Normal cells go through controlled division, differentiation, and apoptosis (programmed cell death); when normal cells lose control of the division, differentiation, and apoptosis, they become tumor cells.
Tumors or neoplasms (any abnormal cell proliferation) can be of two types: benign tumors and malignant tumors.
Cancer cells spread:
Malignant tumors are defined as neoplastic cells that do not remain localized and encapsulated and become progressively invasive and malignant.
They invade surrounding normal tissue, which is known as invasiveness, and spread throughout the body via the circulatory or lymphatic systems, which is known as metastasis.
Cancer specifically refers to malignant tumors.
The transformation from a normal to a transformed state is a multi-step process involving genetic .and epigenetic changes, as well as the selection of cells with progressively increasing proliferative, invasion, and metastasis capacity.
