Risk Factors and Diagnosis of Advanced Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common cancer affecting humans. The combination of the increasing incidence and high mortality in advanced stages of the disease, defines cSCC as an emerging public health problem. Advanced disease includes metastatic and locally advanced cSCC. Metastatic disease refers to the presence of locoregional metastasis (in transit or to regional lymph nodes) or distant metastasis. Locally advanced disease has been defined as non-metastatic cSCC that is unlikely to be cured with surgery, radiotherapy, or combination treatment. While metastatic cSCC is easily diagnosed, locally advanced disease lacks consensus definition and diagnosis is made after multidisciplinary board consultation. Identifying patients with aggressive cSCC at highest risk for relapse may prevent the occurrence of advanced disease. Prognostic factors suggested by most guidelines include tumor diameter (>2 cm), localization on temple/ear/lip/area, thickness (>6 mm), or invasion beyond subcutaneous fat, poor grade of differentiation, desmoplasia, perineural invasion, bone erosion, immunosuppression, undefined borders, recurrence, growth rate, site of prior radiotherapy, and lymphatic or vascular involvement. Although risk factors associated with worse outcomes are well known, there is still a gap of knowledge on the precise risk of each factor taken individually. The aim of this review is to summarize cSCC prognostic factors and encompass the various staging systems to guide management and follow-up in cSCC patients at higher risk for local recurrence and metastasis. Finally, we describe the hallmarks of the advanced disease. Advanced cSCC diagnosis should be made by a multidisciplinary board considering patients' performance status and disease characteristics.

Molecular alterations in basal cell carcinoma subtypes.

A number of genes have been implicated in the pathogenesis of BCC in addition to the Hedgehog pathway, which is known to drive the initiation of this tumour. We performed in-depth analysis of 13 BCC-related genes (CSMD1, CSMD2, DPH3 promoter, PTCH1, SMO, GLI1, NOTCH1, NOTCH2, TP53, ITIH2, DPP10, STEAP4, TERT promoter) in 57 BCC lesions (26 superficial and 31 nodular) from 55 patients and their corresponding blood samples. PTCH1 and TP53 mutations were found in 71.9% and 45.6% of BCCs, respectively. A high mutation rate was also detected in CSMD1 (63.2%), NOTCH1 (43.8%) and DPP10 (35.1%), and frequent non-coding mutations were identified in TERT (57.9%) and DPH3 promoter (49.1%). CSMD1 mutations significantly co-occurred with TP53 changes (p = 0.002). A significant association was observed between the superficial type of BCC and PTCH1 (p = 0.018) and NOTCH1 (p = 0.020) mutations. In addition, PTCH1 mutations were significantly associated with intermittent sun exposure (p = 0.046) and the occurrence of single lesions (p = 0.021), while NOTCH1 mutations were more frequent in BCCs located on the trunk compared to the head/neck and extremities (p = 0.001). In conclusion, we provide further insights into the molecular alterations underlying the tumorigenic mechanism of superficial and nodular BCCs with a view towards novel rationale-based therapeutic strategies.

Intra-patient Heterogeneity of BRAF and NRAS Molecular Alterations in Primary Melanoma and Metastases.

Mutations in MAPK signalling genes are driver events in melanoma, and have therapeutic relevance in the metastatic and adjuvant setting. This study evaluated the intra-patient heterogeneity of BRAF, NRAS and c-KIT mutational status between 30 primary melanomas and 39 related metastases, using molecular analysis and immunohistochemistry. BRAF mutations were identified in 46.7% of primary melanomas and 48.7% of metastases and NRAS mutations in 20% and 25.6%, respectively. Intra-patient heterogeneity was detected in 13.3% of patients for both BRAF and NRAS genes and was not associated with clinico-pathological characteristics of melanomas or metastases. High consistency was observed between immunostaining and molecular methods for BRAFV600E (k = 0.90; p < 0.001) and NRASQ61R (k = 0.87; p < 0.001). These findings demonstrate a relevant intra-patient heterogeneity between primary and metastatic lesions that is independent of clinical variables and methodological approach.

Telomeres and Telomerase in Cutaneous Squamous Cell Carcinoma.

The role of telomere biology and telomerase activation in skin cancers has been investigated in melanoma and basal cell carcinoma but limited evidence is available for cutaneous squamous cell carcinoma (cSCC). We will review the current knowledge on the role of telomere and telomerase pathway in cSCC pathogenesis. At the somatic level, both long and short telomere lengths have been described in cSCC. This telomere dichotomy is probably related to two different mechanisms of tumour initiation which determines two tumour subtypes. Telomere shortening is observed during the invasive progression from in situ forms of cSCC, such as Bowen's disease (BD) and actinic keratosis (AK), to invasive cSCC. At the germline level, controversial results have been reported on the association between constitutive telomere length and risk of cSCC. Approximately 75⁻85% of cSCC tumours are characterized by a high level of telomerase activity. Telomerase activation has been also reported in AKs and BD and in sun-damaged skin, thus supporting the hypothesis that UV modulates telomerase activity in the skin. Activating TERT promoter mutations have been identified in 32⁻70% of cSCCs, with the majority showing the UV-signature. No significant correlation was observed between TERT promoter mutations and cSCC clinico-pathological features. However, TERT promoter mutations have been recently suggested to be independent predictors of an adverse outcome. The attention on telomere biology and telomerase activity in cSCC is increasing for the potential implications in the development of effective tools for prognostic assessment and of therapeutic strategies in patients with cutaneous cSCC.

Syringotropic Lichen Planus: A Potential Histopathologic Mimicker of Syringotropic Mycosis Fungoides.

Perieccrine inflammation may be observed in several different dermatoses, but true permeation of the secretory coil by lymphocytes (lymphocytic syringotropism) is a rather uncommon finding, usually observed in mycosis fungoides (MF-syringotropic MF). Rare cases of syringotropic lichen striatus and lymphocytic autoimmune hidradenitis showing a similar pattern have been described as well. We describe an exceptional case of lichen planus (LP) characterized by marked lymphocytic syringotropism with focal hyperplasia of the eccrine epithelium. Histopathology was characterized by the combination of features of conventional LP, prominent permeation of the secretory portion of the eccrine glands by reactive lymphocytes, and focal involvement of a hair follicle. Syringotropic LP may be regarded as a histologic mimicker of syringotropic MF, thus representing a potential diagnostic pitfall.

Staging and follow-up of cutaneous melanoma patients.

Melanoma is responsible for the greatest number of deaths caused by skin malignancies. The purpose of monitoring patients diagnosed with melanoma is to allow early detection of recurrence and any subsequent primary tumors. Several dermatological and oncological societies developed their own set of guidelines for the surveillance and management of melanoma patients depending on the stage of the disease. The object of this article is to provide a comprehensive, systematic overview that summarizes and interprets previous studies, to characterize current practices regarding progression of melanoma, division into stages of development, and subsequent surveillance. We have performed a systematic review search to December 2016 using the MEDLINE database and performed a manual search of selected references. We examined the staging system and the different surveillance programs for melanoma patients. Consistent recommendations with proven evidence are available for staging melanoma patients. Conversely, recommendations are more controversial for follow-up procedures. Given the inadequate number of randomized controlled trials, consensus on the best, universally-applicable follow-up procedure has not been reached and interpretation of the roles of imaging and laboratory tests, as well as of the appropriate frequency and duration of physical examinations, vary widely. Based on a universally-accepted staging system different surveillance procedures have been developed, which may be mainly classified in two groups: low- and high-intensity strategies.