Cancer is a group of more than 100 diseases marked by the uncontrolled and abnormal growth of cells in the body. Unlike normal cells, which grow, divide, and die in a regulated cycle, cancer cells ignore these signals, leading to the formation of tumors or the displacement of healthy cells in the blood.
One of the most dangerous characteristics of cancer is its ability to spread. Cancer cells can invade surrounding tissues and travel to other parts of the body through the bloodstream or lymphatic system, a process known as metastasis. Medical experts say metastasis accounts for most cancer-related deaths.
Despite its seriousness, many cancers can be treated successfully when detected early. Improvements in early screening, diagnosis, and treatment have continued to improve survival rates for several cancer types.
Causes and Risk Factors
Cancer develops as a result of genetic mutations that disrupt normal cell growth and division. These mutations may be inherited or acquired over time.
Inherited genetic mutations account for a small percentage of cases, estimated at about 5 to 10 percent, and are passed from parents to their children.
The majority of cancers result from acquired mutations linked to lifestyle and environmental factors. Key risk factors include tobacco use, excessive alcohol consumption, exposure to ultraviolet or ionizing radiation, unhealthy diets, physical inactivity, and obesity. Certain infections, such as human papillomavirus (HPV) and hepatitis B and C, are also known to increase cancer risk. Long-term exposure to chemical carcinogens like asbestos and the natural ageing process further contribute to cancer development.
Symptoms and Diagnosis
Cancer symptoms vary depending on the type and location of the disease, but several warning signs should not be ignored. These include persistent lumps or swellings, unexplained weight loss, constant fatigue, changes in bowel or bladder habits, sores that do not heal, unusual bleeding or bruising, and persistent cough or breathing difficulties.
Diagnosis typically begins with a physical examination and a review of medical history. Doctors may also recommend screening tests such as mammograms or colonoscopies, followed by imaging tests. In many cases, a biopsy is required to confirm the presence of cancer cells.
Types and Treatment
There are more than 100 types of cancer, usually named after the organ or tissue where they begin, such as breast, lung, or prostate cancer. Broadly, cancers are classified as solid cancers, including carcinomas and sarcomas, or blood cancers, such as leukemias and lymphomas.
Treatment depends on the type and stage of cancer and may involve surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, or hormone therapy. Health professionals continue to emphasize that early detection and timely treatment remain critical in reducing cancer-related deaths.
