Wikipedia demo page

  Cancer, also known as a malignant tumor or malignant neoplasm, is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. [1][2] Not all tumors are cancerous; benign tumors do not spread to other parts of the body. [2] Possible signs and symptoms include: a new lump, abnormal bleeding, a prolonged cough, unexplained weight loss, and a change in bowel movements among others. [3] While these symptoms may indicate cancer, they may also occur due to other issues. [3] There are over 100 different known cancers that affect humans. [2]

Tobacco use is the cause of about 22% of cancer deaths. [1] Another 10% is due to obesity, a poor diet, lack of physical activity, and consumption of alcohol. [1][4] Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. [5] In the developing world nearly 20% of cancers are due to infections such as hepatitis B, hepatitis C, and human papillomavirus (HPV). [1] These factors act, at least partly, by changing the genes of a cell. [6] Typically many such genetic changes are required before cancer develops. [6] Approximately 5–10% of cancers are due to genetic defects inherited from a person's parents. [7] Cancer can be detected by certain signs and symptoms or screening tests. [1] It is then typically further investigated by medical imaging and confirmed by biopsy. [8]

Cancers are a large family of diseases that involve abnormal cell growth with the potential to invade or spread to other parts of the body. [1][2] They form a subset of neoplasms. A neoplasm or tumor is a group of cells that have undergone unregulated growth, and will often form a mass or lump, but may be distributed diffusely. [21][22]

Six characteristics of cancer have been proposed:

self-sufficiency in growth signalling
insensitivity to anti-growth signals
evasion of apoptosis
enabling of a limitless replicative potential
induction and sustainment of angiogenesis
activation of metastasis and invasion of tissue. [23]
The progression from normal cells to cells that can form a discernible mass to outright cancer involves multiple steps known as malignant progression.

Many cancers can be prevented by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating plenty of vegetables, fruits and whole grains, being vaccinated against certain infectious diseases, not eating too much processed and red meat, and avoiding too much exposure to sunlight. [9][10] Early detection through screening is useful for cervical and colorectal cancer. [11] The benefits of screening in breast cancer are controversial. [11][12] Cancer is often treated with some combination of radiation therapy, surgery, chemotherapy, and targeted therapy. [1][13] Pain and symptom management are an important part of care. Palliative care is particularly important in those with advanced disease. [1] The chance of survival depends on the type of cancer and extent of disease at the start of treatment. [6] In children under 15 at diagnosis the five-year survival rate in the developed world is on average 80%. [14] For cancer in the United States the average five-year survival rate is 66%