According to the tissue of origin, types of cancers are-
1. Carcinoma (arising from epithelial cells)
2. Sarcoma (developed from connective tissue or muscle cells)
3. Melanoma (derived from skin pigment)
4. Leukemia (cancers of white blood cells)
5. Lymphoma & Myeloma (originated from immune cells)
More than 100 types of cancers are classified according to the organs involved (WHO, 2018). The most common are-
1. Lung cancer (2.09 million cases)
2. Breast cancer (2.09 million cases)
3. Colorectal cancer (1.80 million cases)
4. Prostate cancer (1.28 million cases)
5. Skin cancer (non-melanoma) (1.04 million cases)
6. Stomach cancer (1.03 million cases)