ERBB2 amplifications across sex, race, and cancer types studied to guide HER2 therapies

Dr Marc Machaalani - Dana-Farber Cancer Institute, Boston, USA

Fam-trastuzumab deruxtecan has recently received accelerated FDA approval for the treatment of metastatic and unresectable HER2 positive tumours. Our study aimed to understand the distribution of ERBB2 amplifications, which are often associated with HER2 overexpression, across different subgroups, including race, sex and cancer types. So we analysed data from over 100,000 patients in the GENIE registry and we identified ERBB2 amplification in about 4% of the samples, with the highest rates being found in oesophageal adenocarcinoma, breast cancer and bladder cancer.

Significant differences were found between different subgroups. For instance, male patients with bladder or oesophageal gastric cancers had higher rates of ERBB2 amplifications compared to females. In contrast, female patients with breast cancer had higher rates of ERBB2 amplifications compared to males. Racial disparities were also found as higher rates of ERBB2 amplifications were identified in bladder and colorectal cancers among Asian patients and in endometrial cancer among Black patients. In addition, metastatic versus primary tumours had higher rates of ERBB2 amplifications among hepatobiliary cancers.

These findings highlight the importance of understanding subgroup differences to guide the use of HER2-targeted therapies in a more personalised and a more individualised manner.