Changes in the presentation of nodular and superficial spreading melanomas over 35 years

Diagnostic and prognostic risk factors analysis for distant metastasis in melanoma: a population-based study

BACKGROUND

We aimed to develop tools that could predict the occurrence of distant metastases in melanoma and its prognosis based on clinical and pathological characteristics.

MATERIALS AND METHODS

We obtained data from the Surveillance, Epidemiology, and End Results (SEER) database of melanoma patients diagnosed between 2010 and 2019. Logistic analyses were performed to identify independent risk factors associated with distant metastasis. Additionally, multivariate Cox analyses were conducted to determine independent prognostic factors for patients with distant metastasis. Two nomograms were established and evaluated with the receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Furthermore, we performed a retrospective analysis of melanoma with distant metastasis from our institute between March 2018 and June 2022.

RESULTS

Of the total 19 396 melanoma patients, 352 (1.8%) had distant metastases at the time of diagnosis. The following clinical and pathological characteristics were identified as independent risk factors for distant metastasis in melanoma: N stage, tumor size, ulceration, mitosis, primary tumor site, and pathological subtype. Furthermore, tumor size, pathological subtype, and radiotherapy were identified as independent prognostic factors. The results of the training and validation cohorts' ROC curves, calibration, DCA, and Kaplan-Meier survival curves demonstrate the effectiveness of the two nomograms. The retrospective study results from our center supported the results from the SEER database.

CONCLUSION

The clinical and pathological characteristics of melanoma can predict a patient's risk of metastasis and prognosis, and the two nomograms are expected to be effective tools to guide therapy decisions.

Metastatic Nodular Melanoma with Angiosarcomatous Transdifferentiation-A Case Report and Review of the Literature

Diagnosing cutaneous melanomas relies mainly on histopathological analysis, which, in selected cases, can be aided by immunohistochemical evaluation of conventional melanocytic markers. Nevertheless, these malignancies, particularly in metastatic settings, may display divergent differentiation with unusual histological and immunohistochemical features. In this context, we present the case of a 65-year-old male diagnosed with typical superficial spreading melanoma who developed recurrence and metastatic lesions featuring angiosarcomatous differentiation. The diagnosis of the initial tumour and the subsequently dedifferentiated lesions was confirmed by ample immunohistochemical analysis, which included several melanocytic markers, as well as mesenchymal and vascular markers. The recurrent tumour and lymph nodes metastases were completely negative for Melan-A and PRAME, and focally positive for SOX10. Additionally, they also displayed diffuse, intense positivity for CD10 and WT1 and focal positivity for CD99, ERB, and CD31. Thus, the diagnosis of primary cutaneous melanoma with recurrent and metastatic divergent angiosarcomatous differentiation was established. This occurrence is particularly rare and can pose important diagnostic challenges. Therefore, in addition to presenting this highly unusual case, we also performed a comprehensive review of the literature on divergent differentiation in melanomas.

Case report: Exceptional disease progression in a 70-year-old patient: generalized melanosis and melanuria in the course of metastatic melanoma - a case study

This case study documents an extraordinary disease progression in a 70-year-old patient diagnosed with metastatic melanoma. The patient's condition advanced to an unusual manifestation characterized by generalized melanosis and melanuria, a rare and foreboding complication of metastatic melanoma. The clinical presentation involved rapid-onset skin darkening, primarily affecting the face and torso, along with darkened urine, marking the onset of melanuria. Despite extensive diagnostic evaluations, including abdominal ultrasound, neck ultrasound, thoracic CT scans, and endoscopic examinations, the exact metastatic sites remained elusive, demonstrating the diagnostic challenges associated with this condition. Laboratory tests revealed abnormal hematological and biochemical markers, along with elevated S100 protein levels, indicating disease progression. The patient underwent a surgical skin biopsy that confirmed the diagnosis of metastatic melanoma, leading to a multidisciplinary approach to treatment. Following this, the patient-initiated chemotherapy with dacarbazine (DTIC). Regrettably, this was necessitated by the absence of reimbursement for BRAF and MEK inhibitors as well as immunotherapy, and it subsequently led to rapid disease progression and a decline in the patient's clinical condition. The patient's condition further complicated with erysipelas and increased distress, ultimately leading to their unfortunate demise. This case highlights the aggressive nature of generalized melanosis, characterized by a rapid clinical course, substantial pigmentation, and limited response to conventional chemotherapy. Importantly, the patient had a BRAF mutation, emphasizing the urgency of exploring alternative treatment strategies. Patients with a BRAF mutation are excellent candidates for BRAF and MEK inhibitor treatment, potentially allowing them to extend their lifespan if this therapy were available. The challenges encountered in diagnosing, managing, and treating this aggressive form of metastatic melanoma underline the need for early detection, tailored therapeutic approaches, and ongoing research efforts to improve patient outcomes in such cases.

Prognostic significance of age on superficial spreading melanoma after resection: lessons from SEER database involving 12 536 patients

BACKGROUND

This study sought to analyse the impact of elderly age on long-term prognosis of superficial spreading melanoma (SSM) after surgery.

METHODS

A population-based cohort of patients undergoing resection for SSM from 2004 to 2015 was collected, using data from National Cancer Institute' Surveillance, Epidemiology, and End Results (SEER)* Stat software. Patients were divided into the non-elderly group (≤70 years) and elderly group (>70 years). Baseline characteristics and long-term survivals were compared between the two groups. A 1:1 propensity score matching (PSM) was used to reduce the risk of bias. The impact of the elderly age on overall survival (OS) and cause-specific mortality (CSM) was estimated by Cox-regression and competing-risk regression models.

RESULTS

Among 12 536 patients with SSM after resection included into the cohort, 8664 patients were ≤70 years, and 3872 were >70 years. Patients in the elderly group had higher incidences of multiple tumours, worse tumour stage and infiltration degree, lymphatic metastasis, and larger size of primary lesions. Using PSM, 3581 pairs of patients were created. On matched analysis, the elderly group was associated with worse OS and CSM. On multivariable Cox-regression and competing-risk regression analyses, elderly age was identified as an independent risk factor of OS and CSM after adjusting for other prognostic variables.

CONCLUSIONS

The elderly age of patients was independently associated with worse OS and CSM after resection of SSM when baseline and tumour characteristics were balanced. Adjuvant therapy and individualized strategy on follow-up should be made for elderly patients after resection of SSM.

Cytokine and Chemokine Receptor Patterns of Human Malignant Melanoma Cell Lines

Cytokine and chemokine receptors can promote tumor progression, invasion, and metastasis development by inducing different intracellular signaling pathways. The aim of this study was to determine the cytokine and chemokine receptor gene expression patterns in human melanoma cell lines. We found a large set of cytokine and chemokine receptor genes that were significantly differentially expressed between melanoma cell lines that originated from different subtypes of primary melanomas as well as cell lines that originated from melanoma metastases. The relative expressions of two receptor genes (CCR2 and TNFRSF11B) were positively correlated with the invasive potential of the cell lines, whereas a negative correlation was observed for the TNFRSF14 gene expression. We also found a small set of receptor genes that exhibited a significantly decreased expression in association with a BRAFV600E mutation. Based on our results, we assume that the analyzed cytokine and chemokine receptor collection may provide potential to distinguish the different subtypes of melanomas, helping us to understand the biological behavior of BRAFV600E-mutated melanoma cells.

A biomarker panel predicts recurrence-free survival in ulcerated primary cutaneous melanoma

BACKGROUND

Ulceration is an independent adverse prognostic factor in cutaneous malignant melanoma (CMM). There is, however, a need for additional prognostic markers to identify patients with ulcerated stage I-II CMM who have a high-risk for recurrence. The aim of this study was to examine the prognostic impact of BRAF mutation, proliferation and presence of tumour infiltrating lymphocytes (TILs) in primary ulcerated CMM.

MATERIAL AND METHODS

We have used a consecutive cohort consisting of 71 primary ulcerated CMM (T1b-T4b). BRAF mutation was detected using Cobas test and pyrosequencing. Protein expression of the proliferation marker Ki67 was analysed using immunohistochemistry. Presence of TILs was evaluated in representative hematoxylin-eosin stained formalin-fixed paraffin-embedded tumour sections.

RESULTS

Proportion of BRAF mutated alleles, proliferation and presence of TILs all had a statistically significant impact on recurrence free survival in univariate analyses (HR 2.44, 95% CI 1.23-4.84, p = 0.011; HR 2.66, 95% CI 1.32-5.35, p = 0.006 respectively HR 0.48, 95% CI 0.24-0.98, p = 0.045). A trend test found a statistically significant decrease in the proportion of recurrence by including the three favourable factors (BRAF wildtype/low proportion of BRAF mutated alleles, low proliferation and high presence of TILs) (p = 0.0004). When at least two out of three factors were present there was a statistically significant association with longer recurrence free survival in the multivariate analysis (HR 0.30, 95% CI 0.15-0.61, p = 0.001) when adjusted for Breslow thickness, an established independent prognostic marker for CMM.

CONCLUSION

Thus, this panel of markers could be an interesting novel concept for predicting the clinical outcome in patients with high-risk stage I-II ulcerated CMM.

Clinical Study on the Increased Incidence of Nodular Melanoma Cases Compared to Superficial Melanoma

Our study group was comprised of 67 patients with melanoma, admitted and operated in our clinic between 2010-2018. Only the patients with melanoma localized on the head, torso and upper limb were selected for our study. We attempted to establish a link between the clinical appearance, presence or absence of ulceration, presence or absence of regional lymphadenopathy or distant metastases, surgical technique, histopathological type, Clark level and Breslow depth, disease stage (TNM), adjuvant therapies and survival rates at 1, 3, 5 and 10 years.

Trends in the characteristics of skin melanoma in accordance with time intervals: A single Turkish tertiary referral center experience

AIM

The incidence of skin melanoma has increased dramatically in recent years. The aim of this study was to analyze the trends in the features of Turkish cutaneous melanoma patients in a 25-year period.

MATERIALS AND METHODS

A total of 1258 adult melanoma patients who had been managed and followed up at a tertiary referral center between 1993 and 2017 were included in the study.

RESULTS

Males were predominant which did not vary between time intervals. There was an increase in the percentage of older patients over the years, whereas no change was observed in the percentage of younger patients. As the percentage of lower extremity melanoma dropped, the percentage of truncal melanomas rose. Both the incidences of thick (T3-T4) and thin melanomas (T1) were found to increase over time by 13.4% and 3.8%, respectively. There was no significant change in the percentage of the metastatic disease; however, Stage III disease was found to multiply by 10.1% and local disease was found to fall by 8.5% over the period. The percentages of patients with nodular histopathology and tumor-infiltrating lymphocytes were found to plummet, and there was a slight decline in the percentages of patients with high mitotic rate and lymphovascular invasion.

CONCLUSIONS

Most likely because of the delayed diagnosis, cutaneous melanoma was found to be associated with less favorable prognostic features as the time lapsed. We suggest that effective campaigns for public awareness of melanoma be implemented so the screening and early diagnosis of the disease can be promoted.

Patient-identified early clinical warning signs of nodular melanoma: a qualitative study

BACKGROUND

Nodular (NM) and superficial spreading melanoma (SSM) show different disease trajectories, with more rapid development in NM and fewer opportunities for early detection often resulting in worse outcomes. Our study described the patient-identified early signs of thin NM via comparisons to thin (≤ 2 mm) SSM and thick (> 2 mm) NM.

METHODS

We conducted semi-structured interviews with NM and SSM patients and analyzed the data using thematic analysis.

RESULTS

We enrolled 34 NM and 32 SSM patients. Melanoma early signs uniquely identified by patients with thin NM included white, blue or black coloration, "dot-like" size, fast changes in shape and color observed over 2 weeks, elevation and texture or "puffiness" over 6-12 months, and the sensation that the mole "did not feel right". Early signs reported by both thin NM and thin SSM patients included round or oblong shape, "jagged" border, pink/red, brown/reddish or dark coloration, "elevated like a pimple" or "tiny bump", fast color darkening, diameter growth, and border irregularity, and mole feeling "really itchy".

CONCLUSIONS

We found evidence that early signs of NM can be self-identified, which has important implications for the earlier detection of this most aggressive type of melanoma by both health professionals and patients.

Five-year survival in patients with nodular and superficial spreading melanomas in the US population

BACKGROUND

Although superficial spreading melanomas (SSM) are diagnosed as thinner lesions, nodular melanomas (NM) have a more rapid growth rate and are biologically more aggressive compared with other histologic subtypes.

OBJECTIVE

To determine the difference in 5-year relative survival in patients with NM and SSM at the same Breslow depth and TNM stage.

METHODS

A population-based cross-sectional analysis compared the 5-year relative survival of patients with NM and SSM using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)∗Stat software (version 8.2.1-8.3.5). Chi-square tests compared the proportions, and Kaplan-Meier method with Z-score compared 5-year relative survival.

RESULTS

For patients receiving a diagnosis between 2004 and 2009, 5-year relative survival was lower in NM compared with SSM (53.7% vs 87.3%; Z score, -41.35; P < .001). Similarly, for patients receiving a diagnosis between 2010 and 2015, 5-year relative survival was lower in NM compared with SSM (61.5% vs 89.7%; Z score, -2.7078; P < .01). Subgroup analyses showed inferior survival in NM in T1b, and survival differences remained significant after excluding patients with nodal or distant metastases.

CONCLUSIONS

Five-year relative survival is worse in NM compared with SSM especially in T1b, T2a, and T2b melanomas. Melanoma subtype should be taken into consideration when making treatment recommendations.

Differences in Risk Factors for Melanoma in Young and Middle-aged Higher-risk Patients

BACKGROUND/AIM

Differences in risk factors for melanoma between young adults (18-39 years) and middle-aged (40-60 years) are not well documented. In this study, we aimed to determine differences in risk factors and characteristics of melanoma between these groups.

PATIENTS AND METHODS

This retrospective study is a review on 330 patients, including 250 middle-aged and 80 young adults, during the period 2006-2016 in the Tampere university hospital, in Finland.

RESULTS

Forty-one per cent of middle-aged and 47% of young adults were defined as higher-risk patients. High nevus count was the most common host risk factor in both groups. Young were more likely to have a family history of melanoma. Middle-aged had more often excessive intermittent sun exposure and a history of sunburn. Host risk characteristics were less commonly associated with thicker melanomas.

CONCLUSION

A high number of patients have host risk factors for melanoma. Several differences exist in risk factors and characteristics of melanomas between young adults and middle-aged patients.

Subtyping Cutaneous Melanoma Matters

Background

Our aim was to investigate the role of melanoma subtype on survival and focus on the effects stratified by Breslow thickness and ulceration status.

Methods

Patients with cutaneous melanoma stage I, II, or III diagnosed between 2000 and 2014 were derived from the Dutch Nationwide Pathology Registry and overall survival data from the Netherlands Cancer Registry. Patients were followed until 2018. Using multivariable Cox proportional hazards models, hazard ratios were calculated for each melanoma subtype, per Breslow thickness category and ulceration status, and adjusted for age, sex, stage, and localization.

Results

A total of 48 361 patients were included: 79.3% had superficial spreading melanoma (SSM), 14.6% nodular melanoma (NM), 5.2% lentigo maligna melanoma, and 0.9% acral lentiginous melanoma (ALM). In the total patient group, using SSM as the reference category, adjusted hazard ratios were 1.06 (95% confidence interval [CI] = 1.01 to 1.12) for NM, 1.02 (95% CI = 0.93 to 1.13) for lentigo maligna melanoma, and 1.26 (95% = CI 1.06 to 1.50) for ALM. Among patients with 1.0 mm or less Breslow thickness and no ulceration, NM showed a twofold increased risk (hazard ratio = 1.96, 95% CI = 1.58 to 2.45) compared with SSM. Compared with 1.0 mm or less SSM without ulceration, the hazard ratio for 1.0 mm or less SSM with ulceration was 1.94 (95% CI = 1.55 to 2.44), and the hazard ratio for 1.0 mm or less NM with ulceration was 3.46 (95% CI = 2.17 to 5.50). NM patients with tumors greater than 1.0 mm did not show worse survival than SSM patients with tumors greater than 1.0 mm.

Conclusions

In this large nationwide study, ALM patients showed worse survival than SSM patients. Among patients with melanomas that were thin (1.0 mm or less), NM subtype patients also showed worse survival than SSM patients.

MC1R variants and cutaneous melanoma risk according to histological type, body site, and Breslow thickness: a pooled analysis from the M-SKIP project

Little is known on whether melanocortin 1 receptor (MC1R) associated cutaneous melanoma (CM) risk varies depending on histological subtype and body site, and whether tumour thickness at diagnosis (the most important prognostic factor for CM patients) differs between MC1R variant carriers and wild-type individuals. We studied the association between MC1R variants and CM risk by histological subtype, body site, and Breslow thickness, using the database of the M-SKIP project. We pooled individual data from 15 case-control studies conducted during 2005-2015 in Europe and the USA. Study-specific, multi-adjusted odds ratios were pooled into summary odds ratios (SOR) and 95% confidence intervals (CI) using random-effects models. Six thousand eight hundred ninety-one CM cases and 5555 controls were included. CM risk was increased among MC1R variant carriers vs. wild-type individuals. The increase in risk was comparable across histological subtypes (SOR for any variant vs. wild-type ranged between 1.57 and 1.70, always statistical significant) except acral lentiginous melanoma (ALM), for which no association emerged; and slightly greater on chronically (1.74, 95% CI 1.47-2.07) than intermittently (1.55, 95% CI 1.34-1.78) sun-exposed skin. CM risk was greater for those carrying 'R' vs. 'r' variants; correlated with the number of variants; and was more evident among individuals not showing the red hair colour phenotype. Breslow thickness was not associated with MC1R status. MC1R variants were associated with an increased risk of CM of any histological subtype (except ALM) and occurring on both chronically and intermittently sun-exposed skin.

Dermatoscopic features of thin (≤2 mm Breslow thickness) vs. thick (>2 mm Breslow thickness) nodular melanoma and predictors of nodular melanoma versus nodular non-melanoma tumours: a multicentric collaborative study by the International Dermoscopy Society

BACKGROUND

Thin nodular melanoma (NM) often lacks conspicuous melanoma-specific dermatoscopic criteria and escapes clinical detection until it progresses to a thicker and more advanced tumour.

OBJECTIVE

To investigate the dermatoscopic morphology of thin (≤2 mm Breslow thickness) vs. thick (>2 mm) NM and to identify dermatoscopic predictors of its differential diagnosis from other nodular tumours.

METHODS

Retrospective, morphological case-control study, conducted on behalf of the International Dermoscopy Society. Dermatoscopic images of NM and other nodular tumours from 19 skin cancer centres worldwide were collected and analysed.

RESULTS

Overall, 254 tumours were collected (69 NM of Breslow thickness ≤2 mm, 96 NM >2 mm and 89 non-melanoma nodular lesions). Light brown coloration (50.7%) and irregular brown dots/globules (42.0%) were most frequently observed in ≤2 mm NMs. Multivariate analysis revealed that dotted vessels (3.4-fold), white shiny streaks (2.9-fold) and irregular blue structureless area (2.4-fold) were predictors for thinner NM compared to non-melanoma nodular tumours. Overall, irregular blue structureless area (3.4-fold), dotted vessels (4.6-fold) and serpentine vessels (1.9-fold) were predictors of all NM compared to non-melanoma nodular lesions.

LIMITATIONS

Absence of a centralized, consensus pathology review and cases selected form tertiary centres maybe not reflecting the broader community.

CONCLUSIONS

Our study sheds light into the dermatoscopic morphology of thin NM in comparison to thicker NM and could provide useful clues for its differential diagnosis from other non-melanoma nodular tumours.

Comparison of Hydrogels for the Development of Well-Defined 3D Cancer Models of Breast Cancer and Melanoma

Bioprinting offers the opportunity to fabricate precise 3D tumor models to study tumor pathophysiology and progression. However, the choice of the bioink used is important. In this study, cell behavior was studied in three mechanically and biologically different hydrogels (alginate, alginate dialdehyde crosslinked with gelatin (ADA–GEL), and thiol-modified hyaluronan (HA-SH crosslinked with PEGDA)) with cells from breast cancer (MDA-MB-231 and MCF-7) and melanoma (Mel Im and MV3), by analyzing survival, growth, and the amount of metabolically active, living cells via WST-8 labeling. Material characteristics were analyzed by dynamic mechanical analysis. Cell lines revealed significantly increased cell numbers in low-percentage alginate and HA-SH from day 1 to 14, while only Mel Im also revealed an increase in ADA–GEL. MCF-7 showed a preference for 1% alginate. Melanoma cells tended to proliferate better in ADA–GEL and HA-SH than mammary carcinoma cells. In 1% alginate, breast cancer cells showed equally good proliferation compared to melanoma cell lines. A smaller area was colonized in high-percentage alginate-based hydrogels. Moreover, 3% alginate was the stiffest material, and 2.5% ADA–GEL was the softest material. The other hydrogels were in the same range in between. Therefore, cellular responses were not only stiffness-dependent. With 1% alginate and HA-SH, we identified matrices that enable proliferation of all tested tumor cell lines while maintaining expected tumor heterogeneity. By adapting hydrogels, differences could be accentuated. This opens up the possibility of understanding and analyzing tumor heterogeneity by biofabrication.

Primary Melanoma Histologic Subtype: Impact on Survival and Response to Therapy

BACKGROUND

Two primary histologic subtypes, superficial spreading melanoma (SSM) and nodular melanoma (NM), comprise the majority of all cutaneous melanomas. NM is associated with worse outcomes, which have been attributed to increased thickness at presentation, and it is widely expected that NM and SSM would exhibit similar behavior once metastasized. Herein, we tested the hypothesis that primary histologic subtype is an independent predictor of survival and may impact response to treatment in the metastatic setting.

METHODS

We examined the most recent Surveillance, Epidemiology, and End Results (SEER) cohort (n = 118 508) and the New York University (NYU) cohort (n = 1621) with available protocol-driven follow-up. Outcomes specified by primary histology were studied in both the primary and metastatic settings with respect to BRAF-targeted therapy and immunotherapy. We characterized known driver mutations and examined a 140-gene panel in a subset of NM and SSM cases using next-generation sequencing. All statistical tests were two-sided.

RESULTS

NM was an independent risk factor for death in both the SEER (hazard ratio [HR] = 1.55, 95% confidence interval [CI] = 1.41 to 1.70, P < .001) and NYU (HR = 1.47, 95% CI = 1.05, 2.07, P = .03) cohorts, controlling for thickness, ulceration, stage, and other variables. In the metastatic setting, NM remained an independent risk factor for death upon treatment with BRAF-targeted therapy (HR = 3.33, 95% CI = 1.06 to 10.47, P = .04) but showed no statistically significant difference with immune checkpoint inhibition. NM was associated with a higher rate of NRAS mutation (P < .001), and high-throughput sequencing revealed NM-specific genomic alterations in NOTCH4, ANK3, and ZNF560, which were independently validated.

CONCLUSIONS

Our data reveal distinct clinical and biological differences between NM and SSM that support revisiting the prognostic and predictive impact of primary histology subtype in the management of cutaneous melanoma.

Epidemiological trends in the diagnosis of melanoma in a Southern European population: analysis of a large database from a tertiary referral center

The aim of this study was to present the epidemiological, clinicopathological, and treatment characteristics of patients diagnosed and treated in a tertiary referral center and to analyze independent factors associated with these characteristics. In this cohort study, epidemiological, clinicopathological, and treatment characteristics of 1461 consecutive melanoma patients diagnosed and treated in a tertiary referral center in 1987-2015 were prospectively collected in a registry. All patients underwent resection of their melanoma lesion. Multiple logistic regression analysis was used to examine independent correlations between characteristics. Internal validation of these correlations was performed by the bootstrap method. The median age of the patients was 53 years. Female sex had a slight predominance, whereas the majority were of Southern European origin. Superficial spreading melanoma was associated with younger age (P<0.001), whereas the nodular melanoma histological subtype was associated independently with indoor occupation (P=0.021) and diagnosis in the years 2004-2015 (P=0.002). Melanomas with Breslow thickness above 1.0 mm were associated with skin type III-IV (P=0.021) and diagnosis in the years 1987-2003 (P=0.046). In addition, histological ulceration was associated with older age (P=0.004) and diagnosis in the years 1987-2003 (P<0.001), whereas histological regression was associated independently with older age (P=0.001). This study presented independent associations between epidemiological, histopathological, and treatment characteristics, which might help to better understand melanoma disease and treatment practices in Southern Europe.

Diagnostic accuracy of dermatofluoroscopy in cutaneous melanoma detection: results of a prospective multicentre clinical study in 476 pigmented lesions

BACKGROUND

Early detection is a key factor in improving survival from melanoma. Today, the clinical diagnosis of cutaneous melanoma is based mostly on visual inspection and dermoscopy. Preclinical studies in freshly excised or paraffin-embedded tissue have shown that the melanin fluorescence spectra after stepwise two-photon excitation, a process termed dermatofluoroscopy, differ between cutaneous melanoma and melanocytic naevi. However, confirmation from a larger prospective clinical study is lacking.

OBJECTIVES

The primary end point of this study was to determine the diagnostic accuracy of dermatofluoroscopy in melanoma detection. Secondary end points included the collection of data for improving the computer algorithm that classifies skin lesions based on melanin fluorescence and the assessment of safety aspects.

METHODS

This was a prospective, blinded, multicentre clinical study in patients with pigmented skin lesions (PSLs) indicated for excision either to rule out or to confirm cutaneous melanoma. All included lesions underwent dermoscopy and dermatofluoroscopy in vivo before lesions were excised and subjected to histopathological examination.

RESULTS

In total, 369 patients and 476 PSLs were included in the final analysis. In 101 of 476 lesions (21·2%) histopathology revealed melanoma. The observed sensitivity of dermatofluoroscopy was 89·1% (90 of 101 melanomas identified), with an observed specificity of 44·8%. The positive and negative predictive values were 30·3% and 93·9%, respectively. No adverse events occurred.

CONCLUSIONS

Dermatofluoroscopy is a safe and accurate diagnostic method to aid physicians in diagnosing cutaneous melanoma. Limitations arise from largely amelanotic or regressing lesions lacking sufficient melanin fluorescence.

Association between Ki-67 expression and clinical outcomes among patients with clinically node-negative, thick primary melanoma who underwent nodal staging

BACKGROUND

Patients with thick primary melanomas (≥4 mm) have highly variable survival outcomes. Cell proliferation marker Ki-67 has been identified as promising biomarker in thick melanoma but has not been evaluated since the wide spread adoption of sentinel lymph node biopsy. We revisit its prognostic relevance in the sentinel node era.

METHODS

We studied patients with thick (≥4 mm) primary melanoma prospectively enrolled in a clinicopathological biospecimen database from 2002 to 2015, and evaluated the prognostic value of Ki-67 expression while controlling for features included in the existing staging criteria.

RESULTS

We analyzed 68 patients who underwent lymph node sampling and who had an available tumor for Ki-67 immunohistochemical (IHC) staining. The median tumor thickness was 6.0 mm; the median follow-up was 2.6 years. In multivariable analysis including nodal status and primary tumor ulceration, Ki-67 expression was an independent predictor of worse recurrence-free survival (HR 2.19, P = 0.024) and overall survival (HR 2.49, P = 0.028). Natural log-transformed tumor thickness (ln [thickness]) was also significantly associated with worse OS (HR 2.39, P = 0.010).

CONCLUSION

We identify Ki-67 and ln (thickness) as potential biomarkers for patients with thick melanoma who have undergone nodal staging. If validated in additional studies, these biomarkers could be integrated into the staging criteria to improve risk-stratification.

Association of clinicopathological features of melanoma with total naevus count and a history of dysplastic naevi: a cross-sectional retrospective study within an academic centre

BACKGROUND

High naevus count (HNC) (≥ 50 naevi) and presence of dysplastic naevi (DN) are risk factors for malignant melanoma (MM); however, MMs also occur in patients with low naevus count (LNC) (< 50 naevi) and in patients without DN. Little is known about differences between MMs in these groups.

AIM

To characterize the clinicopathological differences between MMs in patients with HNC and those in patients with LNC, with or without biopsy-proven DN.

METHODS

This was a cross-sectional retrospective chart review of 281 patients with MM seen between April 2013 and March 2014 at an academic pigmented lesion clinic (Boston, MA, USA).

RESULTS

Patients with LNC MMs were diagnosed at an older age (51 vs. 41 years, P < 0.001, OR = 0.95, 95% CI 0.93-0.97), with more aggressive MM features, including greater Breslow thickness (1.1 vs. 0.8 mm, P = 0.01), more mitoses (2 vs. 1 mitoses/mm² , P < 0.001), lower rate of superficial spreading subtype (58 vs. 78%, P < 0.01, OR = 2.57, 95% CI 1.31-5.03) and higher MM stage (P < 0.001), compared to patients with HNC. Patients with DN had similar trends as those in patients with HNC described above, and in addition, were more likely to have a truncal MM (55 vs. 39%, P < 0.01, OR = 1.97, 95% CI 1.22-3.18) with less ulceration (13 vs. 29%, P < 0.01, OR = 0.36, 95% CI 0.19-0.71). Patients without DN were more likely to have a history of a non-MM skin cancer (32 vs. 19%, P = 0.01, OR = 0.49, 95% CI 0.28-0.85) and an amelanotic MM (33 vs 21%, P = 0.03, OR = 0.55, 95% CI 0.31-0.96).

CONCLUSIONS

Patients with LNC may develop MMs with more aggressive features at an older age than patients with HNC. A history of biopsy-proven DN reveals distinct MM differences compared to patients without DN.

Clinicopathological predictors of recurrence in nodular and superficial spreading cutaneous melanoma: a multivariate analysis of 214 cases

BACKGROUND

Nodular melanoma (NM) accounts for most thick melanomas and because of their frequent association with ulceration, fast growth rate and high mitotic rate, contribute substantially to melanoma-related mortality. In a multicentric series of 214 primary melanomas including 96 NM and 118 superficial spreading melanoma (SSM), histopathological features were examined with the aim to identify clinicopathological predictors of recurrence.

METHODS

All consecutive cases of histopathologically diagnosed primary invasive SSM and NM during the period 2005-2010, were retrieved from the 12 participating Italian Melanoma Intergroup (IMI) centers. Each center provided clinico-pathological data such as gender, age at diagnosis, anatomical site, histopathological conventional parameters, date of excision and first melanoma recurrence.

RESULTS

Results showed that NM subtype was significantly associated with Breslow thickness (BT) at multivariate analysis: [BT 1.01-2 mm (OR 7.22; 95% CI 2.73-19.05), BT 2.01-4 mm (OR 7.04; 95% CI 2.54-19.56), and BT > 4 mm (OR 51.78; 95% CI 5.65-474.86) (p < 0.0001)]. Furthermore, mitotic rate (MR) was significantly correlated with NM histotype: [(MR 3-5 mitoses/mm2 (OR 2.62; 95% CI 1.01-6.83) and MR > 5 mitoses/mm2 (OR 4.87; 95% CI 1.77-13.40) (p = 0.002)]. The risk of recurrence was not significantly associated with NM histotype while BT [BT 1.01-2.00 mm (HR 1.55; 95% CI 0.51-4.71), BT 2.01-4.00 mm (HR 2.42; 95% CI 0.89-6.54), BT > 4.00 mm. (HR 3.13; 95% CI 0.95-10.28) (p = 0.05)], mitotic rate [MR > 2 mitoses/mm2 (HR 2.34; 95% CI, 1.11-4.97) (p = 0.03)] and the positivity of lymph node sentinel biopsy (SNLB) (HR 2.60; 95% CI 1.19-5.68) (p = 0.007) were significantly associated with an increased risk of recurrence at multivariate analysis.

CONCLUSIONS

We found that NM subtype was significantly associated with higher BT and MR but it was not a prognostic factor since it did not significantly correlate with melanoma recurrence rate. Conversely, increased BT and MR as well as SNLB positivity were significantly associated with a higher risk of melanoma recurrence.

Impact of Socioeconomic Status and Ethnicity on Melanoma Presentation and Recurrence in Caucasian Patients

OBJECTIVES

The impact of ethnicity and the socioeconomic status (SES) among Caucasians is not well studied. Here, we examine the impact of income on melanoma presentation and prognosis within a Caucasian cohort, accounting for ethnicity, as some reports suggest increased melanoma incidence in Ashkenazi Jewish (AJ) BRCA mutation carriers.

METHODS

We studied prospectively enrolled primary melanoma patients at New York University. SES data were estimated using United States' Census Bureau data and patient zip codes. We evaluated associations between ethnicity, SES, and baseline characteristics using the χ² test and multivariate logistic regression. We compared survival distributions using Kaplan-Meier curves, log-rank tests, and Cox proportional hazard ratios.

RESULTS

Of the 1,339 enrolled patients, AJ represented 32% (n = 423). Apart from AJ being older at presentation (p < 0.001), no significant differences were observed in baseline characteristics between ethnic groups. Patients with a median household income (MHI) lower than the median of the cohort were significantly more likely to present with advanced stages (p < 0.001) compared to patients with a higher MHI. Shorter overall (p = 0.016) and post-recurrence survival (p = 0.042) was also observed in patients from lower-income households.

CONCLUSION

Data suggest that disparities in melanoma presentation in Caucasians stratify according to income independent of ethnic background.

Revisiting determinants of prognosis in cutaneous melanoma

The American Joint Committee on Cancer staging system for cutaneous melanoma is based on primary tumor thickness and the presence of ulceration, mitoses, lymph node spread, and distant metastases as determinants of prognosis. Although this cutaneous melanoma staging system has evolved over time to more accurately reflect patient prognosis, improvements are still needed, because current understanding of the particular factors (genetic mutation, expression alteration, host response, etc) that are critical for predicting patient outcomes is incomplete. Given the clinical and biologic heterogeneity of primary melanomas, new prognostic tools are needed to more precisely identify patients who are most likely to develop advanced disease. Such tools would affect clinical surveillance strategies and aid in patient selection for adjuvant therapy. The authors reviewed the literature on prognostic molecular and immunologic markers in primary cutaneous melanoma, their associations with clinicopathologic and survival outcomes, and their potential for incorporation into current staging models. Overall, the studies considered in this review did not define prognostic markers that could be readily incorporated into the current staging system. Therefore, efforts should be continued in these and other directions to maximize the likelihood of identifying clinically useful prognostic biomarkers for cutaneous melanoma.

Assessment of melanoma histotypes and associated patient related factors: basis for a predictive statistical model

BACKGROUND

Certain melanoma histotypes carry a worse prognosis than others. We aimed to identify patient related factors associated with specific melanoma histotypes.

PATIENTS AND METHODS

Single center study including 347 melanoma patients, prospectively assessed for 22 variables leading to a database of more than 7,600 features.

RESULTS

Melanomas were histologically categorized as superficial spreading (SSM, 70.6%), nodular (NM; 12.7%), acrolentiginous (ALM; 4.0%), lentigo maligna (LMM; 3.8%), or unclassified melanoma (UCM; 8.9%). Well recognized melanoma risk indicators (i. e. many atypical nevi, freckles, previous melanoma), were significantly associated with SSM and LMM histotypes. NM and ALM patients carried significantly less common and/or atypical nevi. NM were mostly self-detected or detected by relatives. In contrast, SSM, LMM, and ALM were most frequently detected by dermatologists. NM and UCM were preferentially located on poorly observable sites, SSM on the lower limbs, ALM on plantar sites, and LMM on the head and neck. ALM and LMM patients were significantly older than other patients. A multinomial logistic model was designed to predict a certain melanoma histotype (overall accuracy 81%), which could be helpful to focus the attention of clinicians or may be integrated into fully automated diagnostic algorithms.

CONCLUSIONS

Melanoma histotypes show significant differences regarding patients' characteristics.

Early detection of melanoma: reviewing the ABCDEs

Over the course of their nearly 30-year history, the ABCD(E) criteria have been used globally in medical education and in the lay press to provide simple parameters for assessment of pigmented lesions that need to be further evaluated by a dermatologist. In this article, the efficacy and limitations of the ABCDE criteria as both a clinical tool and a public message will be reviewed.

RSK1 activation promotes invasion in nodular melanoma

The two major melanoma histologic subtypes, superficial spreading and nodular melanomas, differ in their speed of dermal invasion but converge biologically once they invade and metastasize. Herein, we tested the hypothesis that distinct molecular alterations arising in primary melanoma cells might persist as these tumors progress to invasion and metastasis. Ribosomal protein S6 kinase, 90 kDa, polypeptide 1 (RSK1; official name RPS6KA1) was significantly hyperactivated in human melanoma lines and metastatic tissues derived from nodular compared with superficial spreading melanoma. RSK1 was constitutively phosphorylated at Ser-380 in nodular but not superficial spreading melanoma and did not directly correlate with BRAF or MEK activation. Nodular melanoma cells were more sensitive to RSK1 inhibition using siRNA and the pharmacological inhibitor BI-D1870 compared with superficial spreading cells. Gene expression microarray analyses revealed that RSK1 orchestrated a program of gene expression that promoted cell motility and invasion. Differential overexpression of the prometastatic matrix metalloproteinase 8 and tissue inhibitor of metalloproteinases 1 in metastatic nodular compared with metastatic superficial spreading melanoma was observed. Finally, using an in vivo zebrafish model, constitutive RSK1 activation increased melanoma invasion. Together, these data reveal a novel role for activated RSK1 in the progression of nodular melanoma and suggest that melanoma originating from different histologic subtypes may be biologically distinct and that these differences are maintained as the tumors invade and metastasize.

Screening, early detection, education, and trends for melanoma: current status (2007-2013) and future directions: Part I. Epidemiology, high-risk groups, clinical strategies, and diagnostic technology

While most cancers have shown both decreased incidence and mortality over the past several decades, the incidence of melanoma has continued to grow, and mortality has only recently stabilized in the United States and in many other countries. Certain populations, such as men >60 years of age and lower socioeconomic status groups, face a greater burden from disease. For any given stage and across all ages, men have shown worse melanoma survival than women, and low socioeconomic status groups have increased levels of mortality. Novel risk factors can help identify populations at greatest risk for melanoma and can aid in targeted early detection. Risk assessment tools have been created to identify high-risk patients based on various factors, and these tools can reduce the number of patients needed to screen for melanoma detection. Diagnostic techniques, such as dermatoscopy and total body photography, and new technologies, such as multispectral imaging, may increase the accuracy and reliability of early melanoma detection.

Demographic, behavioural and physician-related determinants of early melanoma detection in a low-incidence population

BACKGROUND

Knowledge of the factors that influence early detection of melanoma is important in developing strategies to reduce associated mortality.

OBJECTIVES

To identify sociodemographic, behavioural and medical care-related factors associated with melanoma thickness in a low-incidence population but with a high case fatality.

PATIENTS AND METHODS

In a multicentre, retrospective, survey-based study of 202 patients with a recent diagnosis of invasive melanoma (< 1 year), we collected data on demographic and behavioural factors, attitudes towards prevention, access to medical care, frequency of skin self-examination (SSE) and physician skin examination (PSE) in relation to melanoma thickness.

RESULTS

Thinner tumours (≤ 1 mm, 80 melanomas) were associated with female sex (P ≤ 0.049), nonnodular (superficial spreading melanoma, lentigo maligna melanoma, acral lentiginous melanoma) histological subtypes (P < 0.001), absence of ulceration (P ≤ 0.001), and location other than lower extremity or trunk location (P ≤ 0.004). Patients married at the time of diagnosis or who performed SSE during the year prior to diagnosis were more likely to have thinner tumours than those who did not [odds ratio (OR) 3.45, 95% confidence interval (CI) 1.48-8.04 and OR 2.43, 95% CI 1.10-5.34, respectively]. Full-body skin examination by a physician was not significantly associated with thinner melanoma (OR 1.99, 95% CI 0.66-6.07).

CONCLUSIONS

SSE was shown to be an important factor in the detection of thin melanoma, in contrast to partial or full-body PSE, which did not show any statistically significant effect on tumour thickness.

Analysis of clinical, dermoscopic and histopathological features of primary melanomas of patients with metastatic disease--a retrospective study at the Department of Dermatology, Medical University of Graz, 2000-2010

BACKGROUND

Incidence rates of malignant melanoma have been increasing worldwide and metastatic melanoma is still a significant problem despite widespread prevention programmes.

OBJECTIVES

We made a systemic review of all metastasized melanoma patients treated at the Department of Dermatology, Medical University of Graz in the years 2000-2010 and looked at the kind of melanoma type, e.g. if it has been slowly growing superficial spreading melanoma (SSM) or fast growing nodular melanoma (NM).

METHODS

Histological slides and clinical images of patients treated at our department between 2000 and 2010, who received chemotherapy because of proven metastatic disease were analysed with regard to growth type of their primary tumours.

RESULTS

A total of 88 patients met the inclusion criteria. Mean age of all patients was 57 years (median 59 years, SD ± 15 years). Of these 88 patients 51 patients (58%) (28 male patients and 23 female patients) had SSM; mean age 58 years (median 58 years, SD ± 14 years) and 37 patients (42%) (18 male patients and 19 female patients) had NM; mean age 56 years (median 61 years, SD ± 17 years). Mean Breslow thickness in the SSM group was 2.26 mm (median: 1.6 mm, SD ± 2.11 mm). In the NM group, mean Breslow thickness was 4.59 mm (median: 3.50 mm, SD ± 4.07 mm). When separated by gender, 46 melanomas were seen in the male group (28 SSM and 18 NM) and 42 melanomas in the female group (23 SSM and 19 NM).

CONCLUSIONS

Our results showed that more than half of the patients with metastatic disease had SSMs and not, as suspected, NMs. As SSMs are growing over a longer period to become invasive and potentially metastatic, there might be a chance to focus primary and secondary prevention programmes not only on fast growing tumours but also on slowly changes of tumours.

Telomerase reverse transcriptase promoter mutations in primary cutaneous melanoma

We previously reported a disease segregating causal germline mutation in a melanoma family and recurrent somatic mutations in metastasized tumours from unrelated patients in the core promoter region of the telomerase reverse transcriptase (TERT) gene. Here we show that the TERT promoter mutations, besides causing an increased gene expression, associate with increased patient age, increased Breslow thickness and tumour ulceration in 287 primary melanomas. The mutations are more frequent at both intermittently and chronically sun-exposed sites than non-exposed sites and tend to co-occur with BRAF and CDKN2A alterations. The association with parameters generally connected with poor outcome, coupled with high recurrence and mechanistic relevance, raises the possibility of the eventual use of TERT promoter mutations in the disease management.

Outcomes and prognostic factors in superficial spreading melanoma

BACKGROUND

Prognostic factors and risk factors for positive sentinel lymph node (SLN) biopsy results are important to identify in superficial spreading melanoma (SSM).

METHODS

A single-center database and a prospective clinical trial database were reviewed for all patients with diagnoses of SSM. Logistic regression, Kaplan-Meier survival analysis, and univariate and multivariate Cox models were used.

RESULTS

A total of 1,643 patients with SSM were identified. Independent risk factors for positive SLN biopsy results were Breslow thickness (BT) ≥2.0 mm, age <60 years, and presence of ulceration. BT ≥2.0 mm, ulceration, lymphovascular invasion, and positive SLN and positive non-SLN biopsy results were independent risk factors for worse disease-free survival. Independent overall survival risk factors included BT ≥2.0 mm, age ≥60 years, ulceration, nonextremity tumor location, lymphovascular invasion, and positive SLN biopsy results.

CONCLUSIONS

BT, ulceration, lymphovascular invasion, and SLN and non-SLN status are important risk factors for SSM.

Melanoma risk loci as determinants of melanoma recurrence and survival

Background

Steadily high melanoma mortality rates urge for the availability of novel biomarkers with a more personalized ability to predict melanoma clinical outcomes. Germline risk variants are promising candidates for this purpose; however, their prognostic potential in melanoma has never been systematically tested.

Methods

We examined the effect of 108 melanoma susceptibility single nucleotide polymorphisms (SNPs), associated in recent GWAS with melanoma and melanoma-related phenotypes, on recurrence-free survival (RFS) and overall survival (OS), in 891 prospectively accrued melanoma patients. Cox proportional hazards models (Cox PH) were used to test the associations between 108 melanoma risk SNPs and RFS and OS adjusted by age at diagnosis, gender, tumor stage, histological subtype and other primary tumor characteristics.

Results

We identified significant associations for rs7538876 (RCC2) with RFS (HR = 1.48, 95% CI = 1.20-1.83, p = 0.0005) and rs9960018 (DLGAP1) with both RFS and OS (HR = 1.43, 95% CI = 1.07-1.91, p = 0.01, HR = 1.52, 95% CI = 1.09-2.12, p = 0.01, respectively) using multivariable Cox PH models. In addition, we developed a logistic regression model that incorporates rs7538876, rs9960018, primary tumor histological type and stage at diagnosis that has an improved discriminatory ability to classify 3-year recurrence (AUC = 82%) compared to histological type and stage alone (AUC = 78%).

Conclusions

We identified associations between melanoma risk variants and melanoma outcomes. The significant associations observed for rs7538876 and rs9960018 suggest a biological implication of these loci in melanoma progression. The observed predictive patterns of associated variants with clinical end-points suggest for the first time the potential for utilization of genetic risk markers in melanoma prognostication.

Constitutive RAC activation is not sufficient to initiate melanocyte neoplasia but accelerates malignant progression

Deregulated Ras signaling initiates and maintains melanocyte neoplasia. The Rho-like GTPase Rac has been implicated in Ras-induced neoplastic transformation. Moreover, a recurrent UV-induced mutation activating RAC1 has recently been detected in human melanoma. Here, a role for Rac in melanoma initiation and progression was investigated in human melanomas and zebrafish models of melanocyte neoplasia. Immunohistochemical analysis revealed RAC expression and activity restricted to melanocytes at the junction of the epidermis and dermis in benign neoplasms. Malignant melanocytes displayed elevated RAC activity that extended into the suprabasal epidermis, deeper into the dermis, and was maintained in metastases. Previously, we have used zebrafish transgenic models to demonstrate that deregulated Ras/Raf/mitogen-activated protein kinase signaling can initiate melanocyte neoplasia. Expression of a constitutively active RAC1 mutant (V12RAC1) was not sufficient to initiate melanocyte neoplasia in this organism. Furthermore, we did not detect an additive effect when combined with V600EBRAF, nor could V12RAC1 substitute for suppressed Pi3k signaling to restore melanoma progression. However, coexpression of V12RAC1 and oncogenic RAS accelerated tumor nodule formation. Immunohistochemical analysis revealed that the Rac activator Tiam1 (T-cell lymphoma invasion and metastasis 1) is overexpressed in melanoma tumor nodules in both zebrafish and humans. Thus, our data suggest that Rac contributes to the progression of melanoma and that Tiam1 may activate Rac in nodular presentations.

KIR gene variability in cutaneous malignant melanoma: influence of KIR2D/HLA-C pairings on disease susceptibility and prognosis

Natural killer and CD8(+) T cells are believed to be involved in the immune protection against melanoma. Their function may be regulated by a group of receptors defined as killer immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands. In this study, we analyzed the influence of KIR genes and KIR/HLA-I combinations on melanoma susceptibility and/or prognosis in a Spanish Caucasian population. For this purpose, KIR genotyping by PCR-SSP and HLA-C genotyping by reverse PCR-SSO were performed in 187 melanoma patients and 200 matched controls. We found a significantly low frequency of KIR2DL3 in nodular melanoma (NM) patients (P = 0.001) and in ulcerated melanoma patients (P < 0.0001). Similarly, the KIR2DL3/C1 combination was significantly decreased in melanoma patients (Pc = 0.008) and in patients with sentinel lymph node (SLN) melanoma metastasis (Pc = 0.002). Multivariate logistic regression models showed that KIR2DL3 behaves as a protective marker for NM and ulcerated melanoma (P = 0.02, odds ratio (OR) = 0.14 and P = 0.04, OR = 0.28, respectively), whereas the KIR2DL3/C1 pair acts as a protective marker for melanoma (P = 0.017, OR = 0.54), particularly superficial spreading melanoma (P = 0.02, OR = 0.52), and SLN metastasis (P = 0.0004, OR = 0.14). In contrast, the KIR2DL3(-)/C1C2 genotype seems to be correlated with NM and ulceration. We also report that the KIR2DL1(+)/S1(-)/C2C2 genotype is associated with susceptibility to melanoma and SLN metastasis. Altogether, the study of KIR2D genes and HLA-C ligands may help in assessing cutaneous melanoma risk and prognosis.

Outcomes and prognostic factors in nodular melanomas

BACKGROUND

The nodular subtype of cutaneous melanoma has a more pronounced vertical phase and less of a radial growth phase compared with other histologic subtypes. This study was performed to determine prognostic factors and outcomes for nodular melanomas.

METHODS

A post hoc analysis of a prospective clinical trial was performed in all patients with nodular histologic subtype. Univariate and multivariate analyses of factors associated with disease-free survival (DFS), overall survival (OS), and local and in-transit recurrence-free survival (LITRFS) were performed. Kaplan-Meier survival analyses were performed.

RESULTS

There were 736 patients available for analysis, and 189 (25.7%) were sentinel lymph node (SLN) positive. Breslow thickness of ≥2.3 mm, presence of ulceration, nonextremity tumor location, positive SLN, and non-SLN-positive status were independent risk factors for worse OS and DFS. Kaplan-Meier analysis demonstrated that ulceration predicted worse OS and DFS in all nodular melanoma patients, and in both SLN-positive and -negative subsets. The presence of ulceration and a positive SLN together predicted significantly worse DFS and OS.

CONCLUSION

The most important risk factors that determine prognosis in nodular melanomas are SLN status and ulceration. The presence of both a positive SLN and ulceration significantly affect DFS and OS, and to a lesser degree LITRFS.

Superficial spreading and nodular melanoma are distinct biological entities: a challenge to the linear progression model

The classification of melanoma subtypes into prognostically relevant and therapeutically insightful categories has been a challenge since the first description of melanoma in the 1800s. One limitation has been the assumption that the two most common histological subtypes of melanoma, superficial spreading and nodular, evolve according to a linear model of progression, as malignant melanocytes spread radially and then invade vertically. However, recent clinical, pathological, and molecular data indicate that these two histological subtypes might evolve as distinct entities. Here, we review the published data that support distinct molecular characterization of superficial spreading and nodular melanoma, the clinical significance of this distinction including prognostic relevance and the therapeutic implications.

Histology-specific microRNA alterations in melanoma

We examined the microRNA signature that distinguishes the most common melanoma histological subtypes, superficial spreading melanoma (SSM) and nodular melanoma (NM). We also investigated the mechanisms underlying the differential expression of histology-specific microRNAs. MicroRNA array performed on a training cohort of 82 primary melanoma tumors (26 SSM, 56 NM), and nine congenital nevi (CN) revealed 134 microRNAs differentially expressed between SSM and NM (P<0.05). Out of 134 microRNAs, 126 remained significant after controlling for thickness and 31 were expressed at a lower level in SSM compared with both NM and CN. For seven microRNAs (let-7g, miR-15a, miR-16, miR-138, miR-181a, miR-191, and miR-933), the downregulation was associated with selective genomic loss in SSM cell lines and primary tumors, but not in NM cell lines and primary tumors. The lower expression level of six out of seven microRNAs in SSM compared with NM was confirmed by real-time PCR on a subset of cases in the training cohort and validated in an independent cohort of 97 melanoma cases (38 SSM, 59 NM). Our data support a molecular classification in which SSM and NM are two molecularly distinct phenotypes. Therapeutic strategies that take into account subtype-specific alterations might improve the outcome of melanoma patients.