Immunotherapy for the treatment of perineural spread in cutaneous head and neck squamous cell carcinoma: Time to rethink treatment paradigms

Surgical Approaches to Pre-Auricular Cutaneous Squamous Cell Carcinomas Extending to the Temporal Bone

BACKGROUND

Standardized surgical approaches to advanced pre-auricular cutaneous squamous cell carcinomas (cSCC) are lacking.

METHODS

Fifty-four patients who underwent lateral temporal bone resection (LTBR) for pre-auricular cSCC were grouped into "Levels" of increasing disease spread. Surgical approaches to achieve negative-margin resection were designed for each Level and replicated on cadaveric specimens.

RESULTS

Level 1 extended to the external auditory canal, requiring LTBR ± superficial parotidectomy. Level 2 involved the retromandibular space ± temporomandibular joint, necessitating partial mandibulectomy, in addition to the above. Level 3 and 4 involved the deep parotid, being situated either away from (> 5 mm) or close (≤ 5 mm) to the anterior carotid sheath (ACS), respectively. These tumors require radical parotidectomy, with incorporation of the ACS for Level 4. Level 5 involved the ACS at the skull base and should be treated non-surgically.

CONCLUSION

This Level-based system will hopefully lead to further prospective studies and improvements in outcomes for advanced pre-auricular cSCC.

PD-1 Inhibitors for Periocular Squamous Cell Carcinoma With Perineural Spread to the Orbit and Skull Base

BACKGROUND

Periocular squamous cell carcinoma with perineural spread and orbital and skull base involvement is challenging to treat, as complete surgical resection is usually not feasible and radiotherapy carries a high risk of ocular toxic effects. PD-1 inhibitors have emerged as an alternative treatment for such cases.

METHODS

A retrospective study of all consecutive patients with periocular squamous cell carcinoma and perineural spread to the orbit treated with PD-1 inhibitors was carried out. Patients who had concurrent radiotherapy were excluded. The main outcome measure was treatment response.

RESULTS

Most patients had recurrent squamous cell carcinoma that had been heavily treated with Mohs surgery, radiotherapy, chemotherapy, or a combination of these modalities before referral with perineural spread to the orbit and skull base. All patients had V1 involvement; other cranial nerves involved were III (n = 1), V2 (n = 1), V3 (n = 1), VI (n = 1), VII (n = 2), and VIII (n = 1). The PD-1 inhibitors cemiplimab and pembrolizumab were used in 9 patients and 1 patient, respectively. The treatment duration ranged from 2 to 24 months (median, 19 months). Six patients had a partial response, and 4 had a complete response. With a median follow-up time of 16 months, all patients were without evidence of progressive disease at last contact.

CONCLUSION

Treatment with PD-1 inhibitors can lead to meaningful responses in patients with periocular squamous cell carcinoma with perineural spread to the orbit and skull base and avoids the need for radiotherapy, which is toxic to the eye. Careful long-term follow-up is needed to assess long-term response durability.

PD-L1 Inhibitor Cosibelimab for Cutaneous Squamous Cell Carcinoma: Comprehensive Evaluation of Efficacy, Mechanism, and Clinical Trial Insights

Cutaneous squamous cell carcinoma (CSCC) is one of the most common non-melanoma skin cancers, and particularly challenging to treat in advanced or metastatic stages. Traditional therapies, including chemotherapy and radiation, often result in limited efficacy and severe side effects. Cosibelimab, a fully human monoclonal antibody targeting PD-L1, has emerged as a promising immunotherapy for advanced CSCC. In this review, we evaluate the therapeutic potential of cosibelimab by analyzing its mechanism of action, clinical trial data, and its role compared to other PD-1/PD-L1 inhibitors, such as pembrolizumab and cemiplimab. We synthesized the available preclinical and clinical data on cosibelimab, focusing on published Phase I and II trial results involving 76 patients. Objective response rates (ORRs), progression-free survival (PFS), overall survival (OS), and safety profiles were compared between cosibelimab, pembrolizumab, and cemiplimab. Mechanistic insights into cosibelimab's dual action, including PD-L1 blockade and antibody-dependent cellular cytotoxicity (ADCC), were also explored. Phase II trials demonstrated an ORR of 47.5%, with a median PFS of 12.9 months in advanced CSCC patients. Cosibelimab demonstrated a favorable safety profile, with predominantly mild to moderate adverse events. Comparative analysis with pembrolizumab and cemiplimab showed similar efficacy, although long-term survival data for cosibelimab is still emerging. Given its efficacy and safety, cosibelimab holds promise not only as a monotherapy but also for future exploration in combination regimens and broader oncologic indications. Future trials are required to validate its long-term outcomes, including overall survival, and to explore its use in combination therapies and neoadjuvant/adjuvant settings.

Immunotherapy for orbital squamous cell carcinoma

PURPOSE

To evaluate the demographics, clinical features and response of orbital squamous cell carcinoma treated with immunotherapy in an Australian and New Zealand cohort.

METHODS

This is a multi-institutional, retrospective case series. Data was collected on patient demographics, clinical presentation, imaging findings, treatment course and outcomes. Details of post-immunotherapy surgical interventions were documented along with their histological findings.

RESULTS

Ten patients were included. All patients had invasive orbital squamous cell carcinoma. Perineural spread was present in six patients. Seven patients received Cemiplimab, while three patients received Pembrolizumab. No patients experienced side effects requiring cessation of immunotherapy. One patient died during follow up due to an unrelated cause. Eight (80%) patients had measurable radiological response, whereas one (10%) patient had progressive disease. Two patients had orbital exenteration: one due to progressive disease and one due to residual disease on MRI. One patient had orbital mapping biopsies. Two (66%) patients that had tissue analysis following immunotherapy showed complete pathologic response.

CONCLUSION

Our findings support the emerging role of immunotherapy in the management of invasive orbital squamous cell carcinoma.

Integrated analysis of single-cell, spatial and bulk RNA-sequencing identifies a cell-death signature for predicting the outcomes of head and neck cancer

Background

Cell death plays an essential role in carcinogenesis, but its function in the recurrence and postoperative prognosis of head and neck cancer (HNC), which ranks as the 7th most common malignancy globally, remains unclear.

Methods

Data from five main subtypes of HNC related single-cell RNA sequencing (scRNA-seq) were recruited to establish a single-cell atlas, and the distribution of cell death models (CDMs) across different tissues as well as cell subtypes were analyzed. Bulk RNA-seq from the Cancer Genome Atlas Program (TCGA) dataset was subjected to a machine learning-based integrative procedure for constructing a consensus cell death-related signature risk score (CDRscore) model and validated by external data. The biofunctions including different expression analysis, immune cell infiltration, genomic mutations, enrichment analysis as well as cellchat analysis were compared between the high- and low- risk score groups categorized by this CDRscore model. Finally, samples from laryngeal squamous cell cancer (LSCC) were conducted by spatial transcriptomics (ST) to further validate the results of CDRscore model.

Results

T cells from HNC patients manifested the highest levels of cell death while HPV infection attenuates malignant cell death based on single-cell atlas. CDMs are positively correlated with the tumor-cell stemness, immune-related score and T cells are infiltrated. A CDRscore model was established based on the transcription of ten cell death prognostic genes (MRPL10, DDX19A, NDFIP1, PCMT1, HPRT1, SLC2A3, EFNB2, HK1, BTG3 and MAP2K7). It functions as an independent prognostic factor for overall survival in HNC and displays stable and powerful performance validated by GSE41613 and GSE65858 datasets. Patients in high CDRscore manifested worse overall survival, more active of epithelial mesenchymal transition, TGF-β-related pathways and hypoxia, higher transcription of T cell exhausted markers, and stronger TP53 mutation. ST from LSCC showed that spots with high-risk scores were colocalized with TGF-β and the proliferating malignant cells, additionally, the risk scores have a negative correlation with TCR signaling but positive association with LAG3 transcription.

Conclusion

The CDRscore model could be utilized as a powerful prognostic indicator for HNC.

Clinical outcomes in perineural spread of cutaneous squamous cell carcinoma via the ophthalmic nerve

BACKGROUND

There are no large studies reporting oncological or survival outcomes for patients diagnosed with perineural spread (PNS) of cutaneous squamous cell carcinoma (cSCC) via the ophthalmic nerve (V1). Where orbital exenteration may be necessary for curative treatment, it is critical to have survival data with which the morbidity associated with surgical treatment can be justified. Furthermore, with the emerging treatment option of immunotherapy, current standard of care outcomes are needed to help guide future trial design and eventually changed management guidelines.

OBJECTIVE

To determine the oncological and survival outcomes observed in patients with PNS of cSCC via V1.

MATERIALS AND METHODS

Retrospective analysis of prospectively maintained cohort of patients with PNS of cSCC via V1 treated in a tertiary Australian head and neck oncology/skull base referral center. Consecutive sample of 53 patients managed between March 1, 1999 and April 30, 2020. Follow-up closure date was September 1, 2021. Curative-intent surgery, curative-intent radiotherapy, or palliative care was undertaken. Endpoints included five-year overall, disease-specific, and disease-free survival from the date of treatment.

RESULTS

Five-year Kaplan-Meier overall survival was 61.9% (95% CI 46.2%-74.3%), with disease-specific survival of 74.6% (95% CI 58.8%-85.3%), and disease-free survival 62.1% (95% CI 46.5%-74.3%). Survival was superior in patients treated via surgery and adjuvant radiotherapy than in those receiving surgery alone or definitive radiotherapy. Survival was superior among patients with less advanced disease as assessed by the Williams zonal staging system; patients with Zone 1 disease had disease-specific survival of 94.1% at 5 years with 82.5% disease-free survival.

DISCUSSION

Five-year oncological and survival outcomes in this cohort were favorable. Superior survival was observed in patients treated with curative-intent surgery and adjuvant radiotherapy. Less extensive disease as delineated by the Williams zonal staging system was associated with improved survival.

CONCLUSION

Surgical resection with adjuvant radiotherapy confers favourable oncological and survival outcome in patients with V1 PNS, particularly with early disease limited to Zone 1.

Persisting facial nerve palsy or trigeminal neuralgia - red flags for perineural spread of head and neck cutaneous squamous cell carcinoma (HNcSCC)

BACKGROUND

Perineural spread (PNS) of head and neck cutaneous squamous cell carcinoma (HNcSCC) is a unique diagnostic challenge, presenting with insidious trigeminal (CN V) or facial nerve (CN VII) neuropathies without clinically discernible primary masses. These patients are often sub-optimally investigated and misdiagnosed as Bell's palsy or trigeminal neuralgia. This case series highlights the red flags in history and pitfalls that lead to delays to diagnosis and treatment.

METHODS

A retrospective case series of 19 consecutive patients with complete clinical histories with HNcSCC PNS without an obvious cutaneous primary lesion at time of presentation to a quaternary head and neck centre in Australia were identified and included for analysis.

RESULTS

Fifteen had CN VII PNS, 17 had CN V PNS, and 13 had both. The overall median symptom-to-diagnosis time was 12-months (IQR-15 months). Eight patients had CN VII PNS and described progressive segmental facial nerve palsy with a median symptom-to-diagnosis time of 9-months (IQR-11.75 months). Eleven patients had primary CN V PNS and described well localized parathesia, formication or neuralgia with a median symptom-to-diagnosis time of 19-months (IQR 27.5 months).

CONCLUSION

PNS is often mistaken for benign cranial nerve dysfunction with delays in diagnosis worsening prognosis. Red flags such as progressive CN VII palsy or persistent CN V paraesthesia, numbness, formication or pain, particularly in the presence of immuno-compromise and/or a history of facial actinopathy should raise suspicion for PNS. Gadolinium-enhanced MR Neurography should be obtained expediently in patients with persistent/progressive CN V/CN VII palsies in patients with red flags, with low threshold for referral to a Head and Neck Surgeon.

Radiation therapy for low- and high-risk perineural invasion in head and neck cutaneous squamous cell carcinoma: Clinical outcomes and patterns of failure

BACKGROUND

Perineural invasion (PNI) in head and neck squamous cell carcinoma (HNSCC) portends poor prognosis. Extent of treatment of nerve pathways with varying degrees of PNI and patterns of failure following elective neural radiotherapy (RT) remain unclear.

METHODS

Retrospective review of HNSCC patients with high-risk (clinical/gross, large-nerve, extensive) or low-risk (microscopic/focal) PNI who underwent curative-intent treatment from 2010 to 2021.

RESULTS

Forty-four patients (mean follow-up 22 months; 59% high-risk, 41% low-risk PNI) were included. Recurrence following definitive treatment occurred in 31% high-risk and 17% low-risk PNI patients. Among high-risk patients, 69% underwent surgery with post-operative RT and 46% underwent elective neural RT. Local control (83% low-risk vs. 75% high-risk), disease-free, and overall survival did not differ between groups.

CONCLUSIONS

High local control rates were achieved in high-risk PNI patients treated with adjuvant or primary RT, including treatment of both involved and uninvolved, communicating cranial nerves, with few failures in electively treated regions.

Durable tumor regression and restoration of neurologic function after treatment with anti-PD-1 in patients with functionally unresectable cutaneous squamous cell carcinoma with perineural spread into the cavernous sinus

PURPOSE

To describe tumor response and cranial nerve function outcomes after administration of anti-PD-1 to patients with cutaneous squamous cell carcinoma (CSCC) with perineural spread to cranial nerves (CN) extending into the cavernous sinus.

METHODS

Electronic patient records from a single institution were queried for patients with CSCC of the head and neck causing diplopia (ICD-10 H53.2) who were treated with anti-PD-1. Data extracted included demographics, duration of anti-PD-1 therapy, immune-mediated adverse reactions, tumor response per adapted RECIST v1.1, and changes in CN function and symptoms (e.g., pain). All patients were prescribed cemiplimab 350 mg IV q3 weeks.

RESULTS

Four patients met inclusion criteria. They had varying degrees of pain and sensory deficits in branches of the trigeminal nerve (CN V). One, 2, 3 and 1 patients had baseline involvement of CN III, IV, VI and VII, respectively. MRI confirmed perineural cavernous sinus involvement in all patients. Duration of anti-PD-1 therapy ranged 15-60 weeks. All patients experienced an objective anti-tumor response to anti-PD-1; partial response n = 2, complete response n = 2. At a median follow-up of 22 months, responses were ongoing in all patients. All patients demonstrated improvement in ocular motility deficits and pain with resolution of symptoms in 3 and 1 patients, respectively.

CONCLUSION

Administration of anti-PD-1 to patients with CSCC with perineural spread into the cavernous sinus can generate durable anti-tumor regressions and restore CN function, while sparing the morbidity associated with surgical resection and/or radiotherapy. Our findings add to emerging literature supporting this treatment approach for this patient population.

Immunotherapy in advanced cutaneous squamous cell carcinoma: Sydney west cancer network experience

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) is the second most common malignancy in the Caucasian population. A minority of cases are inoperable at presentation, recur or develop metastatic disease with a historical 5-year overall survival of ~10%. Treatment options in this setting are generally palliative. Immunotherapy has emerged as a new paradigm in managing these patients.

METHODS

Patients presenting to Sydney West Cancer Network with locally advanced or metastatic CSCC treated with the anti-PD1 agent cemiplimab were identified. Response to treatment was objectively assessed based on RECIST1.1 or PERCIST criteria. Primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), overall survival (OS), therapy toxicity, and predictors of treatment response.

RESULTS

A total of 19 patients were identified with a median age of 76 (range 56-94) and 4 immunosuppressed. The longest follow up duration was 28 months. ORR, complete response (CR), and partial response (PR) were 68% (13/19), 53% (10/19), and 16% (3/19), respectively. Median PFS was 12 months (95% CI 9-14) whilst median OS was not reached by end of study. Responders (CR or PR) had significantly superior OS compared to those with no response (P < 0.01). A primary site of head and neck cancer was significantly associated with ORR (P = 0.04). A single patient experienced Grade 3 toxicity with the rest being Grades 0-1.

CONCLUSION

This study confirms the clinical efficacy of cemiplimab in patients with advanced CSCC with many experiencing a durable response and an acceptable adverse effect profile.

Epidemiology and treatment outcomes of cutaneous squamous cell carcinoma extending to the temporal bone

BACKGROUND

Accurate epidemiological and outcomes data regarding cutaneous squamous cell carcinoma (cSCC) extending to the temporal bone is lacking.

METHODS

Retrospective analysis of 167 Australian patients with primary and peri-temporal bone cSCC.

RESULTS

cSCC extending from secondary subsites (93.4%) was 14 times more frequent than primary temporal bone SCC (6.6%). For patients who underwent curative surgery ± post-operative radiotherapy (n = 146, 87.4%), 5-year disease-free survival, locoregional recurrence-free survival, disease-specific survival, and overall survival was 53.0%, 59.4%, 67.9%, and 44.7%, respectively. External ear and pre-auricular tumors, salvage surgery, tumor size (≥40 mm medial-lateral), nodal disease, and involved margins were negative predictors of survival in multivariable analysis.

CONCLUSION

In regions of high sun exposure, cSCCs extending to the temporal bone are more common than primary cancers. Outcomes are improved with clear margins, justifying the need for radical resection. Further research regarding pre-auricular cancers is required given poorer associated survival outcomes.