“Metastatic carcinoma with an unknown primary.” A diagnosis doesn’t get much scarier than that. Somewhere in the recesses of her body, a cell had divided into two daughter cells, leaving one of them with a microscopic birth defect -- a mutation to its genome that caused it to divide a little faster than its neighbors.

Normally, that wouldn’t be a problem. The body is equipped with a phalanx of defenses. But as the aberrant cell divides, more mutations accumulate -- and some of these might be the very ones that disable the safeguards or enact mechanisms to work around them.

Freed from these constraints, the cell divides even faster. As one generation gives rise to another and another, more mutations occur, and the chances increase that a family of cells will develop the biochemical intelligence to outwit the rest of the body and grow into a malignant tumor.

What is happening is a sped-up version of Darwinian evolution, with the tumor becoming fitter and fitter, better equipped to dominate and thrive.

I've come to realize that any human who lives long enough WILL eventually get some form of cancer.

Perhaps this source of pain and suffering also serves a higher purpose.