One of the issues with ILC and prognosis is the way that it presents. As it can be hard to detect, it is often more advanced than IDC when it is picked up. Also, it wasn't always recognised as a distinct type of cancer so it's behaviour is not as well known - combine that with the numbers affected (depending on what you read, 5-15% of breast cancers), means that it doesn't have the same body of knowledge behind it. That said, my oncologist reckons he sees a lot of women with ILC so maybe not as uncommon as reported in the literature. And as @youngdogmum has said, much of what you read on Google is old information. I'm sure @zoffiel will have more to say.