HomeMedicine & HealthDiseases & ConditionsWhat is Cancer?
Medicine & Health·2 min·Updated Mar 12, 2026

What is Cancer?

Cancer

Quick Answer

Cancer is a group of diseases where cells in the body grow uncontrollably. This abnormal growth can form tumors and spread to other parts of the body, disrupting normal functions.

Overview

Cancer occurs when the body's normal cell cycle is disrupted, leading to uncontrolled cell division. Instead of dying off as they should, these cancerous cells continue to grow and can form masses known as tumors. For example, breast cancer develops in the cells of the breast tissue and can spread to nearby lymph nodes and other organs if not treated early. The way cancer works involves mutations in the DNA of cells, which can be caused by various factors such as genetics, lifestyle choices, and environmental exposures. These mutations allow cancer cells to evade the body's immune system and resist normal signals that would cause them to stop growing. Understanding how cancer develops is crucial for developing effective treatments and improving survival rates. Cancer matters because it affects millions of people worldwide and can have devastating effects on individuals and families. It is one of the leading causes of death, but advancements in research and treatment have improved outcomes for many types of cancer. Early detection and new therapies have made it possible for people to live longer and healthier lives even after a cancer diagnosis.


Frequently Asked Questions

Some common types of cancer include breast cancer, lung cancer, prostate cancer, and colorectal cancer. Each type affects different parts of the body and may have different symptoms and treatment options.
Cancer is usually diagnosed through a combination of physical exams, imaging tests like X-rays or MRIs, and biopsies where a sample of tissue is examined. Doctors look for abnormal cells or growths to confirm the diagnosis.
Treatment options for cancer typically include surgery, chemotherapy, radiation therapy, and targeted therapies. The choice of treatment depends on the type of cancer, its stage, and the patient's overall health.