High-risk cSCC Research Articles

347P - Relationship between modified surgical margin and prognosis of cutaneous squamous cell carcinoma

BackgroundControversy exists regarding the optimal margin of surgical excision for cutaneous squamous cell carcinoma (cSCC). Japanese clinical practice guidelines for skin cancer (second edition) recommend an excision with a 4–6-mm clinical margin for low-risk cSCC and >6-mm clinical margin for high-risk cSCC. However, it is difficult to follow this guideline for all cSCCs because high-risk cSCCs frequently occur on the face or in older patients. The purpose of this study was to investigate the correlation between surgical margin and prognosis in patients with cSCC. MethodsPatients with cSCC who underwent surgical excision of the primary site between 2011 and 2019 at Saitama Medical University International Medical Center were included in this retrospective observational study. Patients were divided into two groups: group A (standard surgery with guideline-recommended margin) and group B (modified surgery with narrow margin). Overall survival (OS), relapse-free survival (RFS), local recurrence-free survival (LRFS), regional metastasis-free survival (RMFS), and distant metastasis-free survival (DMFS) were compared between the two groups. ResultsA total of 107 patients with cSCC were included in this study: 39 in group A and 68 in group B. There were no significant differences in patient characteristics such as sex, tumor border, and risk factors; age and tumor size differed between groups. There were no statistically significant differences in OS (p=.470), LRFS (p=.631), RMFS (p=.502), and DMFS (p=.475) between the two groups. However, RFS was significantly lower in group A than in group B (p=.049). ConclusionsThis study did not reveal a significant impact of clinical margin on OS in patients with cSCC. Although this conclusion may have been limited by selection bias, excision with narrower margins than those suggested by current guidelines may be appropriate. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Sentinel Node Biopsy in 105 High-Risk Cutaneous SCCs of the Head and Neck: Results of a Multicenter Prospective Study.

Regional nodal metastases from cutaneous squamous cell carcinoma (cSCC) is strongly associated with a poor prognosis, but these metastases are difficult to predict clinically. Sentinel node biopsy (SNB) has been used for a wide range of malignancies to assess for regional nodal metastasis, but is not widely used for cSCC. Patients presenting with high-risk cSCC of the head and neck with clinically N0 necks were offered SNB at the time of primary cSCC excision or secondary wide local excision. Patients with positive sentinel nodes were offered completion lymph node dissection, and all the patients were followed up at regular intervals for up to 5years. In this study, 105 lesions underwent SNB, and 10 sentinel nodes (9.5%) were positive. In an additional five patients, regional recurrence developed after a negative sentinel node, with a total subclinical nodal metastasis rate of 14.3%. Nodal metastases were significantly associated with reduced disease-specific survival. The significant predictors of metastasis were four or more high-risk features or tumors with a concurrent invasion deeper than 5mm and PNI. For high-risk cSCC, SNB is a safe and feasible staging technique. The total number of high risk features and certain combinations of high-risk features predicted metastasis better than individual high-risk features.

Outcomes in MAGE+ cutaneous squamous cell carcinoma with perineural invasion treated with surgery followed by postoperative radiation therapy.

e21043 Background: Perineural invasion (PNI) is associated with a high risk for recurrence and metastasis from cutaneous squamous cell carcinoma (cSCC). Recommendations vary regarding use of post-operative radiation therapy (PORT). Biomarkers for poor outcome from cSCC with PNI are lacking. We aimed to evaluate outcomes in high-risk cSCC with PNI treated surgically +/- PORT and to evaluate tissue from the primary tumor to identify biomarkers for highest risk. Methods: We conducted a retrospective chart review of PNI SCC patients seen between 2005 and 2014. We compared outcomes for surgery vs. surgery plus PORT. Gene expression from tumor debulk was evaluated via Nanostring. MAGEA3 function was evaluated using PAM 212 SCC cells in a BALB/c mouse model. CRISPR-Cas9 MAGEA3 PAM 212 knockouts were developed to assess role of MAGEA3 in SCC growth. Results: Thirty-two patients with PNI SCC were identified. All were treated surgically, and 18/32 elected to undergo PORT. Nodal metastases were noted in 5/14 patients who did not undergo PORT, whereas no metastases were noted in any patient who underwent PORT. Thus, surgery plus PORT was associated with better outcome than surgery alone (P < 0.01). Local recurrence was not observed in any patients treated by surgery, including 30 patients treated by Mohs micrographic surgery (MMS). MAGEA3 was highly expressed in PNI SCC. MAGEA3 expression in PAM 212 SCC was associated with tumor growth and increased expression of cyclins A, B, and E. CRISPR-Cas9 MAGEA3 PAM 212 knockouts exhibited reduced growth in BALB/c mice. Conclusions: MAGEA3 expression is increased in human PNI SCC. We can mitigate against worst case outcome with surgery plus PORT. MAGEA3 merits further investigation as a potential biomarker for best candidates for surgery plus PORT.

Cetuximab as a Component of Multimodality Treatment of High-Risk Cutaneous Squamous Cell Carcinoma: A Retrospective Analysis From a Single Tertiary Academic Medical Center.

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer and has potential for regional or distant metastasis. Despite the standardization of features associated with high-risk cSCC, an advanced subset of cSCC, there is no established consensus regarding proper management of this tumor. To evaluate the efficacy of cetuximab, add to existing management options, and aid in the development of standardized treatment for this tumor. Medical records were searched using Current Procedural Terminology codes for cetuximab and cSCC. Demographic data and tumor characteristics, along with treatment regimens and follow-up times, were collected. A total of 20 cases were examined. Of the 20 cases, 3 experienced a complete response and 7 experienced a partial response, yielding an overall response of 50% and a combined median disease-free survival of 6.35 months (range 1-46.8 months). As most of the patients who experienced a response received cetuximab as part of a multimodality treatment approach, cetuximab may be most efficacious when administered with concurrent therapies such as surgery or radiation. Further larger prospective studies to determine the optimal dosing and frequency of cetuximab and the utility of concurrent therapies are warranted.

Tumor Characteristics Predicting Perineural Invasion in Cutaneous Squamous Cell Carcinoma Identified by Stepwise Logistic Regression Analysis

Background: Perineural invasion (PNInv) is a significant risk factor for metastasis and death in cutaneous squamous cell carcinoma (cSCC). Despite this known association, factors contributing to the presence of PNInv are not well characterized.Aims: To determine risk factors associated with the presence of PNInv using the high-risk cSCC criteria developed by the National Comprehensive Cancer Network (NCCN).Methods: After receiving Institutional Review Board approval for this retrospective review, the presence of NCCN high-risk factors for cSCC were recorded for patients treated at a tertiary referral academic medical center, from January 1, 2010 to March 31, 2012. Stepwise logistic regression was used to identify factors associated with the presence of PNInv.Results: PNInv was present in 34 of 507 cSCCs (6.7%). Moderately or poorly differentiated histology (P < .001, OR 6.6 [95% CI, 3.2-13.7]), acantholytic, adenosquamous, or desmoplastic subtype (P =.01, OR 1.8 [95% CI, 0.8-4.2]), and tumors in areas M (≥10mm) and H ( ≥6mm) (P = .05, OR 5.0 [95% CI, 1.2-21.0]) were significantly associated with the presence of PNInv.Conclusions: This data suggests clinicians should have a higher suspicion and may be able to identify PNInv in high-risk cSCC based on the presence of specific high-risk factors.

Management of the Neck for Non-melanoma Skin Cancer

To summarize the current management of the neck lymph node basin for head and neck non-melanoma skin cancers. Over the last 5 years, there have been updates to staging for cSCC and MCC. T classification of the AJCC staging system has been changed to match the UICC staging system. MCC staging has been updated based on data from the National Cancer Data Base. Sentinel lymph node biopsy, while established in MCC, is playing a growing role in the management of high-risk N0 cSCC. The optimal management of N0 neck varies by metastatic potential. In low-risk malignancy, no workup is necessary. In cSCC, risk stratification is necessary. High-risk tumors with N0 necks should undergo preoperative imaging with CT and targeted FNA of suspicious lymph nodes. If radiologically negative, a SLNB should be considered. Selective neck dissection should be performed for N+ disease and positive SLNB. Elective neck dissection is not routinely recommended and should be reserved for positive parotid nodal disease. Merkel cell carcinoma has high rates of nodal metastases and requires preoperative imaging with targeted FNA of suspected metastases. SLNB should be performed for N0 disease to guide prognostication and further treatment. Management of negative SLN is controversial, and most can be observed while radiation may be considered for high-risk patients. Positive SLN requires completion neck dissection and radiation.

The Value of Adjuvant Radiotherapy in Cutaneous Squamous Cell Carcinoma: A Review

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer in humans and its incidence is rising. Although surgery is the treatment of choice for cSCC, postoperative adjuvant radiotherapy has an important role in local and locorregional disease control. In this review, we analyze the value of postoperative radiotherapy in the management of high-risk cSCC (in particular, cases with perineural invasion), cSCC with positive surgical margins, and locally advanced cSCC (with parotid gland and/or lymph node metastasis).

Utilidad de la radioterapia en adyuvancia en el carcinoma epidermoide cutáneo

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer in humans and its incidence is rising. Although surgery is the treatment of choice for cSCC, postoperative adjuvant radiotherapy has an important role in local and locorregional disease control. In this review, we analyze the value of postoperative radiotherapy in the management of high-risk cSCC (in particular, cases with perineural invasion), cSCC with positive surgical margins, and locally advanced cSCC (with parotid gland and/or lymph node metastasis).

Systematic review of the prevalence of nodal metastases and the prognostic utility of sentinel lymph node biopsy in cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer and its incidence is rising. The prognosis is mostly good but patients with high-risk cSCC have a greater risk of recurrence and death. The aim of the present study was to conduct a systematic review analyzing the prevalence, predictors and prognostic utility of sentinel lymph node (SLN) involvement in cSCC. We performed a published work search in Ovid MEDLINE and reviewed the reference lists of selected studies. Based on the 23 studies included in the systematic review, the proportion of patients with cSCC and positive SLN biopsy findings was 8% (95% confidence interval, 5.1-10.8%; I2 = 44.51%). We found no studies reporting on predictors of SLN involvement in cSCC or on the prognostic utility of this finding following adjustment for confounders. The rate of positive SLN in cSCC is less than previously reported. Criteria for recommending SLN biopsy as a staging tool for cSCC vary considerably from study to study, and none of the studies were large enough to reliably identify predictors of SLN positivity. No randomized controlled trials have yet analyzed whether SLN biopsy may improve the prognosis of cSCC. More studies are required on the prognostic value of SLN positivity and the associated risk factors in cSCC.

High-Risk Cutaneous Squamous Cell Carcinoma

The aim of this report is to review the literature on patients diagnosed with a “high-risk” cutaneous squamous cell carcinoma (cSCC), defined as the subset (5–10%) of cSCC patients at increased risk of developing predominantly local and/or regional recurrence and, to a lesser extent, distant metastasis. There are no universally accepted criteria for defining or managing patients with a high-risk cSCC. We reviewed the literature and examined risk stratification, management strategies, and promising future directions. A new staging system, from the Brigham and Women’s Hospital, has provided important data on high-risk cSCC patients, highlighting the increasing risks associated with the interaction of a number of high-risk independent variables a patient has. Only a minority of cSCC patients can be considered as high risk for developing recurrence and potentially dying from cSCC. Most patients are cured following local treatment, usually surgery. It is the high-risk patients that need to be identified and managed appropriately, often requiring multimodality treatment.

Cutaneous squamous cell carcinoma and the emerging role of sentinel lymph node biopsy.

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer and is usually associated with a favorable prognosis in most patients. However, a small minority of patients will be diagnosed with a high-risk cSCC (HRcSCC) and a proportion will have a poor outcome, in some cases causing death. HRcSCC is characterized by an increase in aggressiveness manifested as local recurrence, the development of lymph node metastases, and occasionally death. The utility of sentinel lymph node biopsy (SLNB) in this group of patients is unclear without high-level evidence or clear-cut recommendations. If clinicians accept as a cut-off threshold of a >10% of risk of harboring occult nodal metastasis, then selected HRcSCC patients may benefit from SLNB and/or additional investigations. Herein, we performed a review of the current evidence regarding SLNB in HRcSCC. We believe that SLNB may be considered in selected HRcSCC patients to potentially better predict prognosis and influence management. However larger prospective studies are needed to better define the subset of patients that may benefit from SLNB and if early detection of occult nodal metastases is associated with an improved outcome.

Combination of post-operative radiotherapy and cetuximab for high-risk cutaneous squamous cell cancer of the head and neck: A propensity score analysis

ObjectivesThe objective of this study was to investigate the safety, tolerability and preliminary efficacy of radiotherapy plus cetuximab in high risk CSCC patients. Materials and MethodsPatients with high-risk CSCC diagnosed between 2006 and 2013 were analyzed. Patients were divided into two groups: radiotherapy alone versus radiotherapy plus cetuximab. Among 68 patients meeting study criteria, we identified 29 treated with cetuximab plus RT and 39 with RT alone. Primary analysis examined disease-free and overall survival, freedom from local and distant recurrence in the propensity score matched cohort. Propensity score analysis was performed with weighted factors including: Charlson Comorbidity Index score, age. KPS, primary location, T and N stage, recurrent status, margin status, LVSI, PNI and grade. Toxicity was assessed using the CTCAE v4.0. ResultsMedian follow-up for living patients was 30 months. Patients in the cetuximab group were more likely to have advanced N stage, positive margins and recurrent disease. After propensity score matching the groups were well balanced. Six patients experienced ≥ grade 3 acute toxicity in the cetuximab group. The 1-year, 2-year and 5-year progression free survival (PFS) for patients in the cetuximab group were 86%, 72% and 66%, respectively. The 1-year, 2-year and 5-year overall survival (OS) for patients in the cetuximab group was 98%, 80% and 80%, respectively. ConclusionsAlthough limited by small numbers, the combination of cetuximab and radiotherapy in CSCC appears well tolerated there were more long-term survivors and less distant metastasis in the cetuximab group. These promising finding warrant further studies.

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

Programmed cell death 1 (PD-1) and its ligands (PD-L1) play a major role in the immune responses of a variety of cancers. To investigate the expression of PD-L1 in different progression forms of cutaneous squamous cell carcinoma (cSCC) and keratoacanthoma (KA). 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. 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. 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.

High-risk Cutaneous Squamous Cell Carcinoma

ABSTRACT Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer worldwide. Cutaneous squamous cell carcinoma can potentially be treated fully with minimal morbidity when detected early; however, certain subtypes of cSCC have been shown to confer a poorer prognosis for patients. In these high-risk tumors, increased incidence of recurrence, as well as metastasis to local lymph nodes and distant sites, is seen as a result of certain patient characteristics and pathological features. While guidelines regarding the management of high-risk cSCC have been produced, no clear consensus management or prognostic algorithms exist. In this review, we discuss current definitions of high-risk cSCC, recommendations regarding the management of cSCC, and current guidelines. How to cite this article Fitzgerald C, O'Neill JP. High-risk Cutaneous Squamous Cell Carcinoma. Int J Head Neck Surg 2017;8(2):37-44.

Abstract 1098: MiR-203 suppresses cutaneous squamous cell carcinoma growth and targets the myc oncogene

Abstract Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer in man and accounts for approximately 20% of non-melanoma skin cancers. Although most cSCC are benign, poorly differentiated cSCC poses a significant risk of metastasis and death. To date, little is known about the difference in molecular background between low-risk and high risk cSCC. MicroRNAs are short regulatory RNAs that can regulate gene expression and cellular functions. Here we demonstrate for the first time that the expression of miR-203 in cSCC correlates with tumor differentiation grade, being down-regulated in poorly but not in moderately or well differentiated cSCC. In vitro, miR-203 causes a delay in G1 to S phase transition and suppresses cell proliferation in human cSCC cells. Furthermore, miR-203 suppresses scratch-wound closure, cell migration, cell invasion, colony forming ability and angiogenesis-inducing capacity of cSCC cells. Transcriptomic analysis of cSCC cells with ectopic overexpression of miR-203 reveals dramatic changes in gene networks related to carcinogenesis, with significant suppression of genes with known oncogenic functions (e.g. PCNA, EGFR, HGF). Using luciferase reporter assays and site-specific mutagenesis, we identify c-MYC as a novel target of miR-203. Highlighting the importance of c-MYC within miR-203-regulated gene network, in rescue experiments overexpression of c-MYC reverses miR-203-induced growth arrest in cSCC. In vivo, overexpression of miR-203 in cSCC cell lines result in reduced xenograft tumor volume and decreased vessel density. Together our data show that miR-203 acts a tumor suppressor in cSCC, affecting several oncogenic and angiogenic mechanisms. Importantly, its restoration may provide therapeutic benefit in particular in poorly differentiated cSCC. Citation Format: Warangkana Lohcharoenkal, Masako Harada, Jakob Lovén, Florian Meisgen, Ning Xu Landén, Lingyun Zhang, Liisa Nissinen, Veli-Matti Kähäri, Mona Ståhle, Enikö Sonkoly, Dan Grander, Marie Arsenian-Henriksson, Andor Pivarcsi. MiR-203 suppresses cutaneous squamous cell carcinoma growth and targets the myc oncogene. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1098.

Cutaneous Squamous Cell Carcinoma: A Review of High-Risk and Metastatic Disease.

Non-melanoma skin cancer represents one-third of all malignancies and its incidence is expected to rise until the year 2040. Cutaneous squamous cell carcinoma (cSCC) represents 20% of all non-melanoma skin cancer and is a deadly threat owing to its ability to metastasize to any organ in the body. Therefore, a better understanding of cSCC is essential to strengthen preventative measures and curable treatment options. Currently, research demonstrates that cSCC is diagnosed at a rate of 15-35 per 100,000 people and is expected to increase 2-4% per year. With respect to metastatic cSCC, this disease is more common in men; people over the age of 75years; and inhabitants of the south and mid-west USA. In 2010, the American Joint Committee on Cancer updated the Cancer Staging Manual's primary tumor designation to now include high-risk factors; however, factors such as immunosuppression and tumor recurrence were not included. Other staging systems such as Brigham and Women's Hospital have allowed for increased stratification of cSCC. High-risk cSCC is defined as a cSCC that is staged as N0, extends beyond basement membrane, and has high-risk features associated with sub-clinical metastasis. High-risk features are depth of invasion (>2mm), poor histological differentiation, high-risk anatomic location (face, ear, pre/post auricular, genitalia, hands, and feet), perineural involvement, recurrence, multiple cSCC tumors, and immunosuppression. Epidermal growth factor receptor and nuclear activeIκB kinase (IKK) expression are also predictive of metastatic capabilities. Clinically, the initial lesions of a cSCC tumor can present as a painless plaque-like or verrucous tumor that can ultimately progress to being large, necrotic, and infected. Tumors can also present with paresthesias or lymphadenopathy depending on the location involved. With respect to prognosis, metastatic cSCC is lethal, with several large studies demonstrating a mortality rate of >70%. Therefore, treatment of metastatic cSCC is difficult and depends on the location involved and extent of metastasis. Treatment options include surgery, radiation therapy, chemotherapy, and any combination of the above. Surgery alone can be used for metastatic cSCC treatment, but is not as effective as surgery in conjunction with radiation therapy. Radiation therapy has some success as a monotherapy in low-risk or cosmetically sensitive areas such as the external ear, eyelid or nose. According to the 2013 National Comprehensive Cancer Network Guidelines, cisplatin as a single agent or combined with 5-fluorouracil hold the strongest support for the treatment of metastatic cSCC; however, the supporting evidence is inconsistent and a curative chemotherapeutic approach is still lacking. Epidermal growth factor receptor inhibitors are a newer class of agents being used in metastatic cSCC and hold some promise as a therapy for this disease. Other areas of interest in finding curative treatments for metastatic cSCC include p53, hypermethylation of specific genes, chromatin remodeling genes, and the RAS/RTK/PI3K pathway. This review addresses the epidemiology, staging, risk factors, clinical presentation, management, and new trends in the treatment of high-risk and metastatic cSCC.

Advances and Applications of Ion Torrent Personal Genome Machine in Cutaneous Squamous Cell Carcinoma Reveal Novel Gene Mutations.

The Ion Torrent Personal Genome Machine (Ion PGM) is a semiconductor-based sequencing technology that is high quality, scalable, and economic. Its applications include genomic sequencing, drug resistance testing, microbial characterization, and targeted sequencing in cancer studies. However, little is known about the application of Ion PGM in cutaneous squamous cell carcinoma (cSCC). We therefore investigated the utility and validity of Ion PGM in cSCC and also gained a better understanding of the underlying molecular biology of cSCC. We detected novel gene mutations (KDR, FGFR2, and EGFR) in two cSCC patients. Moreover, we validated these mutations by pyrosequencing and Sanger sequencing. Our results indicated that the mutation screen using Ion PGM is consistent with traditional sequencing methods. Notably, these identified mutations were present at significantly higher rates in high-risk cSCC. Our results demonstrate a method to detect targetable genes in high-risk cSCC, and suggest that Ion PGM may enable therapeutic decision-making and future potential targets for personalized therapies in cSCC.

Non-melanoma skin cancer: United Kingdom National Multidisciplinary Guidelines.

This is the official guideline endorsed by the specialty associations involved in the care of head and neck cancer patients in the UK. This paper provides consensus recommendations on the management of cutaneous basal cell carcinoma and squamous cell carcinoma in the head and neck region on the basis of current evidence. Recommendations • Royal College of Pathologists minimum datasets for NMSC should be adhered to in order to improve patient care and help work-force planning in pathology departments. (G) • Tumour depth is of critical importance in identifying high-risk cutaneous squamous cell carcinoma (cSCC), and should be reported in all cases. (R) • Appropriate imaging to determine the extent of primary NMSC is indicated when peri-neural involvement or bony invasion is suspected. (R) • In the clinically N0 neck, radiological imaging is not beneficial, and a policy of watchful waiting and patient education can be adopted. (R) • Patients with high-risk NMSC should be treated by members of a skin cancer multidisciplinary team (MDT) in secondary care. (G) • Non-infiltrative basal cell carcinoma (BCC) <2 cm in size should be excised with a margin of 4-5 mm. Smaller margins (2-3 mm) may be taken in sites where reconstructive options are limited, when reconstruction should be delayed. (R) • Where there is a high risk of recurrence, delayed reconstruction or Mohs micrographic surgery should be used. (R) • Surgical excision of low-risk cSCC with a margin of 4 mm or greater is the treatment of choice. (R) • High-risk cSCC should be excised with a margin of 6 mm or greater. (R). • Mohs micrographic surgery has a role in some high-risk cSCC cases following MDT discussion. (R) • Delayed reconstruction should be used in high-risk cSCC. (G) • Intra-operative conventional frozen section in cSCC is not recommended. (G) • Radiotherapy (RT) is an effective therapy for primary BCC and cSCC. (R) • Re-excision should be carried out for incompletely excised high-risk BCC or where there is deep margin involvement. (R) • Incompletely excised high-risk cSCC should be re-excised. (R) • Further surgery should involve confirmed marginal clearance before reconstruction. (R) • P+ N0 disease: Resection should include involved parotid tissue, combined with levels I-III neck dissection, to include the external jugular node. (R) • P+ N+ disease: Resection should include level V if that level is clinically or radiologically involved. (R) • Adjuvant RT should include level V if not dissected. (R) • P0 N+ disease: Anterior neck disease should be managed with levels I-IV neck dissection to include the external jugular node. (R) • P0 N+ posterior echelon nodal disease (i.e. occipital or post-auricular) should undergo dissection of levels II-V, with sparing of level I. (R) • Consider treatment of the ipsilateral parotid if the primary site is the anterior scalp, temple or forehead. (R) • All patients should receive education in self-examination and skin cancer prevention measures. (G) • Patients who have had a single completely excised BCC or low-risk cSCC can be discharged after a single post-operative visit. (G) • Patients with an excised high-risk cSCC should be reviewed three to six monthly for two years, with further annual review depending upon clinical risk. (G) • Those with recurrent or multiple BCCs should be offered annual review. (G).

421 Over-expression of periostin is associated with clinical outcomes and poor prognosis in cutaneous squamous cell carcinoma

421 Over-expression of periostin is associated with clinical outcomes and poor prognosis in cutaneous squamous cell carcinoma L Chao, V Gor, DF Murrell, M Kim, E O’Toole, A Ly, D Woodley, A Wysong and M Chen 1 University of Southern California, Los Angeles, CA, 2 University of New South Wales, Sydney, NSW, Australia and 3 Barts and the London School of Medicine and Dentistry, London, United Kingdom Cutaneous squamous cell carcinoma (cSCC), the second most common cancer in the US, is increasing in incidence globally. No specific molecular markers exist to evaluate the risk of cSCC progression and metastasis. Periostin (PN), an extracellular matrix macromolecule, is implicated in tumorigenesis and serves as a prognosis marker for many cancer types. However, there are no data on PN expression in cSCC. This study examined PN expression in patients with cSCC and explored its relationship with clinicopathologic factors and prognosis. We compared PN expression in 103 cSCCs representing a spectrum of cSCC aggressiveness: cSCC in situ (cSSCI) (n1⁄420), low-risk cSCC (LR-cSCC) (n1⁄446), high-risk cSCC (HR-cSCC) (n1⁄416), high-risk in immunocompromised hosts (HRIM-cSCC) (n1⁄413) and cSCC in recessive dystrophic epidermolysis bullosa (RDEB) patients (RDEB-SCC) (n1⁄48). Immunohistochemistry demonstrated PN expression within intra-tumoral stroma but not within tumor cells. PN levels significantly (p < 0.001) increased from cSSCI, LR-cSCC, HR-cSCC, HRIM-cSCC to RDEBSCC. RDEB SCCs represented the most aggressive SCC type. The high level of PN staining in RDEB cSCC was tumor specific with levels notably higher than the non-cancerous skin of RDEB patients. Moreover, the stroma of most SCCs contained cancer-associated fibroblasts with a myofibroblastic (a-SMA-positive) phenotype. Using Transwell assays and an in vivo xenograft tumor model, the addition of RDEB fibroblast-derived PN or recombinant PN significantly promoted in vitro RDEB cSCC invasion and in vivo tumor formation, suggesting that the over-expression of PN in RDEB fibroblasts may play a critical permissive role for SCC development. Our data show that PN expression is highly correlated with the aggressiveness of cSSC, thereby providing a molecular basis for development of novel diagnostic and therapeutic strategies targeting PN for high-risk cSCC. 422 Dsg2 increases exosome release and enhances EGFR/c-Src content: A mechanism for an intercellular mitogenic effect AM Overmiller, J Pierluissi, P Wermuth, U Martinez-Outschoorn, J Curry, A South and MG Mahoney Thomas Jefferson University, Philadelphia, PA Exosomes are nanoscale membrane-derived vesicles that serve as vehicles for the intercellular transfer of protein, mRNA, miRNA and DNA. Substantial evidence has shown that cancerderived exosomes, secreted by tumor cells into the blood and other bodily fluids, play a critical role in modulating the tumor microenvironment and the pathogenesis of cancer. Desmoglein 2 (Dsg2), a desmosomal cadherin often overexpressed in skin malignancies, can activate EGFR/c-Src signaling, enhance cell growth and migration, and promote oncogenesis. Here, we purified exosomes from SCC cells by ultracentrifugation or one-step polymer precipitation. Enrichment of exosomes was confirmed by Nanoparticle Tracking Analysis and by immunoblotting for exosome positive (CD9 and CD63) and negative (CoxIV and GM130) markers. We demonstrate that Dsg2 undergoes ectodomain shedding, and the residual 65 kDa membrane-associated C-terminal fragment (CTF) is enriched in exosomes. Cells were transfected with adenovirus expressing Dsg2 tagged with GFP (29 kDa) at the C-terminus, which was readily detected in exosomes via GFP fluorescence and immunoblotting detected a 95kDa CTF-GFP fusion product in exosomes. Confocal microscopy demonstrates uptake of the Dsg2-labeled exosomes by normal keratinocytes. While Dsg2 is expressed at low levels in the normal epidermis, it is highly upregulated in head and neck SCCs, and exosomes extracted from SCC patients’ sera are enriched in Dsg2 CTF. Overexpression of Dsg2 in SCC cells increased exosome release by 2 fold and enhanced not only total, but also activated, EGFR and c-Src in exosomes, providing a potent mechanism for paracrine mitogenic signal activation. In addition, Dsg2 down-regulates caveolin-1, loss of which has been shown to promote exosome endocytosis. This study defines a mechanism by which cancer cells modulate the tumor microenvironment through enhanced Dsg2 levels, leading to altered exosome dynamics with the potential to promote oncogenic signaling.

Evaluation of positron emission tomography imaging to detect lymph node metastases in patients with high‐risk cutaneous squamous cell carcinoma

Ten to twenty percent of high-risk cutaneous squamous cell carcinoma (cSCC) can metastasize to regional lymph nodes. Detection of nodal metastasis is mandatory to manage high-risk cSCC. This study was aimed to evaluate the 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging to assess lymph node (LN) metastasis of high-risk cSCC patients. Twenty-six patients with histologically proven primary cSCC were enrolled. All patients underwent whole-body PET prior to lymphoscintigraphy and subsequent sentinel LN biopsy. The maximum standardized uptake value (SUVmax) of more than 2.5 is generally evaluated as a positive PET finding indicative of malignancy. On the basis of the histopathological and PET findings, 30 LN from 26 patients were categorized into four groups: (i) histologically negative and PET negative (true-negative; n = 22); (ii) histologically positive and PET negative (false-negative; n = 0); (iii) histologically positive and PET positive (true-positive; n = 3); and (iv) histologically negative and PET positive (false-positive; n = 5). The mean SUVmax was significantly higher in the true-positive cases (11.0 ± 2.8) than in the false-positive cases (3.4 ± 0.6). In the false-positive cases, the number of tumor-infiltrating inflammatory cells at the primary skin site was highest among the four groups, suggesting that inflammation contributed to the false-positive uptake of FDG. Although we cannot negate the possibility of the presence of PET-undetectable micrometastasis, the SUVmax value may be useful for avoidance of excess performance of sentinel LN biopsy.