This is the end sought by surgical interference, but notwithstanding seemingly thorough removal, the tumor often reappears after an interval of months or years.

There are many conditions which may render the complete removal of a tumor difficult or impossible.

It is often impossible to ascertain just how far the tumor cells have invaded the neighboring structures; the situation of the tumor may be such that an extended removal would injure organs which are essential for life, or at the time of removal the tumor cells may have been conveyed elsewhere by the blood or lymphatic vessels.
Successful removal depends mainly upon the length of time the tumor has been growing.

At an early stage even the most malignant tumor may be successfully removed.

It is evident from this how disastrous may be the neglect of proper surgical treatment of a tumor.