Immunotherapy for orbital SCC
Reviewed by Hetvi Bhatt

In the UK, cemiplimab is recommended for treating metastatic or locally advanced cutaneous squamous cell carcinoma (SCC) in adults when curative surgery or curative radiotherapy is not suitable. Pembrolizumab is recommended as an option for untreated metastatic or unresectable recurrent head and neck SCC in adults whose tumours express PD-L1. This paper looks at a case series of 10 patients with orbital SCC in Australia and New Zealand who were offered immunotherapy if they had disease unsuitable for curative surgery or radiotherapy. Seven were treated with cemiplimab and 3 with pembrolizumab. At presentation, 80% of patients had perineural invasion. Eight of 10 patients had either a partial or complete response to treatment, with only one patient requiring exenteration due to progressive disease. An interesting point that the authors raise is the discordance between treatment response assessed on CT or MRI and a complete pathological response. They demonstrate this in 2 of their cases where immunotherapy was given prior to orbital exenteration or orbital mapping biopsies. Both patients showed partial response on imaging but there was no evidence of disease on histology; although it is difficult to know if this is because of incorrect tissue sampling in the second case. The authors suggest in these cases PET scans may be a more useful tool in assessing disease response and may help differentiate between active disease and post-treatment fibrous tissue. Immunotherapy can provide hope in cases that were previously thought to be palliative, however more real-world data is required to determine long-term safety and efficacy.

Immunotherapy for orbital squamous cell carcinoma.
Rana K, Beecher M, Tong JY, et al.
ORBIT
2025;44(5):504–10.