Cancer.pptx
- 1. Cancer
- 2. Facts Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020, or nearly one in six deaths. The most common cancers are breast, lung, colon and rectum and prostate cancers. Around one-third of deaths from cancer are due to tobacco use, high body mass index, alcohol consumption, low fruit and vegetable intake, and lack of physical activity. Cancer-causing infections, such as human papillomavirus (HPV) and hepatitis, are responsible for approximately 30% of cancer cases in low- and lower-middle-income countries. Many cancers can be cured if detected early and treated effectively.
- 3. Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread
- 9. Benign tumors Benign tumors are those that stay in their primary location without invading other sites of the body. They do not spread to local structures or to distant parts of the body. Benign tumors tend to grow slowly and have distinct borders. Benign tumors are not usually problematic.
- 10. Malignant tumors Malignant tumors have cells that grow uncontrollably and spread locally and/or to distant sites. Malignant tumors are cancerous (ie, they invade other sites). They spread to distant sites via the bloodstream or the lymphatic system. This spread is called metastasis
- 11. The spread of cancer cells from the place where they first formed to another part of the body. In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymph system, and form a new tumor in other organs or tissues of the body.
- 13. Cancer types Cancers are often described by the body part that they originated in. However, some body parts contain multiple types of tissue, so for greater precision, cancers are additionally classified by the type of cell that the tumor cells originated from
- 14. Carcinoma Cancers derived from epithelial cells. This group includes many of the most common cancers that occur in older adults. Nearly all cancers developing in the breast, prostate, lung, pancreas, and colon are carcinomas.
- 15. Sarcoma Cancers arising from connective tissue (i.e. bone, cartilage, fat, nerve), each of which develop from cells originating in mesenchymal cells outside of the bone marrow.
- 16. Lymphoma and leukemia Lymphoma and leukemia, these two classes of cancer arise from immature cells that originate in the bone marrow, and are intended to fully differentiate and mature into normal components of the immune system and the blood, respectively. Acute lymphoblastic leukemia is the most common type of cancer in children, accounting for ~30% of cases. However, far more adults than children develop lymphoma and leukemia.
- 17. Germ cell tumor Cancers derived from pluripotent cells, most often presenting in the testicle or the ovary (seminoma and dysgerminoma, respectively).
- 18. Blastoma Cancers derived from immature "precursor" cells or embryonic tissue. Blastomas are generally more common in children (e.g. neuroblastoma, retinoblastoma, nephroblastoma, hepatoblastoma, med ulloblastoma, etc.) than in older adults.
- 19. Cancers are usually named using -carcinoma, -sarcoma or -blastoma as a suffix, with the Latin or Greek word for the organ or tissue of origin as the root. For example, the most common cancer of the liver parenchyma ("hepato-" = liver), arising from malignant epithelial cells ("carcinoma"), would be called a hepatocarcinoma While a malignancy arising from primitive liver precursor cells is called a hepatoblastoma. Similarly, a cancer arising from malignant fat cells would be termed a liposarcoma.
- 20. Some types of cancer are named for the size and shape of the cells under a microscope, such as giant cell carcinoma, spindle cell carcinoma, and small- cell carcinoma.
- 21. Benign tumors (which are not cancers) are usually named using -oma as a suffix with the organ name as the root. For example, a benign tumor of smooth muscle cells is called a leiomyoma (the common name of this frequently occurring benign tumor in the uterus is fibroid). Confusingly, some types of cancer use the -noma suffix, examples including melanoma and seminoma.
- 22. Causes Cancer arises from the transformation of normal cells into tumour cells in a multi-stage process that generally progresses from a pre-cancerous lesion to a malignant tumour. These changes are the result of the interaction between a person's genetic factors and three categories of external agents, including: physical carcinogens, such as ultraviolet and ionizing radiation; chemical carcinogens, such as asbestos, components of tobacco smoke, alcohol, aflatoxin (a food contaminant), and arsenic (a drinking water contaminant); and biological carcinogens, such as infections from certain viruses, bacteria, or parasites
- 23. Hallmarks of Cancer: Resisting Cell Death One thing we know about cancer cells: they can resist death. They evade apoptosis, the mechanism that programs cell death once cells become damaged. Normally, apoptosis helps keep an organism healthy through growth and development, maintaining body tissue by removing infected or damaged cells. But cancer cells do not follow this process, no matter how abnormally they grow.
- 24. The cancer cells may alter the mechanisms that detect the damage or irregularities, preventing proper signaling and apoptosis activation. Cancer cells may also introduce defects in the downstream signaling itself, or the proteins involved in apoptosis, which would also prevent proper apoptosis (