genes can be used for medical treatments. For example, a knockout cell line for liver cancer might turn off a gene linked with tumor growth. Cancer isn’t directly passed down from parents to children the way some traits and health conditions are, but it is Cancer-related changes to your genes, also called mutations or variants, can: • be inherited from a parent • be caused by exposure to carcinogens, such as chemicals in tobacco smoke or ultraviolet (UV) radiation from the sun • occur randomly in your DNA as cells multiply Although medical researchers know this is the case, they don’t always know why it happens. In recent years, there’s been a lot of focus on the genetics of cancer and whether the future of cancer treatments might be found there. Knockout cell lines are an area with real promise. Researchers can remove or inactivate specific genes to achieve a specific effect, such as stopping cancer cells from reproducing. More research still needs to be done, and most uses of knockout cell lines are still in clinical trials. But studies have already shown that liver cancer cells, and other cancer cells, might respond to these types of treatments. A knockout cell is a cell created by scientists to test what happens when one or more genes in an organism are removed or inactivated. Researchers use knockout cells to learn how genes function and to figure out how they might harness genes for medical pu...

The Latin word cancer, meaning “crab,” was also given as a name to several diseases. One of the diseases was the abnormal, spreading mass of tissue we call a tumor. A possible explanation for this extended use of cancer is that the Romans thought some tumors looked like many-legged crabs. A French descendant of this Latin word was borrowed into English as canker. It is now applied to several plant and animal disorders. In the 14th century the Latin word cancer in the sense of “tumor” was borrowed directly into English, giving us our modern spelling and sense. Recent Examples on the Web Beth Lynn McGee, the director of science and agricultural policy for the Chesapeake Bay Foundation and a longtime scientist, died of breast cancer June 4 at her Chesapeake Bay home in Churchton, surrounded by family. — Jordan D. Brown, Baltimore Sun, 12 June 2023 Kelis’ second husband, Mike Mora, died of stomach cancer in March 2022. — Gil Kaufman, Billboard, 12 June 2023 Gold missed the 2022 season because of health issues that led to a cancer diagnosis in late December. — Mark Heim | [email protected], al, 9 June 2023 The smoke from the conflagration blanketing much of the nation has caused air quality in multiple U.S. cities to hit hazardous levels, increasing the risk of respiratory infections, heart disease and lung cancer, according to the World Health Organization. — Eric Lagatta, USA TODAY, 8 June 2023 The largest was a randomized control study of more than 500 U.S. cancer patients with a...

Cancer is a disease that occurs when cells become abnormal and grow out of control. Normal cells grow—and then die—when they are given signals to do so. Cancer cells ignore these signals and continue to multiply. Cancer cells also may form a tumor at the original site and then spread and form new tumors in other places. Types of Cancer Cells There are as many types of cancer cells as there are types of • Adenocarcinoma: Cancer that affects epithelial cells in glandular tissue, such as the breast, colon, and prostate • Basal cell carcinoma: Cancer that affects epithelial cells in the basal (lower) layer of the epidermis (skin) • Squamous cell carcinoma: Cancer that affects squamous epithelial cells, which are found just beneath the outer surface of the skin and in the stomach, intestines, lungs, bladder, and kidneys • Transitional cell carcinoma: Cancer that affects transitional epithelium (urothelium), which are various-sized, multi-layered epithelial cells in the bladder, ureters, and kidneys • Dermatofibrosarcoma protuberans: A type of skin cancer • Kaposi sarcoma: Cancer that forms in the skin, lymph nodes, internal organs, and mucous membranes • Leiomyosarcoma: Cancer that affects smooth muscle tissue • Liposarcoma: Cancer that forms in fatty tissues • Malignant fibrous histiocytoma: Cancer that can affect bone or soft tissue • Osteosarcoma: A type of bone cancer How Do Cancer Cells Form? Cancer cells start to form when genes, made up of DNA, experience certain changes...