• Guardant Health has the first FDA-approved liquid biopsy that can spot colon cancer. • Co-CEO Helmy Eltoukhy tells Business Insider the story of how they used Silicon Valley strategy to build it. • This article is part of "Transforming Treatments," a series on medical innovations that save time, money, or discomfort.

At first, cancer is a quiet disease. Inside the body, cells are aggressively multiplying out of control, changing everything. But on the outside, there's nothing special to see or feel. Not yet.

For Guardant co-CEO Helmy Eltoukhy, that invisibility looked like an engineering challenge. What if cancer could be detected early — through blood tests — before you even knew it was there?

"So many patients go through this really nerve-racking diagnostic odyssey," Eltoukhy to

See Full Page