Cancer is a disease where uncontrollable cells grow and spread to other parts of the body. It can start anywhere in the human body and can be cancerous or benign. Cancerous tumors invade nearby tissues and can spread to distant areas through metastasis. Benign tumors do not spread or invade nearby tissues and can cause serious symptoms or be life-threatening, such as brain tumors.
Cancer is a genetic disease caused by changes in genes controlling cell growth and division. These changes can occur due to errors in cell division, environmental damage, or inherited inherited mutations. As we age, the body’s ability to eliminate damaged DNA decreases, increasing the risk of cancer. Each person’s cancer has unique genetic changes.
Types of Cancer
Over 100 types of cancer are named for their origin, organs, or cell types. NCI’s website provides information on specific types, including lung and brain cancers, childhood cancers, and adolescents and young adults, as well as their location in the body. Here are some categories of cancers that begin in specific types of cells:
- Carcinoma
Carcinomas are the most common type of cancer, formed by epithelial cells covering the body’s inside and outside surfaces. There are several types of carcinomas, including adenocarcinoma, basal cell carcinoma, squamous cell carcinoma, and transitional cell carcinoma. Adenocarcinoma forms in fluid-producing epithelial cells, while basal cell carcinoma begins in the outer skin layer. Squamous cell carcinomas form in squamous cells, which line various organs. Transitional cell carcinomas form in transitional epithelium, found in bladder, ureters, kidneys, and other organs.
2. Sarcomas
Sarcomas are cancers forming in bone and soft tissues, with osteosarcoma being the most common bone cancer. Common soft tissue types include leiomyosarcoma, Kaposi sarcoma, and liposarcoma.
3. Leukemia
Leukemias are cancers originating from bone marrow, characterized by abnormal white blood cells crowding out normal ones, causing difficulties in oxygen delivery, bleeding control, and infection prevention. There are four types, categorized by severity (acute or chronic) and blood cell type (lymphoblastic or myeloid), with acute forms growing faster.
4. Lymphoma
Lymphoma is a cancer originating from lymphocytes, which are part of the immune system. There are two main types: Hodgkin lymphoma, characterized by Reed-Sternberg cells from B cells, and non-Hodgkin lymphoma, a large group of cancers that can grow rapidly or slowly.
5. Multiple myeloma, Melanoma
Multiple myeloma is cancer originating from abnormal plasma cells in the bone marrow, forming tumors throughout the body. It is also known as plasma cell myeloma and Kahler disease. Melanoma, on the other hand, begins in melanocytes, responsible for producing melanin pigment.
6. Other types
Germ cell tumors, neuroendocrine tumors, and carcinoid tumors are types of tumors that can occur in various parts of the body. Germ cell tumors, which originate in sperm or egg cells, can be benign or malignant. Neuroendocrine tumors, which release hormones, can be benign or malignant. Carcinoid tumors, slow-growing and typically found in the gastrointestinal system, can spread to the liver.
(Information Taken from cancer.gov)
(picture source Franck Magurany)
