Did my genetic counselor give me incorrect info?

Hi elise24601:

Meeting abstracts are often preliminary in nature, and BC.org summaries may not include important caveats. To identify a possible subsequent publication with more information, data, and a more thorough analysis, I googled "Van 't Veer survival brca1 carriers" and found this full-length publication:

van den Broek (2015): http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120189

Data supplements are available under "Supporting Information" and can be downloaded:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120189#sec027

van den Broek (2015) PDF version: http://journals.plos.org/plosone/article/asset?id=10.1371/journal.pone.0120189.PDF

I have not read the entire article in detail, but note that there appear to be numerous studies in this area. As explained in the Introduction:

"An impressive number of studies have already been conducted to address the association between BRCA1 and/or BRCA2 mutation carriership and breast cancer survival (Table 1 and Table 2). Study results were inconsistent, possibly due to differences in study design, study size, study populations and methodological rigor."

This meta-analysis reviewed a specific subset of published studies:

"Eligible publications were observational studies assessing the survival of breast cancer patients carrying a BRCA1/2 mutation compared to non-carriers or the general breast cancer population."

Using these criteria, "Sixty-six relevant studies were identified" for analysis (See Tables 1 and 2).

The overall conclusions taken from the Abstract were:

"Conclusions

In contrast to currently held beliefs of some oncologists, current evidence does not support worse breast cancer survival of BRCA1/2 mutation carriers in the adjuvant setting; differences if any are likely to be small. More well-designed studies are awaited."

See also the Discussion section, for example:

"Considering that certain prognostically important clinico-pathological features are different for BRCA1-associated tumours (S10 Supporting Information, part A) [2,3], a crucial question is to which extent BRCA1/2 mutation carriership and the specific tumour features associated with carriership can be considered to be independent when studying prognosis. The heterogeneity of the reported results did not allow a conclusion regarding the contribution of BRCA1/2 status and tumour features to a worse survival (Fig. 3 and Fig. 4; Table 4 and Table 5). However, individual and pooled adjusted HRs compared to unadjusted HRs often resulted in a shift to a relatively more favourable survival for both BRCA1 and BRCA2 mutation carriers compared to 'non-carriers' (Table 3 and Table 6). Based on these results we can conclude that clinico-pathological characteristics of the tumour might indeed play a confounding or mediating role in the association between BRCA1/2 mutation carriership and breast cancer survival, though more research should be performed to further elucidate this.

Primary breast cancer treatments may be different for BRCA1 and BRCA2 mutation carriers compared to non-carriers, mostly related to different pathological features of tumours in carriers (S10 Supporting Information, part A) [2,3]. Although the data are scarce, our review supports what was earlier suggested by others [66], i.e. that that the therapy response of tumours in BRCA1/2 mutation carriers might be better compared to that in non-carriers. Future studies should provide insight into the potential confounding or mediating role of treatment when examining survival of BRCA1/2 mutation carriers."

BarredOwl