Clinical behaviour of breast cancer in young BRCA carriers and prognostic impact of the timing of genetic testing
Dr Matteo Lambertini - San Martino Hospital, Genoa, Italy
At the ASCO 2024 conference we have presented a large international study focussing on young BRCA carriers with breast cancer. So this is a large international network called the BRCA BCY Collaboration in which we included young women, meaning patients diagnosed below the age of 40 years, or up to the age of 40 years, all of them with known germline pathogenic or likely pathogenic variants in the BRCA genes. It’s a cohort of 78 centres in 26 countries who were able to collect data from 4,752 patients. With this specific analysis that we presented at ASCO, we wanted to answer two different questions. The first, if there are differences in terms of clinical behaviour of breast cancer between BRCA1 and BRCA2 carriers; and, the second one, if the timing of genetic testing, and particularly if it was done before diagnosis or at the time of diagnosis, would have any impact on the care of the patients as well as on the survival outcomes of the patients.
The main conclusion is that BRCA1 and BRCA2 carriers developed tumours with different characteristics and have a different clinical behaviour. The second main conclusion is that being tested before diagnosis, so meaning that probably these women enter the screening procedures that are recommended for BRCA carriers, was associated with a major downstaging of the disease at diagnosis, or more small tumours and node negative disease. This translated into improved outcomes and particularly improved overall survival.
The main implication of these findings from the first results, so the BRCA1 versus BRCA2 comparison, the main implication is that we should consider this patient population as two different groups of patients that may require different and more tailored prevention and screening procedures, survivorship and treatment strategies. So we should not consider them as the same group of BRCA carriers but are two different patient populations. For the second part, which I think is even more important, is to raise awareness on the importance of testing for BRCA all those women that have the criteria to be tested for BRCA. Because knowing to be BRCA carriers and entering the screening procedures that are recommended in this setting will lead into major improvement in early breast cancer diagnosis, lower treatment burden and improved prognosis.