Question

How does cancerous growth occur?

Answer 1

Cancerous cells are those transformed form of normal cells that have lost the property of contact inhibition (stoppage of growth on coming in contact with other cells). Cancer cells divide continuously to give rise to mass of cells ( malignant tumours) and this is known as cancerous growth. Malignant tumours exhibit metastasis i.e., the cells sloughed from such tumours reach distant sites and wherever they reach, new tumour is formed. These tumours actually represent cancer. The cells actively divide, grow, and starve the normal cells of vital nutrients.
There are various factors which damage gene and cause cancerous growth. Expression of oncogene in cells makes them cancerous cells.