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)