Narrator: This is Science Today. The most common pre-malignant form of breast cancer is called ductal carcinoma-in-situ, or DCIS. Oncologist John Park of the University of California, San Francisco says about 10 to 15 percent of women diagnosed with breast cancer each year have DCIS.
Park: It's really the earliest stage at which breast cancer is found ... the earliest stage at which something is a cancer, but they recur at a very high rate and they can become invasive cancers at almost any time, so they have this sort of a time bomb kind of aspect. They're highly worrisome lesions.
Narrator: Park and his colleagues are working on a promising vaccine strategy which targets specific proteins common in these lesions and cuts tumor development by half.
Park: There's a big clinical need for something like this. DCIS is something that we're beginning to know more about because it's being diagnosed at a much, much higher rate than ever before. And it's an opportunity to nip the problem in the bud and prevent cancer from becoming more advanced...becoming invasive and even metastatic.
Narrator: For Science Today, I'm Larissa Branin.