Lentigo Maligna Research Articles

Characterization of the CpG Island Hypermethylated Phenotype Subclass in Primary Melanomas

Cutaneous melanoma can be lethal even if detected at an early stage. Epigenetic profiling may facilitate the identification of aggressive primary melanomas with unfavorable outcomes. We performed clustering of whole-genome methylation data to identify subclasses that were then assessed for survival, clinical features, methylation patterns, and biological pathways. Among 89 cutaneous primary invasive melanomas, we identified three methylation subclasses exhibiting low methylation, intermediate methylation, or hypermethylation of CpG islands, known as the CpG island methylator phenotype (CIMP). CIMP melanomas occurred as early as tumor stage 1b and, compared with low-methylation melanomas, were associated with age at diagnosis ≥65 years, lentigo maligna melanoma histologic subtype, presence of ulceration, higher American Joint Committee on Cancer stage and tumor stage, and lower tumor-infiltrating lymphocyte grade (all P < 0.05). Patients with CIMP melanomas had worse melanoma-specific survival (hazard ratio= 11.84; confidence interval= 4.65‒30.20) than those with low-methylation melanomas, adjusted for age, sex, American Joint Committee on Cancer stage, and tumor-infiltrating lymphocyte grade. Genes hypermethylated in CIMP compared with those in low-methylation melanomas included PTEN, VDR, PD-L1, TET2, and gene sets related to development/differentiation, the extracellular matrix, and immunity. CIMP melanomas exhibited hypermethylation of genes important in melanoma progression and tumor immunity, and although present in some early melanomas, CIMP was associated with worse survival independent of known prognostic factors.

Fluorescence-advanced videodermatoscopy (FAV) for the differential diagnosis of suspicious facial lesions: A single-centre experience with pattern analysis and histopathological correlation.

Fluorescence-advanced videodermatoscopy (FAV) is a new non-invasive high-resolution skin imaging technique to assess pigmented lesions in conjunction with the clinical examination and dermatoscopy. This is the first prospective study to identify morphologic descriptors and standardized terminology to examine facial pigmented lesions using FAV. The objectives were to identify FAV indicators, which can assist physicians in diagnosing suspicious flat facial pigmented lesions. Consecutive equivocal pigmented lesions were retrospective analysed. Histopathological examination was performed for all the lesions. The main cytomorphological and cytoarchitectural FAV features were described and correlated with histopathological characteristics. From January to October 2020, 21 consecutive clinically suspected pigmented lesions in 20 patients were analysed using dermatoscopy and FAV and then surgically excised. Histopathological examination identified lentigo maligna (LM), lentigo maligna melanoma (LMM), solar lentigo (SL), flat seborrheic keratosis (SK) and pigmented actinic keratosis (PAK). Thirteen malignant melanocytic lesions were removed (11 LM, 2 LMM), two were diagnosed as PAK, and the remaining six pigmented lesions were SL-SKs. With FAV, large ovoid pleomorphic and dendritic cells arranged in the intrafollicular disposition, are typical of most malignant melanocytic lesions (12/13, 92.3%). No benign lesions displayed these features. In dermatoscopy, this folliculotropism corresponded to the presence of an annular-granular pattern with slate grey dots that were aggregated asymmetrically around follicular openings. FAV features can provide an improved diagnostic approach in the differential diagnosis of flat pigmented facial lesions.

The clinicopathologic spectrum and genomic landscape of de-/trans-differentiated melanoma

Dedifferentiation and transdifferentiation are rare and only poorly understood phenomena in cutaneous melanoma. To study this disease more comprehensively we have retrieved 11 primary cutaneous melanomas from our pathology archives showing biphasic features characterized by a conventional melanoma and additional areas of de-/trans-differentiation as defined by a lack of immunohistochemical expression of all conventional melanocytic markers (S-100 protein, SOX10, Melan-A, and HMB-45). The clinical, histologic, and immunohistochemical findings were recorded and follow-up was obtained. The patients were mostly elderly (median: 81 years; range: 42–86 years) without significant gender predilection, and the sun-exposed skin of the head and neck area was most commonly affected. The tumors were deeply invasive with a mean depth of 7 mm (range: 4–80 mm). The dedifferentiated component showed atypical fibroxanthoma-like features in the majority of cases (7), while additional rhabdomyosarcomatous and epithelial transdifferentiation was noted histologically and/or immunohistochemically in two tumors each. The background conventional melanoma component was of desmoplastic (4), superficial spreading (3), nodular (2), lentigo maligna (1), or spindle cell (1) types. For the seven patients with available follow-up data (median follow-up period of 25 months; range: 8–36 months), two died from their disease, and three developed metastases. Next-generation sequencing of the cohort revealed somatic mutations of established melanoma drivers including mainly NF1 mutations (5) in the conventional component, which was also detected in the corresponding de-/trans-differentiated component. In summary, the diagnosis of primary cutaneous de-/trans-differentiated melanoma is challenging and depends on the morphologic identification of conventional melanoma. Molecular analysis is diagnostically helpful as the mutated gene profile is shared between the conventional and de-/trans-differentiated components. Importantly, de-/trans-differentiation does not appear to confer a more aggressive behavior.

High regional mortality due to malignant melanoma in Eastern Finland may be explained by the increase in aggressive melanoma types

BackgroundA regional skin cancer prevention program in Eastern Finland revealed a relatively high age-standardized mortality due to malignant melanoma during 2013–2017. An explanation for this is needed.PurposeTo analyse the 543 melanoma samples in 524 subjects collected during 2000–2013 at Kuopio University Hospital and reposited in the Biobank of Eastern Finland. A focus was directed to factors related to metastasis.MethodsThe samples were analysed anonymously by examining the histopathological report, referral text and the list of diagnoses. A possible state of immunosuppression was evaluated.ResultsThe mean age at the diagnosis of malignant melanoma (MM), lentigo maligna (LM) and melanoma in situ was relatively high, i.e., 66.2, 72.1 and 63.3, respectively. Especially the MM type increased markedly during 2000–2013. In further analyses of a representative cohort of 337 samples, the proportion of nodular melanoma and LM/LMM melanoma was relatively high, 35.6 and 22.0%, respectively, but that from superficial spreading melanoma relatively low (33.8%). Metastasis correlated with immunosuppression, male gender, Clark level, Breslow thickness, ulceration, mitosis count, invasion into vessels and/or perineural area, microsatellites, melanoma subtype, body site, recidivism, and the absence of dysplastic nevus cells.ConclusionThe marked increase in aggressive melanomas with associated metastasis, and the relatively high age at diagnosis, can partially explain the mortality.

A Review of Immunocryosurgery and a Practical Guide to Its Applications.

Immunocryosurgery is a minimally invasive combinational therapeutic procedure that has been designed, developed, and evaluated in the Dermatology Department of the University of Ioannina from 2004. In a fixed time protocol, this approach combines immune stimulatory therapy with imiquimod and cryosurgery, i.e., cryosurgery is applied during continuous imiquimod treatment. Laboratory findings in tissue and blood level credit the efficacy to the synergy of imiquimod and cryosurgery. The synergy has been established through clinical trials and the excellent feasibility and efficacy demonstrated in clinical practice. Immunocryosurgery has extensive proof of excellent efficacy, comparable to surgery, in the treatment of basal cell carcinoma. It has also been evaluated in cases of Bowen’s disease, keratoacanthoma, Merkel cell carcinoma, lentigo maligna, and cutaneous squamous cell carcinoma with or without the addition of adjuvants. The aims of this review are to detail the immunocryosurgery protocol with the addition of daily practice clinical tips, compile data on the mechanism of action of immunocryosurgery, and delineate indications and possible future applications. Most of the available data originate from the treatment of BCC, of all histological types and localizations, and the principles reported mainly reflect on evidence related to the treatment of this common skin cancer.

795 Adequacy of Surgical Excision Margins in Lentigo Maligna: An Audit

Abstract Aim The optimal excision margin for Lentigo Maligna (LM) lesions has been a frequent topic of debate. An audit was carried out to compare the excision margins used for LM excisions with current NICE guidelines, and to assess the adequacy of these excision margins. Method A retrospective study was carried out to analyse all excisions of LM lesions in 2018. 33 patients were identified from the plastic surgery departmental database. Patient demographics, the site and distribution of LM lesions, and any history of previous skin cancer were analysed. Patient electronic records, operative notes, and histopathological reports were examined to determine the number of excisions done for each LM lesion along with the peripheral and deep surgical excision margins, and the histological clearance achieved. Complete histological clearance was determined by the Multidisciplinary team for each lesion. Results 60 cases were identified. 60% of cases were located on the head and neck. The average peripheral surgical excision margin at first excision was 2.3mm. 55% of patients had a 2nd excision. The average peripheral surgical excision margin at 2nd excision was 5.4mm. 70.6% of cases achieved complete histological clearance at 2nd excision. 72.7% of lesions excised at 2nd excision with a 5mm or less surgical excision margin achieved complete histological clearance. Conclusions Taking &amp;gt;5mm surgical excision margins did not increase the rate of complete histological clearance for Lentigo Maligna lesions.

HSP105 expression in cutaneous malignant melanoma: Correlation with clinicopathological characteristics.

BackgroundHeat shock proteins can protect against stress-associated cellular challenges, but they can also protect some tumors from human immune system monitoring. Heat shock protein 105 (HSP105/110) is a high molecular weight protein whose expression has been reported in many cancers, but few studies on its role in cutaneous malignant melanoma have been published. In this study, we analyzed the relationship between HSP105 expression and the clinicopathological characteristics of CMM.MethodsThis retrospective study included 91 patients with CMM. The clinicopathological characteristics of CMM patients, including age, lesion duration, location, pathological classification, Clark’s level, Breslow thickness, metastasis and recurrence, were collected. Immunohistochemical staining and Western blot analysis for HSP105 were performed. Pigmented nevi (n = 20) served as a control. The staining intensity and percentage of stained cells were expressed as a histochemical score (HSCORE).ResultsHSP105 was overexpressed in melanoma compared with nevi. Differences in the HSCORE between nevi (HSCORE = 1.05(0.15,1.50)) and CMM (HSCORE = 2.68(1.80,3.60)) were remarkable (P<0.001). Exposed site lesions, recurrent and metastatic lesions, nodular melanoma and lentigo maligna melanoma were closely associated with higher HSP105 expression (P = 0.011, P = 0.001 and P = 0.001, respectively). Moreover, no significant difference was observed in Clark’s level, Breslow thickness, or lesion duration (P>0.05).ConclusionHSP105 is overexpressed in CMM. Higher HSP105 expression in lesions is associated with different clinicopathological variables. HSP105 may be a potential target for the diagnosis, treatment and prognostic prediction of CMM.

A practical guide on the use of imiquimod cream to treat lentigo maligna.

Lentigo maligna (LM) is a common insitu melanoma subtype arising on chronically sun-damaged skin and mostly affects the head and neck region. Localisation in cosmetically sensitive areas, difficulty to obtain wide resection margins and advanced patient age/comorbidities have encouraged investigation of less invasive therapeutic strategies than surgery in managing complex cases of LM. Radiotherapy and imiquimod have emerged as alternative treatment options in this context. The treatment of LM with imiquimod cream can be challenging due to the nature of the disease including its often large size, variegated appearance, involvement of adnexal structures, poorly defined peripheral edge and frequent localisation close to sensitive structures such as the eyes and lips, and elderly patients with multiple comorbidities. Prolonged and unpredictable inflammatory reaction and side effects and compliance with a patient-delivered therapy can also be challenging. In the literature to date, studies evaluating the use of imiquimod to treat LM have utilised varying methodologies and provided short follow-up and these limitations have impaired the development of clear guidelines for dosage and management of side effects. Based on our multidisciplinary experience and review of the literature, we propose practical clinical strategies for the use of imiquimod for treating LM, detailing optimal administration procedures in various clinical scenarios and long-term management, with the aim of facilitating optimal patient outcomes.

Improvement of Imiquimod Solubilization and Skin Retention via TPGS Micelles: Exploiting the Co-Solubilizing Effect of Oleic Acid.

Imiquimod (IMQ) is an immunostimulant drug approved for the topical treatment of actinic keratosis, external genital-perianal warts as well as superficial basal cell carcinoma that is used off-label for the treatment of different forms of skin cancers, including some malignant melanocytic proliferations such as lentigo maligna, atypical nevi and other in situ melanoma-related diseases. Imiquimod skin delivery has proven to be a real challenge due to its very low water-solubility and reduced skin penetration capacity. The aim of the work was to improve the drug solubility and skin retention using micelles of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), a water-soluble derivative of vitamin E, co-encapsulating various lipophilic compounds with the potential ability to improve imiquimod affinity for the micellar core, and thus its loading into the nanocarrier. The formulations were characterized in terms of particle size, zeta potential and stability over time and micelles performance on the skin was evaluated through the quantification of imiquimod retention in the skin layers and the visualization of a micelle-loaded fluorescent dye by two-photon microscopy. The results showed that imiquimod solubility strictly depends on the nature and concentration of the co-encapsulated compounds. The micellar formulation based on TPGS and oleic acid was identified as the most interesting in terms of both drug solubility (which was increased from few µg/mL to 1154.01 ± 112.78 µg/mL) and micellar stability (which was evaluated up to 6 months from micelles preparation). The delivery efficiency after the application of this formulation alone or incorporated in hydrogels showed to be 42- and 25-folds higher than the one of the commercial creams.

Laterality and site-specific distribution patterns of Lentigo Maligna and Lentigo Maligna Melanoma

Background: Melanoma has been described to have preferential left-sided laterality on the human body. The distribution and invasion patterns of lentigo maligna (LM) and lentigo maligna melanoma (LMM) have not been well described.&#x0D; Methods: This was a cross-sectional, retrospective study at a single, academic center. LM and LMM cases from 2008-2018 in the dermatopathology registry were analyzed.&#x0D; Results: A total of 392 cases were included (241 LM and 151 LMM). There was no laterality preference overall. The only exception were neoplasms located on the head/neck, which showed a left-sided laterality. LM and LMM had the highest incidence on the head/neck, followed by upper extremities, trunk, then lower extremities. Men had a higher incidence on the head/neck and trunk, while women had a higher incidence on the extremities. Interestingly, the upper extremities and the right side of the female body had a higher propensity for invasive lesions.&#x0D; Conclusion: While melanomas demonstrate preferential left-sided laterality, LM and LMM only share this pattern in respect to the head/neck region. Our results complement previous study findings which characterize LM and LMM as a head/neck and upper extremity pathology. Finally, our study suggests that certain body sites and laterality have an increased propensity for invasion.

Molecular Markers and Targets in Melanoma.

Melanoma develops as a result of several genetic alterations, with UV radiation often acting as a mutagenic risk factor. Deep knowledge of the molecular signaling pathways of different types of melanoma allows better characterization and provides tools for the development of therapies based on the intervention of signals promoted by these cascades. The latest World Health Organization classification acknowledged the specific genetic drivers leading to melanoma and classifies melanocytic lesions into nine distinct categories according to the associate cumulative sun damage (CSD), which correlates with the molecular alterations of tumors. The largest groups are melanomas associated with low-CSD or superficial spreading melanomas, characterized by frequent presentation of the BRAFV600 mutation. High-CSD melanomas include lentigo maligna type and desmoplastic melanomas, which often have a high mutation burden and can harbor NRAS, BRAFnon-V600E, or NF1 mutations. Non-CSD-associated melanomas encompass acral and mucosal melanomas that usually do not show BRAF, NRAS, or NF1 mutations (triple wild-type), but in a subset may have KIT or SF3B1 mutations. To improve survival, these driver alterations can be treated with targeted therapy achieving significant antitumor activity. In recent years, relevant improvement in the prognosis and survival of patients with melanoma has been achieved, since the introduction of BRAF/MEK tyrosine kinase inhibitors and immune checkpoint inhibitors. In this review, we describe the current knowledge of molecular pathways and discuss current and potential therapeutic targets in melanoma, focusing on their clinical relevance of development.

Nitrosamine (and /or Losartan/ Hydrochlorothiazide) Induced Pretibial Located Lentigo Maligna: First Reported Case in the World Literature

A 66-year-old Caucasian woman presented to the dermatology department with complaints of a pigmented lesion on the left shin. She first noticed the lesion in March 2020, several months prior to presentation but decided to seek medical advice after observing substantial growth in the size and shape of the lesion. She was diagnosed with type II arterial hypertension 6 years ago and was started losartan/hydrochlorothiazide 50 mg / 12.5mg half a tablet daily. The patient visits her general practitioner regularly and her hypertension is well controlled on these medications, had no other concomitant diseases and was relatively healthy for her age. No family history for dermatologic diseases was available. On dermatologic examination, a single superficially spreading pretibial lesion covering 1.8 cm wide and 1.2cm high was noted(Figure 1a). The light greyish-pink pigmented lesion was oval in shape with sharply demarcated borders and no elevation above the surrounding skin. Further laboratory work-up showed no signs of deviations. Based on the clinical and dermatoscopic evidence, the diagnosis of melanoma in situ, lentigo maligna type was made. She was sent for treatment at a specialised hospital for oncological diseases in June 2020 where a surgical excision was performed under local anaesthesia with 0.5cm clear/ negative margins in all directions. The defect was thereafter closed using a full-thickness mesh graft taken from the abdominal region(Figure 1b). The excised tumour was subsequently sent for histological evaluation and was keeping with the clinicopathological diagnosis of lentigo maligna. Immunohistochemical analysis also identified S100 positive nests of cells within the basal lamina, confirming the diagnosis.Postsurgical wound healing with the skin graft was poor due to inadequate graft transplantation whereby necrotic as well as macerated areas were observed leadingto bad cosmetic results (Figure 1c-h).After a multidisciplinary review and follow up, a second operation was performed a month later to remove the necrotic, together with the hypertrophic tissue and a new split skin mesh graft was utilised. Stringent post-operative care, including prophylactic antibiotic therapy was also provided to promote good wound healing which was achieved several months later (Figure 1i).

Head and Neck Melanoma: What is the Goal for Margins?

Head and Neck Melanoma: What is the Goal for Margins?

Diagnosis and Management of Lentigo Maligna: Clinical Presentation and Comprehensive Review.

Lentigo maligna (LM), also known as Hutchinson's melanotic freckle, is a form of in situ melanoma characterized by the proliferation of atypical melanocytes along the basal epidermis in sun-damaged skin. If left untreated, LM will progress to lentigo maligna melanoma (LMM), a form of invasive melanoma with the same prognosis as other forms of invasive melanoma. LM is more common in the elderly, with a peak occurrence between the ages of 65 and 80 years. LM, however, is rarely present on the trunk and extremities. The diagnosis of LM, confirmed by histopathological and biopsy examination, is based on clinical and dermoscopic features. It typically begins as a tan-brown macule or patch, but it can progress to a variegated pigmentation with dark black color or even amelanotic characteristics. The risk factors involved in the LM development include a history of sunburns, lighter skin types, advanced age, history of nonmelanoma skin cancers, and tendency to form solar lentigines. This article explains the clinical presentation of LM, also reviews the available information on the diagnosis and management of LM, and discusses the potential of such information in facilitating the future prospective.

Tratamiento quirúrgico del melanoma primario: consideraciones prácticas

The treatment of choice for localized primary melanoma is excisional biopsy followed by margin expansion based on the Breslow depth. Partial biopsies may be appropriate in the initial study of extensive melanomas or in complex locations. The recommended margins for melanoma in situ are 0.5-1 cm, although it seems that, especially in the lentiginous type, they are more convenient the closer to the centimeter. For invasive melanomas, margins of 1 cm in Breslow depth < 1 mm, 1-2 cm in Breslow depth 1-2 mm, and 2 cm in Breslow depth > 2 mm are recommended. Single-stage excision can be considered when selective sentinel node biopsy is rejected, but it is not currently supported by the guidelines. In those cases in which the precision of the complete excision of the lesion must be maximized, mainly in facial lentigo maligna, margin control techniques are recommended. On the other hand, acral melanomas, both subungual, palmar or plantar, require special management given their anatomical complexity.

Collision Cutaneous Neoplasms Consisting of Melanoma and Basal Cell Carcinoma.

Collision tumors are defined as two histologically different tumor types that arise at the same anatomical location. According to the literature review performed, there are reports of 27 cases of collision tumors involving lentigo maligna melanoma (LMM) in-situ and basal cell carcinoma (BCC). In the absence of melanocytic extension beyond the lamina propria of the BCC compartment, mixed tumors are considered as melanoma in-situ colonizing the BCC, rather than invasive melanomas. We report an uncommon case of collision of BCC with LMM, two primary skin tumors that are seen in patients with significant sunlight exposure. In our case, the patient is a 91-year-old male presented with a translucent plaque with areas of brown pigmentation on his left lateral canthus. He had a history of multiple BCCs, squamous cell carcinomas and an invasive melanoma of right cheek. Given the clinical impression of BCC, the lesion was curetted. Histological examination demonstrated melanoma in-situ heavily infiltrating the dermal nodules of BCC. Deposits of melanin pigment were scattered throughout the tumor. The BCC contained about 50% atypical melanocytes. Further immunohistochemical evaluation with melanocytic and epithelial markers (melanin A, SOX-10, pan-cytokeratin and p63) confirmed the diagnosis. An unequivocal independent invasive melanoma component was not identified in this material. The collision of BCC and LMM is very rare. However, given the sun-damaged changes promote both tumors, their development at the same site, although unexpected, can be explained. Since the prognosis of the two entities is independent, wider excision to exclude invasive malignant melanoma is indicated.

Real‐world experience of off‐label use of imiquimod 5% as an adjuvant therapy after surgery or as a monotherapy for lentigo maligna

Because of the tendency of lentigo maligna (LM) for subclinical extension, staged excisions with margin control achieve lower recurrence rates than conventional wide local excision (0-9.5% vs 8-20%). However, these surgical techniques are limited by their requirement in time, costs and training.

Surgical procedures in melanoma: recommended deep and lateral margins, indications for sentinel lymph node biopsy, and complete lymph node dissection.

Surgery is the main treatment for cutaneous melanoma including the primary melanoma as well as lymph node metastases. The recommended margins have changed over time. Similarly, indications for sentinel lymph node biopsy and complete lymph node dissection are constantly evolving if knowledge on the biological behavior of melanomas increases. The current guidelines and the most relevant literature were reviewed to provide an update on the existing recommendations for surgical management of melanoma. Wide excision margins are evidenced-based but not for all situations. Melanoma in situ requires 0.5-1 cm with increasing evidence for 1 cm particularly those presenting on the head-and-neck in the setting of chronic sun damage. Invasive melanomas need 1-2 cm margins, 2 cm for tumors thicker than 2 mm and some large tumors with >1-2 mm thickness and with a lentiginous growth pattern. Lentigo maligna, subungual melanoma, and acral lentiginous melanoma require surgical techniques with complete circumferential peripheral margin assessment. Sentinel lymph node biopsy provides relevant information for melanoma staging. Therefore, it is consistently recommended for melanomas >1-4 mm and highly recommended for melanomas >4 mm, >0.8-1.0 mm or ≤0.8 mm with additional risk factors. Complete lymph node dissection has high morbidity and no impact on survival and is restricted to regional control for clinically detected metastasis. Although the trend is to reduce progressively the recommended surgical margins, further evidence is needed to clarify its role in patients' survival. Sentinel lymph node biopsy is important for establishing a prognosis especially upon considering adjuvant therapy; complete lymph node dissection is only relevant for regional disease control.

A technique for external beam radiotherapy to the eyelid without the need for an internal eye shield

Cancer of the eyelids is difficult to treat. Surgery can lead to tissue loss. Superficial radiotherapy (SXRT) can be used in this scenario, but each fraction requires topical ophthalmic local anaesthetic and the insertion of an internal eye shield (IES) to protect the radiation sensitive anterior structures from the incident beam during beam-on time. The use of an IES comes with challenges. A technique was developed to avoid the IES based on the ability of selected cooperative patients to move the anterior structures out of the incident beam during beam-on time. We present two cases in which this technique was used. Case 1 involves the lower eyelid and case 2 the upper eyelid. Case 1 was a 69-year old, immunosuppressed woman needing definitive SXRT for lentigo maligna (LM) of the lower eye lid. She was treated using the new non-IES technique to a total dose of 50 Gy in 25 fractions using a 100 kV beam from a superficial Xstrahl 300 radiotherapy unit (Xstrahl, Surrey, UK). In vivo dosimetry (IVD) measured during a fraction on the posterior of the external eye shield located above the anterior structures showed that the transmitted dose through the external eye shield was less than ten percent of the dose applied. The patient developed conjunctivitis during SXRT that responded to topical antibiotics. Ophthalmology review five months post SXRT showed no change in eye function from baseline. Reflectance confocal microscopy (RCM) eight months after SXRT showed no LM. Case 2 was a 72-year old woman needing post-operative radiotherapy (PORT) for sebaceous cell carcinoma (SebC) of the upper eyelid. She was treated with 60 Gy in 30 fractions at 5 fractions per week with 100kV SXRT using the new non-IES technique. All the treatment was delivered on time. As per Case 1, IVD under the external eye shield showed the transmitted dose was ten percent of the dose applied. Ophthalmology review pre- and post-RT showed no change in eye function. She remains in complete remission six months after the end of PORT. The new non-IES technique is safer and quicker and simplifies the workflow. This has become the standard technique in our department for treating eyelids with SXRT. Multidisciplinary care involving an ophthalmologist pre- and post-SXRT is advised.

Abstract 796: Investigating incidence and survival patterns of cutaneous malignant melanoma in the United States from 2006-2017

Abstract Introduction: Skin cancers are one of the most common cancers in the United States with melanoma being the fifth leading cause of cancer. Despite its increasing incidence, there are limited studies on how skin cancer affects different races and ethnicities. Here, we conduct a population-based registry study to derive incidence and survival patterns of cutaneous malignant melanoma (CMM) in the US from 2006-2017. 17 population-based cancer registries from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute were reviewed. A total of 58,666 cases with histologically confirmed cases of cutaneous malignant melanoma were evaluated. Surprisingly, the CMM subtype that was predominantly found in the non-Hispanic whites (56%) and Hispanic whites (45%) was acral lentiginous melanoma, while “other” melanomas were predominant in the Asian (54%) and Black (77%) populations. Superficial spreading and lentigo maligna melanomas presented more commonly in men (69% and 63%). In addition, nodular and lentigo maligna melanomas had the poorest survival rates and had a median survival of 26 and 21 months. Methods: The Surveillance, Epidemiology, and End Results Program (SEER) of the National Cancer Institute was used to calculate the incidence, proportion, and survival data. 58,66 histologically confirmed CMM cases reported by the 17 cancer registries from 2006-2017 were used. The 17 registries include 14 states (Alaska, greater and California, Connecticut, Georgia, Hawaii, Idaho, Iowa, Kentucky, Louisiana, Massachusetts, New Mexico, New York, Utah, Washington) and 4 standard metropolitan areas (Los Angeles, San Francisco-Oakland, and San Jose-Monterey, California; and Seattle-Puget Sound, Washington). Cases of the 4 major CMM subtypes as well as the “other” subtypes were identified using the World Health Organization's International Classification of Diseases for Oncology (ICD-0-3) morphology code. Conclusion and future direction: CMM has been steadily increasing in incidence within the US. Moreover, the incidence rate of CMM in the Hispanic population has been rising. It is important that we continue to assess the epidemiological characteristics and trends of CMM subtypes in the US and increase awareness of skin cancer and its preventative measures in the Hispanic population. In addition, future studies should analyze the genetic and environmental factors that may be contributing to observed incidence rates in the Hispanic population. Citation Format: Yae Kye, Luis Alvarado, Alok Dwivedi, Jessica Chacon. Investigating incidence and survival patterns of cutaneous malignant melanoma in the United States from 2006-2017 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 796.