Malignant tumors are sometimes treated with drugs that halt mitosis and thus stop production of new cancer cells. Two such drugs, vincristine sulfate
in the case of cancerous tumors, cells lost the ability to divide normally. And when these cells come in contact with other normal cells, they stop dividing known as contact inhibition.
drugs like vincristine sulfate halt the cell division by damage the genetic material of infected cells ( either RNA or DNA) that controls the mechanism of cell division. this way cells do not divide and die.
Drugs like mitomycin C also stops cell division or kill tumor cells.
It attaches to cancer cell's DNA from preventing them to mobilise other body cells or tissue. This way cells cannot divide slowing cancer growth.