Intensive breast screening in BRCA2 mutation carriers is associated with reduced breast cancer specific and all cause mortality | Hereditary Cancer in Clinical Practice | Full Text

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Discussion

Although there is evidence for a projected improvement in survival from annual mammography screening in familial breast cancer (from those largely at low risk of BRCA1/2) under 50 years of age [17, 18], this is the first time that a prospectively observed reasonably large series of BRCA2 carriers has been shown to have an apparent survival advantage from annual screening. Recently a Dutch group showed no improvement in survival, based on only two deaths out of 18 BRCA2 related breast cancers compared to three events in controls [19]. Nonetheless the same group reported that annual mammography screening beyond 60 years of age in BRCA1/2 carriers is associated with a marked improvement in tumour stage at diagnosis, with 58 % diagnosed at stage two or above with usual two-yearly screening compared to only 21 % in the annual group [20]. Additionally, the interval cancer rate was doubled by extending screening to two years. The data from this and the present study concur with NICE guidelines in England and Wales who recommend annual mammography for BRCA1/2 carriers until 70 years of age [21]. Although the present study has used a pragmatic comparison group of BRCA2 carriers not undergoing intensive screening a true matched control series would be impossible as women who knew they were mutation carriers would be very unlikely to not undergo added surveillance.

 The current situation is that no single centre has a series large enough and well enough constructed and documented to provide a definitive answer to the question of whether MRI breast screening improves survival in BRCA2 mutation carriers. This is why close to all major organisations world-wide addressing these questions have organised ‘THE BRCA CHALLENGE’ (http://​www.​humanvariomeproj​ect.​org/​brca-challenge.​html) which at the 2015 meeting in the UNESCO centre in Paris called for a broad international collaboration to provide answers to the unanswered questions. In this context we report our findings and encourage others to do the same, so as to move our knowledge on effects of interventions to prevent BRCA2-associated breast cancer death from assumptions to empirical observed effects of interventions. Until the time when more definitive answers are available female BRCA2 carriers will still require guidance on whether surveillance with MRI and mammography offers similar improvements in life expectancy than can be gained from risk reducing surgery [13, 22].