Overrepresentation of human epidermal growth factor receptor 2 positive- and Luminal B breast cancer metastases in the eyes and orbit

• Published in: Eye (London) Vol. 37; no. 12; pp. 2499 - 2504
• Main Authors: Stålhammar, Gustav, Grossniklaus, Hans E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2023; Nature Publishing Group
• Subjects: 13/51; 692/53/2423; 692/699/67/322; Biomarkers; Biomarkers, Tumor - analysis; Breast cancer; Breast Neoplasms - pathology; Epidermal growth factor; ErbB-2 protein; Estrogens; Female; Humans; Ki-67 Antigen - metabolism; Laboratory Medicine; Medicine; Medicine & Public Health; Metastases; Metastasis; Ophthalmology; Orbit - pathology; Orbital Neoplasms; Patients; Pharmaceutical Sciences/Technology; Progesterone; Progesterone receptors; Surgery; Surgical Oncology; Tumors
• ISSN: 0950-222X; 1476-5454; 1476-5454
• DOI: 10.1038/s41433-022-02363-1

Background Breast cancer is the most common cancer to spread to the choroid and orbit. Depending on a set of prognostic and predictive biomarkers, breast cancer can be divided into at least four distinct subtypes with separate treatment and clinical course. Subjects Thirty-two patients with metastases to the eye and periocular area diagnosed between 2005 and 2020, of which 11 also had primary tumour tissue available. Expression levels of oestrogen- (ER) and progesterone receptors (PR), Human epidermal growth factor receptor 2 (HER2) and the proliferation marker Ki67 were analysed. Results Twenty-five of 32 patients (78%) had a history of primary breast cancer, whereas the remaining 7 (22%) presented with metastatic disease. Of available metastases, 83% were positive for ER, 37% for PR, 54% for HER2, and 50% for Ki67. Metastases had significantly lower proportions of PR-positive cells than primary tumours, and the distribution of the Luminal A, Luminal B, HER2 enriched and triple-negative subtypes differed between primary tumours and metastases ( P  = 0.012): Six of 9 patients with a full set of biomarkers on both primary tumours and metastases switched subtype (67%), and 23 of 32 metastases (77%) were of the Luminal B subtype. Conclusions Nearly 4 in 5 breast cancer metastases in the eyes and orbit are of the Luminal B subtype, and a majority are HER2 positive. The breast cancer subtype frequently switches between primary tumours and metastases. Future studies should evaluate these results in larger cohorts.