Evidence-Based Consensus Recommendations for the Evolving Treatment of Patients with High-Risk and Advanced Cutaneous Squamous Cell Carcinoma

The hidden Australian skin cancer epidemic, high-risk cutaneous squamous cell carcinoma: a narrative review

Deaths from non-melanoma skin cancers (NMSCs) have almost doubled in Australia in recent years. Cutaneous squamous cell carcinoma (cSCC) constitutes approximately 20% of NMSCs, but is responsible for most of the deaths. Most skin cancers are easy to diagnose and treat and therefore cSCC are often trivialised; however, there is a high-risk subgroup of cSCC (HRcSCC) that is associated with a high risk of metastasis and death. The definition of early HRcSCC and our ability to identify them is evolving. Many significant prognostic factors have been identified, but a universally accepted prognostic index does not exist. Guidelines for workup, treatment, and follow-up leave many important decisions open to broad interpretation by the treating physician or multidisciplinary team. Some of the treatments used for metastatic cSCC are not supported by robust evidence and the prognosis of metastatic cSCC is guarded. In this review, we highlight the rapid rise in NMSC deaths and discuss some of the deficiencies in our knowledge of how to define, diagnose, stage, and manage HRcSCC.

Pseudoprogression of cutaneous squamous cell carcinoma invading the super vermillion border following programmed death-1 inhibitor monotherapy

A 55-year-old woman with a moderately differentiated cutaneous squamous cell carcinoma (cSCC) of the upper lip experienced initial tumour growth and new lymphadenopathy after starting immunotherapy with Cemiplimab, but achieved complete remission with no adverse events after five infusions. This case underscores the potential of immunotherapy for cSCC in sensitive head and neck areas and illustrates the phenomenon of pseudoprogression, where apparent tumour growth can occur before clinical improvement.

Postoperative permanent section evaluation of Mohs micrographic surgery debulk specimens does not result in upstaging of cutaneous squamous cell carcinoma compared to stage at the completion of surgery: A retrospective case series

Background

Mohs micrographic surgery (MMS) is used for the treatment of high-risk cutaneous squamous cell carcinoma (cSCC). MMS examines the surgical margins in real time and does not commonly examine the central component of the tumor.

Objective

To determine if debulk specimens provide additional details relevant to tumor staging not gained from routine MMS.

Methods

A retrospective chart review of debulk specimens taken during MMS for cSCC was performed. Dermatopathology reports were analyzed and tumors were staged using Brigham and Women's Hospital and American Joint Committee on Cancer's 8th edition staging systems.

Results

Permanent section evaluation of debulk specimens did not result in clinically meaningful information for staging that could not be gained from MMS layers or initial biopsy analysis.

Limitations

A single institution, and a small sample size of 39 tumors.

Conclusions

Evaluation of debulk specimens during MMS may not always be an effective use of time or health care resources.

The combined immunohistochemical expression of AMBRA1 and SQSTM1 identifies patients with poorly differentiated cutaneous squamous cell carcinoma at risk of metastasis: A proof of concept study

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) incidence continues to increase globally with, as of yet, an unmet need for reliable prognostic biomarkers to identify patients at increased risk of metastasis. The aim of the present study was to test the prognostic potential of the combined immunohistochemical expression of the autophagy regulatory biomarkers, AMBRA1 and SQSTM1, to identify high-risk patient subsets.

METHODS

A retrospective cohort of 68 formalin-fixed paraffin-embedded primary cSCCs with known 5-year metastatic outcomes were subjected to automated immunohistochemical staining for AMBRA1 and SQSTM1. Digital images of stained slides were annotated to define four regions of interest: the normal and peritumoral epidermis, the tumor mass, and the tumor growth front. H-score analysis was used to semi-quantify AMBRA1 or SQSTM1 expression in each region of interest using Aperio ImageScope software, with receiver operator characteristics and Kaplan-Meier analysis used to assess prognostic potential.

RESULTS

The combined loss of expression of AMBRA1 in the tumor growth front and SQSTM1 in the peritumoral epidermis identified patients with poorly differentiated cSCCs at risk of metastasis (*p < 0.05).

CONCLUSIONS

Collectively, these proof of concept data suggest loss of the combined expression of AMBRA1 in the cSCC growth front and SQSTM1 in the peritumoral epidermis as a putative prognostic biomarker for poorly differentiated cSCC.

Lycorine transfersomes modified with cell-penetrating peptides for topical treatment of cutaneous squamous cell carcinoma

BACKGROUND

Topical anticancer drugs offer a potential therapeutic modality with high compliance for treating cutaneous squamous cell carcinoma (cSCC). However, the existing topical treatments for cSCC are associated with limited penetrating ability to achieve the desired outcome. Therefore, there remains an urgent requirement to develop drugs with efficient anticancer activity suitable for treating cSCC and to overcome the skin physiological barrier to improve the efficiency of drug delivery to the tumor.

RESULTS

We introduced lycorine (LR) into the topical treatment for cSCC and developed a cell-penetrating peptide (CPP)-modified cationic transfersome gel loaded with lycorine-oleic acid ionic complex (LR-OA) (LR@DTFs-CPP Gel) and investigated its topical therapeutic effects on cSCC. The anti-cSCC effects of LR and skin penetration of LR-OA transfersomes were confirmed. Simultaneously, cationic lipids and modification of R5H3 peptide of the transfersomes further enhanced the permeability of the skin and tumor as well as the effective delivery of LR to tumor cells.

CONCLUSIONS

Topical treatment of cSCC-xenografted nude mice with LR@DTFs-CPP Gel showed effective anticancer properties with high safety. This novel formulation provides novel insights into the treatment and pathogenesis of cSCC.