About Cancer

Cancer is a broad term for a group of diseases that occur when abnormal cells in the body begin to grow uncontrollably. Normally, cells grow, divide, and die in an orderly fashion. Cancer disrupts this process — cells keep growing and dividing when they shouldn't, and they don't die when they're supposed to.

There are more than 200 known types of cancer, and they can start almost anywhere in the body — from the skin and internal organs to the blood and brain. Some cancers grow slowly, while others progress rapidly. Some remain confined to one area, while others spread to distant parts of the body.

Cancer is not a single disease but a collection of related diseases. What they all have in common is the uncontrolled growth of cells that can invade surrounding tissues and, in many cases, spread to other parts of the body through the bloodstream or lymphatic system.

Cancer begins when changes — called mutations — occur in the DNA of a cell. DNA is the instruction manual inside every cell that tells it how to function, grow, and divide. When certain genes in the DNA are damaged or altered, the cell may start to grow and divide without the normal controls.

These mutations can accumulate over time due to a variety of factors, including exposure to tobacco smoke, ultraviolet radiation, certain viruses, and other environmental influences. Some mutations are inherited from parents, while most occur during a person's lifetime as a result of wear and tear on cells or exposure to carcinogens.

As mutated cells continue to divide, they can form a mass of abnormal tissue called a tumor. If the tumor is confined to one place and does not invade nearby tissues, it is considered benign. If it invades surrounding tissues or spreads to distant parts of the body, it is malignant — meaning it is cancerous.

The process by which cancer spreads from its original site to other parts of the body is called metastasis. Metastatic cancer retains the name of its original location — for example, breast cancer that spreads to the lungs is still called metastatic breast cancer, not lung cancer.

Cancer is one of the leading causes of death worldwide. According to the World Health Organization, approximately 20 million new cancer cases were diagnosed globally in 2022, with roughly 9.7 million deaths attributed to the disease.

Despite these sobering numbers, there is reason for hope. Survival rates for many cancer types have improved significantly over the past several decades thanks to advances in early detection, treatment, and supportive care. In many high-income countries, overall cancer mortality rates have been declining steadily.

The burden of cancer, however, is not evenly distributed. Lower- and middle-income countries face a growing cancer crisis, often with limited access to screening, diagnosis, and treatment. Reducing global disparities in cancer care remains one of the most pressing public health challenges of our time.

Cancers are commonly named after the organ or tissue where they begin. Some of the most prevalent types include breast cancer, lung cancer, colorectal cancer, prostate cancer, and skin cancer. Each type behaves differently, has unique risk factors, and requires its own approach to screening, diagnosis, and treatment.

Blood cancers — such as leukemia, lymphoma, and myeloma — are different in that they affect the blood, bone marrow, and lymphatic system rather than forming solid tumors.

Understanding the specific characteristics of different cancer types is essential for effective prevention, early detection, and treatment planning.

Cancer awareness is about more than wearing a ribbon. It means understanding the risk factors you can control, recognizing the warning signs that should prompt a visit to the doctor, and knowing when and how to get screened.

Research consistently shows that early detection saves lives. When many cancers are found at an early stage, treatment options are more varied, less aggressive, and often more effective. Awareness empowers individuals to take proactive steps — from making lifestyle changes to scheduling routine screenings.

Beyond individual action, awareness drives community and legislative change. It encourages funding for research, supports patients and survivors, and helps reduce the stigma that too often surrounds a cancer diagnosis.