I am confused by what you say ... that PLCIS accounts for 5% of lobular cancers. PLCIS is not cancer. My breast surgeon said they still don't know if it's a direct pre-cursor of invasive breast cancer (if left alone). There is, however, a pleomorphic version of invasive lobular cancer. Is that what you are referring to? If so, that is different from PLCIS (a rare variant of the more classic LCIS) and is considered a risk factor for invasive lobular or invasive ductal cancer within one's lifetime (maybe more so ILC).

I hope you are doing well.