Unresectable squamous cell carcinoma in a patient with spina bifida

Spina bifida is a congenital malformation of foetal neural structures which may present as a skin fold or sac containing cerebrospinal fluid and neural structures with a variety of neurological deficits. Surgical repairs of spina bifida may not ensure complete functions, neural improvement or recovery. We present this palliative report of an adult male in his early 40s with a medical history of meningocele repair in his infancy, with long-standing Marjolin ulcers, fractures, contractures, diverting ileostomy and urostomy and a fungating mass externally measuring 33×25 cm. The mass involved the buttocks, perineum and scrotum with a tumour overlying the meningocele and extending into the thigh through an internally draining tract. Factors such as immobility, pressure injuries and poor social support in the setting of chronic disability led to a conservative approach in the management of this unresectable carcinoma.

Cemiplimab for metastatic squamous cell carcinoma of the orbit, periocular adnexa, and thigh

The current case presentation highlights the potential of cemiplimab, a programmed cell death protein-1 (PD-1) inhibitor, as first-line treatment for periocular metastatic cutaneous squamous cell carcinoma (SCC) without requiring curative surgery or radiotherapy. A 64-year-old male presented with a progressing 4.5 × 3.0 cm left upper eyelid lesion initially diagnosed as psoriasis. Work-up revealed cutaneous SCC with tumor invasion into extraconal fat and lacrimal gland, and metastasis to the left parotid lymph node. The patient also presented with a suspicious lesion on his left medial thigh found to be a second primary on pathology. To avoid orbital exenteration and treat the multifocal disease, the patient was started on intravenous cemiplimab immunotherapy. Following six doses, repeated FGD-PET-CT revealed a complete response of the left eyelid lesion and residual low-grade hypermetabolic activity of the left medial thigh lesion. Biopsy confirmed chronic inflammation and fibrosis with no signs of malignancy. This unique case with dual primary cutaneous SCC provides support for cemiplimab in treating locally invasive periocular SCC, and potentially abrogating the need for highly morbid exenteration procedures to preserve binocular vision.

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

Neoadjuvant Immunotherapy for Head and Neck Squamous Cell Carcinoma: Expecting Its Application in Temporal Bone Squamous Cell Carcinoma

Temporal bone malignant tumors are characterized by atypical clinical symptoms, and easy recurrence and metastasis. They account for 0.2% of head and neck tumors, and the most common pathological type is squamous cell carcinoma. Patients with squamous cell carcinoma of the temporal bone are often at advanced stages when diagnosed, and lose the chance for surgery. Neoadjuvant immunotherapy has recently been approved as the first-line treatment for refractory recurrent/metastatic squamous cell carcinoma of the head and neck. However, it remains to be determined whether neoadjuvant immunotherapy can be used as the first-line treatment for temporal bone squamous cell carcinoma to reduce the tumor stage before surgery, or as a palliative treatment for patients with unresectable advanced stage carcinoma. The present study reviews the development of immunotherapy and its clinical application in head and neck squamous cell carcinoma, summarizes the treatment of temporal bone squamous cell carcinoma, and prospects the neoadjuvant immunotherapy as the first-line treatment for temporal bone squamous cell carcinoma.

Recurrent squamous cell carcinoma of the skin treated with immunotherapy

Squamous cell carcinoma (SCC) has a good prognosis, while metastatic tumors have aggressive behavior. Immunotherapy has become a standard line of treatment in metastatic cancers; pembrolizumab has shown promising results and improved quality of life in recurrent and metastatic cancers. We report a case of recurrent SCC of the skin with extensive disease and a known case of human immunodeficiency virus. He completed standard lines of treatment and currently on immunotherapy. After 3 cycles of immunotherapy plus chemotherapy, he got a complete metabolic response. Our experience showed palliative benefits and increased quality of life.

Combined response of advanced cutaneous squamous cell carcinoma and renal cell carcinoma to immunotherapy: a case report

Immune checkpoint inhibitors have significantly improved the therapeutic scenario of many different advanced malignancies and could be an effective treatment strategy in synchronous or metachronous tumors. The authors describe the clinical case of a patient who experienced a long-lasting response of his metastatic renal cell carcinoma and an optimal response of his locally advanced cutaneous squamous cell carcinoma to immunotherapy. The systemic treatment was chosen based on a literature review of several clinical reports, since there was no prospective study on anti-PD-1 blockade activity in cutaneous squamous cell carcinoma when the patient started the treatment. This clinical case supports the growing evidence for immunotherapy as a valid treatment option across different types of advanced tumors.

The State of the Art of Radiotherapy for Non-melanoma Skin Cancer: A Review of the Literature

Due to the general aging population and the fashion trend of sun exposure, non-melanoma skin cancer (NMSC) is rising. The management of NMSC is difficult and necessitates a multidisciplinary team (i.e., pathologists, dermatologists, medical oncologists, surgeons, and radiation oncologists). When surgery is not an option or will cause unacceptably functional morbidity, radiation therapy (RT) may be a preferable tissue-preserving option. Whether used alone or in conjunction with other treatments, RT has been shown to be quite effective in terms of cosmetic results and local control. Contact hypofractionated RT, brachytherapy, and electronic brachytherapy are all promising new treatments. However, rigorous, randomized trials are missing, explaining the disparity in dose, fractionation, and technique recommendations. Therefore, it is essential that interdisciplinary teams better understand RT modalities, benefits, and drawbacks. Our review will provide the role and indications for RT in patients with NMSC.

Identifying Candidates for Immunotherapy among Patients with Non-Melanoma Skin Cancer: A Review of the Potential Predictors of Response

BACKGROUND

Non-melanoma skin cancer (NMSC) stands as an umbrella term for common cutaneous malignancies, including basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), together with rarer cutaneous cancers, such as Merkel cell carcinoma (MCC) and other forms of adnexal cancers. The majority of NMSCs can be successfully treated with surgery or radiotherapy, but advanced and metastatic stages may require systemic approaches such as immunotherapy with immune checkpoint inhibitors (ICIs).

SUMMARY

Since immunotherapy is not effective in all patients and can potentially lead to severe adverse effects, an important clinical question is how to properly identify those who could be suitable candidates for this therapeutic choice. In this paper, we review the potential features and biomarkers used to predict the outcome of ICIs therapy for NMSCs. Moreover, we analyze the role of immunotherapy in special populations, such as the elderly, immunocompromised patients, organ transplant recipients, and subjects suffering from autoimmune conditions.

KEY MESSAGES

Many clinical, serum, histopathological, and genetic features have been investigated as potential predictors of response in NMSCs treated with ICIs. Although this field of research is very promising, definitive, cost-effective, and reproducible biomarkers are still lacking and further efforts are needed to validate the suggested predictors in larger cohorts.

Immune Checkpoint Inhibition in Non-Melanoma Skin Cancer: A Review of Current Evidence

Immuno-oncology is a rapidly evolving field with growing relevance in the treatment of numerous malignancies. The prior study of immunotherapy in dermatologic oncology has largely focused on cutaneous melanoma. However, recent focus has shifted to the use of immunotherapy to treat non-melanoma skin cancers (NMSCs), such as basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and Merkel cell carcinoma (MCC). NMSCs represent the most ubiquitous cancers globally and, while they have a lower propensity to develop into advanced disease than cutaneous melanoma, their absolute mortality burden has recently surpassed that of melanoma. Patients with advanced NMSC are now benefiting from the successes of immunotherapy, including checkpoint inhibition with anti-CTLA-4 and anti-PD-1 monoclonal antibodies. In this review, we discuss the existing clinical evidence for immunotherapy in the treatment of NMSCs, with an emphasis on checkpoint inhibitor therapies. We highlight key studies in the field and provide up-to-date clinical evidence regarding ongoing clinical trials, as well as future study directions. Our review demonstrates that checkpoint inhibitors are positioned to provide unparalleled results in the previously challenging landscape of advanced NMSC treatment.

Investigative Landscape in Advanced Non-Melanoma Skin Cancers

OPINION STATEMENT

Advanced non-melanoma skin cancers have been challenging to treat due to limited treatment options. Treatment paradigm has shifted with the approval of immunotherapeutic agents cemiplimab and pembrolizumab which have been a key development and have changed the landscape of advanced or metastatic squamous cell skin cancers. Hedgehog inhibitors, vismodegib and sonidegib, remain upfront options for advanced or metastatic basal cell carcinomas. Current clinical trials are continuing to evaluate the use of immune checkpoint inhibitors and hedgehog pathway inhibitors. There is further need for ongoing research and development of new therapies in both malignancies.

Topical arginase inhibition decreases growth of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinomas (cSCC) are among the most commonly diagnosed malignancies, causing significant morbidity and mortality. Tumor-associated macrophage (TAM) expression of arginase is implicated in tumor progression, and therapeutic use of arginase inhibitors has been studied in various cancers. However, investigating potential cSCC immunotherapies including arginase inhibition in pre-clinical models is hampered by the lack of appropriate tumor models in immunocompetent mice. PDV is a cSCC cell line derived from chemical carcinogenesis of mouse keratinocytes. PDVC57 cells were derived from a PDV tumor in C57BL/6 (B6) mice. Unlike PDV, PDVC57 tumors grow consistently in B6 mice, and have increased TAMs, decreased dendritic and T cell intra-tumor infiltration. Arginase inhibition in cSCC tumors using Nω-hydroxy-nor-arginine (nor-NOHA) reduced tumor growth in B6 mice but not immunodeficient Rag1-deficient mice. nor-NOHA administration increased dendritic and T cell tumor-infiltration and PD-1 expression. The combination of nor-NOHA and anti-PD-1 therapy with nivolumab enhanced anti-PD-1 therapeutic efficacy. This study demonstrates the therapeutic potential of transcutaneous arginase inhibition in cSCC. A competent immune microenvironment is required for tumor growth inhibition using this arginase inhibitor. Synergistic co-inhibition of tumor growth in these results, supports further examination of transcutaneous arginase inhibition as a therapeutic modality for cSCC.

Association of Immunosuppression With Outcomes of Patients With Cutaneous Squamous Cell Carcinoma of the Head and Neck

Importance

Patients with immunosuppression have a higher incidence of cutaneous squamous cell carcinoma (cSCC) and often present with more aggressive, multifocal disease.

Objectives

To determine the risks for mortality in patients with cSCC and immunosuppression compared with nonimmunosuppression and to compare the difference in mortality risk based on the cause of immunocompromise.

Design, Setting, and Participants

This retrospective cohort study of patients with cSCC of the head and neck recruited participants from a tertiary cancer care center. Patients who underwent no treatment, wide local excision, or biopsy of the lesions were eligible for inclusion from January 1, 1995, to September 30, 2015. Data were analyzed from March 21, 2018, to April 4, 2019.

Exposures

Immunocompromise, defined as having solid organ transplant, stem cell transplant, hematopoetic malignant disease, autoimmune disease requiring treatment with immunosuppressive therapy, type 1 or 2 diabetes treated with insulin, HIV or AIDS, or other hematoproliferative disorder.

Main Outcomes and Measures

Patients were divided into 2 groups according to their immune status (immunosuppression vs no immunosuppression). The primary outcome measure was disease-specific survival. A Cox proportional hazards regression model was used to determine the association of immune status with disease outcome.

Results

A total of 796 patients (680 men [85.4%]; median age, 69 [range, 27-98] years), including 147 with and 649 without immunosuppression (IS and non-IS groups, respectively), constituted the final cohort. In the IS group, 77 (52.4%) had diabetes, 39 (26.5%) had lymphoma or leukemia, 25 (17.0%) had an organ or stem cell transplant, and 3 (2.0%) had HIV. Five-year disease-specific survival was 68.2% in the IS group compared with 84.1% in the non-IS group (difference, 15.9%; 95% CI, 3.5%-27.4%). Immunosuppression was independently associated with worse disease-specific survival (hazard ratio, 2.32; 95% CI, 1.53-3.50).

Conclusions and Relevance

This study's findings suggest that immunosuppression is independently associated with a worse outcome in cSCC, with a 2.32 times increased risk of disease-specific death after adjusting for age, history of skin cancer, recurrent or persistent disease status, disease stage, and treatment.

Immune Checkpoint Blockade in Advanced Cutaneous Squamous Cell Carcinoma: What Do We Currently Know in 2020?

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer that predominantly arises in chronically sun-damaged skin. Immunosuppression, genetic disorders such as xeroderma pigmentosum (XP), exposure to certain drugs and environmental noxae have been identified as major risk factors. Surgical removal of cSCC is the therapy of choice and mostly curative in early stages. However, a minority of patients develop locally advanced tumors or distant metastases that are still challenging to treat. Immune checkpoint blockade (ICB) targeting CTLA-4, PD-L1 and PD-1 has tremendously changed the field of oncological therapy and especially the treatment of skin cancers as tumors with a high mutational burden. In this review, we focus on the differences between cSCC and cutaneous melanoma (CM) and their implications on therapy, summarize the current evidence on ICB for the treatment of advanced cSCC and discuss the chances and pitfalls of this therapy option for this cancer entity. Furthermore, we focus on special subgroups of interest such as organ transplant recipients, patients with hematologic malignancies, XP and field cancerization.

Immune checkpoint inhibitors to treat cutaneous malignancies

As the incidence of cutaneous malignancies continues to rise and their treatment with immunotherapy expands, dermatologists and their patients are more likely to encounter immune checkpoint inhibitors. While the blockade of immune checkpoint target proteins (cytotoxic T-lymphocyte-associated protein-4, programmed cell death-1, and programmed cell death ligand-1) generates an antitumor response in a substantial fraction of patients, there is a critical need for reliable predictive biomarkers and approaches to address refractory disease. The first article of this Continuing Medical Education series reviews the indications, efficacy, safety profile, and evidence supporting checkpoint inhibition as therapeutics for metastatic melanoma, cutaneous squamous cell carcinoma, and Merkel cell carcinoma. Pivotal studies resulting in the approval of ipilimumab, pembrolizumab, nivolumab, cemiplimab, and avelumab by regulatory agencies for various cutaneous malignancies, as well as ongoing clinical research trials, are discussed.

Programmed cell death ligand-1 and cytotoxic T cell infiltrates in metastatic cutaneous squamous cell carcinoma of the head and neck

BACKGROUND

Metastatic cutaneous squamous cell carcinoma (cSCC) carries a poor prognosis. Increased numbers of CD8+ cytotoxic T cells are associated with a favorable prognosis and programmed cell death receptor-1 is a suppressor of the CD8+ cytotoxic T cell response. We aim to define their expression in metastatic cutaneous squamous cell carcinoma.

METHODS

Cytotoxic T cell infiltrates and tumoral PD-L1 expression in lymph node metastases from patients with cSCC of the head and neck were analyzed.

RESULTS

High tumoral PD-L1 expression, intratumoral and peritumoral CD8+ cell density in metastases were significantly associated with poor primary tumor differentiation. Low PD-L1 expression, intratumoral and peritumoral CD8+ density were associated with lower grade primary tumor differentiation. Low PD-L1 expression correlated with disease progression.

CONCLUSIONS

Increased expression of PD-L1 correlates with increased CD8+ cell density. Increased expression of PD-L1 in poorly differentiated tumors may be more likely to benefit from anti PD-1/PD-L1 therapy.

Cutaneous Squamous Cell Carcinoma: From Biology to Therapy

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and its incidence continues to rise. Although CSCC usually display a benign clinical behavior, it can be both locally invasive and metastatic. The signaling pathways involved in CSCC development have given rise to targetable molecules in recent decades. In addition, the high mutational burden and increased risk of CSCC in patients under immunosuppression were part of the rationale for developing the immunotherapy for CSCC that has changed the therapeutic landscape. This review focuses on the molecular basis of CSCC and the current biology-based approaches of targeted therapies and immune checkpoint inhibitors. Another purpose of this review is to explore the landscape of drugs that may induce or contribute to the development of CSCC. Beginning with the pathogenetic basis of these drug-induced CSCCs, we move on to consider potential therapeutic opportunities for overcoming this adverse effect.

Advanced cutaneous squamous cell carcinoma: how is it defined and what new therapeutic approaches are available?

PURPOSE OF REVIEW

Despite the overall excellent survival rates in patients with cutaneous squamous cell carcinoma (cSCC), advanced cutaneous SCCs are associated with high patient morbidity and mortality. Therefore, important unmet clinical needs persist: identifying high risk patients and choosing optimal treatment approaches.

RECENT FINDINGS

In recent years, a better understanding of the biology of cSCC and its clinical progression have led to improved staging systems and new promising treatments for advanced disease. Such treatments include PD1 inhibitors, such as cemiplimab, which was recently approved for the treatment of cutaneous SCC, and pembrolizumab whose efficacy in the treatment cSCC is still being investigated. Other treatments, such as epidermal growth factor receptor inhibitors have also been used in the treatment of cSCC with moderate success. Several clinical and histological risk factors are considered key in estimating the risk or recurrence or metastasis in cSCCs and, therefore, influence the appropriate treatment choice and patient monitoring.

SUMMARY

The present study reviews the current definition of advanced cSCC and discusses the new systemic approaches, including checkpoint inhibitors.

Article Commentary: Cancer Immunotherapy for the General Surgeon

Progress in the arena of cancer immunotherapy has been immense in recent years. The fact remains that most of the cancer resections in the United States are performed by general surgeons and not oncologic specialists. A busy practice in general surgery will invariably make it difficult to keep pace with such rapid advancement. This review offers a concise summary of the major concepts and trials that have driven the immunotherapy revolution and their implications for surgeons who deliver cancer care.

Cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) accounts for approximately 20% of all skin cancers. Its rising incidence represents a major public health concern. The majority of cSCC are curable by surgical resection. Although less than 5% of cSCC patients develop metastases or local recurrence after complete excision, advanced cSCC is difficult to treat. Until recently, no standard therapeutic regimen for advanced cSCC exists. Traditional therapies include chemotherapy and EGFR-targeted therapy, but their clinical benefit remains modest and has been demonstrated mostly in retrospective studies. On the contrary, PD-1 inhibitors dramatically improve outcomes in many immunocompetent cSCC patients, resulting in the approval of cemiplimab as the first FDA-approved systemic drug for patients with locally advanced or metastatic cSCC who are not candidates for curative surgery or radiation. In the coming years combination therapies are an emerging treatment strategy that could improve efficacy of PD-1 inhibitors in advanced cSCC. Moreover, several prospective controlled trials have been designed to explore the potential role of PD-1 inhibitors in the adjuvant and neodjuvant setting. Given the paucity of data, the management of immunocompromised cSCC patients requires a heightened awareness in this new era of cancer therapeutics.

Epidermal Growth Factor Receptor's Function in Cutaneous Squamous Cell Carcinoma and Its Role as a Therapeutic Target in the Age of Immunotherapies

OPINION STATEMENT

Recent studies have evidenced the potential of combining anti-EGFR therapies with anti-PD-1/PD-L1 checkpoint therapies. Both anti-EGFR and anti-PD-1/PD-L1 have been separately tested in the treatment of cutaneous SCC (cSCC). Here, we review recent data on EGFR in the context of cancer progression, as a prognostic and as a therapeutic target in cSCC. Anti-EGFR/checkpoint immunotherapy and other combination therapy approaches are discussed. With the advent of immunotherapy, EGFR is still a valid cSCC target.

PD-L1 Detection-Pearls and Pitfalls Associated With Current Methodologies Focusing on Entities Relevant to Dermatopathology

PD-L1 is a transmembrane glycoprotein with an extracellular as well as an intracellular cytoplasmic domain. Physiologically, it plays a pivotal role in regulating T-cell activation and tolerance. Many tumor cells have exploited this regulatory mechanism by overexpressing PD-L1 in an effort to escape immunologic surveillance. In this review, we parse the literature regarding the prognostic value of tumoral PD-L1 expression before discussing the various methodologies as well as the pearls and pitfalls associated with each for predicting response to anti-PD-1/PD-L1 therapies. Special attention is given to cutaneous entities in which PD-L1 expression has been documented with an emphasis on cutaneous malignancies that have seen the broadest applications of anti-PD-L1/PD-1 therapies. Currently, immunohistochemistry is the method that is most commonly used for detection of PD-L1. However, with the wide array of immunohistochemistry protocols and staining platforms available in the market, there seems to be different cutoffs not just for different entities but also for the same entity. This review is an attempt to address the need for standardization and validation of existing protocols for PD-L1 detection.

Molecular Biology of Basal and Squamous Cell Carcinomas

The prevalent keratinocyte-derived neoplasms of the skin are basal cell carcinoma and squamous cell carcinoma. Both so-called non-melanoma skin cancers comprise the most common cancers in humans by far. Common risk factors for both tumor entities include sun exposure, DNA repair deficiencies leading to chromosomal instability, or immunosuppression. Yet, fundamental differences in the development of the two different entities have been and are currently unveiled. The constitutive activation of the sonic hedgehog signaling pathway by acquired mutations in the PTCH and SMO genes appears to represent the early basal cell carcinoma developmental determinant. Although other signaling pathways are also affected, small hedgehog inhibitory molecules evolve as the most promising basal cell carcinoma treatment options systemically as well as topically in current clinical trials. For squamous cell carcinoma development, mutations in the p53 gene, especially UV-induced mutations, have been identified as early events. Yet, other signaling pathways including epidermal growth factor receptor, RAS, Fyn, or p16INK4a signaling may play significant roles in squamous cell carcinoma development. The improved understanding of the molecular events leading to different tumor entities by de-differentiation of the same cell type has begun to pave the way for modulating new molecular targets therapeutically with small molecules.

[Regression of cutaneous basal cell and squamous cell carcinoma under pembrolizumab]

BACKGROUND

The recommended treatments for advanced squamous cell carcinoma (SCC) (chemotherapy, radiotherapy, anti-EGFR) and advanced basal cell carcinoma (BCC) (vismodegib and sonidegib) have many side effects. Nivolumab (anti-PD1 antibody) may be used as second-line therapy in SCC of the head and neck. We report the case of a patient with advanced SCC and BCC which regressed under pembrolizumab.

PATIENTS AND METHODS

A 69-year-old man consulted for a large vertex SCC measuring 15cm in diameter. He also had BCC on the left nostril and sternal Bowen disease. Radiological assessment revealed cervical and parotid lymph node involvement. Treatment with pembrolizumab 2mg/kg every 3 weeks was decided at a Multidisciplinary Concertation Meeting. Tumor regression of the vertex SCC was noted at the third course of treatment, as well as regression of the nasal BCC and the sternal Bowen disease. A complete response was observed after 11 courses of treatment for SCC, 7 courses for BCC, and 10 courses for Bowen disease.

CONCLUSION

We report an original case of cure of BCC with anti-PD1 (pembrolizumab) prescribed for locally advanced inoperable SCC. The place of this treatment in the therapeutic arsenal remains to be defined. Clinical trials are in progress concerning use of this treatment in advanced cutaneous SCC and inoperable BCC.

Stage IV cutaneous squamous cell carcinoma: treatment outcomes in a series of 42 patients

BACKGROUND

The prevalence and incidence of cutaneous squamous cell carcinoma (cSCC) are increasing due to the ageing of the population and sun exposure. Advanced cSCC forms (locally advanced and/or locoregional metastatic and/or distant metastatic) account for approximately 3% of cSCC and can result in death.

OBJECTIVE

Analysis of the clinical characteristics and treatment outcomes in stage IV cSCC with unresectable locoregional extension and/or the presence of metastases.

METHODS

A retrospective study was conducted at a single-centre university hospital for stage IV cSCC patients followed between 1 January 2008 and 31 December 2015. Descriptive analyses (demographic, anatomo-clinical characteristics, treatment sequences, response to treatment and survival analysis) were performed.

RESULTS

The study included 42 patients (median age = 75.5 years) with a diagnosis of stage IV cSCC who were treated with at least one line of chemotherapy and/or cetuximab. At the time of diagnosis, 85.7% of the patients had locoregional extension (19% of locally advanced and 67% of locoregional metastatic) and 14.3% had distant metastatic disease. Regarding treatment, 40% and 36% of patients received no more than 1 and 2 systemic treatment lines, respectively. The 4-year overall survival was 6%, and the median follow-up was 18.6 months. The objective response rate was 55% after the first line of treatment with a median progression-free survival (PFS) of 6.18 months and 12% after the second line with a median PFS of 6.51 months. Grade 3 and 4 adverse events were observed for 33% of patients.

CONCLUSION

Our study confirms a very poor prognosis of stage IV cSCC and a poor response to conventional therapies, indicating that the stage IV cSCC patient population remains with unmet medical needs.

Evolving Role of Systemic Therapies in Non-melanoma Skin Cancer

Keratinocyte cancers - basal and cutaneous squamous cell carcinoma (BCC, cSCC) - are the most common forms of non-melanoma skin cancer (NMSC) and there has been a significant increase in their incidence globally in recent decades. Although the majority of BCC and cSCC are cured with conventional surgery or radiotherapy, certain tumour or patient-determined factors may result in these modalities being inadequate or inappropriate, for example, locally advanced or metastatic disease, high tumour multiplicity, patient comorbidities and patient preferences. In these clinical circumstances, systemic treatment may be indicated, and over the past 10 years a number of new systemic agents have been approved. Nonetheless, effective systemic therapy for keratinocyte cancers remains an area of significant unmet clinical need. Improved understanding of the molecular and immune pathogenesis underlying tumour growth and development is critical for driving future advances and is a research priority. The aim of this review is to provide clinicians with an overview of systemic treatments for BCC and cSCC and will focus on current evidence for conventional chemotherapy, targeted therapies, immunotherapy, adjuvant and neoadjuvant therapy, chemoprevention and future prospects for novel systemic treatment approaches.

Metastatic porocarcinoma achieving complete radiological and clinical response with pembrolizumab

A 67-year-old woman presented in 2012 with a crusty nodule on the left lower limb. Histopathological examination at this time reported a poorly differentiated squamous cell carcinoma (SCC). Two years later, she underwent lymphadenectomy and radiotherapy due to unilateral inguinal and pelvic sidewall nodal metastases. The following year she required excision of two subcutaneous lesions, reported pathologically to be SCC metastases. Further imaging following cyberknife radiotherapy to new brain metastases demonstrated widespread metastatic visceral disease. Twelve cycles of carboplatin and capecitabine failed to halt disease progression. In February 2017, she commenced pembrolizumab, achieving an excellent response and currently has no clinical or radiological evidence of disease. Given the unusual behaviour of her cancer, a histopathological review was requested. The diagnosis was revised to that of porocarcinoma (PC). This represents the first documented case of PC treated with immunotherapy. As of March 2019, the patient remains free of disease.

Squamous Cell Carcinoma with Regional Metastasis to Axilla or Groin Lymph Nodes: a Multicenter Outcome Analysis

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) of the trunk/extremities with nodal metastasis represents a rare but significant clinical challenge. Treatment patterns and outcomes are poorly described.

PATIENTS AND METHODS

Patients with cSCC who developed axilla/groin lymph node metastasis and underwent curative-intent surgery between 2005 and 2015 were identified at four Canadian academic centers. Demographics, tumor characteristics, treatment patterns, recurrence rates, and mortality were described. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan-Meier analysis. Predictors of survival and any recurrence were explored using Cox regression and logistic regression models, respectively.

RESULTS

Of 43 patients, 70% were male (median age 74 years). Median follow-up was 38 months. Median time to nodal metastasis was 11.3 months. Thirty-one and 12 patients had nodal metastasis to the axilla and groin, respectively. A total of 72% and 7% received adjuvant and neoadjuvant radiation, respectively, while 5% received adjuvant chemotherapy. Following surgery, 26% patients developed nodal and/or distant disease recurrence. Crude mortality rate was 39.5%. Mean OS was 5.3 years [95% confidence interval (CI) 3.9-6.8 years], and 5-year OS was 55.1%. Mean DFS was 4.8 years (95% CI 3.3-6.2 years), and five-year DFS was 49.3%. Any recurrence was the only independent predictor of death [p = 0.036, odds ratio (OR) = 29.5], and extracapsular extension (p = 0.028, OR = 189) and age (p = 0.017, OR = 0.823) were independent predictors of recurrence.

CONCLUSIONS

This represents the largest contemporary series to date of outcomes for patients with axilla/groin nodal metastases from cSCC. Despite aggressive treatment, outcomes remain modest, indicating the need for a continued multidisciplinary approach and integration of new systemic agents.

Review of systemic agents in the treatment of advanced cutaneous squamous cell carcinoma

Advanced cutaneous squamous cell carcinoma (cSCC) accounts for only 5% of all cases of cSCC but up to 60% of disease related deaths. Historically, this disease has lacked effective treatment options due to a combination of poor response rate, poor response durability and significant treatment-associated morbidity. Autumn of 2018 marked the first time ever that an agent received US FDA approval for advanced cSCC and the future is looking much brighter for this previously neglected patient population. The purpose of this article is to review the various systemic treatment options for advanced cSCC moving from the past to the present, highlighting their relative merits and shortcomings, and to briefly speculate on future developments in the field of advanced cSCC.

Immune Checkpoint Inhibitors for Treating Advanced Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is one of the most common human malignancies, and the incidence is increasing with time. High mutational loads, known infiltration with lymphocytes, and programmed death (PD)-ligand 1 (PD-L1) expression suggest that immune checkpoint inhibitors, such as PD-1 inhibitors, may show utility in treating CSCC, similar to response see in other solid tumor types. Recently, the robust responsiveness of CSCCs to the PD-1 inhibitor cemiplimab was revealed in the results of a combined phase I/II clinical trial, with an overall response rate of 50% and a durable response exceeding 6 months in 57% of responders. Compared to prior systemic therapies with scant data for efficacy and safety, cemiplimab is a breakthrough therapy, the first systemic drug approved for advanced CSCCs. Other immune checkpoint inhibitors have shown promise through case reports and series, and are currently in clinical development for CSCCs.

Programmed cell death 1 protein and programmed death-ligand 1 inhibitors in the treatment of nonmelanoma skin cancer: A systematic review

BACKGROUND

Immunotherapy using programmed cell death 1 protein (PD-1) or programmed death-ligand 1 (PD-L1) inhibitors has been increasingly reported in a variety of nonmelanoma skin cancers (NMSCs).

OBJECTIVE

To analyze the evidence of PD-1 and PD-L1 inhibitors in the treatment of NMSC.

METHODS

A primary literature search was conducted with the PubMed, Cochrane Library, EMBASE, Web of Science, and CINAHL databases through October 28, 2018, to include studies on the use of PD-1 or PD-L1 inhibitors in patients for NMSC. Two reviewers independently performed study selection, data extraction, and critical appraisal.

RESULTS

This systematic review included 51 articles. The most robust evidence was in the treatment of Merkel cell carcinoma and cutaneous squamous cell carcinomas, as supported by phase 1 and 2 clinical trials. Treatment of basal cell carcinoma, cutaneous sarcoma, sebaceous carcinoma, and malignant peripheral nerve sheath tumor also showed benefit with PD-1/PD-L1 inhibitors, but data are limited. There does not appear to be efficacy for PD-1/PD-L1 inhibitors in cutaneous lymphomas.

LIMITATIONS

More investigation is needed to determine the efficacy, tumor responsiveness, and the safety profile of PD-1 and PD-L1 inhibitors in NMSC.

CONCLUSION

PD-1 and PD-L1 inhibitors exhibit treatment efficacy in a variety of NMSCs.

Systemic Immunotherapy for Advanced Cutaneous Squamous Cell Carcinoma

OPINION STATEMENT

Advanced (i.e., unresectable) cutaneous squamous cell carcinoma (cSCC) is a rare condition with a dismal prognosis. Although less than 5% of cSCC patients develop metastases or local recurrence after complete excision, advanced cSCC is difficult to treat. These conditions tend to develop in elderly patients, although, at times, metastases are noted in middle-aged patients. Once metastasis occurs in cSCC, the 10-year survival rates fall to less than 20% for patients with regional lymph node involvement and less than 10% for patients with distant metastases, indicating that cSCC can be difficult to treat effectively when it is advanced. Traditionally, platinum-based therapy has been considered as a conventional option for advanced cSCC. It is efficacious to some degree, but the toxic effects of the combination treatments often prohibit their use in elderly patients. It has been a decade since the development of epidermal growth factor receptor (EGFR) inhibitors as agents that are less toxic. However, evidence regarding systemic therapy for advanced cSCC is limited because of a lack of high-quality prospective studies. Remarkably, the US Food and Drug Administration (FDA) approved an anti-PD-1 antibody treatment (cemiplimab) for the treatment of patients who are not candidates for curative surgery or curative radiation. It will be a promising treatment option for these types of rare conditions.

Multiple keratin granulomata: A potential histologic clue to cutaneous squamous cell carcinoma responding to programmed cell death protein 1 inhibitor therapy

We present histologic features of a locally advanced cutaneous squamous cell carcinoma (cSCC) treated with the programmed cell death protein-1 (PD-1) antagonist, pembrolizumab, with a partial response. This contributes to a growing body of literature supporting the efficacy of pembrolizumab in treatment of surgically unresectable cSCC. We also provide a detailed description of the histologic features, particularly keratin granulomata with adjacent lymphocytic aggregates and fibrosis, observed in cSCC under treatment with a PD-1 antagonist.

PD-L1 Expression is Increased in Metastasizing Squamous Cell Carcinomas and Their Metastases

Programmed cell death ligand 1 (PD-L1) expression by tumor cells plays an important role in the inhibition of T cell-mediated immune response in cancer. PD-L1 expression by tumor cells has been linked to poor prognosis in a wide variety of cancers. However, PD-L1 expression in cutaneous squamous cell carcinoma (cSCC) has been scarcely studied, and its role as a prognosis biomarker remains controversial. The association of PD-L1 expression and the metastatic risk in a series of cSCC was assessed. PD-L1 and CD8 immunostainings of full excision sections of 99 primary tumors and 24 lymphatic metastases were semiquantitatively evaluated. Primary cSCCs were grouped according to the development of lymphatic metastatic spread [metastasizing squamous cell carcinoma (MSCC)] (n = 48) or the absence of progression [nonmetastasizing squamous cell carcinoma (NMSCC)] (n = 51). PD-L1-positive expression (cut off ≥1%) was found in 26% NMSCCs and in 50% MSCCs (P = 0.02). PD-L1 association with an increased metastatic risk was confirmed in the multivariate analysis (P < 0.05), along with the following features: recurrence, poor differentiation, and perineural invasion. Ninety percent of the metastases of PD-L1-positive tumors were also positive for PD-L1, displaying a trend toward a higher PD-L1 expression when compared with their primary tumors (P = 0.058). No significant differences in the peritumoral inflammatory infiltrate or in the expression of CD8 were found between metastasizing and nonmetastasizing primary tumors. Our results suggest that PD-L1 may play a relevant role in metastatic spread and may be a candidate prognostic biomarker in cSCC.

PD-L1 Expression and Tumor-Infiltrating Lymphocytes in High-Risk and Metastatic Cutaneous Squamous Cell Carcinoma

OBJECTIVE

To characterize programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocyte (TIL) positivity for locally aggressive or regionally metastatic cutaneous head and neck squamous cell carcinoma (cHNSCC).

STUDY DESIGN

Retrospective chart review, followed by immunohistochemical staining of archived tumor specimens.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

After identification of 101 patients treated surgically for locally advanced or regionally metastatic cHNSCC, archived tissue was stained and graded for PD-L1 expression in addition to TIL presence. Cross-tabulation was performed to examine the association between either of these variables and clinicopathologic features and outcomes.

RESULTS

A total of 101 patients met inclusion criteria, but archived tissue was available only for 83 (31 primaries, 52 metastases). The majority of primary tumors demonstrated grade 1 PD-L1 staining, while grade 2 staining was more likely for metastases. Neither high- nor low-grade PD-L1 expression correlated with any clinicopathologic variable for primary tumors. However, for metastases, high-grade staining was significantly associated with regional recurrence (15 of 19, P = .02). TILs were present for 65% of primary tumors and 90% of regional metastases but did not correlate with any clinicopathologic variables.

CONCLUSION

Diffuse expression of PD-L1 in this study highlights the possibility of using immunotherapy in the form of programmed death 1/PD-L1 blockade to improve treatment for this devastating disease. However, further studies are needed to clarify the significance of PD-L1 expression and TIL positivity for locally advanced or regionally metastatic cHNSCC.

Incidence of Basal Cell Carcinoma and Squamous Cell Carcinoma in Patients on Antiprogrammed Cell Death-1 Therapy for Metastatic Melanoma

Systemic melanoma therapies have the potential to affect basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cuSCC) development. In this study, we aim to compare the incidence of BCC and cuSCC in patients with metastatic melanoma treated with antiprogrammed cell death-1 (anti-PD1), BRAF inhibitor (BRAFi) monotherapy or dabrafenib and trametinib combination therapy (CombiDT) with a group of control patients having similar risk factors. We reviewed the records of melanoma patients on anti-PD1, BRAFi, or CombiDT, and patients from the High-Risk Melanoma Clinic, Westmead Hospital. We also performed an immunohistochemical analysis of BCCs under anti-PD1 compared with controls using PD1, PD-L1, CD3, CD8, and CD20 stains. For the results, in all, 340 patients were included; 82 on anti-PD1, 134 on BRAFi, 69 on CombiDT, and 55 controls. BRAFi had the highest incidence of BCC (12.7%), followed by CombiDT (10.1%) and anti-PD1 (2.4%). The incidence of BCC was significantly lower in patients on anti-PD1 (2.4% vs. 19.4%; P<0.001) compared with controls. Patients on anti-PD1 were 8.54 times less likely to develop BCC than the controls [hazard ratio, 0.117 (95% confidence interval, 0.026-0.526), P=0.005]. BRAFi and CombiDT showed no significant differences in BCC incidence compared with controls. BRAFi had the highest cuSCC incidence (23.9%), followed by anti-PD1 (7.3%) and CombiDT (2.9%). The incidence of cuSCC was significantly higher in patients on BRAFi (23.9% vs. 3.5%; P<0.001) compared with controls, but anti-PD1 and CombiDT showed no differences in cuSCC incidence compared with controls. Immunohistochemistry analysis of 10 BCC from under anti-PD1 and 8 BCC from controls patients showed that while all BCC had negative PD-L1 staining, the percentage of PD1 staining in anti-PD1 group is significantly lower than that of the control group (independent t test, 8% vs. 26%; P<0.001). In conclusion, our study suggests that anti-PD1 therapy decreases the incidence of BCC, as a result of the PD1/PD-L1 blockade. Future studies investigating the role of anti-PD1 in suppressing or treating BCC may be warranted.

PD-L1, B7-H3, and PD-1 expression in immunocompetent vs. immunosuppressed patients with cutaneous squamous cell carcinoma

BACKGROUND

To characterize the expression of co-signaling molecules PD-L1, PD-1, and B7-H3 in cutaneous squamous cell carcinoma (cSCC) by immune status.

METHODS

We retrospectively analyzed 66 cases of cSCC treated with surgical resection from 2012 to 2015. Immunostained tumor sections were analyzed for percent of tumor cells expressing PD-L1 (Tum-PD-L1%), B7-H3 (Tum-B7-H3%), density of peri and intratumoral CD8 T cells (CD8 density), proportion of CD8 T cells expressing PD-1 (CD8-PD-1%) and of tumor-infiltrating immune cells (TII) expressing PD-L1 (TII-PD-L1%).

RESULTS

Of 66 cases, 42 were immunocompetent, 24 immunosuppressed (13 organ transplant, 8 HIV+, 3 other). Defining positive expression at > 5%, 26% of tumors were positive for PD-L1, 85% for B7-H3, 80% had CD8 T cells that expressed PD-1 and 55% had TII that expressed PD-L1. Tum-B7-H3% was significantly higher (median 60 vs. 28%, p = 0.025) in immunocompetent vs. immunosuppressed patients, including when factoring in cause of immunosuppression. No significant difference in Tum-PD-L1%, TII-PD-L1%, CD8 density, or CD8-PD-1% was observed. Tumors from HIV+ patients lacked PD-L1 expression, and had lower B7-H3% (median 2.5 vs. 60%, p = 0.007), and higher CD8 density (median 75% vs. 40%, p = 0.04) compared to immunocompetent patients. Higher tumor grade (Rs = 0.34, p = 0.006) and LVI (Rs = 0.61, p < 0.001) were both associated with higher Tum-PD-L1%.

CONCLUSION

cSCC showed expression of PD-L1 on tumor in 26% of cases, and high tumor B7-H3 expression (85%) and PD-1 expression on CD8 TILs (80%). Tumor B7-H3 expression was significantly higher in immunocompetent vs. immunosuppressed patients, largely driven by very low expression in HIV+ patients.

Clinical Remission of Cutaneous Squamous Cell Carcinoma of the Auricle with Cetuximab and Nivolumab

Cutaneous squamous cell carcinomas (SCC) affecting the regions of the head and neck can be challenging to resect surgically and refractory to chemotherapy or radiation therapy. Consequently; the treatment of squamous cell carcinomas of the skin is a focus of current research. One such advancement is immunotherapy. Herein we describe clinical remission of invasive, poorly differentiated squamous cell carcinoma of the pre-auricular region with external auditory canal involvement using cetuximab, an epidermal growth factor receptor (EGFR) antibody; and nivolumab, a programmed death receptor-1 (PD-1) antibody. Such durable and comprehensive disease resolution demonstrates the therapeutic potential of cetuximab and nivolumab in surgically challenging, treatment-resistant cutaneous squamous cell carcinoma.

Expression of PD-L1 in keratoacanthoma and different stages of progression in cutaneous squamous cell carcinoma

BACKGROUND

Programmed cell death 1 (PD-1) and its ligands (PD-L1) play a major role in the immune responses of a variety of cancers.

OBJECTIVES

To investigate the expression of PD-L1 in different progression forms of cutaneous squamous cell carcinoma (cSCC) and keratoacanthoma (KA).

METHODS

We performed immunohistochemical staining of 21 KA, 26 actinic keratoses (AK), 20 Bowen´s diseases (BD), and 26 high-risk cSCC. The staining patterns were assessed using the tumour proportion score and staining intensity evaluation. Immunohistology scores were statistically analysed.

RESULTS

PD-L1 expression of tumour cells as well as tumour-infiltrating cells (TILs) was significantly higher in KA and cSCC when compared to AK and BD (P = 0.00028 and P = 0.00033, respectively). We observed a very strong positive correlation between the PD-L1 protein expression of tumour cells of KA and the PD-L1 protein expression of TILs (r = 0.97; P < 0.0001). A similar correlation was also found for cSCC (r = 0.86; P < 0.0001). The percentage of PD-L1 + tumours was 33.3% for KA and 26.9% for cSCC. Similarly, the percentage of PD-L1 + TILs in KA and cSCC was 33.3 and 34.6%, respectively.

CONCLUSIONS

PD-L1 is differently expressed in cSCC and closely related non-melanoma skin cancer. cSCC exhibit PD-L1 expression in a fourth of cases, indicating that PD1/PD-L1 inhibitors might be beneficial in a proportion of patients with an inoperable or metastatic cSCC. Unlike AK and BD, TILs and tumour cells of KA and cSCC present very similar PD-L1 expression profiles indicating a common immune escape mechanism.

Management of High-Risk Squamous Cell Carcinoma of the Skin

OPINION STATEMENT

Non-melanoma skin cancer (NMSC) is the most common malignancy in the USA, with cutaneous squamous cell carcinomas (cSCCs) constituting approximately 20 % of all NMSC. While cSCCs typically behave in an indolent fashion and can be cured with local destructive or surgical methods, a small subset metastasizes and induces significant morbidity and mortality. Identifying and aggressively treating these "high-risk" cSCCs (HRcSCCs) is thus paramount. Recent improvements in staging cSCCs appear to offer better risk stratification than earlier staging criteria. Radiologic imaging and sentinel lymph node biopsy may be beneficial in certain cases of HRcSCC, although more studies are needed before these techniques should be uniformly incorporated into management. Surgery with complete margin control, such as that offered by the Mohs micrographic technique, represents the first-line treatment for these tumors. Radiation therapy is likely most beneficial in the adjuvant setting. Chemotherapy is typically best reserved for patients with metastatic or locally advance disease that is not controllable with surgical and/or radiation therapies. Newer targeted treatments, such as EGFR inhibitors and immunotherapies may offer greater efficacy in these settings, although further evaluation is needed.