Explain cancer.

Explain cancer.

• A. Cancer is a disease in which cells grow uncontrollably and invade healthy tissue.
• B. Cancer is caused by a viral infection.
• C. Cancer is always curable.
• D. Cancer only affects children.

Answer: (A)

Cancer is a disease in which cells grow uncontrollably and invade healthy tissue. This happens when DNA changes disrupt the normal brakes on the cell cycle and the signals that tell cells to die. With those safeguards weakened, cells keep dividing, can form a lump, and may spread into nearby tissues or travel through the bloodstream or lymph system to establish new tumors elsewhere. Because cancer stems from genetic and environmental factors that alter cell behavior, it isn’t simply caused by a viral infection, even though some cancers are linked to viruses. It’s also not true that cancer is always curable—outcomes depend on the type, stage, and available treatments. And cancer can occur at any age, not just in children, though risk tends to increase with age.

Cancer is a disease in which cells grow uncontrollably and invade healthy tissue. This happens when DNA changes disrupt the normal brakes on the cell cycle and the signals that tell cells to die. With those safeguards weakened, cells keep dividing, can form a lump, and may spread into nearby tissues or travel through the bloodstream or lymph system to establish new tumors elsewhere. Because cancer stems from genetic and environmental factors that alter cell behavior, it isn’t simply caused by a viral infection, even though some cancers are linked to viruses. It’s also not true that cancer is always curable—outcomes depend on the type, stage, and available treatments. And cancer can occur at any age, not just in children, though risk tends to increase with age.