Mar 24, 2018 06:16AM leaf wrote:
Well, if you're expecting reliable numbers, I'm going to disappoint you.
Almost everything about LCIS is controversial, and that goes double for PLCIS. PLCIS is more unusual than LCIS.
I did find this paper that said out of 7 (PLCIS or LCIS cases with pleomorphic features) cases, about half got breast cancer in the other breast by 67 months (which is about 5 years). This is a TINY sample size. https://www.ncbi.nlm.nih.gov/pubmed/28612228
To me, I would not be surprised if bilateral PLCIS is common, since they know that bilateral LCIS is common. They know that LCIS is often bilateral because before around the 1990s, they routinely did bilateral mastectomies on LCIS women, and they could look at the mastectomy specimens. (Note that pathologists were just in the process of developing a category for PLCIS in the 1990s, so undoubtedly some (small) number of patients diagnosed with LCIS before around 1990 probably did have PLCIS in addition.)
Note not all pathologists agree: even recently (2015) there is this paper that found when a group of 3 pathologists looked at a SINGLE biopsy slide (which would be really unusual - they would normally have many more slides than that to look at) - all 3 agreed on a diagnosis about 75% of the time. https://www.ncbi.nlm.nih.gov/pubmed/25781441. "...overall agreement between the individual pathologists' interpretations and the expert consensus-derived reference diagnoses was 75.3%, with the highest level of concordance for invasive carcinoma and lower levels of concordance for DCIS and atypia" In other words, its usually fairly easy to diagnose invasive breast cancer, but its more difficult to diagnose DCIS or atypia.
I don't want to go hunt for the references now, but around when I was diagnosed with classic LCIS (2005), there was controversy about the definition of classic LCIS - such as how many atypical cells you see in a lobular sac (if I'm using the right terminology.)
We don't know much about PLCIS, but at least in classic LCIS, they do know that often subsequent breast cancers that occur in classic LCIS, they often form not at the known LCIS site, but elsewhere in the breast, that looked totally normal previously. LCIS is really hard to study because it doesn't RELIABLY show up in imaging, so we don't have any good way of knowing if the area that now has DCIS or invasive breast cancer previously had LCIS. They used to say that LCIS was usually a MARKER of some unknown risk factor that put both breasts at increased risk of breast cancer.
I think most/almost all docs feel that PLCIS is more aggressive than classic LCIS. And they know that ILC (invasive lobular carcinoma, which apparently you DON'T have) is more frequently bilateral.
Whether or not to have a mastectomy is a very personal decision. Weigh the pros and cons, and take the information and your feelings about a mastectomy to your decision. There is no RIGHT decision for everyone in this matter.