Pregnant and diagnosed with cancer--not the end of the world?

CNN
reported this morning about women who survived chemo while pregnant and gave birth to healthy babies. Usually, it's simply a terrible accident of timing: The pregnancy has nothing to do with the cancer's emergence.

You might be thinking that higher hormone levels are causing cancer at this time, but CNN reports that studies show that pregnant women are more likely to have hormone-receptor negative tumors than hormone-receptor positive tumors--meaning they are not fed by pregnancy's higher levels of estrogen and progesterone.