Bilateral Prophylactic and Contralateral Risk-Reducing Mastectomy in Women With Germline CDH1 Pathogenic or Likely-Pathogenic Variants.

Bilateral prophylactic mastectomy (BPM) or contralateral risk-reducing mastectomy (CRRM) are considered in CDH1 carriers as a strategy to reduce lobular breast cancer (LBC) risk in women. In this study we aimed to evaluate the overall number of these procedures reported in literature. We conducted a literature search and a scoping review through the PUBMED database. We identified eleven studies eligible for our interest. Overall numbers, frequencies, geographic distribution, family history, and post-operative histopathological findings of BPM or CRRM were the main outcomes considered. Articles reporting information about BPM or CRRM were reported only in Europe and North America. A total of 75 (32.1%) women were treated with any mastectomy (BPM or CRRM), from a population of 234 positive at CDH1 genetic testing; 81.3% of these women, were treated in North America and 18.7% in Europe. In total, 69.3% of surgical procedures were BPM and 30.7% were CRRM; 76.9% of BPMs were performed in North America, and 23.1% in Europe. Instead, 91.3% of CRRMs were reported in North America, and 8.7% in Europe, respectively. A positive family history for BC was documented in 81.8% and post-operative histopathological findings described at least one in situ LBC in nearly all breast specimens. In conclusion, BPM or CRRM were performed in about 1/3 of women with germline CDH1 pathogenic or likely pathogenic variants; studies were reported only in Western countries. Family history for BC in CDH1 carriers and detection of LCIS in post-operative specimens were also frequently described.