05:16 PM CDT on Monday, May 29, 2006

Watch Lisa Manzo’s report

(KMOV) - It's harder than looking for a needle in a haystack.

Washington University doctors don't know exactly what they're searching for as they battle a rare cancer that strikes about a dozen kids a year.

Lisa Manzo talked with one family who’s future depends on doctors finding that missing piece of the cancer puzzle.

The Schoettler's are one of three families in the world where more than one child developed a rare childhood lung cancer called pleuropulmonary blastoma or PPB.

They now worry about their children's children.

Washington University is the only medical school researching PPB by studying patient's DNA.

More information:

Washington University's PPB study

PPB Registry