Mohs Micrographic Surgery for the Treatment of External Ear Melanoma: an Outcome Study

The circular RNA expression profile of human auricle cartilage and the role of circCOL1A2 in isolated microtia

Microtia is one of the most common craniofacial birth defects worldwide, and its primary clinical manifestation is auricle deformity. Epigenetic factors are known to contribute to the etiology of microtia, yet the involvement of circular RNAs (circRNAs) in human auricle development and their association with microtia remains poorly understood. In this study, we aimed to analyze differentially expressed circRNAs and explore their functional implications in isolated microtia. By employing circRNA microarray analysis and bioinformatics approaches, we identified 340 differentially expressed circRNAs in auricle cartilage of patients with isolated microtia, comprising 152 upregulated and 188 downregulated circRNAs. A circRNA-mRNA co-expression network was constructed, followed by gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Subsequently, we selected four significantly upregulated circRNAs from the co-expression network based on their association with cartilage development and validated their expressions in 30 isolated microtia and 30 control clinical auricle cartilage samples. Among these circRNAs, circCOL1A2, the most significantly upregulated circRNA, was selected as a representative circRNA for investigating its role in isolated microtia. Overexpression of circCOL1A2 significantly inhibited chondrocyte proliferation and chondrogenic differentiation of human mesenchymal stem cells. Additionally, circCOL1A2 upregulated Dermatan Sulfate Epimerase Like (DSEL) expression by sponging miR-637 through the competing endogenous RNA (ceRNA) mechanism. Notably, the downregulation of DSEL attenuated the inhibitory effect of circCOL1A2 overexpression on cell proliferation and chondrogenic differentiation. Collectively, these findings highlight the involvement of circCOL1A2 in the pathogenesis of isolated microtia and emphasize the potential significance of dysregulated circRNAs in disease development.

A review of Mohs Micrographic Surgery for skin cancer: Part 1 - melanoma and rare skin cancers

Mohs micrographic surgery is a precise and effective method commonly used to treat high risk basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) on the head and neck. Whilst the majority of evidence for Mohs relates to keratinocyte cancers, there is published evidence for other types of skin cancer. This review aims to discuss the evidence for using MMS to treat six different types of skin cancer, including melanoma, lentigo maligna, dermatofibrosarcoma protuberans, atypical fibroxanthoma, microcystic adnexal carcinoma and pleomorphic dermal sarcoma, particularly in the context of survival rates and cancer recurrence. These cancers were chosen as there was sufficient literature for inclusion and given MMS is most useful when cancers are contiguous, rather than for cancers with marked metastatic potential such as angiosarcoma or merkel cell carcinoma. We searched Medline, Pubmed and Embase using the keywords: 'melanoma', 'mohs micrographic surgery', 'lentigo maligna', 'dermatofibrosarcoma protuberans', 'atypical fibroxanthoma', 'microcystic adnexal carcinoma' and 'pleomorphic dermal sarcoma' along with their appropriate synonyms, to identify the relevant English-language articles from the year 2000 onwards given that literature for Mohs on non-keratinocyte is sparse prior to this date. A MeaSurement Tool to Assess systematic Reviews (AMSTAR) was used to assess the validity of systematic reviews. Further high-quality, multi-centre randomised trials are necessary to establish the indications and efficacy of MMS for rarer cancers, particularly for AFX and PDS, where limited studies were identified.

Systematic Review of the Role of Mohs Micrographic Surgery in the Management of Early-Stage Melanoma of the Head and Neck

BACKGROUND

The role of Mohs micrographic surgery (MMS) in the management of melanoma of the head and neck (HNM) has been controversial. The authors systematically reviewed the local recurrence rate of melanoma in situ (MIS) and T1a melanomas using MMS compared with conventional wide local excision (WLE) and staged excision (SE).

OBJECTIVE

To systematically review the local recurrence rate of early-stage melanomas of the HNM treated with MMS versus WLE or SE.

METHODS AND MATERIALS

A search of English medical literature was conducted through the common databases until November 26, 2019. Using PRISMA guidelines for the treatment of MIS and T1a melanoma with MMS, WLE, or SE, our search yielded a total of 32 articles.

RESULTS

Mohs micrographic surgery has a lower local recurrence rate for early-stage melanomas over both SE and WLE {pooled recurrence risk 0.8% (95% confidence interval [CI] 0.4-1.1) versus 2.5% (95% CI 1.5-3.4) versus 8.7% (95% CI 5.1-12.2) (p < .001), respectively}.

CONCLUSION

Mohs micrographic surgery may offer a lower recurrence rate than SE or WLE in the management of early-stage melanomas of the face or HNM. Further clinical validation in a randomized controlled trial is required.