Question:Do all in situ breast cancers become invasive breast cancers?
Answer:Do all in situ breast cancers become invasive breast cancers? That's a really good question. The answer is no to that. Many in situ breast cancers stay in situ and never develop invasion. But they have the potential to do that.
The corollary question is do all invasive cancers, were they preceded by an in situ version. And the answer is they probably were, or most of them were. A colleague of mine looked at 100 consecutive invasive breast cancers and he found in situ cancer in 98 out of 100 patients.
So here's the bottom line: in situ cancers can become invasive cancers, they don't all have to do that, but most invasive breast cancers were preceded by an in situ or non-invasive breast cancer.