Pediatric melanoma: incidence, treatment, and prognosis

Treatment outcomes following partial shave biopsy of atypical and malignant melanocytic tumors in pediatric patients

Pediatric melanoma is the most common skin cancer in children and treatment relies on accurate staging. The American Academy of Dermatology recommends excisional biopsy for suspicious skin lesions, however, partial shave biopsies are often performed, the impact of which is unknown in pediatric and adolescent/young adult (AYA) patients. The aim of this retrospective case series study was to evaluate the impact of the diagnostic biopsy method on staging, treatment, and treatment-related outcomes in pediatric/AYA patients with melanoma. Among 103 pediatric/AYA patients with atypical cutaneous melanocytic lesions, the most common biopsy method was partial shave (68/103, 66.0%) followed by punch (20/103, 19.4%), excisional (14/103, 13.6%), and incisional nonshave (1/103, 1%). Over half of all biopsies yielded a positive deep margin, reflecting compromised microstaging (56/103, 55.4%), the majority occurred following partial shave (52/56, 92.9%) compared with other techniques ( P  < 0.001). All 11 patients with wider surgical target margins of wide local excision and 8/9 patients with sentinel lymph node biopsy performed due to positive deep margin, underwent a partial shave biopsy ( P  = 0.05 and 0.32, respectively). Almost half of all patients who underwent partial shave biopsy had a clinically suspected abnormal melanocytic tumor prior to biopsy (31/68, 45.6%; P  = 0.03). Of 56 patients who had compromised microstaging, 17 (30.4%) had a diagnosis of melanoma ( P  = 0.17). Pediatric/AYA patients frequently undergo partial shave biopsy, which is associated with more invasive definitive surgical treatment due to compromised microstaging. These results may help optimize care of patients with cutaneous melanocytic tumors.

Nevi and Melanoma in Children: What to Do in Daily Medical Practice: Encyclopedia for Pediatricians and Family Doctors

Melanocytic nevi, commonly known as moles, are benign skin lesions that often occur in children and adolescents. Overall, they are less common in children compared to adults. Understanding the diagnosis and management of melanocytic nevi and risk factors for melanoma development is crucial for their early detection and appropriate treatment. This paper presents children's most common melanocytic nevi, including their epidemiology, morphology, diagnostic methods, and treatment.

Utility of Indocyanine Green for Sentinel Lymph Node Biopsy in Pediatric Sarcoma and Melanoma

BACKGROUND

Indocyanine green (ICG) is a fluorescent dye with increasing use for adult sentinel lymph node biopsy (SLNB). The utility of ICG in pediatric oncology remains understudied. We aim to describe our experience using ICG for SLNB in pediatrics versus standard blue dye.

METHODS

A retrospective review of pediatric patients with melanoma or sarcoma who underwent SLNB with technetium plus ICG or blue dye from 2014 to 2023 at a large academic children's hospital was conducted.

RESULTS

Twenty-four patients were included; 58.3% were male with median age 13 years (range 4-21 years). The majority had a melanocytic tumor (91.7%) and 8.3% had sarcoma. All patients received technetium with concomitant blue dye (62.5%) or ICG (37.5%). ICG more reliably identified radioactive SLNs, compared to blue dye (mean 100% vs 78.3 ± 8.3%, p = 0.03). There was no significant difference in median operative time (ICG 82 min [68-203] vs blue dye 93 min [78-105], p = 0.84). Seven patients had positive SLNs (29.2%), with recurrence in 2 patients (8.3%) and 1 death (4.2%). There were no adverse events.

CONCLUSION

ICG-directed SLNB in children is a safe and effective alternative to blue dye. Use of ICG did not add to operative time, and more often identified sentinel nodes versus blue dye.

TYPE OF STUDY

Original Research Article, Retrospective Comparative Study.

LEVEL OF EVIDENCE

III.

Diagnostic and Therapeutic Challenges in Pediatric Cutaneous Melanoma: Two Case Reports From the Moroccan Population

Although cutaneous melanoma (CM) is one of the most prevalent cancers in adults, it is rarely reported in children. Often, the diagnosis is delayed and difficult to make. We presented two novel examples of pediatric CM from the Department of Pediatric Plastic Surgery Unit at Rabat Children's Hospital. The first case included a 14-year-old girl who had a cutaneous nodule on her right leg. She first came with an inguinal enlargement, for which a lymph node biopsy was positive. A further inguinal dissection of 10 lymph nodes revealed four metastatic ones (4N+\10N). She received a wide local excision of the lesion, which revealed nodular melanoma with an 8 mm thickness as determined by Breslow, as well as safe lateral and deep margins. The course was distinguished by the emergence of new metastatic lymph node locations, and the patient died a few weeks later. The second case included a 13-year-old girl who appeared with a cutaneous lesion centered on a scar on her right leg. She also underwent a large local excision, which revealed nodular melanoma with a thickness of 12 mm according to Breslow, as well as complete lateral and deep excisions. Her follow-up revealed favorable results, with no local recurrence or distant metastases. This case series emphasized the difficult management of two separate occurrences of pediatric CM. We also emphasized the importance of early detection of suspicious lesions, regular follow-ups, and raising awareness among high-risk patients.

Causes of Childhood Cancer: A Review of the Recent Literature: Part I-Childhood Factors

PURPOSE

To review the childhood risk factors for pediatric cancer (diagnosis before age 20).

METHODS

We conducted literature searches using Ovid Medline and Scopus to find primary research studies, review articles, and meta-analyses published from 2014 to 3 March 2021.

RESULTS

Strong evidence indicates that an array of genetic and epigenetic phenomena, structural birth defects, and chromosomal anomalies are associated with an increased risk of various childhood cancers. Increased risk is also associated with prior cancer, likely due to previous treatment agents and therapeutic ionizing radiation. Convincing evidence supports associations between several pediatric cancers and ionizing radiation, immunosuppression, and carcinogenic virus infection both in healthy children and in association with immune suppression following organ transplantation. Breastfeeding and a childhood diet rich in fruits and vegetables appears to reduce the risk of pediatric leukemia but the evidence is less strong. Childhood vaccination against carcinogenic viruses is associated with a lower risk of several cancers; there is less strong evidence that other childhood vaccinations more broadly may also lower risk. Ultraviolet (UV) radiation is associated with increased melanoma risk, although most melanomas following childhood UV exposure occur later, in adulthood. Evidence is weak or conflicting for the role of body mass index, other childhood infections, allergies, and certain treatments, including immunomodulator medications and human growth therapy.

Regional lymph node evaluation in pediatric conventional melanoma subtype: a single-center 10-year review

PURPOSE

To assess the prognostic and therapeutic significance of sentinel lymph node biopsy (SLNB) and completion lymph node dissection (CLND) in pediatric conventional melanoma (CM), while evaluating potential predictive factors for outcomes.

METHODS

We conducted a retrospective analysis of medical records spanning 2009-2020, focusing on patients aged 18 or younger with localized cutaneous conventional melanoma.

RESULTS

Among the 33 patients, SLNB detected metastasis in 57.6% of cases, with 52.6% undergoing CLND. Positive SLN patients had higher relapse risk (HR 5.92; 95% CI 1.27-27.7; P = 0.024) but similar overall survival (HR 3.19; 95% CI 0.31-33.1, P = 0.33). No significant differences in disease-free survival (DFS) and OS were found between patients who underwent CLND and those who did not (HR 1.91; 95% CI 0.49-7.43, P = 0.35, and HR 0.52; 95% CI 0.03-8.32, P = 0.64, respectively). Univariate analysis showed age at diagnosis (P = 0.02) correlated with higher recurrence risk, with a 21% hazard increase per additional year of age.

CONCLUSIONS

Positive SLN status and age at diagnosis were associated with worse DFS in CM patients. Our study did not find any prognostic or therapeutic value in CLND for pediatric melanoma. Further multicenter trials are needed to confirm our single-institution experience.

LEVEL OF EVIDENCE

Level IV.

Anti-PD-1 Therapy in Advanced Pediatric Malignancies in Nationwide Study: Good Outcome in Skin Melanoma and Hodgkin Lymphoma

BACKGROUND/AIM

The role of immune checkpoint inhibitors (ICIs; anti-PD1) in the treatment of childhood cancers is still evolving. The aim of this nationwide retrospective study was to assess the safety and effectiveness of ICIs used in a group of 42 patients, with a median age of 13.6 years, with various types of advanced malignancies treated in pediatric oncology centers in Poland between 2015 and 2023.

RESULTS

The indications for treatment with anti-PD1 were as follows: Hodgkin lymphoma (11); malignant skin melanoma (9); neuroblastoma (8); and other malignancies (14). At the end of follow-up, complete remission (CR) was observed in 37.7% (15/42) of children and disease stabilization in 9.5% (4/42), with a mean survival 3.6 (95% CI = 2.6-4.6) years. The best survival (OS = 1.0) was observed in the group of patients with Hodgkin lymphoma. For malignant melanoma of the skin, neuroblastoma, and other rare malignancies, the estimated 3-year OS values were, respectively, 0.78, 0.33, and 0.25 (p = 0.002). The best progression-free survival value (0.78) was observed in the group with malignant melanoma. Significantly better effects of immunotherapy were confirmed in patients ≥ 14 years of age and good overall performance ECOG status. Severe adverse events were observed in 30.9% (13/42) patients.

Pediatric Melanoma Arising in a Background of Melanocytic Nevi

Malignant melanoma is an aggressive neoplasm primarily involving the skin. They may arise de novo or from a premalignant melanocytic lesion. Melanomas are primarily known to occur in adults. Pediatric melanomas (PM) are rare and predominantly occur de novo following ultraviolet deoxyribonucleic acid (DNA) damage. They may also be associated with the presence of congenital melanocytic nevi. We report a rare case of a 6-year-old child with multiple melanocytic nevi subsequently diagnosed with melanoma of the back and metastatic disease.

Risk for second primary cancers among pediatric and young adult melanoma survivors

BACKGROUND/OBJECTIVES

Second primary cancers (SPCs) are a leading cause of morbidity and mortality among cancer survivors. In this study, we aimed to characterize the incidence of SPCs among pediatric and young adult survivors of CM.

METHODS

Using the Surveillance, Epidemiology, and End Results Program data spanning 2000-2018, we calculated standardized incidence ratios (SIR) to assess SPC risk in all pediatric (0-18 years) and young adult (19-29 years) patients with a first primary cancer diagnosis of CM.

RESULTS

Of 7,169 total CM survivors, 632 (8.82%) developed a SPC, corresponding to a 5-fold increased risk (standardized incidence ratio [SIR] 4.98; 95% confidence interval [CI] 4.60-5.38) compared to the general population. There was a highly elevated risk for second primary melanoma across all age groups (SIR 32.5; 95% CI 29.7-35.6), constituting the majority of SPC diagnoses (N = 485). Infants diagnosed with CM before 1 year of age had the highest risk for any SPC (SIR 164; 95% CI 19.8-592) and young adults diagnosed at 25-29 years had the lowest risk (SIR 4.64; 95% CI 4.19-5.13). SPC incidence was highest within the first year of CM diagnosis (SIR 27.5; 95% CI 23.7-31.6) and progressively decreased with time.

CONCLUSIONS

Variation exists in the incidence and type of SPC according to age among pediatric and young adult survivors of CM.

Pediatric Atypical Melanocytic Proliferations: Single-Site Retrospective Cohort Assessment of Treatment and Long-Term Follow-Up

Atypical and malignant cutaneous tumors are understudied in the pediatric population, with limited data on long-term follow-up. This study examines pediatric (0-18 years) atypical melanocytic proliferations over a twenty-year period (January 2002-December2022) using the EPIC SlicerDicer at our institution. Over a twenty-year period, there were 55 cases of pediatric melanoma (53 patients). The median follow-up time was 8 years, 11 months. A proportion of 96% were treated with wide local excision (WLE), and 47% had a sentinel lymph node biopsy (SLNB) (35% positive rate). There were 101 atypical Spitz tumor cases (85% atypical Spitz tumors, 15% Spitz melanoma), with a median follow-up duration of 9 years. A proportion of 77% were treated with WLE (with one patient dying of metastatic disease). There were 10 cases of atypical melanocytic proliferations not otherwise specified, including 5 pigmented epithelioid melanocytomas (PEM), 4 deep-penetrating nevi, and 1 atypical cellular blue nevus. This study adds to the growing body of knowledge on pediatric atypical cutaneous melanocytic proliferations, aligning with many described characteristics such as disease location and overall survival rates, with distinct exceptions (higher melanoma positive SLNB rate, lower atypical Spitz tumor WLE rate, and a case of fatal metastatic atypical Spitz tumor).

Ulcerated amelanotic melanoma of the ear in an 11 year old with Fitzpatrick VI skin type: A case report

Melanoma is rare in pediatric patients and even more so in those with darker Fitzpatrick skin types. Although risk factors for conventional melanoma are similar in both adult and pediatric cases, the presentation of melanoma in pediatric patients is often distinct from adults. Here, we describe a case of amelanotic ulcerated nodular melanoma with regional lymph node metastases treated with nivolumab in a patient with Fitzpatrick skin type VI.

Spitz Nevus: Review and Update

The Spitz nevus is an uncommon melanocytic nevus. These lesions classically appear in childhood as a red, dome-shaped papule. They appear rarely in adults and may be pigmented. The Spitz nevus can develop suddenly and grow rapidly, reaching a 1-cm diameter in 6 months or less. There are 3 classes of spitzoid neoplasms: typical Spitz nevus, atypical Spitz nevus, and spitzoid melanoma. The diagnosis should be cautiously differentiated, especially in children. Immunohistochemistry and molecular studies have been helpful in differentiating difficult cases; however, no set of criteria has been accepted to predict biological behavior of atypical Spitz nevi.

Correlates Between Physical Activity and Sunburn Prevalence Among a Nationally Representative Sample of US High School Students, 2015-2017

BACKGROUND

Physical activity is associated with greater odds of sunburn in adults, increasing harmful sun exposure and skin cancer risk. The authors sought to investigate parallel associations between sunburn and physical activity among US high school students.

METHODS

The authors examined pooled cross-sectional data from the 2015 and 2017 Youth Risk Behavior Survey. A nationally representative sample of 21,894 US high school students who responded to the sunburn question was included.

RESULTS

Prevalence of sunburn was 56.6% between 2015 and 2017. Sunburn prevalence was higher in physically active students (88.3%; 95% confidence interval [CI], 86.7%-90.0%; P < .0001) and student athletes (63.0%; 95% CI, 59.4%-66.7%; P < .0001). Among male students who were vigorously physically active (≥5 d) or on ≥3 teams, the odds of sunburn were 2.33 (95% CI, 1.81-3.00; P < .0001) and 2.52 (95% CI, 1.96-3.23; P < .0001), respectively. Among female students who were vigorously physically active (≥5 d) or on ≥3 teams, the odds of sunburn were 1.65 (95% CI, 1.36-2.02; P < .0001) and 2.92 (95% CI, 2.07-4.13; P < .0001), respectively.

CONCLUSIONS

Many US high school students are affected by sunburn, and the odds of sunburn are elevated during physical activity and team sports participation. Efforts are needed to improve sun safety regulations, education, and resources for youth during school and physical activity.

Melanocytic nevi on the hyponychium with dermoscopic features of longitudinal brush pigmentation in children

The dermoscopic features of longitudinally aligned pigmentation on the hyponychium were previously described in pediatric patients with longitudinal melanonychia. We report four cases of biopsy-proven acral melanocytic nevi on the hyponychium with a longitudinal brush pigmentation (LBP) pattern in dermoscopy. This LBP pattern on the hyponychium may be a counterpart of the fibrillar pattern of acral melanocytic nevi. Therefore, the LBP pattern in dermoscopy may provide a useful clue for distinguishing benign melanocytic nevi from melanoma in pediatric patients.

Primary Brain Melanoma in a Pediatric Patient: A Case Report

BACKGROUND Primary malignant melanoma of the brain is a challenging radiological diagnosis and a high index of suspicion is required about patients with the condition. In the pediatric population, only a few cases have been reported in the literature. The purpose of this report was to describe the expected imaging characteristics and the importance of a multidisciplinary approach in the diagnosis of this rare entity. CASE REPORT A 17-year-old Hispanic male who presented with new-onset tonic-clonic seizures had no focal neurologic deficits on physical examination. An initial computed tomography scan showed a hyperdense, right frontal, parafalcine mass. Brain magnetic resonance imaging was performed and revealed a T1 hyperintense and T2 hypointense, right-frontal-lobe, extra-axial mass with foci of susceptibility. Resection of the mass revealed a lesion that had a dark, pigmented macroscopic appearance. Histopathologic analysis confirmed that it was a primary intracranial malignant melanoma after no primary site was identified on dermatologic and ophthalmologic evaluations. CONCLUSIONS Diagnosing a primary intracranial melanoma with imaging alone is virtually impossible if clinical data and findings from a thorough physical examination are unavailable. Intracranial primary malignant melanoma remains a complex radiological diagnosis that relies on the exclusion of other potentially more common entities and an optimal multidisciplinary approach.

Melanotic Neuroectodermal Tumor of Infancy at Skull: Rare and Rapid-Growing Tumor but Histologically Benign

INTRODUCTION

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare and rapid-growing tumor. However, a neurosurgeon should not overlook this entity when differential diagnosing rapid-growing skull tumor because its histology nature is just benign, and the prognosis is much better than other malignant tumors.

CASE PRESENTATION

We reported the case of a 5-month old male presenting with progressive rapid-growing skull tumor which became 10 cm in diameter in only 5 months compared to the normal head circumference at birth. At first, we thought of malignant skull tumor and performed only biopsy to establish diagnosis. But, when the pathology revealed benign MNTI, we performed preoperative tumor embolization and then radical surgery. Good result was observed.

DISCUSSION

Skull MNTI is the second most common location after the maxilla. Even advanced imaging nowadays cannot distinguish MNTI from other malignant tumors definitely. Urgent biopsy is recommended to establish diagnosis of this benign tumor first. Preoperative angiography with tumor embolization is recommended when feasible, followed by craniotomy with radical resection.

Survival analysis of children and adolescents with melanoma

OBJECTIVES

to analyze the survival in juvenile melanoma.

METHODS

retrospective study conducted by hospital record review and cancer records of patients aged 0 to 19 years, with histologically proven melanoma and treated between 1997 and 2017 at the Erasto Gaertner Hospital in Curitiba-PR.

RESULTS

the sample comprised 24 patients, female (62.5%), mean 14.14 ± 4.72 years old, with head and neck melanoma (37.5%), chest (25%) and extremities. (20.8%). Signs and symptoms at diagnosis were increased lesion size (25%), bleeding (20.8%) and pruritus (16.6%). There was a Breslow II and IV index and Clark IV level, with a statistical tendency between Breslow IV and death (p = 0.127), and significance between Clark V and death (p = 0.067). Nine (37.5%) patients had metastases, six (25%) with distant metastases died (p = 0.001), five were girls (20.8%). Surgery was the standard treatment and chemotherapy the most used adjuvant (37.5%). The average time between diagnosis and death was 1.3 ± 1.2 years and survival were 3.7 ± 3.2 years.

CONCLUSION

there was a delay in diagnosis, high morbidity and mortality and average survival less than five years.

Survival Differences Between Pediatric Head and Neck Versus Body Melanoma in the Surveillance, Epidemiology, and End Results Program

OBJECTIVES/HYPOTHESIS

To review the demographics, treatment, and survival of pediatric melanoma of the head and neck and to determine if melanoma of the head and neck has worse survival than melanoma of other body sites.

STUDY DESIGN

Retrospective database review.

METHODS

Pediatric patients from 0 to 21 years in the Surveillance, Epidemiology, and End Results 18 registries database were included from 1975 to 2016 based on a diagnosis of melanoma of the skin using the primary site International Classification of Diseases for Oncology, Third Edition codes from C44.0-C44.9.skin of lip, C44.1-eyelid, C44.2-external ear, C44.3-skin other/unspecified parts of face, C44.4-skin of scalp and neck, C44.5-skin of trunk, C44.6-skin of upper limb and shoulder, C44.7-skin of lower limb and hip, C44.8-overlapping lesion of skin, and C44.9-skin, NOS (not otherwise specified).

RESULTS

A total of 4,561 pediatric melanomas of the skin were identified. There were 854 (18.7%) cases of melanoma of the head and neck (MHN) and 3,707 (81.3%) cases of melanoma of the body (MOB). The hazard ratio for MHN versus MOB was 1.6 (95% confidence interval: 1.3-2.1) after accounting for sex, race, and age. Of MHN sites, the hazard ratio for melanoma of the scalp and neck was 2.2 (1.1-4.7). The 2- and 5-year Kaplan-Meier overall survival for MHN were 94.6% and 90.7%, respectively, compared with 96.6% and 94.7%, respectively, for MOB (P < .01).

CONCLUSIONS

Survival outcomes of pediatric melanoma are notably related to anatomic site. Children with melanoma of the scalp and neck have the worst survival of all sites. Additionally, children who are older/white/male are at greater risk for worse survival outcomes.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E635-E641, 2021.

α5-nAChR modulates melanoma growth through the Notch1 signaling pathway

The roles of α5-nicotinic acetylcholine receptors (α5-nAChRs) in various types of solid cancer have been reported; however, its role in melanoma remains unknown. We knocked down α5-nAChR expression in melanoma cells to investigate the role of α5-nAChR in the proliferation, migration, and invasion of melanoma cells, and its effect on downstream signaling pathways. Using immunohistochemical analysis, we determined that α5-nAChR expression is significantly increased in human melanoma tissues and cell lines compared with normal human skin tissues. Knocking down α5-nAChR expression in melanoma cells in culture significantly inhibited the proliferation, migration, and invasiveness of melanoma cell lines. Specifically, knockdown of α5-nAChR inhibited PI3K-AKT and ERK1/2 signaling activity. Moreover, we confirmed that the Notch1 signaling pathway is the downstream target of α5-nAChR in melanoma. Our findings suggest that α5-nAChR plays a critical role in melanoma development and progression, and that targeting α5-nAChR may be a strategy for melanoma treatment.

Characteristics of melanoma in white and nonwhite children, adolescents, and young adults: Analysis of a pediatric melanoma institutional registry, 1995-2018

OBJECTIVES

To characterize clinical differences among nonwhite/multiethnic vs white children, adolescents, and young adults with melanoma or atypical melanocytic neoplasms, including atypical Spitz tumors.

PATIENTS AND METHODS

A cohort of 55 patients (< 25 years of age) prospectively followed from 1995 to 2018 in the Stanford Pigmented Lesion and Melanoma Program was analyzed for differences in clinical presentation, including skin phototype, race/ethnicity, age, sex, tumor/melanoma characteristics, and outcome.

RESULTS

Seventeen patients (9 males and 8 females) were classified as nonwhite (predominantly skin phototype IV) and of Hispanic, Asian, or Black/African American ethnicity, and 38 patients (21 males and 17 females) were classified as white (predominantly phototypes I/II). Ages ranged from 6 months to 24 years, and median follow-up was 36 months (range 1-180 months). Melanomas were diagnosed in 87% of whites in our cohort, compared to 65% of nonwhites, with the remainder representing mainly atypical Spitz tumors. Lesions were usually brought to the attention of a health care provider by the patient or family (P < 0.05). Compared with whites, nonwhites were more likely to present at a younger mean age (10.9 years vs 15.4 years, P < 0.05) and with pink/clinically amelanotic tumors (59% vs 24%, P = 0.02).

CONCLUSIONS

This long-term prospective institutional study showed clinically relevant differences between nonwhite vs white children, adolescents, and young adults diagnosed with melanoma and atypical melanocytic neoplasms. Nonwhite patients presented at a younger age and had more clinically amelanotic melanocytic tumors. Increased recognition of clinical factors and risk of these tumors in nonwhites could result in earlier diagnosis.

Hyperprogression in Pediatric Melanoma Metastatic to the Breast Treated with a Checkpoint Inhibitor

Metastatic melanomas in the pediatric population are rare, but they have been appearing more frequently. Unfortunately, little is known about the differences in the biology and therapeutic implications of pediatric metastatic melanomas when compared to those found in adults. Herein, we have presented the case of a 13-year-old girl with a stage IIID malignant melanoma arising from a congenital nevus. This patient underwent surgical management, and she received adjuvant interferon therapy; however, this treatment was incomplete due to a grade 3 transaminase elevation and the early recurrence of the disease. An isolated metastasis to the breast was documented, and a mastectomy was performed. Soon afterward, low-volume lung metastases developed, and she was treated with nivolumab. After two treatment cycles, the disease continued to develop in a hyperprogressive manner. Advances in the characterization and understanding of pediatric melanomas are needed, as well as experience in the management of new therapies in these cases, which would help clarify the extent to which we can extrapolate the data obtained from the adult population. Therapeutic interventions in melanoma cases are evolving rapidly, and the role of metastasectomies in the era of immunotherapy and BRAF and MEK-targeted therapies is largely unknown. Moreover, the identification of risk factors for the development of hyperprogression and its underlying mechanisms are also warranted.

microRNA-134 inhibits melanoma growth and metastasis by negatively regulating collagen triple helix repeat containing-1 (CTHRC1)

Melanoma, a malignant tumor of melanocytes, is considered to be the most aggressive of skin cancers and its incidence keeps increasing worldwide. miR-134 and CTHRC1 have been demonstrated to be involved in the occurrence and development of various tumors. However, their roles are still elusive in the progression of melanoma. qRT-PCR and western blot (WB) were used to examine the expressions of miR-134 and CTHRC1 in clinical specimens of melanoma patients and melanoma cell lines. Dual-luciferase reporter assay was applied to verify the target interaction between miR-134 and CTHRC1. The mRNA and protein expressions of CTHRC1 were measured by qRT-PCR and WB after treatment by miR-134 inhibitor and mimic. Subsequently, CCK8, colony formation assay, and flow cytometry were utilized to assess the influences of miR-134 and CTHRC1 on cell growth of melanoma. Cell migration and invasion experiments were performed to evaluate the effects of miR-134 and CTHRC1 on metastasis of melanoma. It was shown that CTHRC1 was up-regulated and miR-134 was down-regulated in melanoma patients and cell lines. CTHRC1 was demonstrated to be a direct target of miR-134. Ultimately, we also found that up-regulated miR-134 expression and down-regulated CTHRC1 expression could suppress cell proliferation and cell colony formation, promote apoptosis, delay the cell cycle, and hinder cell migration and invasion. Our findings suggest that miR-134 could inhibit the growth and metastasis of melanoma by negatively regulating CTHRC1.