my sister has always taken good care of herself. last year 7/10 she had her first baby at age 40 - the baby is allergic to everything and is a bit "sickly" - for several months they passed being sick back and forth - antibiotic, lots of doctor visits - chest x-rays etc. - this past May (5/11) on the x-ray was a cloud on the lung - further tests showed cancer - cancer in brain, lungs, back, pelvis - stage 4 was stated - how fast does cancer spread that it couldn't be found out sooner than stage 4?