From Italian research comes the discovery of a new form of hereditary breast cancer, previously unknown. It is caused by the mutation of a gene, Cdh1, which was already known to be linked to a hereditary form of gastric cancer. The new genetic risk factor for breast cancer differs from the classic forms of hereditary breast cancer, linked to mutations in the Brca1 and 2 genes (also known as “Jolie genes”), and was identified by a study by researchers at European Institute of Oncology (Ieo) and the State University of Milan, published on Jama Network Open.
The discovery was born from an intuition of Giovanni Corso, a breast surgeon at the IEO and the State University, and was carried out by analyzing the presence of mutations in the CdH1 gene in a cohort of 394 patients who developed a form of breast cancer known as lobular carcinoma. . “Our discovery – explains Corso – defines a new syndrome called 'hereditary lobular breast cancer', associated with the Cdh1 gene. We have in fact identified pathogenetic mutations of the Cdh1 gene in women operated on for lobular breast cancer. We then investigated the reason for this presence and discovered that this gene, already known for the predisposition of hereditary gastric cancer, is also linked to a new rare variant of lobular tumor, which occurs mainly in young women under the age of 45. at diagnosis, or with a positive family history of breast cancer, or with bilateral breast cancer.”
The results of the study reveal that the presence of mutated Cdh1, although rare, can predispose to the development of a malignant neoplasm even more than Brca1 and 2. The link with gastric cancer in these patients remains uncertain for now, but it is however possible. And for this reason, the authors of the discovery believe that genetic screening for the Cdh1 gene should probably be evaluated for patients who may be carriers of this hereditary cancer syndrome, in order to inform the prevention choices of patients and their families. “Women with a lobular tumor, aged under 45, or with a positive family history or with bilateral lobular tumor – concludes Corso – should all be tested for the Cdh1 gene”.