Why is cancer harmful

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.

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Bioinformatics, Big Data, and Cancer. Annual Report to the Nation. Research Advances by Cancer Type. Stories of Discovery. Milestones in Cancer Research and Discovery. Biomedical Citizen Science. Director's Message. Budget Proposal. Stories of Cancer Research. Driving Discovery. Some genetic changes occur after birth, and factors such as smoking and sun exposure can increase the risk. Finally, a person can inherit a predisposition for a type of cancer.

A doctor may refer to this as having a hereditary cancer syndrome. Inherited genetic mutations significantly contribute to the development of 5—10 percent of cancer cases. The most common type of cancer in the U. Each year, more than 40, people in the country receive a diagnosis of one of the following types of cancer:. Other forms are less common. According to the National Cancer Institute, there are over types of cancer. For example, sarcomas develop in bones or soft tissues, while carcinomas form in cells that cover internal or external surfaces in the body.

Basal cell carcinomas develop in the skin, while adenocarcinomas can form in the breast. Improvements in cancer detection, increased awareness of the risks of smoking, and a drop in tobacco use have all contributed to a year-on-year decrease in the number of cancer diagnoses and deaths. According to the American Cancer Society, the overall cancer death rate declined by 26 percent between and When a person has cancer, the outlook will depend on whether the disease has spread and on its type, severity, and location.

It also prevents them from dying at the natural point in their life cycle. Genetic factors and lifestyle choices, such as smoking, can contribute to the development of the disease. Several elements affect the ways that DNA communicates with cells and directs their division and death. After nonmelanoma skin cancer, breast cancer is the most common type in the U. However, lung cancer is the leading cause of cancer-related death.

Treatments are constantly improving. Examples of current methods include chemotherapy, radiation therapy, and surgery. Some people benefit from newer options, such as stem cell transplantation and precision medicine. Radiation therapy is a treatment for cancer. A person may receive it alongside another treatment or alone. Find out why doctors recommend it, what it…. Bladder polyps occur when abnormal cells grow in the bladder. But some unhealthy habits, especially cigarette smoking or drinking too much alcohol every day, can make you a lot more likely to get cancer when you become an adult.

It can take a while for a doctor to figure out a kid has cancer. That's because the symptoms cancer can cause — weight loss, fevers, swollen glands, or feeling overly tired or sick for a while — usually are not caused by cancer.

When a kid has these problems, it's often caused by something less serious, like an infection. With medical testing, the doctor can figure out what's causing the trouble. If the doctor suspects cancer, he or she can do tests to figure out if that's the problem. A doctor might order X-rays and blood tests and recommend the person go to see an oncologist say: on-KAH-luh-jist. An oncologist is a doctor who takes care of and treats cancer patients. The oncologist will likely run other tests to find out if someone really has cancer.

If so, tests can determine what kind of cancer it is and if it has spread to other parts of the body. Based on the results, the doctor will decide the best way to treat it. One test that an oncologist or a surgeon may perform is a biopsy say: BY-op-see. During a biopsy, a piece of tissue is removed from a tumor or a place in the body where cancer is suspected, like the bone marrow.

Don't worry — someone getting this test will get special medicine to keep him or her comfortable during the biopsy. The sample that's collected will be examined under a microscope for cancer cells. The sooner cancer is found and treatment begins, the better someone's chances are for a full recovery and cure.

Cancer is treated with surgery, chemotherapy, or radiation — or sometimes a combination of these treatments. The choice of treatment depends on:. Surgery is the oldest form of treatment for cancer — 3 out of every 5 people with cancer will have an operation to remove it.

During surgery, the doctor tries to take out as many cancer cells as possible. Some healthy cells or tissue may also be removed to make sure that all the cancer is gone. Chemotherapy say: kee-mo-THER-uh-pee is the use of anti-cancer medicines drugs to treat cancer. These medicines are sometimes taken as a pill, but usually are given through a special intravenous say: in-truh-VEE-nus line, also called an IV.

An IV is a tiny plastic catheter straw-like tube that is put into a vein through someone's skin, usually on the arm. The catheter is attached to a bag that holds the medicine.

The medicine flows from the bag into a vein, which puts the medicine into the blood, where it can travel throughout the body and attack cancer cells. Chemotherapy is usually given over a number of weeks to months. Often, a permanent catheter is placed under the skin into a larger blood vessel of the upper chest.