• Cancer is the world’s second largest killer,characterized by uncontrolled proliferation of cells & implicating environmental & genetic factors& perhaps due to ONCOGENE & ANTIONCOGENE imbalance.
• Cancer is derived from Latin word meaning CRAB. It originated from the characteristic of cancerous cells which can migrate & adhere and cancer pain(like a crab).
• Cancer is characterized by loss of control of cellular growth & development leading to excusive proliferation & spread of cells.
HOW CANCER CELLS DIFFER FROM NORMAL CELL
• Mature & differentiated normal cells have a finite life span.They are usually replaced by new cells generated by cell division & differentiation .Normally, it is regulated in such a manner that at any given times,the number of a cell type remains nearly constant.
• normal cells live in a complex,interdependent manner,regulating one another’s rapid in proliferation.
• Occasionally,some cells may arise,which do not respond to normal growth control mechanism.
• These cells proliferate in an unregulated manner, & give rise to CLONES of cells that can expand to a considerable size, the growth is called TUMOUR.
They usually grow by expansion & remain encapsulated in a layer of connective tissue.
They are not life threatening (fatal) e.g Moles and Warts. These types of Benign tumour. are not considered as cancers.
MALIGANT TUMOURS OR CANCERS.
• They are characterized by uncontrolled proliferation and spread of cells to various parts of body, a process referred to as METASTASIS.
• They are invariably life threatening e.g. lungs cancers, leukemia etc.
• Only the malignant tumors are properly fired to as true cancer of NEOPLASM
CHARACTERISTICS OF CANCER CELLS
• They acquire the ability to invade new sites a phenomenon designated as METASTASIS
• They exhibit a number of alterations on cell surface, in the cytoplasm, and in their genes.
• The ability of...