Cancer is not usually inherited because:

A. the chromosomal changes in cancer are usually confined to somatic cells.
B. the cancerous cells usually interfere with the ability to produce gametes.
C. the causes of cancer are not usually genetic.

Cancer is not inherited is described below.

Explanation:

Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren’t right, so too little activity of these inhibitors can promote cancer. Similarly, positive regulators of cell division can lead to cancer if they are too active. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins.

Cancer cells behave differently than normal cells in the body.For example, cancer cells can multiply in culture (outside of the body in a dish) without any growth factors, or growth-stimulating protein signals, being added. This is different from normal cells, which need growth factors to grow in culture.

Cancer cells may make their own growth factors, have growth factor pathways that are stuck in the "on" position, or, in the context of the body, even trick neighboring cells into producing growth factors to sustain them^1  

digestion

it excretes wastes