A systematic review on the role of imiquimod in lentigo maligna and lentigo maligna melanoma: need for standardization of treatment schedule and outcome measures

Successful implementation of handheld reflectance confocal microscopy as the standard of care in the (surgical) management of lentigo maligna (melanoma)

BACKGROUND

Reflectance confocal microscopy (RCM) has shown promise in predicting surgical outcomes by non-invasively detecting subclinical lentigo maligna (melanoma) (LM/LMM).

OBJECTIVES

To assess the effects of presurgical mapping using handheld RCM (HH-RCM) on surgical treatment, follow-up outcomes and management decisions.

METHODS

A total of 117 consecutive LM/LMM cases (2015-2023) were included. The diagnostic accuracy of HH-RCM in detecting subclinical LM and invasive components was evaluated. The primary endpoints included histological margin status and changes in management based on the outcomes of the HH-RCM mapping procedure. Margin and follow-up outcomes were compared to a historical cohort before HH-RCM was introduced in our center (n = 94) (2003-2014).

RESULTS

HH-RCM detected subclinical LM in 60% (n = 60) of cases. The median mapping duration was 14 min (range 4-50). In 27% (n = 33), the mapping procedure resulted in modified management, the majority consisting of limited surgery with adjuvant imiquimod (n = 15) or imiquimod monotherapy (n = 14). The remaining cases (n = 84) underwent HH-RCM-assisted surgery. Histological margins were cleared in 96.5% of the patients with a median histological margin of 3.0 mm, significantly higher than 81% in the historical cohort (median 2.0 mm) (p = 0.001). The sensitivity and specificity for detecting the extent of subclinical LM were 94% (95% CI 80.4-99.3) and 84% (95% CI 70.3-92.7), respectively. The negative predictive value for the detection of LMM was 94% (95% CI 84.4-97.7), and 75% of the initially missed LMM (n = 12) were identified during the HH-RCM mapping procedure. The study cohort had a 1.6% local recurrence rate compared with 25% in the historical cohort.

CONCLUSIONS

Integrating HH-RCM as the standard of care could lead to more personalized treatment strategies for LM/LMM and allows for the selection of patients suitable for nonsurgical treatment.

Cutaneous melanoma in situ: a review

Cutaneous melanoma in situ (MIS), also known as 'stage 0 melanoma', is a collection of malignant melanocytes in the epidermis and epithelial adnexa, without evidence of microinvasion to the papillary dermis. Distinct histological subtypes include lentigo maligna (LM), superficial spreading (SS) MIS and acral lentiginous (AL) MIS. LM is the most common subtype, usually diagnosed later in life (median age at diagnosis of 66-72 years) and associated with cumulative ultraviolet radiation exposure. SS MIS is associated with intense episodes of sun exposure and is more common on the trunk and extremities. AL MIS is seen in nonhair-bearing skin. AL MIS, although rare (0.6% of MIS in England), is found in a higher proportion in more pigmented skin types compared with other MIS subtypes. Most international studies between 1990 and 2019 report rising incidence for MIS. US data show a decline in the incidence of LM between 2015 and 2019. For 2013-2019 in England, the recorded incidence of LM is plateauing, whereas that of other MIS is rising. Definitive diagnosis of MIS is by histological examination of biopsied skin with immunohistochemistry but can be supported with dermoscopy and reflectance confocal microscopy. Surgical treatment (excision or Mohs micrographic surgery) is the gold standard. Depending on MIS subtype, other options such as cryotherapy, topical imiquimod, radiotherapy or watchful waiting may be appropriate. The latest 5-year net-survival rates in England between 2013 and 2015 are 98.6% for AL MIS and exceed 100% for all other MIS. This review summarizes the aetiology, pathogenesis, epidemiology, diagnosis and management of MIS.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2024

A unique collaboration of multi-disciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with one to two-centimeter safety margins. For a correct stage classification and treatment decision, a sentinel lymph node biopsy shall be offered in patients with tumor thickness ≥ 1.0 mm or ≥ 0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions should be primarily made by an interdisciplinary oncology team ("Tumor Board"). Adjuvant therapies can be proposed in completely resected stage IIB-IV. In stage II only PD-1 inhibitors are approved. In stage III anti-PD-1 therapy or dabrafenib plus trametinib for patients with BRAFV600 mutated melanoma can be discussed. In resected stage IV, nivolumab can be offered, as well as ipilimumab and nivolumab, in selected, high-risk patients. In patients with clinically detected macroscopic, resectable disease, neoadjuvant therapy with ipilimumab plus nivolumab followed complete surgical resection and adjuvant therapy according to pathological response and BRAF status can be offered. Neoadjuvant therapy with pembrolizumab followed by complete surgical resection and adjuvant pembrolizumab is also recommended. For patients with disease recurrence after (neo) adjuvant therapy, further treatment should consider the type of (neo) adjuvant therapy received as well as the time of recurrence, i.e., on or off therapy. In patients with irresectable stage III/IV disease systemic treatment is always indicated. For first line treatment PD-1 antibodies alone or in combination with CTLA-4 or LAG-3 antibodies shall be considered. In stage IV melanoma with a BRAFV600 mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy, in selected cases. In patients with primary resistance to immunotherapy and harboring a BRAFV600 mutation, this therapy shall be offered as second line. Other second line therapies include therapy with tumor infiltrating lymphocytes and combinations of immune checkpoint inhibitors not used in first line. This guideline is valid until the end of 2026.

Geriatric dermatologic surgery part I: Frailty assessment and palliative treatments in the geriatric dermatology population

Longer life expectancy and increasing keratinocyte carcinoma incidence contribute to an increase in geriatric patients presenting for dermatologic surgery. Unique considerations accompany geriatric patients including goals of care, physiologic changes in medication metabolism, cognitive decline, and frailty. Limited geriatric training in dermatology residency has created a knowledge gap and dermatologic surgeons should be familiar with challenges facing older patients to provide interventions more congruent with goals and avoid overtreatment. Frailty assessments including the Geriatric 8 and Karnofsky Performance Scale are efficient tools to identify patients who are at risk for poor outcomes and complications. When frail patients are identified, goals of care discussions can be aided using structured palliative care frameworks including the 4Ms (what matters, medications, mentation, and mobility), REMAP (reframing, expecting emotion, mapping patient goals, aligning patient goals, and proposing a plan), and Serious Illness Conversation Guide. Most geriatric patients will tolerate standard of care treatments including invasive modalities like Mohs surgery and excision. However, for frail patients, nonstandard treatments including topicals, energy-based devices, and intralesional chemotherapy may be appropriate options to limit patient morbidity while offering reasonable disease control.

Head and neck melanoma: the eyelid region has a better prognosis and easier management. A retrospective survey and systematic review

Eyelid melanoma (EM) is a malignant neoplasm accounting for around 1% of eyelid malignancies. Because of its rarity, most of our knowledge of EM is currently based on studies of cutaneous melanomas located elsewhere. Accordingly, this study aimed to specifically evaluate EM characteristics, management strategies, and prognosis. A retrospective study was carried out on patients diagnosed with EM at Careggi University Hospital, Florence between May 2012 and May 2022. In addition, a systematic review of relevant literature was conducted, encompassing studies published from 2013 to 2023. Clinical, histopathological, therapeutical, and prognostic data were analyzed to assess the metastasis rate and the 5-year survival rate of patients with EM. Separate data were extracted for in situ and invasive disease. Our original study included 19 patients diagnosed with EM with a 5-year survival rate of 100% for in situ and 83.3% for invasive EM. The literature review identified five poorly detailed large database reviews and 14 original studies on EM with an overall 5-year survival rate of 79.7%. The present research indicates that EM is a challenging malignancy, but has a relatively better prognosis and easier management than other melanomas of the head and neck region. These are probably related to the anatomical location which leads to early diagnosis. Therefore, EM should be considered as a specific disease requiring dedicated treatment. Based on the personal authors' experience and comprehensive overview of the current knowledge, a dedicated protocol is proposed.

Lentigo maligna: a comprehensive review on diagnosis and treatment

Lentigo maligna (LM), a form of melanoma in situ, and LM melanoma (LMM), its invasive counterpart, exhibit distinctive epidemiology, risk factors, and clinical features compared to other melanoma subtypes. Notably, LM occurs on chronically sun-damaged skin presenting as a slow-growing, ill-defined patch which makes it difficult to diagnose and to treat. Additionally, while LM generally presents a favourable prognosis, it can also lead to dermal invasion and behave similarly to other melanomas with the same Breslow thickness. Hence, surgery continues to be the cornerstone treatment. Wide excisions are often necessary, but challenges arise when these lesions manifest in cosmetically sensitive regions, limiting the feasibility and desirability of large excisions. Specialized approaches, including margin-controlled surgery and image-guided treatment with reflectance confocal microscopy, have been developed to address these issues. Other non-surgical treatments such as cryosurgery, imiquimod, radiotherapy, or photodynamic therapy, may also be used but commonly present with recurrent/persistent disease. Herein we comprehensively review the existing literature on the management of LM/LMM, and discus the potential new advances on managing this challenging skin cancer.

Lentigo Maligna Treatment-An Update

Lentigo maligna (LM) is a melanoma in situ that is prevalent in chronically sun-damaged skin. Characterized by a slow growth pattern and high mutation rates due to chronic UV exposure, LM poses diagnostic and therapeutic challenges, particularly given its tendency to mimic other skin lesions and its occurrence in cosmetically sensitive areas. Its diagnosis is based on an integrated approach using dermoscopy and reflectance confocal microscopy (RCM). Despite its slow progression, LM can evolve into lentigo maligna melanoma (LMM), making its treatment necessary. Treatment modalities encompass both surgical and non-surgical methods. Surgical treatments like Wide Local Excision (WLE) and Mohs Micrographic Surgery (MMS) aim for clear histological margins. WLE, a standard melanoma surgery, faces challenges from LM's subclinical extensions, which increase the recurrence risk. MMS, effective for large or poorly defined lesions, is defined by precise margin control while considering cosmetic outcomes. Non-surgical options, including radiotherapy and imiquimod, are alternatives for non-surgical candidates. Radiotherapy has been effective since the 1950s, offering good control and cosmetic results, especially for older patients. Imiquimod, an immunomodulator, shows promise in treating LM, though its application remains off-label. The increasing incidence of LM/LMM necessitates a balance in treatment choices to minimize recurrence and maintain cosmetic integrity. A multidisciplinary approach, integrating clinical examination with dermoscopy and RCM and histological assessment, is essential for accurate diagnosis and effective LM management.

Lentigo maligna: a review

Lentigo maligna (LM) is a melanoma in situ with distinct clinical features and histology. It commonly affects men after the sixth decade of life. Incidence rates of LM have increased based on early 21st century data from different countries; however, data are suboptimal. Data from England show a plateauing crude incidence between 2013 and 2019. By comparison, invasive melanoma and other types of melanoma in situ commonly appears in younger age groups (median age 58 and 67 years old, respectively) and incidence is rising. The most important risk factors for LM include fair skin and cumulative ultraviolet solar radiation exposure. Although LM is limited to the epidermis and connected skin adnexa, it may progress to invasive LM melanoma. The reported rate of malignant progression varies, reflecting a challenge for LM epidemiology research as often lesions are removed on diagnosis. LM poses a challenge in diagnosis and management. Although it can be diagnosed clinically or dermoscopically, histopathological assessment of biopsied skin tissue remains the gold standard. Reflectance confocal microscopy allows for better appreciation of the complexity of LM at a cellular level, often progressing beyond clinical margins. Management of LM may involve Mohs micrographic surgery or excision, although recurrence may occur even with 5 mm clinical margins. Imiquimod cream may be effective, but incomplete treatment and recurrence has been reported. Conservative management with observation or radiotherapy may be used in selected patients' cases. Five-year net survival rates are excellent. This paper reviews the natural history, epidemiology, aetiology, pathogenesis, diagnosis and management of LM.

The Reporting and Methodological Quality of Systematic Reviews Underpinning Clinical Practice Guidelines Focused on the Management of Cutaneous Melanoma: Cross-Sectional Analysis

BACKGROUND

Clinical practice guidelines (CPGs) inform evidence-based decision-making in the clinical setting; however, systematic reviews (SRs) that inform these CPGs may vary in terms of reporting and methodological quality, which affects confidence in summary effect estimates.

OBJECTIVE

Our objective was to appraise the methodological and reporting quality of the SRs used in CPGs for cutaneous melanoma and evaluate differences in these outcomes between Cochrane and non-Cochrane reviews.

METHODS

We conducted a cross-sectional analysis by searching PubMed for cutaneous melanoma guidelines published between January 1, 2015, and May 21, 2021. Next, we extracted SRs composing these guidelines and appraised their reporting and methodological rigor using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklists. Lastly, we compared these outcomes between Cochrane and non-Cochrane SRs. All screening and data extraction occurred in a masked, duplicate fashion.

RESULTS

Of the SRs appraised, the mean completion rate was 66.5% (SD 12.29%) for the PRISMA checklist and 44.5% (SD 21.05%) for AMSTAR. The majority of SRs (19/50, 53%) were of critically low methodological quality, with no SRs being appraised as high quality. There was a statistically significant association (P<.001) between AMSTAR and PRISMA checklists. Cochrane SRs had higher PRISMA mean completion rates and higher methodological quality than non-Cochrane SRs.

CONCLUSIONS

SRs supporting CPGs focused on the management of cutaneous melanoma vary in reporting and methodological quality, with the majority of SRs being of low quality. Increasing adherence to PRISMA and AMSTAR checklists will likely increase the quality of SRs, thereby increasing the level of evidence supporting cutaneous melanoma CPGs.

Topical and Intralesional Immunotherapy for the Management of Skin Cancer in Special Locations: Lips and Eyelids

The use of topical and intralesional immunotherapy in the treatment of cutaneous malignant neoplasia in sensitive areas such as the lips and eyelids is discussed. Surgery may not be feasible or may result in deformities in these areas, making alternative treatment options necessary. A narrative literature review was conducted using MEDLINE (PubMed) as the main literature database, collecting available evidence of experiences with various topical and intralesional therapies in the aforementioned anatomical locations, ranging from case reports to clinical trials. The clearance rates and potential adverse reactions of therapeutic options such as imiquimod 5%, 5-fluorouracil (5-FU), photodynamic therapy (PDT), ingenol mebutate (IM), diclofenac, intralesional methotrexate, and interferon are reviewed. Although limited by their heterogeneity and the scarcity of clinical trials, these studies point towards promising response rates and minimal adverse effects, making these treatments viable options in selected cases.

Topical Treatment of Melanoma In Situ, Lentigo Maligna, and Lentigo Maligna Melanoma with Imiquimod Cream: A Systematic Review of the Literature

INTRODUCTION

The classical management of melanoma is surgery, but this can be challenging because of several factors, such as age, body area, lesion size, among others. Topical imiquimod may be a therapeutic option for the treatment of melanoma in situ and lentigo maligna melanoma due to its efficacy, tolerability, and non-invasiveness. The purpose of this systematic review is to assemble current evidence on the treatment of non-metastatic melanoma with topical imiquimod.

METHODS

The PubMed/MEDLINE and Cochrane Library databases were searched as the primary sources using the main search terms "imiquimod" combined with "lentigo maligna" and "melanoma" with the command "AND." Articles were identified, screened, and extracted for relevant data, following the PRISMA guidelines.

RESULTS

A total of 87 studies covering 1803 lesions treated with imiquimod cream were identified and included in this sytematic review. Forty-nine studies were case reports, 16 were retrospective analyses, 3 were open label trials, six were case series; one study was a controlled randomized trial, one was a randomized trial, and one was a single-arm phase III trial. Because of the high number of low-evidence studies, the overall risk of bias resulted high. In 55 studies, imiquimod 5% was used in monotherapy as the primary treatment; only in one study was imiquimod 3.75% introduced. In most cases, the topical treatment was applied once daily, with the exception of nine cases where an increased daily dosage was prescribed. The total duration of the treatment regimen was extremely variable and depended on body area and tolerability, with differences among patients of the same study. In six studies, imiquimod was used as neoadjuvant therapy before the surgical excision, and in 11 studies it was used after surgery as complementary or adjuvant therapy. In total, 1133 of the 1803 (62.8%) lesions were reported to be cleared after the treatment, taking into account that not all of the patients completed the treatment. Of these 1133 lesions, histological clearance was achieved in 645 (56.9%) lesions and clinical clearance only was achieved in 490 (43.2%) lesions; relapse occurred in 107 lesions.

CONCLUSIONS

The heterogeneity of the studies included in this systematic review precludes the drawing of any relevant conclusions regarding the application of imiquimod. Its efficacy in melanoma in situ and lentigo maligna melanoma has been demonstrated, but further evidence from controlled studies concerning the modalities is missing.

Topical and Intralesional Immunotherapy for Melanoma In Situ: A Review

The incidence of in situ melanoma (MIS) has increased over the last decades. The mainstay of treatment for MIS, including lentigo maligna (LM), is complete surgical excision with clear margins (0.5 to 1.0 cm). Nevertheless, MIS lesions often affect elderly patients with comorbidities and involve large lesions in cosmetically sensitive areas, which means surgery is not always appropriate. Non-surgical treatments have a role in these cases, and include radiotherapy, cryosurgery, immunotherapy, laser therapy, and other topical medications. This study aims to review the applications of immunotherapy in MIS, either in monotherapy or in combination with other therapeutic alternatives. The main forms of immunotherapy used are imiquimod and, to a lesser extent, intralesional interferon-α (IL-INF-α) and ingenol mebutate (IM). IL-INF-α and IM have not been studied as extensively as imiquimod, whose results in real-life practice are encouraging. The clearance and recurrence rates reported in MIS treated with imiquimod as monotherapy, or as an adjuvant after surgery with affected or narrow margins, make imiquimod a reliable therapeutic alternative in selected cases. Also, its use as a neoadjuvant therapy before surgery was shown to reduce the final surgical defect size required to confirm negative histologic margins. In conclusion, local immunotherapy is frequently used in clinical practice and experience confirms it to be an excellent option for certain patients.

Efficacy of imiquimod in the management of lentigo maligna

BACKGROUND

Lentigo maligna (LM) is a melanocytic proliferation occurring on photo-exposed skin that may progress to LM melanoma. Surgery is recommended as first-line treatment. Excision margins of 5-10 mm remain, without international consensus. Several studies have shown that imiquimod, an immunomodulator, induces LM regression. This study investigated the effect of imiquimod versus placebo in neoadjuvant settings.

PATIENTS AND METHODS

We performed a prospective, randomized, multicentre, phase III clinical study. Patients were randomly assigned in 1:1 ratio to receive imiquimod or placebo for 4 weeks, followed by LM excision 4 weeks after the last application of imiquimod or placebo. The primary endpoint was extra-lesional excision, with a 5 mm margin from the residual pigmentation after imiquimod or vehicle. Secondary endpoints included the gain on the surface removed between the two groups; number of revision surgeries to obtain extra-lesional excisions; relapse-free time; and number of complete remissions after treatment.

RESULTS

A total of 283 patients participated in this study; 247 patients, 121 patients in the placebo group and 126 in the imiquimod group, accounted for the modified ITT population. The first extralesional extirpation was performed in 116 (92%) imiquimod patients and in 102 (84%) placebo patients; the difference was not significant (p = 0.0743). Regarding the surface of LM, imiquimod reduced the LM surface (4.6-3.1 cm2 ) significantly (p < 0.001) more compared to the placebo (3.9-4.1 cm2 ).

CONCLUSION

Imiquimod reduces the lentigo maligna surface after 1 month of treatment, without a higher risk of intralesional excision and with a positive aesthetic outcome.

Imiquimod as Local Immunotherapy in the Management of Premalignant Cutaneous Conditions and Skin Cancer

Cutaneous cancers are, by far, the most common malignant neoplasms of the human being. Due to the great array of clinical conditions, their worldwide increasing incidence and the steady ageing of the population, non-invasive treatments modalities that show a good clinical response, a proper benefit-risk ratio and cosmetic results are becoming increasingly important in the clinical setting. Imiquimod is a topically applied immunomodulator which is often used in the management of several premalignant and malignant cutaneous disorders. This article is a review of the current literature on its mechanism of action, pharmacokinetics, and therapeutical effects.

[Translated article] Update on Lentigo Maligna: Diagnostic Signs and Treatment

Lentigo maligna is an in situ cutaneous melanoma that arises in sun-damaged skin. Its most common presentation is a progressive, slow-growing, irregularly pigmented spot on the face of older patients. Although the exact percentage of lentigo maligna that progresses to invasive tumors is unknown, it is thought to lie between 2% and 5%. Both the clinical and histologic diagnosis of lentigo maligna can be challenging, especially in patients with early-stage or atypical disease. Treatment also holds challenges, because lesions are located in highly visible areas and are often large. Surgery can thus compromise cosmetic and sometimes functional outcomes. We review clinical and histopathological findings that can facilitate the diagnosis of lentigo maligna. We also examine treatment options, with a focus on surgery.

Long-Term Follow-Up of Lentigo Maligna Patients Treated with Imiquimod 5% Cream

BACKGROUND

The study investigated the long-term efficacy of imiquimod 5% cream for LM, with a focus on disease recurrence and the possible prognostic factors of disease-free survival (DFS) in a cohort, with long-term follow-up.

METHODS

Consecutive patients with histologically confirmed LM were included. Imiquimod 5% cream was applied until weeping erosion appeared on the LM-affected skin. The evaluation was performed through clinical examination and dermoscopy.

RESULTS

We analyzed 111 patients with LM (median age: 72 years, 61.3% women) with tumor clearance after imiquimod therapy, with a median follow-up of 8 years. The overall patient survival rates were 85.5% (95% confidence interval (CI): 78.5-92.6) and 70.4% (95% CI: 60.3-80.5) at 5 and 10 years, respectively. Among the 23 patients (20.1%) with relapse at follow-up, 17 (73.9%) were treated with surgery, five (21.7%) continued imiquimod therapy, and one (4.3%) underwent both surgery and radiotherapy. After adjustment for age and LM area in multivariable models, localization of LM in the nasal region was identified as a prognostic factor for DFS (HR = 2.66; 95% CI: 1.06-6.64).

CONCLUSION

If surgical excision is not possible due to the patients' age/comorbidities or critical cosmetic localization, imiquimod could provide optimal outcomes with an optimal risk of relapse for the management of LM.

Treatment of periocular lentigo maligna with topical 5% Imiquimod: a review

Lentigo Maligna is a benign subtype of melanoma in situ and can progress to lentigo maligna melanoma, which is invasive. Complete surgical excision is the gold standard of treatment but requires large margins. If affecting the peri-ocular region, surgical excision leads to extensive defects, complex reconstructions, and functional impairment of the protection of the ocular surface. Here we review the reported literature about the use of Imiquimod 5% topical cream for lentigo maligna of the eyelid, the treatment outcomes, side effects and tolerance. In addition, the side effects of imiquimod treatment of non-LM lesions are described to help better inform the decision-making process. Treatment for peri-ocular Lentigo maligna showed a 56-86% complete treatment response and a 90% tolerability rate. However, reported treatment protocols vary and histopathological confirmation of clearance was only obtained in 56%. Further studies are required to determine the optimal treatment protocol to maximise clearance rates. Overall, Imiquimod was well tolerated in the peri-ocular area.

Lentigo maligna (melanoma): A systematic review and meta-analysis on surgical techniques and presurgical mapping by reflectance confocal microscopy

Because of an increased risk of local recurrence following surgical treatment of lentigo maligna (melanoma) (LM/LMM), the optimal surgical technique is still a matter of debate. We aimed to evaluate the effect of different surgical techniques and reflectance confocal microscopy (RCM) on local recurrence and survival outcomes. We searched MEDLINE, Embase and PubMed databases through 20 May 2022. Randomized and observational studies with ≥10 lesions were eligible for inclusion. Bias assessment was performed using the Methodological Index for Non-Randomized Studies instrument. Meta-analysis was performed for local recurrence, as there were insufficient events for the other clinical outcomes. We included 41 studies with 5059 LM and 1271 LMM. Surgical techniques included wide local excision (WLE) (n = 1355), staged excision (n = 2442) and Mohs' micrographic surgery (MMS) (n = 2909). Six studies included RCM. The guideline-recommended margin was insufficient in 21.6%-44.6% of LM/LMM. Local recurrence rate was lowest for patients treated by MMS combined with immunohistochemistry (<1%; 95% CI, 0.3%-1.9%), and highest for WLE (13%; 95% CI, 7.2%-21.6%). The mean follow-up varied from 27 to 63 months depending on surgical technique with moderate to high heterogeneity for MMS and WLE. Handheld-RCM decreased both the rate of positive histological margins (p < 0.0001) and necessary surgical stages (p < 0.0001). The majority of regional (17/25) and distant (34/43) recurrences occurred in patients treated by WLE. Melanoma-associated mortality was low (1.5%; 32/2107), and more patients died due to unrelated causes (6.7%; 107/1608). This systematic review shows a clear reduction in local recurrences using microscopically controlled surgical techniques over WLE. The use of HH-RCM showed a trend in the reduction in incomplete resections and local recurrences even when used with WLE. Due to selection bias, heterogeneity, low prevalence of stage III/IV disease and limited survival data, it was not possible to determine the effect of the different surgical techniques on survival outcomes.

Advances in Topical Treatments of Cutaneous Malignancies

Surgical excision has been the preferred treatment for cutaneous malignancies, but can be affected by various considerations. Noninvasive, self-administered topical treatments represent an alternative option. The aim of this review was to evaluate and summarize evidence-based recommendations for topical treatments of basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (CSCC), in situ melanoma (MIS), and extramammary Paget's disease (EMPD). Studies were reviewed on PubMed. Included studies were summarized, assessed for biases, and assigned a level of evidence to develop treatment recommendations. For the treatment of superficial BCC, complete clearance rates ranged from 90 to 93% for 5% 5-fluorouracil (5-FU) and 71 to 76% for imiquimod (IMQ). For the treatment of nodular BCC, clearance rates for photodynamic therapy (PDT) were 91% at 3 months, with a sustained lesion clearance response rate of 76% after 5 years of follow-up. Clearance rates were 53 to 76% with IMQ. For squamous cell carcinoma in situ, clearance rates ranged from 52 to 98% for PDT, 67 to 92% for 5-FU, and 75 to 93% for IMQ. For MIS, clearance rates ranged from 53 to 92% for IMQ. For EMPD, 54% of 110 patients in cohort studies and case series had a clinical complete response with IMQ. While surgical intervention remains the standard of care for skin cancer, non-invasive, self-administered topical treatments are highly desirable alternative options. Ultimately, the patient and provider should find a treatment modality that aligns with the patient's expectations and maintenance of quality of life.

Clinical findings are not helpful in detecting lentigo maligna melanoma in patients with biopsy-proven lentigo maligna

BACKGROUND

Lentigo maligna (LM) based on biopsy material might be lentigo maligna melanoma (LMM) after excision.

OBJECTIVES

Investigate whether clinical and dermoscopic mapping increases the detection rate of LMM when investigating staged excision specimens of biopsy proven LM.

METHODS

Patients with biopsy-proven LM planned for staged excision were included. Using clinical inspection and dermoscopy, spots suspicious for LMM were marked. After the excision, needles were placed at the marked spots. Histological examination using vertical sections was done at the needles followed by the standard amount of vertical sections.

RESULTS

In 28 of the 58 biopsy-proven LM, there was clinical suspicion of LMM, only 3 of these 28 cases were upgraded into LMM. These three cases showed LMM in other sections, whereas only 1 case showed LMM around the needle. Within the group without clinical suspicion of LMM, 2 cases were LMM. Biopsy-proven LM were in fact LMM in 8.6% of the cases and were found without the clinical guidance of the dermatologist.

CONCLUSIONS

8.6% of the biopsy-proven LM were LMM after complete histological examination. In this study, the dermatologist was not able to increase the detection rate of LMM by using clinical and dermoscopic mapping.

A cohort analysis of surgically treated primary head and neck lentigo maligna (melanoma): Prognostic value of melanoma subtype and new insights in the clinical value of guideline adherence

BACKGROUND

Knowledge about lentigo maligna (melanoma) (LM/LMM) and its associated prognostic clinicopathological characteristics are limited compared to that of non-LM/LMM subtypes. The current study aimed to determine the clinical relevance of the LM/LMM subtype and its influence on recurrence and survival outcomes.

METHODS

All consecutive cases of primary cutaneous head and neck LM/LMM treated by wide local excision over a ten-year period were retrospectively reviewed and compared to non-LM/LMM. Clinical outcome and prognostic factors were assessed by cumulative incidence and competing risk analyses.

RESULTS

A total of 345 patients were identified. Specific clinicopathological characteristics such as lower median Breslow thickness (1.6 mm versus 2.1 mm; P = 0.013), association with diagnostic sampling errors (17.3% versus 5.2%; P = 0.01), and increased risk of local recurrences due to incomplete resection (18.7% versus 2.3%; P < 0.001), were significantly associated with LM/LMM. Guideline adherence was similar between the two study groups. The positive nodal status at baseline for LMM was low compared to non-LM/LMM (4.2% vs 17.9%; P = 0.037). The LMM subtype, facial localization, and reduced surgical margins (i.e., guideline non-adherence) were not shown to be independent prognostic factors for disease-free, melanoma-specific, or overall survival after correction for competing risks such as patient age and Breslow thickness.

CONCLUSIONS

The LMM subtype was not shown to be prognostically different from non-LM/LMM when corrected for other variables of influence such as patient age and Breslow thickness. Reduced resection margins did not seem to affect disease-free, and melanoma-specific survival and warrant LM/LMM-specific guidelines. Further research is needed to evaluate the value of SLNB in LMM patients.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2022

A unique collaboration of multidisciplinary experts from the European Dermatology Forum (EDF), the European Association of Dermato-Oncology (EADO), and the European Organization of Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on the systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with one to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumor thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("tumor board"). Adjuvant therapies can be proposed in stage III/completely resected stage IV patients and are primarily anti-PD-1, independent of mutational status, or alternatively dabrafenib plus trametinib for BRAF mutant patients. In distant metastases (stage IV), either resected or not, systemic treatment is always indicated. For first-line treatment particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In stage IV melanoma with a BRAF-V600  E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harboring a BRAF-V600  E/K mutation, this therapy shall be offered as second-line therapy. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Lentigo Maligna on a Difficult Location of the Face Treated with 5% Imiquimod: A Case Report of 2-Year Follow-Up

Topical imiquimod is an off-label alternative treatment for lentigo maligna used when surgery cannot be performed. Severe inflammatory response induced by this drug may generate many complaints and force patients to discontinue use. We present a case in which interval treatment with 5% topical imiquimod was implemented for severe inflammatory response. An 82-year-old Caucasian woman presented with a large, irregularly pigmented lesion on her left cheek within the scar of a previously excised melanocytic lesion diagnosed as junctional nevus. Based on dermatoscopical examination confirmed by histopathological description, lentigo maligna was diagnosed. Since the lesion was large and covered the lower left eyelid and due to the risk of disfigurement, the patient refused surgical excision. Therefore, treatment with imiquimod 5% once daily, five times per week, was offered. After 5 weeks, the treatment was stopped because of intense inflammatory reaction and ulceration. On the follow-up visit after 3 months, videodermatoscopical examination revealed changes in the pigmentation of the lentigo maligna including the presence of residual gray dots and fading of the previous dark brown and black colors. The inflammatory response had almost resolved. The second course of treatment with imiquimod five times a week was implemented again for 5 weeks, and after a 2-month interval the third course with the same regimen was started. Total clearance of the lesion was achieved, which was confirmed by videodermatoscopical examination. During the 2-year follow-up, no relapse was observed based on dermatoscopical examination. We propose interval treatment with topical imiquimod 5% lentigo maligna for severe inflammatory reactions in patients with contraindications to surgery. This could help patients overcome this typical response effect and decrease their cessation of treatment.

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

Lentigo maligna (LM) is a common in situ 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.

Clinical and histologic features associated with lentigo maligna clearance after imiquimod treatment

BACKGROUND

Imiquimod cream may be used as a non-surgical treatment for lentigo maligna or as adjuvant therapy following excision to decrease the risk of recurrence.

OBJECTIVES

To evaluate histologic and clinical factors associated with clinical clearance of lentigo maligna treated with imiquimod.

METHODS

We performed a retrospective review of all patients diagnosed with lentigo maligna and treated with imiquimod between 1997 and 2019 at our academic institution.

RESULTS

We observed clinical clearance in 93% (66/71) of participants who received adjuvant imiquimod following surgery and 79% (19/24) in the primary non-surgical treatment group over a median of 38 months of follow-up. In the adjuvant therapy group, positive surgical margins were associated with a decreased rate of clinical clearance when compared to cases with close (<1 mm) margins or background melanocytic dysplasia (83.3 vs. 100%, p = .01). The presence of an inflammatory response during treatment was associated with increased clearance (94.1 vs. 66.7%, p = .02).

CONCLUSIONS

Adjuvant imiquimod treatment may decrease LM recurrence rates in cases with background melanocytic dysplasia or close margins. LM cases with positive surgical margins need close clinical follow-up given higher recurrence rates.

Case of large lentigo maligna melanoma of the scalp treated with 5% and 3.75% Imiquimod

The paper presents a case of lentigo maligna melanoma of the scalp in an elderly patient treated for the nodular part with surgery and the residual melanoma in situ with 5% Imiquimod and subsequently with 3.75% Imiquimod (each concentration for 4 months, 5 times per week), with complete regression of the lesion. 3.75% Imiquimod, which is already used for the treatment of actinic keratosis, could be a useful weapon with the same effectiveness and fewer side effects compared to 5% Imiquimod.

Therapeutic cancer vaccines

Therapeutic cancer vaccines have undergone a resurgence in the past decade. A better understanding of the breadth of tumour-associated antigens, the native immune response and development of novel technologies for antigen delivery has facilitated improved vaccine design. The goal of therapeutic cancer vaccines is to induce tumour regression, eradicate minimal residual disease, establish lasting antitumour memory and avoid non-specific or adverse reactions. However, tumour-induced immunosuppression and immunoresistance pose significant challenges to achieving this goal. In this Review, we deliberate on how to improve and expand the antigen repertoire for vaccines, consider developments in vaccine platforms and explore antigen-agnostic in situ vaccines. Furthermore, we summarize the reasons for failure of cancer vaccines in the past and provide an overview of various mechanisms of resistance posed by the tumour. Finally, we propose strategies for combining suitable vaccine platforms with novel immunomodulatory approaches and standard-of-care treatments for overcoming tumour resistance and enhancing clinical efficacy.

Change in lentigo maligna score assessed by in vivo reflectance confocal microscopy after 1 month of imiquimod treatment for lentigo maligna management

BACKGROUND

Treatment of lentigo maligna (LM) is challenging because of the potential functional and esthetic surgical sequelae. Imiquimod has been proposed as a treatment for LM. Reflectance confocal microscopy (RCM) is a noninvasive method for the diagnosis of LM and margin assessment.

OBJECTIVES

To compare the overall LM score (LMS) assessed by RCM before and 1 month after the start of imiquimod treatment compared to placebo and to define the immunohistochemical (IHC) profile of responders to imiquimod.

METHODS

A controlled randomized study was conducted. Forty patients underwent RCM examination with calculation of the LMS at baseline and after 1 month of treatment. An IHC analysis of excised tissues was performed.

RESULTS

The 1-month LMS was significantly lower in patients treated with imiquimod compared to those treated with placebo (P < .001). The criteria in the imiquimod-treated patients that demonstrated significant decrease were nonedged papillae; large, round pagetoid cells; atypical cells at the dermoepidermal junction; and follicular location of atypical cells. IHC analysis showed a higher level of interferon gamma in the resected specimens of patients responding to imiquimod (P = .04).

LIMITATIONS

Sample size was small.

CONCLUSION

Assessing the LMS by RCM was useful to monitor LM response to imiquimod accurately.

Treating Melanoma in Situ During a Pandemic with Telemedicine and a Combination of Imiquimod, 5-Fluorouracil, and Tretinoin

The recent coronavirus disease 2019 (COVID-19) pandemic has created a quandary for the physician in terms of evaluating and treating cutaneous skin cancers, particularly melanomas. At the onset of the pandemic, many planned medical and surgical visits for skin cancers were postponed. Physicians and patients have had to balance the risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with that of worsening morbidity and mortality due to delays in skin cancer treatments. We present a male patient who had two melanoma-in-situs (MISs) that were treated during the COVID-19 pandemic with a combination of topical imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream. The successful treatments occurred without in-person visits and with the aid of telemedicine. Although surgery is the standard for the treatment of melanoma in situ, this case demonstrates an effective viable treatment modality for MIS during a pandemic situation.

Skin Penetration Enhancement Strategies Used in the Development of Melanoma Topical Treatments

Malignant melanoma is an aggressive form of skin cancer for which there is currently no reliable therapy and is considered one of the leading health issues in the USA. At present, surgery is the most effective and acceptable treatment; however, surgical excision can be impractical in certain circumstances. Topical skin delivery of drugs using topical formulations is a potential alternative approach which can have many advantages aside from being a non-invasive delivery route. Nevertheless, the presence of the stratum corneum (SC) limits the penetration of drugs through the skin, lowering their treatment efficacy and raising concerns among physicians and patients as to their effectiveness. Currently, research groups are trying to circumvent the SC barrier by using skin penetration enhancement (SPE) strategies. The SPE strategies investigated include chemical skin penetration enhancers (CPEs), physical skin penetration enhancers (PPEs), nanocarrier systems, and a combination of SPE strategies (cream). Of these, PPEs and cream are the most advanced approaches in terms of preclinical and clinical studies, respectively.

Lentigo Maligna: Clinical Presentation and Appropriate Management

Lentigo maligna (LM) is a type of melanoma in situ that has distinctive characteristics regarding epidemiology, risk factors and clinical features. In addition, LM has a potential to progress to an invasive tumor with potentially aggressive behavior: lentigo maligna melanoma (LMM). Overall, LM has a very good prognosis, whereas LMM has the same prognosis as other invasive melanomas with similar Breslow thickness. LM/LMM represents a challenging entity not only regarding the diagnosis but also regarding the management. Diagnostic criteria are not well established, and there is an overlap of clinical, dermoscopic and pathological features with other benign pigmented skin lesions such as lentigines, pigmented actinic keratoses or macular seborrheic keratoses. LM/LMM's common appearance within photodamaged skin makes lesion border identification difficult. Wide excisions are often required, but since LM/LMM typically appears on cosmetically sensitive areas such as the face, sometimes large excisions are not possible nor desirable. In this sense, specialized approaches have been developed such as margin-controlled surgery or image-guided treatment using reflectance confocal microscopy. Other treatments for LM such as cryosurgery, imiquimod, radiotherapy or photodynamic therapy have been proposed, although recurrence/persistence is common. The current manuscript reviews extensively the published data regarding the diagnosis, treatment and management of both complex entities LM and LMM.

Reflectance confocal microscopy and its role in the follow-up of a topical treatment for lentigo maligna

BACKGROUND

In recent years, there has been an ongoing interest in topical treatment for lentigo maligna (LM) as imiquimod 5% cream owing to the localization of this tumor and the advanced age of patients; however, the efficacy of imiquimod 5% cream is controversial, and the rate of local relapses is about 25-53%. Reflectance confocal microscopy (RCM) is a noninvasive diagnostic tool useful not only for diagnostic purpose but also for monitoring the response to the local treatment of LM. Our aim was to demonstrate the role of RCM in the follow-up of a topical treatment with imiquimod 5% cream in clinical practice.

METHODS

We report three patients with histopathologically confirmed LM who were not candidates for surgery and were successfully treated with imiquimod 5% cream. In such patients, dermatoscopic images and reflectance confocal microscopy were useful to evaluate treatment response and to verify long-term clinical benefits during the follow-up visits.

RESULTS

No relapses were observed in our patients 18 months after the end of treatment; although, continuous follow-up visits are needed in these patients.

CONCLUSIONS

In the case series presented herein, we highlight the importance of RCM as a noninvasive tool to monitor the efficacy of imiquimod to treat LM during and after treatment. Detailed confocal images of two of our patients allowed us to establish the persistence of atypical cells and to continue treatment, although clinical and dermatoscopic examinations showed "apparent complete remission" after the first cycle of therapy.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2019

A unique collaboration of multidisciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organization for Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with 1- to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumour thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("Tumor Board"). Adjuvant therapies in stage III/IV patients are primarily anti-PD-1, independent of mutational status, or dabrafenib plus trametinib for BRAF-mutant patients. In distant metastasis, either resected or not, systemic treatment is indicated. For first-line treatment, particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In particular scenarios for patients with stage IV melanoma and a BRAF-V600 E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harbouring a BRAF-V600 E/K mutation, this therapy shall be offered in second-line. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Evidence-Based Clinical Practice Guidelines for the Management of Patients with Lentigo Maligna

INTRODUCTION

Lentigo maligna (LM) is a subtype of melanoma in situ that usually occurs in sun-damaged skin and is characterised by an atypical proliferation of melanocytes within the basal epidermis. If left untreated, LM can develop into invasive melanoma, termed lentigo maligna melanoma, which shares the same prognosis as other types of invasive melanoma. The incidence rates of LM are steadily increasing worldwide, in parallel with increases in the incidence rates of invasive melanoma, and establishing appropriate guidelines for the management of LM is therefore of great importance.

METHODS

A multidisciplinary working party established by Cancer Council Australia has recently produced up-to-date, evidence-based clinical practice guidelines for the management of melanoma and LM. Following selection of the most relevant clinical questions, a comprehensive literature search for relevant studies was conducted, followed by systematic review of these studies. Data were summarised and the evidence was assessed, leading to the development of recommendations. After public consultation and approval by the full guidelines working party, these recommendations were published on the Cancer Council Australia wiki platform (https://wiki.cancer.org.au/australia/Clinical_question:Effective_interventions_to_improve_outcomes_in_lentigo_maligna%3F). Main Recommendations: Surgical removal of LM remains the standard treatment, with 5- to 10-mm clinical margins when possible. While yet to be fully validated, the use of peri-operative reflectance confocal microscopy to assess margins should be considered where available. There is a lack of high-quality evidence to infer the most effective non-surgical treatment. When surgical removal of LM is not possible or refused, radiotherapy is recommended. When both surgery and radiotherapy are not appropriate or refused, topical imiquimod is the recommended treatment. Cryotherapy and laser therapy are not recommended for the treatment of LM.

Histologic Features Associated With an Invasive Component in Lentigo Maligna Lesions

Importance

Lentigo maligna (LM) presents an invasive component in up to 20% of biopsied cases, but to date the histologic features useful in detecting this invasive component have not been described. Some histologic characteristics are hypothesized to contribute to the progression of LM invasion.

Objective

To identify the histologic characteristics associated with lentigo maligna melanoma (LMM) in patients with LM diagnosed by a partial diagnostic biopsy.

Design, Setting, and Participants

A retrospective cross-sectional study of patients treated between January 1, 2000, and December 31, 2017, was conducted in a referral oncology center in València, Spain. Data and specimens of patients (n = 96) with a diagnosis of primary cutaneous melanoma in the form of either LM or LMM who had undergone surgical treatment, a complete histologic examination of the whole tumor, and an initial diagnostic partial biopsy of LM were included in the study. Histologic assessment was blinded to the presence of an invasive component.

Interventions

All biopsy specimens were evaluated for the presence of certain histologic characteristics.

Main Outcomes and Measures

Comparisons between invasive samples and samples without an invasive component were performed. The differences in the distribution of variables between the groups were assessed using the χ2 and Fisher exact tests, and the degree of association of the relevant variables was quantified by logistic regression models. A classification and regression tree analysis was performed to rank the variables by importance.

Results

In total, 96 patients had sufficient histologic material that could be evaluated. The patients were predominantly male (56 [58.3%]) and had a mean (SD) age at diagnosis of 72 (12) years. Of these patients, 63 (65.6%) had an LM diagnosis and 33 (34.4%) had an LMM diagnosis (an invasive component). The histologic variables associated with the presence of an invasive component were melanocytes forming rows (odds ratio [OR], 11.5; 95% CI, 1.4-94.1; P = .02), subepidermal clefts (OR, 2.8; 95% CI, 1.0-7.9; P = .049), nests (OR, 3.0; 95% CI, 1.1-8.6; P = .04), and a lesser degree of solar elastosis (OR, 0.4; 95% CI, 0.1-1.1; P = .07). A classification and regression tree analysis of the relevant histologic features was able to accurately identify lentigo maligna with an invasive component (LMM) in more than 60% of patients.

Conclusions and Relevance

These findings may be useful in classifying early LM specimens at higher risk of invasion, which may eventually be relevant in identifying the most appropriate management for LM.

The use of 2940-nm ER:YAG laser for the treatment of lentigo maligna

OBJECTIVES

Lentigo maligna is a common in situ malignancy in elderly patients, with a low risk of progression to an invasive tumor. Surgical treatment may be complicated or refused. Non-surgical treatment options (such as lasers) may therefore be needed.

PATIENTS AND METHODS

We report on 17 patients treated with a 2940-nm Er:YAG (erbium-doped yttrium aluminum) laser for histopathologically confirmed lentigo maligna. The lesions were ablated with a 5 mm margin of adjacent skin under local anesthesia with a 3.5 mm overlapping spot, energy density of 6.5 J/cm² and a repetition rate of 5 Hz. If clinically visible pigmentation was seen in the ablated area during the following three months, the lesion was re-treated. All patients were followed up for residual or recurrent tumors.

RESULTS

We achieved clinical clearance in all 17 patients. There were three recurrences during the follow-up period (9, 30 and 36 months after laser therapy). All patients were satisfied with the treatment course and cosmetic outcome. The mean follow-up duration was 28 months.

CONCLUSIONS

Laser ablation is an interesting alternative method for treatment of lentigo maligna. It can be used for selected cases where surgery is contraindicated, complicated or declined by the patient.

Recent advances in localized immunotherapy of skin cancers

Skin cancer is the most frequent malignancy in humans. The immune system has long been known to have an important role in defeating cancer. Immunotherapy, which includes various strategies to enhance tumor immunity, currently represents an exciting option for the treatment of skin cancers. Local immunotherapy is a promising therapeutic approach and may improve response rates without inducing systemic toxicity. Here, we review the main localized immunotherapies for the management of skin cancer with a special focus on advanced melanoma, nonmelanoma skin cancer and primary cutaneous lymphoma.

Long-term outcomes of imiquimod-treated lentigo maligna

BACKGROUND

Lentigo maligna (LM) may be disfiguring and can progress to LM melanoma. Surgical excision remains the mainstay of treatment, but may result in disfigurement when used for large facial lesions. Topical imiquimod is a nonsurgical alternative although data on its long-term efficacy remain limited.

AIM

To assess long-term outcomes of LM treated with imiquimod cream.

METHODS

We collected data retrospectively for 33 patients treated with imiquimod cream for biopsy-proven LM from 2001 to 2016. Patients initially applied imiquimod once daily, 5 days/week for 6 weeks, aiming to produce a brisk local inflammatory response. If there was no response, the dose was increased to twice daily 7 days/week for 6 weeks and if again there was no response, to twice daily for 10 weeks.

RESULTS

An inflammatory response developed in 29 (88%) of the 33 patients, and of these, 4 patients stopped treatment earlier than planned because they could not tolerate the inflammatory reaction, while 3 patients reported systemic side effects. There was lesion clearance in 21 (72%) of the 29 patients, and they remained clear after a mean follow-up of 4.1 years. Eight failed to clear; in five the lesion was excised, while the remaining three were managed expectantly.

CONCLUSIONS

Our results support the use of imiquimod as an alternative to surgery for the treatment of LM in selected cases. With adequate patient preparation, imiquimod is generally tolerated and can achieve excellent cosmetic results. A clinical response is more likely if there is a brisk inflammatory response, and LM will not resolve if there is no inflammatory response.