Cancer is defined as

Cancer is defined as

• A. A disease in which cells grow uncontrollably and invade and destroy healthy tissue
• B. A temporary illness from a virus
• C. A condition where bones weaken with age
• D. A type of autoimmune disorder

Answer: (A)

Cancer is a disease in which cells grow uncontrollably and invade and destroy healthy tissue. Normal cells follow growth controls and usually stop dividing or die off when damaged, but mutations can disrupt these controls, leading to relentless cell division. As abnormal cells multiply, they can penetrate nearby tissues and, in many cancers, spread to distant sites through blood or lymphatic systems, making the condition especially dangerous. This contrasts with infections caused by viruses, which are temporary illnesses; osteoporosis, a condition where bones become weak with age; and autoimmune disorders, where the immune system attacks the body's own tissues. None of those involve the uncontrolled, invasive cell growth that defines cancer.

Cancer is a disease in which cells grow uncontrollably and invade and destroy healthy tissue. Normal cells follow growth controls and usually stop dividing or die off when damaged, but mutations can disrupt these controls, leading to relentless cell division. As abnormal cells multiply, they can penetrate nearby tissues and, in many cancers, spread to distant sites through blood or lymphatic systems, making the condition especially dangerous.

This contrasts with infections caused by viruses, which are temporary illnesses; osteoporosis, a condition where bones become weak with age; and autoimmune disorders, where the immune system attacks the body's own tissues. None of those involve the uncontrolled, invasive cell growth that defines cancer.