麻豆传媒

In this 麻豆传媒 video from the recent San Antonio Breast Cancer Symposium (SABCS), Gaia Griguolo, MD, of the Veneto Institute of Oncology in Padua, Italy, presents findings from a study characterizing breast cancer brain metastases using next-generation sequencing. The research reveals actionable genomic alterations in the homologous recombination deficiency (HRD) and PIK3CA/PTEN pathways, with implications for prognosis and treatment.

The following is a transcript of her remarks:

In this poster, we aimed to characterize a cohort of breast cancer patients with brain metastases, in particular to molecularly characterize using next-generation sequencing tissue from the brain mets [metastasis].

So our aim was to identify the presence of clinically actionable alterations according to the ESCAT [ESMO Scale for Clinical Actionability of Molecular Targets] in the brain mets. And in particular, we observed the quite high, more than 60% of brain mets, had a clinically actionable alteration class I or II. And in particular, we had a high rate of alterations in HRD pathway, in particular, BRCA1, BRCA2, and PALB2 mutations. We were not able to sort out germline from somatic mutations. And we also had a quite high prevalence of alterations in the PIK3CA and PTEN pathway, mainly deletions or mutations in PTEN.

In addition to this, we also assessed the prognostic values of these alterations, and specifically in the HER2-positive breast cancer brain metastasis, we observed that the presence of PIK3CA mutations, in fact, were linked to a worse prognosis. So a worse overall survival from time of breast cancer brain metastasis diagnosis.

We observed that the study was not aimed to detect, in fact, the differences between subtypes. We had quite a small number of breast cancer brain metastasis, 56. Anyway, this is one of the largest cohorts characterized to today.

We observed that as expected we had a higher rate of HRD alterations, so BRCA1 and BRCA2 alterations in triple-negative breast cancer, while we had a lower rate in hormone receptor-positive, HER2-negative breast cancer and substantially lower rate in HER2-positive breast cancer.

Anyway, I want to highlight that even in the hormone receptor-positive, HER2-negative breast cancer brain metastasis cohort, we had almost a 20% rate of HRD alterations. As for what concerned the PIK3CA/PTEN alterations, these were more substantially distributed across all three subtypes.

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