Conway C. Huang

KLF4 and PCNA identify stages of tumor initiation in a conditional model of cutaneous squamous epithelial neoplasia.

KLF4 is induced upon growth-arrest in vitro and during epithelial maturation in vivo, and is essential for proper cell fate specification of post-mitotic cells. In spite of a normal role in post-mitotic cells, expression is upregulated and constitutive in certain tumor types. KLF4 functions as an oncogene in vitro, and enforced expression in basal cells of mouse skin rapidly induces lesions similar to hyperplasia, dysplasia and squamous cell carcinoma (SCC). Here we used conditional expression to characterize early steps in KLF4-mediated tumor initiation. In contrast to SCC-like lesions that result when using a conditional, keratin 14 promoter-dependent strategy, lower conditional expression achieved using a MMTV promoter induced only epidermal cycling within morphologically normal skin, a process we termed occult cell turnover. Surprisingly, KLF4-induced hyperplastic lesions showed increased transgene-derived mRNA and protein in maturing, PCNA-negative cells, a property of endogenous KLF4. In contrast, hyperplastic lesions induced by GLI1, a control, showed uniform transgene expression. In KLF4-induced dysplasia and SCC the complementarity of KLF4 and PCNA was replaced by concordance of the two proteins. These studies show that KLF4 transcripts are normally suppressed in cycling cells in a promoter-independent fashion, consistent with a post-transcriptional control, and reveal loss of this control in the transition from hyperplasia to dysplasia. Like the mouse tumors, human cutaneous SCCs and adjacent dysplasias frequently showed maturation-independence of KLF4, with co-expression of KLF4 and PCNA. A smaller subset of human SCCs showed complementarity of KLF4 and PCNA, similar to hyperplastic mouse skin. The results identify parallels between a mouse model and human primary tumors, and show that successive increases of KLF4 in the nuclei of basal keratinocytes leads to occult cell turnover followed by hyperplasia, dysplasia, and invasive SCC.

Incidence of and Risk Factors for Skin Cancer in Organ Transplant Recipients in the United States

Importance Skin cancer is the most common malignancy occurring after organ transplantation. Although previous research has reported an increased risk of skin cancer in solid organ transplant recipients (OTRs), no study has estimated the posttransplant population–based incidence in the United States. Objective To determine the incidence and evaluate the risk factors for posttransplant skin cancer, including squamous cell carcinoma (SCC), melanoma (MM), and Merkel cell carcinoma (MCC) in a cohort of US OTRs receiving a primary organ transplant in 2003 or 2008. Design, Setting, and Participants This multicenter retrospective cohort study examined 10 649 adult recipients of a primary transplant performed at 26 centers across the United States in the Transplant Skin Cancer Network during 1 of 2 calendar years (either 2003 or 2008) identified through the Organ Procurement and Transplantation Network (OPTN) database. Recipients of all organs except intestine were included, and the follow-up periods were 5 and 10 years. Main Outcomes and Measures Incident skin cancer was determined through detailed medical record review. Data on predictors were obtained from the OPTN database. The incidence rates for posttransplant skin cancer overall and for SCC, MM, and MCC were calculated per 100 000 person-years. Potential risk factors for posttransplant skin cancer were tested using multivariate Cox regression analysis to yield adjusted hazard ratios (HR). Results Overall, 10 649 organ transplant recipients (mean [SD] age, 51 [12] years; 3873 women [36%] and 6776 men [64%]) contributed 59 923 years of follow-up. The incidence rates for posttransplant skin cancer was 1437 per 100 000 person-years. Specific subtype rates for SCC, MM, and MCC were 812, 75, and 2 per 100 000 person-years, respectively. Statistically significant risk factors for posttransplant skin cancer included pretransplant skin cancer (HR, 4.69; 95% CI, 3.26-6.73), male sex (HR, 1.56; 95% CI, 1.34-1.81), white race (HR, 9.04; 95% CI, 6.20-13.18), age at transplant 50 years or older (HR, 2.77; 95% CI, 2.20-3.48), and being transplanted in 2008 vs 2003 (HR, 1.53; 95% CI, 1.22-1.94). Conclusions and Relevance Posttransplant skin cancer is common, with elevated risk imparted by increased age, white race, male sex, and thoracic organ transplantation. A temporal cohort effect was present. Understanding the risk factors and trends in posttransplant skin cancer is fundamental to targeted screening and prevention in this population.

Use of Panitumumab-IRDye800 to Image Cutaneous Head and Neck Cancer in Mice

Objective To assess the feasibility of panitumumab in real-time fluorescent imaging and histologic processing of cutaneous squamous cell carcinoma (cSCC) in mice. Design A near-infrared (NIR) fluorescent probe (IRDye800CW) was covalently linked to a monoclonal antibody–targeting epidermal growth factor receptor (panitumumab) or nonspecific IgG and injected into mice bearing flank xenografts from a cSCC cell line (SCC-13 or SRB-12; n = 7), human split-thickness skin grafts (STSGs; n = 3), or a human tumor explant (n = 1). The tumor and lymph nodes were imaged and dissected using fluorescence guidance with the SPY imaging system and verified with a charge-coupled NIR system. An NIR scanning device (Odyssey) was used to measure fluorescence intensity in histological sections. Subjects Immunodeficient mice. Setting In vivo and in vitro imaging lab. Results Tumor tissue could be delineated from the human STSG with tumor-to-background ratios of 4.5 (Pearl) and 3.4 (SPY). Tumor detection was substantially improved with panitumumab-IRDye800 compared with IgG-IRDye800. Biopsies positive for fluorescence were assessed by histology and immunohistochemistry (n = 18/18) to confirm the presence of tumor, yielding a 100% sensitivity. Biopsies of nonfluorescent tissue negative for malignancy (n = 18/18) yielded a specificity of 100%. Furthermore, the SPY system was able to detect residual disease as small as 200 µm in diameter. In addition, the Odyssey confirmed fluorescence of microscopic disease (in tumor samples of frozen and paraffin-embedded histologic specimens) but not in adjacent noncancerous tissue. Conclusions These data suggest panitumumab-IRDye800 may have clinical utility in detection and removal of subclinical cSCC using Food and Drug Administration–approved imaging hardware.

Cyclosporine a mediates pathogenesis of aggressive cutaneous squamous cell carcinoma by augmenting epithelial‐mesenchymal transition: Role of TGFβ signaling pathway

Organ transplant recipients (OTRs) develop multiple aggressive and metastatic non‐melanoma skin cancers (NMSCs). Yet, the underlying mechanism remains elusive. Employing a variety of immune‐compromised murine models, immunoblotting, immunohistochemical and immunofluorescence techniques, we show that human squamous xenograft tumors in nude mice grow faster and become significantly larger in size following treatment with the immunosuppressive drug, cyclosporine A (CsA). Re‐injected tumor cells isolated from CsA‐treated xenografts continued to form larger tumors in nude mice than those from vehicle‐controls and retained the CsA‐signatures of calcineurin signaling inhibition. Similar results were obtained when these tumors were grown in SCID‐beige mice or in immuno‐competent mice inoculated with syngeinic tumor cells. Consistently, tumors in the CsA group manifested enhanced cellular proliferation and decreased apoptosis. Tumors in CsA‐treated animals also showed an augmented epithelial‐mesenchymal transition (EMT) characterized by an increased expression of fibronectin, α‐SMA, vimentin, N‐cadherin, MMP‐9/‐2, snail and twist with a concomitant decrease in E‐cadherin. CsA‐treated xenograft tumors manifested increased TGFβ1 expression and TGFβ‐dependent signaling characterized by increased nuclear p‐Smad 2/3. Our data demonstrate that CsA alters the phenotype of skin SCCs to an invasive and aggressive tumor‐type by enhancing expression of proteins regulating EMT acting through the TGFβ1 signaling pathway providing at least one unique mechanism by which multiple aggressive and metastatic NMSCs develop in OTRs. Mol. Carcinog.

Pigmented extramammary Paget’s disease of the axilla mimicking melanoma: case report and review of the literature

Pigmented Pagets disease is a rare variant that is often confused clinically and histologically with melanoma in situ. Herein, we describe a case of pigmented extramammary Pagets disease involving the axilla of a 79‐year‐old white male thought initially to represent malignant melanoma clinically and histologically. Review of the literature reveals that pigmented variant of Pagets disease, either mammary or extramammary, could be initially misdiagnosed as melanoma unless this entity is considered in the differential diagnosis, and additional confirmatory studies are performed.

Identification of the optimal therapeutic antibody for fluorescent imaging of cutaneous squamous cell carcinoma.

Intraoperative, real-time fluorescence imaging may significantly improve tumor visualization and resection and postoperatively, in pathological assessment. To this end, we sought to determine the optimal FDA approved therapeutic monoclonal antibody for optical imaging of human cutaneous squamous cell carcinoma (cSCC). A near-infrared (NIR) fluorescent probe (IRDye800) was covalently linked to bevacizumab, panitumumab or tocilizumab and injected systemically into immunodeficient mice bearing either cutaneous tumor cell lines (SCC13) or cutaneous human tumor explants. Tumors were then imaged and resected under fluorescent guidance with the SPY, an FDA-approved intraoperative imaging system, and the Pearl Impulse small animal imaging system. All fluorescently labeled antibodies delineated normal tissue from tumor in SCC13 xenografts based on tumor-to-background (TBR) ratios. The conjugated antibodies produced TBRs of 1.2–2 using SPY and 1.6–3.6 using Pearl; in comparison, isotype control antibody IgG-IRDye produced TBRs of 1.0 (SPY) and 0.98 (Pearl). Comparison between antibodies revealed them to be roughly equivalent for imaging purposes with both the SPY and Pearl (p = 0.89 SPY, p = 0.99 Pearl; one way ANOVA). Human tumor explants were also imaged and tumor detection was highest with panitumumab-IRDye800 when using the SPY (TBR 3.0) and Pearl (TBR 4.0). These data suggest that FDA approved antibodies may be clinically used for intraoperative detection of cSCC.

Association Between Number of Stages in Mohs Micrographic Surgery and Surgeon-, Patient-, and Tumor-Specific Features: A Cross-Sectional Study of Practice Patterns of 20 Early- and Mid-Career Mohs Surgeons

OBJECTIVE To determine the number of Mohs micrographic surgery (MMS) stages per tumor taken by early‐ to mid‐career Mohs surgeons and to assess other factors affecting number of stages. METHODS Statistical analysis of MMS logs of 20 representative early‐ to mid‐career surgeons. RESULTS There was no difference in stages when surgeons were divided into two categories based on whether they had more than 500 cases per year or more than 5 years of experience. Similarly, when surgeons were categorized according to geographic location, there was no difference in number of stages. Anatomic location was associated with the number of stages (analysis of variance, p<.001), with the greatest number of stages for nose (2.01) and ear (2.06) lesions and the fewest for neck (1.47), back and shoulder (1.47), and lower extremity (1.33) lesions. Basal cell carcinomas required 1.92 stages (median 2.00), compared with 1.66 (median 1.00) for squamous cell carcinoma (p<.001). CONCLUSIONS Early‐ and mid‐career Mohs surgeons appear to remove tumors with similar numbers of stages regardless of their experience, case volume, or geographic location. Number of stages varies with anatomic location and tumor type. &NA; The authors have indicated no significant interest with commercial supporters.

Solitary plaque on the scalp as a primary manifestation of Hodgkin lymphoma: a case report and review of the literature

Cutaneous Hodgkin lymphoma is infrequent and typically occurs after extensive involvement of the lymph nodes. The condition decreased significantly in incidence in the past two decades, likely owing to the new treatment protocols composed of chemotherapy, radiotherapy and stem cell transplantation. Nevertheless, recognition of this uncommon but significant disease manifestation is important from a prognostic and therapeutic perspective. We are sharing a recent case of Hodgkin lymphoma where the primary presentation appeared as a solitary plaque on the left side of the occipital scalp, clinically suspected to represent a ruptured follicular cyst. The patient underwent excisional biopsy. Histological assessment revealed Hodgkin lymphoma affecting the skin. Radiological studies showed no regional lymphadenopathy. However, two enlarged lymph nodes were identified in the mediastinum and were positron emission tomography avid. The patient underwent systemic treatment without further histopathological examination of these two lymph nodes. Not being clear if these enlarged two lymph nodes were related to his cutaneous disease or not, we cannot be sure if the patient was afflicted either by primary cutaneous Hodgkin lymphoma or by secondary cutaneous involvement because of hematogenous spread. In either case, primary or secondary cutaneous Hodgkin disease is an extreme rarity. The literature is critically reviewed.

Guidelines of care for the management of basal cell carcinoma

Basal cell carcinoma (BCC) is the most common form of human cancer, with a continually increasing annual incidence in the United States. When diagnosed early, the majority of BCCs are readily treated with office-based therapy, which is highly curative. In these evidence-based guidelines of care, we provide recommendations for the management of patients with BCC, as well as an in-depth review of the best available literature in support of these recommendations. We discuss biopsy techniques for a clinically suspicious lesion and offer recommendations for the histopathologic interpretation of BCC. In the absence of a formal staging system, the best available stratification based on risk for recurrence is reviewed. With regard to treatment, we provide recommendations on treatment modalities along a broad therapeutic spectrum, ranging from topical agents and superficially destructive modalities to surgical techniques and systemic therapy. Finally, we review the available literature and provide recommendations on prevention and the most appropriate follow-up for patients in whom BCC has been diagnosed.

On the horizon: Optical imaging for cutaneous squamous cell carcinoma

Surgical resection with negative margins remains the standard of care for high‐risk cutaneous squamous cell carcinoma (SCC). However, surgical management is often limited by poor intraoperative tumor visualization and inability to detect occult nodal metastasis. The inability to intraoperatively detect microscopic disease can lead to additional surgery, tumor recurrence, and decreased survival.