Thin malignant melanomas (less than 1.5 mm) with metastasis: a histological study and survival analysis

Clinical, dermatoscopic, histological and molecular predictive factors of distant melanoma metastasis: A systematic review and meta-analysis

BACKGROUND

Melanoma metastasis to distant sites is associated with diminished survival rates and poor prognosis. Except of Breslow thickness and ulceration that are currently used in melanoma staging, the investigation of additional clinicopathological, dermatoscopic and molecular factors that could predict tumors with aggressive biologic behavior is of paramount importance.

METHODS

A literature search was conducted in PubMed, Scopus, Cochrane databases and gray literature until November 2023. Observational studies (including cohorts and case-control studies) were included and clinical and histopathological factors of primary cutaneous melanomas, along with dermatoscopic and molecular predictors of distant metastasis (DM) and distant metastasis-free survival (DMFS) were assessed. Random - effect models were preferred, the results were presented as Hazard Ratios (HRs) with 95 %Confidence Intervals (CIs) and the I2 index quantified heterogeneity. Subgroup analysis according to AJCC stage and sensitivity analysis were also conducted.

RESULTS

One hundred forty-three and 101 studies were included in the qualitive and quantitative synthesis, respectively. Regarding clinical factors, males, compared to females, and head and neck location, compared to trunk, demonstrated higher risk for DM [n=36, HR 1.49, 95%CI 1.36 - 1.63, I2 33% and n=21, HR 1.24, 95 %CI 1.01 - 1.52, I2 62 %]. Both factors had similar effects on DMFS. Breslow thickness and ulceration were significant predictors or DM. Additional factors that posed an increased risk for DM were nodular (n=15, HR 2.51, 95 %CI 1.83 - 3.43, I2 56 %) and lentigo maligna subtypes (n=12, HR 1.87, 95 %CI 1.27 - 2.75, I2 0 %), compared to superficial spreading subtype, lymphovascular invasion (n=9, HR 2.05, 95 %CI 1.18 - 3.58, I2 78 %), SLN positivity and BRAF+ mutational status. In contrast, regression was a negative predictor of DM (n=15, HR 0.59, 95 %CI 0.44 - 0.79, I2 68 %). Two studies focused on dermatoscopic factors and found that low pigmentation and the presence of blue-white veil might predict DM development. The results of subgroup analysis for stage I-II patients were essentially similar and sensitivity analysis did not reveal significant alterations, despite the moderate or high heterogeneity in some categories.

CONCLUSIONS

Clinical and histological characteristics of the tumor along with dermatoscopic features and molecular parameters hold significant prognostic information and could be incorporated into models to predict melanomas with high metastatic potential.

Influence of regression, its extent and tumor-infiltrating lymphocytes on sentinel node status, relapse, and survival in a 10-year retrospective study of melanoma patients

This case-control study seeks to investigate the influence of histological findings, specifically regression, its extent and tumor-infiltrating lymphocyte (TILs), on result of sentinel lymph node (SLN) biopsy, 5-year melanoma-specific survival (MSS), and relapse-free survival (RFS). We included all patients with cutaneous melanoma who underwent SLN biopsy at the Melanoma Center of the University of Brescia, following the Italian Association of Medical Oncology National guidelines from January 2008 to August 2018. Regression and its extent (<75 or ≥75%) and the presence of TILs were reevaluated by a trained dermatopathologist, adhering to the 2017 College of American Pathologists Cancer Protocol for Skin Melanoma. These patients were followed up for 5 years. Our study uncovered significant associations between regression and male sex ( P  < 0.05), melanoma location on the trunk, upper limbs, and back ( P  = 0.001), ulceration ( P  < 0.05), lower Breslow thickness ( P  = 0.001), and the presence of lymphocytic infiltration (both brisk and nonbrisk) ( P  < 0.001). Regression and its extent, however, did not appear to affect SLN positivity ( P  = 0.315). Similarly, our data did not reveal a correlation between TILs and result of SLN biopsy ( P  = 0.256). When analyzing MSS and RFS in relation to the presence or absence of regression and TILs, no statistically significant differences were observed, thus precluding the need for logistic regression and Kaplan-Meier curve analysis. This study's findings underscore that regression and TILs do not appear to exert an influence on sentinel lymph node status, MSS, or RFS in our cohort of patients.

Histopathologic regression in patients with primary cutaneous melanoma undergoing sentinel lymph node biopsy is associated with favorable survival and, after metastasis, with improved progression-free survival on immune checkpoint inhibitor therapy: A single-institutional cohort study

BACKGROUND

Histopathologic regression of cutaneous melanoma is considered a favorable prognostic factor, but its significance in clinical practice remains controversial.

OBJECTIVE

To investigate the prognostic importance of regression in patients with primary cutaneous melanoma undergoing sentinel lymph node (SLN) biopsy and to assess its significance in patients progressing to an unresectable stage requiring systemic therapy.

METHODS

We retrospectively reviewed patients with newly diagnosed melanoma undergoing SLN biopsy between 2010 and 2015 and available information on histopathologic regression (n = 1179). Survival data and associations of clinical variables with SLN status were assessed.

RESULTS

Patients with regressive melanoma showed favorable relapse-free (hazard ratio [HR], 0.52; P = .00013), distant metastasis-free (HR, 0.56; P = .0020), and melanoma-specific survival (HR, 0.35; P = .00053). Regression was associated with negative SLN (odds ratio, 0.48; P = .0077). In patients who progressed to an unresectable stage, regression was associated with favorable progression-free survival under immune checkpoint inhibition (HR, 0.43; P = .031) but not under targeted therapy (HR, 1.14; P = .73) or chemotherapy (HR, 3.65; P = .0095).

LIMITATIONS

Retrospective, single-institutional design.

CONCLUSIONS

Regression of cutaneous melanoma is associated with improved prognosis in patients eligible for SLN biopsy as well as in patients with unresectable disease receiving systemic therapy with immune checkpoint inhibitors.

Tumour regression predicts better response to interferon therapy in melanoma patients: a retrospective single centre study

We hypothesise that regression may have an impact on the effectiveness of adjuvant IFN therapy, based on its role in the host immune response. Our purpose is to investigate regression and ulceration as prognostic factors in case of interferon-alpha (IFN)-treated melanoma patients. We followed 357 IFN-treated melanoma patients retrospectively, investigating progression-free survival (PFS) and overall survival (OS) depending on the presence of ulceration and regression. A Kaplan-Meier analysis was performed, and we used a Cox regression analysis to relate risk factors. The survival function of the Cox regression was used to measure the effect of regression and ulceration on PFS and OS depending on the Breslow thickness (T1-T4) of the primary tumour. Regression was significantly positively related to PFS ( P  = 0.0018, HR = 0.352) and OS ( P  = 0.0112, HR = 0.380), while ulceration showed a negative effect (PFS: P  = 0.0001, HR = 2.629; OS: P  = 0.0003, HR = 2.388). They influence survival independently. The most favourable outcome was measured in the regressed/non-ulcerated group, whereas the worse was in the non-regressed/ulcerated one. Of risk factors, Breslow thickness is the most significant predictor. The efficacy of regression is regardless of Breslow thickness, though the more favourable the impact of regression was in the thicker primary lesions. Our results indicate that regression is associated with a more favourable outcome for IFN-treated melanoma patients, whereas ulceration shows an inverse relation. Further studies are needed to analyse the survival benefit of regression in relation to innovative immune checkpoint inhibitors.

Tumoral inflammatory infiltrate does not predict metastases in thin primary cutaneous melanomas

BACKGROUND

In cutaneous melanomas in general, tumor inflammatory infiltrate (TII) can protect against distant metastases, but there is no consensus when only thin primary cutaneous melanomas (TPCM) are considered.

OBJECTIVE

To investigate the presence of TII in TPCM and the relationship between TII and the occurrence of metastases.

METHODS

Case-control study including 50 patients with TPCM, 22 metastatic (MC group) and 28 non-metastatic (NMC group). The presence of TII was evaluated and, if present, qualified as mild, moderate or marked.

RESULTS

The mean age was 50.7 years in the MC and 56.2 years in the NMC group (p = 0.234), and the male sex predominated in the MC group (63.6%). The average Breslow thickness was higher in the MC when compared to that observed in the NMC (respectively 0.8 vs. 0.6 mm, p = 0.012). The presence of ulceration occurred in 22.7% of the MC and 17.9% of the NMC (p = 0.732). TII was present in all 50 TPCM, being marked or moderate in 67.9% of the NMC and 54.5% in the MC group (p = 0.503). In the multivariate analysis, the presence of moderate and marked TII had an Odds Ratio (OR) of 0.57 (95% Confidence Interval [CI]: 0.18‒1.8) and adjusted OR of 0.68 (95% CI 0.13‒3.99).

STUDY LIMITATIONS

Small sample size.

CONCLUSIONS

TII was present in all TPCM (with and without metastases), and it was not possible to demonstrate a protective effect of TII against the appearance of metastases.

Sentinel lymph node assessment in melanoma: current state and future directions

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.

Histological regression in melanoma: impact on sentinel lymph node status and survival

Regression in melanoma is an immunological phenomenon that results in partial or complete replacement of the tumor with variably vascular fibrous tissue, often accompanied by pigment-laden macrophages and chronic inflammation. In some cases, tumor-infiltrating lymphocytes (TILs) may represent the earliest phase of this process. The prognostic significance of regression has long been a matter of debate, with inconsistent findings reported in the literature to date. This study sought to determine whether regression in primary cutaneous melanomas predicted sentinel lymph node (SLN) status and survival outcomes in a large cohort of patients managed at a single centre. Clinical and pathological parameters for 8,693 consecutive cases were retrieved. Associations between regression and SLN status, overall survival (OS), melanoma-specific survival (MSS) and recurrence-free survival (RFS) were investigated using logistic and Cox regression. Histological evidence of regression was present in 1958 cases (22.5%). Regression was significantly associated with lower Breslow thickness, lower mitotic rate, and absence of ulceration (p < 0.0001). Multivariable analysis showed that regression in combination with TILs independently predicted a negative SLN biopsy (OR 0.33; 95% C.I. 0.20-0.52; p < 0.0001). Patients whose tumors showed both regression and TILs had the highest 10-year OS (65%, 95% C.I. 59-71%), MSS (85%, 95% C.I. 81-89%), and RFS (60%, 95% C.I. 54-66%). On multivariable analyses, the concurrent presence of regression and TILs independently predicted the lowest risk of death from melanoma (HR 0.69; 95% C.I. 0.51-0.94; p = 0.0003) as well as the lowest rate of disease recurrence (HR 0.71; 95% C.I. 0.58-0.85; p < 0.0001). However, in contrast, in the subgroup analysis of Stage III patients, the presence of regression predicted the lowest OS and RFS, with MSS showing a similar trend. Overall, these findings indicate a prognostically favorable role of regression in primary cutaneous melanoma. However, in Stage III melanoma patients, regression may be a marker of more aggressive disease.

Malignant melanoma of parotid glands from a neglected lesion: A case report

Observing a metastatic malignant melanoma and its primary lesion at the same time is rare. The histopathological detection of any unusual pigmented lesion is critical.

Regression in melanoma is significantly associated with a lower regional recurrence rate and better recurrence-free survival

BACKGROUND AND OBJECTIVES

The prognostic significance of regression in predicting melanoma recurrences is unknown. We present a large multicenter study correlating regression with recurrence.

METHODS

The Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with regression data. Clinicopathologic factors were correlated with overall and first-site of recurrence and with recurrence-free survival (RFS).

RESULTS

There were 4790 patients and the median follow-up was 39.6 months. Regression and recurrences were seen in 1081 (22.6%) and 773 (16.1%) cases, respectively. First-site locoregional and distant recurrences were seen in 412 (8.6%) and 352 (7.3%) patients, respectively. Regression was seen in 15.8% and 24.7% of all cases with and without recurrences (p < 0.0001), respectively, while regression was seen in 14.3% and 17.9% of first-site locoregional and distant recurrent cases, respectively, compared with 23.3% and 22.9% of patients with regression and without first-site locoregional and distant recurrences, respectively (p = 0.29). On multivariable analysis, after controlling for age, gender, thickness, ulceration, lymphovascular invasion, and sentinel lymph node status, regression significantly predicted improved RFS (p = 0.004) and fewer first-site regional recurrences (p = 0.017).

CONCLUSION

Our data suggest that regression is a favorable prognostic marker in melanoma and predicts significantly better RFS and decreased first-site regional recurrences.

Histological regression in primary melanoma and drug-related immune reaction towards metastatic melanoma: Are they associated??

Histologic regression has recently been associated with a more favorable prognosis in primary melanoma. historically this immune phenomenon was described as a negative prognostic factor able to substage the true Breslow thickness. Since many years we have assisted to the appearance of vitiligo in metastatic melanoma patients. This has been considered one of the explanations of the immunogenicity of this disease, as inducing a strong immune reaction against cancer cells able to kill normal melanocytes even far from the metastatic lesions, This vitiligo like reaction has been seen even stronger in patients treated with immune and target therapy. The three phenomena involve the same pattern of lymphocytes. The association between the three can explain the better prognosis of the patients with primary melanoma with histological regression as well as the longer survival of the vitiligo like immune reaction in metastatic melanoma patients.

Is it Necessary to Perform Sentinel Lymph Node Biopsy in Thin Melanoma? A Retrospective Single Center Analysis

Sentinel lymph node biopsy (SLNB) is a standard procedure for regional lymph node staging and still has the most important prognostic value for the outcome of patients with thin melanoma. In addition to ulceration, SLNB had to be considered even for a single mitotic figure in thin (<1 mm) melanoma according to AJCC7th guideline, therefore, a retrospective review was conducted involving 403 pT1 melanoma patients. Among them, 152 patients suffered from pT1b ulcerated or mitotic rate ≥ 1/ mm2 melanomas according to the AJCC7th staging system. SLNB was performed in 78 cases, of which nine (11.5%) showed SLN positivity. From them, interestingly, we found a relatively high positive sentinel rate (6/78-8%) in the case of thin primary melanomas ˂0.8 mm. Moreover, the presence of regression increased the probability of sentinel positivity by 5.796 fold. After reassessing pT stage based on the new AJCC8th, 37 pT1b cases were reordered into pT1a category. There was no significant relation between other characteristics examined (age, gender, Breslow, Clark level, and mitosis index) and sentinel node positivity. Based on our data, we suggest that mitotic rate alone is not a sufficiently powerful predictor of SLN status in thin melanomas. If strict histopathological definition criteria are applied, regression might be an additional adverse feature that aids in identifying T1 patients most likely to be SLN-positive. After reassessing of pT1b cases according to AJCC8th regression proved to be independent prognostic factor on sentinel lymph node positivity. Our results propose that sentinel lymph node biopsy might also be considered at patients with regressive thin (˂0.8 mm) melanomas.

Current controversies in early-stage melanoma: Questions on incidence, screening, and histologic regression

In the first article in this continuing medical education series we review controversies and uncertainties relating to the epidemiology and initial diagnosis of localized cutaneous melanoma (ie, stage 0, I, or II). Many of these issues are unsettled because of conflicting evidence. Melanoma incidence appears to be increasing, yet its basis has not been fully explained. Despite the advantages of early detection, the US Preventive Services Task Force does not recommend skin screening for the general population. Occasionally, biopsy specimens of melanoma will show histologic regression, but the prognostic importance of this phenomenon is uncertain. Some practitioners recommend obtaining a sentinel lymph node biopsy specimen for thin melanomas showing regression, although this histologic finding is not part of the staging system for thin melanomas. Our goal is to provide the clinician who cares for patients with (or at risk for) melanoma with up-to-date contextual knowledge to appreciate the multiple sides of each controversy so that they will be better informed to discuss these issues with their patients and their families.

Favourable prognostic role of histological regression in stage III positive sentinel lymph node melanoma patients

BACKGROUND

Sentinel lymph node (SLN)-positive melanoma patients are a heterogeneous group of patients with survival rates ranging from ∼20 to over 80%. No data are reported concerning the role of histological regression on survival in stage III melanoma.

METHODS

The study included 365 patients with positive SLN from two distinct hospitals. The model was developed on patients from 'AOU Città della Salute e della Scienza di Torino', and externally validated on patients from IRCCS of Candiolo. Survival analyses were carried out according to the presence of regression and adjusted for all other prognostic factors.

RESULTS

Among patients followed at 'AOU Città della Salute e della Scienza di Torino' (n=264), the median follow-up time to death or censoring (whatever two events occurred earlier) was 2.7 years since diagnosis (interquartile range: 1.3-5.8). In all, 79 patients died from melanoma and 11 from other causes. Histological regression (n=43) was associated with a better prognosis (sub-HR=0.34, CI 0.12-0.92), whereas the other factors above showed an inverse association. In the external validation, the concordance index was 0.97 at 1 year and decreased to 0.66 at 3 years and to 0.59 at 5 years. Adding histological regression in the prognostic model increased the discriminative ability to 0.75 at 3 years and to 0.62 at 5 years. Finally, using a cutoff of 20% for the risk of death led to a net re-classification improvement of 15 and 11% at 3 and 5 years after diagnosis, respectively.

CONCLUSIONS

Histological regression could lead to an improvement in prognostic prediction in patients with stage III-positive SLN melanoma.

Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis

Histological regression in primary cutaneous melanoma occurs in 10-35% of cases. Although a large body of literature exists to suggest that histological regression serves very little purpose in predicting biologic behaviour with melanoma, recognizing the presence of regression at clinical and histological ground may still retain some value in grading melanoma aggressiveness. In the current review, a comprehensive overview of the main aspects of regression will be provided. Histologically, many classifications have been reported so far, but all of them only agreed on the presence of an infiltrate of lymphocytes admixed with pigment-laden macrophages underlying an atrophic epidermis with flattened rete ridges. Upon dermoscopy, regression is also named Blue White Scar-like areas and could be variably admixed with granularity or peppering. Almost fully regressed lesions represent a main diagnostic issue in dermoscopy, and thus, confocal microscopy can be of help to identify whether the tumour is melanocytic or not. The clinical utility of regression as a prognostic factor has been challenged recently. Nowadays, evidences showed that it is less likely associated to SLN metastases.

Study of the immunophenotype of the inflammatory cells in melanomas with regression and halo nevi

The pathogenesis and prognostic implications of regression in melanoma are not well understood. It has traditionally been considered an immunologically mediated phenomenon. Improvement in the knowledge of the mechanisms that lead to regression may prove to be of great value in an era in which treatments oriented to the augmentation of the host's immunity against melanoma have demonstrated excellent clinical results. This study was designed to improve the understanding of the mechanisms underlying melanoma regression and the differences between similar situations in benign melanocytic nevus. The study sample consisted of 77 lesions: 62 melanomas and 15 halo nevi. The following markers were included in the study: CD4, CD8, FoxP3, PD1, CD123, granzyme, and TIA-1. Staining was evaluated in 5 categories, according to the percentage of labeled cells. Granzyme, PD1, and TIA-1 stained significantly more cells in halo nevi than in melanomas with regression (P < 0.01). The ratio CD123/TIA-1 was higher in melanomas than in halo nevi (1 vs. 0.67, P < 0.05). Regression in the 62 melanomas was categorized as early in 14 cases and late in 48 cases. Early regression was associated with a higher percentage of CD123, CD4, and TIA-1 staining than late regression. The inflammatory infiltrate found in halo nevi is characterized by a higher number of active cytotoxic T cells and regulatory PD1-positive T cells than the infiltrate found in melanoma with regression. CD123 staining was higher in early regression than in late regression, suggesting the presence of a tolerogenic mechanism in this phenomenon's initiation phase.

Tissue prognostic biomarkers in primary cutaneous melanoma

Cutaneous melanoma (CM) causes the greatest number of skin cancer-related deaths worldwide. Predicting CM prognosis is important to determine the need for further investigation, counseling of patients, to guide appropriate management (particularly the need for postoperative adjuvant therapy), and for assignment of risk status in groups of patients entering clinical trials. Since recurrence rate is largely independent from stages defined by morphological and morphometric criteria, there is a strong need for identification of additional robust prognostic factors to support decision-making processes. Most data on prognostic biomarkers in melanoma have been evaluated in tumor tissue samples by conventional morphology and immunohistochemistry (IHC) as well as DNA and RNA analyses. In the present review, we critically summarize main high-quality studies investigating IHC-based protein biomarkers of melanoma outcome according to Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK)-derived criteria. Pathways have been classified and conveyed in the "biologic road" previously described by Hanahan and Weinberg. Data derived from genomic and transcriptomic technologies have been critically reviewed to better understand if any of investigated proteins or gene signatures should be incorporated into clinical practice or still remain a field of melanoma research. Despite a wide body of research, no molecular prognostic biomarker has yet been translated into clinical practice. Conventional tissue biomarkers, such as Breslow thickness, ulceration, mitotic rate and lymph node positivity, remain the backbone prognostic indicators in melanoma.

Outcome of sentinel lymph node biopsy and prognostic implications of regression in thin malignant melanoma

Thin melanomas with partial or complete regression may provide clues about antitumor immunity, but their management remains controversial. We have characterized the management and clinical outcomes of regressed thin (<1 mm) T1a melanomas and hypothesized that regression increases the risk of regional metastases when compared with nonregressed thin melanomas. A prospectively collected clinical database was reviewed, and T1a melanomas with regression were identified. Histology, surgical approach, outcome, and survival were evaluated. The primary outcome measures were sentinel node positivity, subsequent lymph node metastasis, and survival. A total of 75 patients with T1a or in-situ melanomas were grouped into three subsets. Group 1: 35 underwent a sentinel node biopsy (SNBx), none of which were positive. No patients developed nodal recurrence. The 5-year survival of this group was 93%, with a median follow-up of 52 months. Group 2: 31 were followed up without SNBx; two developed regional nodal disease (6.5%), neither of whom died of subsequent distant disease. The 5-year survival was 89%, with a median follow-up of 38 months. There was no significant difference in the survival between groups 1 and 2. Group 3: nine patients presented with metastatic disease concurrent with a regressed thin melanoma. These patients had a median survival of 2.3 years and a 4-year survival estimate of 22%. Regression should not be used as an indication for SNBx in T1a melanomas; we recommend that such patients be managed with wide local excision and a long-term clinical follow-up. The poor prognosis of thin regressed primary melanoma with simultaneous metastatic disease may indicate the existence of immune escape phenotypes supporting melanoma progression.

Prognostic parameters for the primary care of melanoma patients: what is really risky in melanoma?

Due to intensified research in recent years, the understanding of the molecular mechanisms involved in the development of melanoma has dramatically improved. The discovery of specific, causal mutations such as BRAF or KIT oncogenes not only renders a targeted and thus more effective therapeutic approach possible, but also gives rise to a new genetic-based classification. Targeting just a few out of several potential mutations, BRAF-Inhibitors such as PLX 4032 achieved already tremendous results in the therapy of metastatic melanoma. Up to now, the correlation of clinical, histomorphologic, and genetic features is, however, not understood. Even more, is it not well known precisely what kind of molecular changes predispose the primary melanoma for metastasis. The identification of morphological surrogates and prognostic parameters in tumors with such genetic alteration seems therefore crucial when differentiating and classifying this heterogeneous tumor entity in more detail and thus facilitates the stratification of prognosis as well as therapy. This review summarizes the current understanding of carcinogenesis and gives a detailed overview of known morphologic and potentially future genetic prognostic parameters in malignant melanoma.

Molecular diagnostics in melanoma: current status and perspectives

CONTEXT

In the current "molecular" era, the advent of technology, such as array-based platforms, systems biology, and genome-wide approaches, has made it possible to examine human cancers, including melanoma, for genetic mutations, deletions, amplification, differentially regulated genes, and epigenetic changes. Advancement in current technologies is such that one can now examine ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein directly from the patient's own tumor.

OBJECTIVE

To apply these new technologies in advancing molecular diagnostics in melanoma has historically suffered from a major obstacle, namely, the scarcity of fresh frozen, morphologically defined tumor banks, annotated with clinical information. Recently, some of the new platforms have advanced to permit utilization of formalin-fixed, paraffin-embedded (FFPE) tumor specimens as starting material.

DATA SOURCES

This article reviews the latest technologies applied to FFPE melanoma sections, narrowing its focus on the utility of transcriptional profiling, especially for melastatin; comparative genomic hybridization; BRAF and NRAS mutational analysis; and micro ribonucleic acid profiling.

CONCLUSION

New molecular approaches are emerging and are likely to improve the classification of melanocytic neoplasms.

Regression Does Not Predict Nodal Metastasis or Survival in Patients with Cutaneous Melanoma

Controversy exists regarding the prognostic implications of regression in patients with cutaneous melanoma. Some consider regression to be an indication for sentinel lymph node (SLN) biopsy because regression may result in underestimation of the true Breslow thickness. Other data support regression as a favorable prognostic indicator, representing immune system recognition of the primary tumor. This analysis was performed to determine whether regression predicts nodal metastasis, disease-free survival (DFS), or overall survival (OS). Post hoc analysis was performed of a multicenter prospective randomized trial that included patients aged 18 to 70 years with cutaneous melanomas 1 mm or greater Breslow thickness. All patients underwent SLN biopsy; those with tumor-positive SLN underwent completion lymphadenectomy. Kaplan-Meier analysis of survival, univariate analysis, and multivariate analysis were performed. A total of 2220 patients (261 with regression; 1959 without regression) were included in this analysis with a median follow-up of 68 months. Patients with regression were more likely to be male, older than 50 years old, and have lower median Breslow thickness, superficial spreading histologic subtype, and a non-extremity anatomic location ( P < 0.05 in all cases). Regression was not significantly associated with Clark level, ulceration, lymphovascular invasion, number of SLNs removed, or SLN metastasis. On multivariate analysis, factors independently predictive of DFS included Breslow thickness, ulceration, and SLN status ( P < 0.05 in all cases); the same factors along with age, gender, and anatomic tumor location were significantly associated with OS ( P < 0.05 in all cases). Regression was not significantly associated with DFS (risk ratio [RR], 0.94; 95% confidence interval [CI], 0.67-1.27; P = 0.68) or OS (RR, 1.01; 95% CI, 0.76-1.32; P = 0.93). These data suggest that regression is not a significant prognostic factor for patients with cutaneous melanoma and should not be used to guide clinical decision-making for such patients.

Cutaneous Melanomas of the Eyelid

Cutaneous eyelid melanomas are very rare lesions. The lentiginous subtypes are the most frequent melanocytic lesions of the eyelid and can be likened to conjunctival melanocytic lesions like PAM, PAM with atypia and conjunctival melanoma. Compared to melanomas elsewhere on the body, eyelid melanomas have special considerations. Eyelid skin is very thin, the mucocutaneous junction at the lid margin can affect prognosis, the lymphatic drainage pattern is very variable and there is an inherent difficulty to excise wide margins without sacrificing important structures. A customized excision approach, using tissue-sparing "Slow-Mohs" technique, is suggested. Sentinel lymph node dissection has an evolving therapeutic role but remains controversial.

Meta-analysis of sentinel lymph node positivity in thin melanoma (<or=1 mm)

BACKGROUND

Despite the lack of an established survival benefit of sentinel lymph node (SLN) biopsy, this technique has been increasingly applied in the staging of thin (

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for rates of SLN positivity in patients with thin melanoma. The methodologic quality of included studies was assessed using the Methodological Index for Non-Randomized Studies criteria. Heterogeneity was assessed using the Cochran Q statistic, and publication bias was examined through funnel plot and the Begg and Mazumdar method. Overall SLN positivity in thin melanoma patients was estimated using the DerSimonial-Laird random effect method.

RESULTS

Thirty-four studies comprising 3651 patients met inclusion criteria. The pooled SLN positivity rate was 5.6%. Significant heterogeneity among studies was detected (P = .005). There was no statistical evidence of publication bias (P = .21). Eighteen studies reported select clinical and histopathologic data limited to SLN-positive patients (n = 113). Among the tumors from these patients, 6.1% were ulcerated, 31.5% demonstrated regression, and 47.5% were Clark level IV/V. Only 4 melanoma-related deaths were reported.

CONCLUSIONS

Relatively few patients with thin melanoma have a positive SLN. To the authors' knowledge, there are no clinical or histopathologic criteria that can reliably identify thin melanoma patients who might benefit from this intervention. Given the increasing diagnosis of thin melanoma, in addition to the cost and potential morbidity of this procedure, alternative strategies to identify patients at risk for lymph node disease are needed.

Collapse

Key Words Collapse

MESH Headings

• Clinical Trials as Topic
• Female
• Humans
• Lymph Node Excision
• Lymphatic Metastasis
• Male
• Melanoma/secondary
• Middle Aged
• Mitosis
• Periodicals as Topic
• Sentinel Lymph Node Biopsy
• Skin Neoplasms/pathology

Collapse

Grants

• P30 CA016087 NCI NIH HHS
• 5 P30 CA 016087-27 NCI NIH HHS

Collapse

Affiliation(s)

Melanie A. Warycha Department of Dermatology, New York University School of Medicine, New York, NY
Jan Zakrzewski Department of Dermatology, New York University School of Medicine, New York, NY
Quanhong Ni Division of Biostatistics and Epidemiology, Department of Public Health, Weill Medical College of Cornell University, New York, NY
Richard L. Shapiro Department of Surgery, New York University School of Medicine, New York, NY
Russell S. Berman Department of Surgery, New York University School of Medicine, New York, NY
Anna C. Pavlick Department of Dermatology, New York University School of Medicine, New York, NY Department of Medicine, New York University School of Medicine, New York, NY
David Polsky Department of Dermatology, New York University School of Medicine, New York, NY Department of Pathology, New York University School of Medicine, New York, NY
Madhu Mazumdar Division of Biostatistics and Epidemiology, Department of Public Health, Weill Medical College of Cornell University, New York, NY
Iman Osman Department of Dermatology, New York University School of Medicine, New York, NY Department of Medicine, New York University School of Medicine, New York, NY

Collapse

Clinical considerations on sentinel node biopsy in melanoma from an Italian multicentric study on 1,313 patients (SOLISM-IMI)

BACKGROUND

Although widely used for the management of patients with cutaneous melanoma, the sentinel lymph node (SLN) biopsy (SNB) procedure raises several issues. This study was designed to investigate: the predictive factors of SLN status, the false-negative (FN) rate, and patients' prognosis after SNB.

PATIENTS AND METHODS

This is an observational, prospective study conducted on a large series of consecutive patients (n = 1,313) enrolled by 23 Italian centers from 2000 through 2002. A commonly shared protocol was adopted for the SNB surgical procedure and the SLN pathological examination.

RESULTS

The SLN positive and false-negative (FN) rates were 16.9% and 14.4%, respectively (median follow-up, 4.5 years). At multivariable logistic regression analysis, the frequency of positive SLN increased with increasing Breslow thickness (p < 0.0001) and decreased in patients with melanoma regression (p = 0.024). At the multivariable Cox regression analysis, SLN status was the most important prognostic factor (hazards ratio (HR) = 3.08) for overall survival; the other statistically significant factors were sex, age, Breslow thickness, and Clark's level. Considering SLN and NSLN status, including FN cases, we identified four groups of patients with different prognoses. The 5-year overall survival of patients with positive SLNs was 71.3% in those with negative nonsentinel lymph nodes (NSLNs) and 50.4% if NSLNs were positive.

CONCLUSIONS

Regression in the primary melanoma seems to be a protective factor from metastasis in the SLN. When correctly calculated, the SNB FN rate is 15-20%. Furthermore, the SNB is important to more precisely assess the prognosis of patients with melanoma.

Malignant melanoma in the 21st century, part 2: staging, prognosis, and treatment

Critical to the clinical management of a patient with malignant melanoma is an understanding of its natural history. As with most malignant disorders, prognosis is highly dependent on the clinical stage (extent of tumor burden) at the time of diagnosis. The patient's clinical stage at diagnosis dictates selection of therapy. We review the state of the art in melanoma staging, prognosis, and therapy. Substantial progress has been made in this regard during the past 2 decades. This progress is primarily reflected in the development of sentinel lymph node biopsies as a means of reducing the morbidity associated with regional lymph node dissection, increased understanding of the role of neoangiogenesis in the natural history of melanoma and its potential as a treatment target, and emergence of innovative multimodal therapeutic strategies, resulting in significant objective response rates in a disease commonly believed to be drug resistant. Although much work remains to be done to improve the survival of patients with melanoma, clinically meaningful results seem within reach.

Prognosticators of melanoma, the melanoma report, and the sentinel lymph node

Since the 1960s, the clinical characteristics of melanoma, its histopathology and its biological basis have been the subject of intense study at pigmented lesion clinics in North America, Europe, and Australia. More recently, the immense database of the Melanoma Committee of the American Joint Committee on Cancer (AJCC) has been exploited through complex mathematical models to measure the impact of various histologic features of primary melanomas and of sentinel lymph node deposits and to correlate these parameters with patient survival. The wealth of modern information available to pathologists and clinicians has become of vital interest to the prognostication of the individual patient with melanoma. The purpose of this review is to bring to the attention of anatomic pathologists the essential characteristics of the pathology report for primary cutaneous melanoma in the modern era.

American Joint Committee on Cancer Clinical Stage as a Selection Criterion for Sentinel Lymph Node Biopsy in Thin Melanoma

BACKGROUND

A significant proportion of newly diagnosed melanomas are thin lesions (< or = 1.00 mm). Because tumor thickness correlates with the risk for nodal metastases, sentinel lymph node (SLN) biopsy in this subset is controversial. Incorporating other prognostic factors (Clark level and ulceration), we evaluated the 6th edition American Joint Committee on Cancer (AJCC) clinical stage as a simple and widely applicable guideline for offering SLN biopsy for thin melanoma.

METHODS

This study was a review of a prospective melanoma SLN database from 1993 to 2003 with emphasis on SLN positivity rates based on the 6th edition AJCC primary tumor thickness intervals and clinical stage.

RESULTS

Three hundred five patients underwent SLN biopsy, with an overall positivity rate of 17.7%. By the 6th edition AJCC, lesions < or = 1.00 mm had an SLN positivity rate of 6.6%. By 6th edition clinical stage, SLN positivity rates were 4.9% for stage IA and 10.4% for stage IB. By using stage IA as the criterion for not offering SLN biopsy, this procedure would have been avoided in 46% (39 of 85) of < or = 1.00-mm melanoma patients with a negative SLN.

CONCLUSIONS

Sixth edition AJCC clinical stage IB as a selection criterion for performing SLN biopsy in thin melanoma identifies most patients with a positive SLN while also avoiding a negative SLN biopsy in many patients. Until additional widely accepted and validated selection criteria are available, SLN biopsy for clinical stage IB, but not stage IA, thin melanomas is a reasonable approach.

Sentinel lymph node biopsy in thin melanoma patients

BACKGROUND

We sought to determine the incidence of positive sentinel lymph nodes in thin melanoma (<or=1.0 mm) patients and if subgroups could be identified with a higher risk of occult nodal disease.

METHODS

Patients with <or=1.0 mm lesions treated between 1997 and 2003 were reviewed. Sentinel nodes underwent microscopic analysis including step sectioning and immunohistochemical examination. Some nodes underwent reverse transcriptase-polymerase chain reaction (RT-PCR) evaluation for melanoma markers.

RESULTS

Sixty-four of 107 thin melanoma patients underwent sentinel node biopsy (SNB). Mapped patients were more likely to have Clark >or= III and thicker lesions (mean 0.77 mm vs. 0.47 mm), but were not different in regards to age, sex, or lesion location. Eight percent and 58% of sentinel nodes were positive by routine histology and RT-PCR, respectively. Among mapped patients, younger age was the only significant prognostic factor for node positivity. With a median follow-up of 18 months among all patients, one regional recurrence (at 2 years) has been identified.

CONCLUSIONS

Given the low morbidity of sentinel lymph node biopsy, this procedure should be discussed with selected thin melanoma patients to detect microscopic disease, however PCR positivity by our methods is too commonly seen to be clinically significant in thin melanoma patients and requires additional study.

Partial regression of primary cutaneous melanoma: is there an association with sub-clinical sentinel lymph node metastasis?

Whether partial regression of a primary melanoma has an adverse impact on prognosis is controversial. As an indirect mechanism of addressing this question we drew a correlation between the histopathological characteristics of 107 cutaneous melanomas and the presence of sub-clinical metastasis in corresponding sentinel lymph nodes. Partial regression of the primary tumor, defined as focal replacement of the lesion by a scar, unrelated to a previous biopsy, was observed in 20 (19%) cases in the group as a whole. Excluding cases in which an accurate Breslow thickness of the primary melanoma could not be established and/or the presence of a capsular nevus was detected in the sentinel node, a total of 97 remained. Seventeen cases (Breslow thickness 0.63-9.7; mean 2.4 mm) showed partial regression and 80 (Breslow thickness 0.25-7.00; mean 1.8 mm) were devoid of regression. Of the 17 cases with regression 5 (29%) had nodal metastasis (by histopathology and/or molecular analysis) and of the 80 cases without regression 23 (29%) had nodal metastasis (by one or both evaluations). Our data reveals no association between partial regression of the primary melanoma and sentinel node involvement by the disease. The Breslow thickness proved to be the only significant independent variable related to nodal metastasis. Of interest, ulceration of the primary lesion was significantly associated with nodal disease on univariate, but not on multivariate, analysis. While acknowledging that the cohort size may lack the statistical power to demonstrate subtle associations, our data supports the known relevance of tumor thickness and ulceration to regional lymph node metastasis and thereby, to outcome of melanoma in its early stages, but fails to support a similar role for partial regression.

Tumor lymphangiogenesis: a novel prognostic indicator for cutaneous melanoma metastasis and survival

Malignant melanomas of the skin are distinguished by their propensity for early metastatic spread via lymphatic vessels to regional lymph nodes, and lymph node metastasis is a major determinant for the staging and clinical management of melanoma. However, the importance of tumor-induced lymphangiogenesis for lymphatic melanoma spread has remained unclear. We investigated whether tumor lymphangiogenesis occurs in human malignant melanomas of the skin and whether the extent of tumor lymphangiogenesis may be related to the risk for lymph node metastasis and to patient survival, using double immunostains for the novel lymphatic endothelial marker LYVE-1 and for the panvascular marker CD31. Tumor samples were obtained from clinically and histologically closely matched cases of primary melanomas with early lymph node metastasis (n = 18) and from nonmetastatic melanomas (n = 19). Hot spots of proliferating intratumoral and peritumoral lymphatic vessels were detected in a large number of melanomas. The incidence of intratumoral lymphatics was significantly higher in metastatic melanomas and correlated with poor disease-free survival. Metastatic melanomas had significantly more and larger tumor-associated lymphatic vessels, and a relative lymphatic vessel area of >1.5% was significantly associated with poor disease-free and overall survival. In contrast, no differences in the density of tumor-associated blood vessels were found. Vascular endothelial growth factor and vascular endothelial growth factor-C expression was equally detected in a minority of cases in both groups. Our results reveal tumor lymphangiogenesis as a novel prognostic indicator for the risk of lymph node metastasis in cutaneous melanoma.

Role of sentinel lymphadenectomy in thin invasive cutaneous melanomas

PURPOSE

Regional lymph node status is the strongest prognostic determinant in early-stage melanoma. Lymphatic mapping and sentinel lymphadenectomy (LM/SL) is standard to stage regional nodes because it is accurate and minimally morbid, yet its role for thin (<or= 1.5 mm) primary melanomas is unknown.

PATIENTS AND METHODS

Our melanoma database of more than 10,000 patients was reviewed for patients with melanomas <or= 1.50 mm thick who underwent LM/SL. All had lymphoscintigrams and LM/SL via dye alone or with radiopharmaceutical. Patients with tumor-positive sentinel nodes (SNs) underwent completion dissections.

RESULTS

Five hundred twelve patients underwent LM/SL. Most were men (57%), and median age was 49 years. Most primary melanomas were on the torso (44%). Twenty-five patients (4.9%) had tumor-positive SNs. The thinnest lesion with a nodal metastasis was 0.35 mm. The SN-negative and SN-positive cohorts were equivalent by sex, but SN+ patients tended to be younger (P =.053), with significantly more SN metastases in those younger than 44 years (P =.005). No consistent pathology among SN-positive primary melanomas was found. Among those with 1.01- to 1.05-mm primaries, 7.1% were SN-positive. Among 272 patients with lesions <or= 1.00 mm, 2.9% had positive SNs and 1.7% with lesions <or= 0.75 mm had SN metastases. All 13 deaths were in SN-negative patients. Median follow-up durations in SN-positive and SN-negative patients were 25 and 45 months, respectively.

CONCLUSION

The high nodal positivity rate associated with primary melanomas 1.01 to 1.50 mm thick suggests that LM/SL is indicated in this group. Younger age may be correlated with nodal metastases in patients with lesions <or= 1.00 mm. Lesions <or= 0.75 mm have minimal metastatic potential, and therefore LM/SL is rarely indicated.

Identification of histological features associated with metastatic potential in thin (<1.0 mm) cutaneous melanoma with metastases. A study on behalf of the EORTC Melanoma Group

Contrary to expectations, a small number of thin (<1 mm) melanomas do metastasize. This collaborative study was performed in an attempt to identify the morphological basis of such aggressive behaviour. Regression was expected to be the explanation for the lack of thickness in some cases. Whether a vertical growth phase (VGP) was present in the remainder was carefully assessed. A pilot study had identified two other patterns associated with metastasis in thin melanomas. These were termed 'junctional expansion nodules' and 'melanomatous follicular invasion'. Both were seen in the absence of other dermal invasion. These two patterns were included in the study, which comprised 54 cases and 56 controls, which were thin melanomas which had not metastasized 5 years after excision. Regression was present in 50% of test cases (30.4% in controls, p=0.036) and VGP was present in 59.3% of cases and 48.2% of controls. The thinnest metastasizing melanoma without regression was 0.27 mm. Eight (14.8%) cases, however, had metastasized but showed neither regression nor VGP; seven of these showed a junctional expansion nodule, present in only three controls (p=0.016). Five of these seven also showed melanomatous follicular invasion. One of these five showed this follicular involvement without a junctional nodule. Melanomatous follicular invasion was not seen in the control cases (p=0.012). Mitoses were seen in the VGP of both test and control cases, but high counts (>3 per mm(2)) were much more common in the metastasizing lesions (p=0.007). These findings support the idea that in most cases, regression and/or a VGP are required for metastasis to occur. However, a small number of thin melanomas without these features, as conventionally described, still metastasize. This implies that VGP may require redefinition and that junctional expansion nodules and melanomatous follicular invasion may be variants of VGP.

Clinicopathologic features and behavior of cutaneous eyelid melanoma

OBJECTIVE

To study the clinical and histopathologic features of cutaneous eyelid melanomas and identify prognostic factors in the behavior of such tumors.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Twenty-three patients with cutaneous eyelid melanomas without conjunctival involvement.

METHODS

Patients' charts were reviewed for clinical information, treatment procedure, and disease course (updated at the time of study). Histopathologic sections from all surgical procedures were reviewed.

MAIN OUTCOME MEASURES

Histologic type of melanoma, tumor growth phase, Clark's level of invasion, tumor thickness, and other microscopic features were evaluated in each case. The width of excision margins was considered and measured histologically when possible.

RESULTS

There was no gender predilection. The lower eyelid was more frequently involved than the upper eyelid or canthi. Seventeen cases (74%) were invasive, and six (26%) were in situ melanomas. Lentigo maligna melanoma was the most common histologic type, accounting for 61% (14 cases) of all melanomas and 53% (9 cases) of invasive melanomas. Superficial spreading melanoma accounted for 22% (5 cases) and nodular melanoma for 17% (4 cases) of all melanomas. Surgical excision, as the treatment of choice, was incomplete in nine cases, two thirds of which were lentigo maligna melanoma (in situ or invasive). Tumor reappeared in 77.8% of these cases. Fourteen patients had initial narrow excisions, and three of them (21.4%) had local recurrences. Although recurrence occurred in one each of our "in situ," "thin," and "thick" melanomas, it proceeded to distant metastases and death only in the "thin" one. Adjuvant radiotherapy was used in six patients with successful disease control in two cases.

CONCLUSIONS

Eyelid skin melanomas have a relatively good clinical prognosis. The histologic type and thickness of the primary melanoma were not clearly related to the clinical behavior once they were completely excised. The use of very narrow excisions of 5 mm or less was associated with greater frequency of local recurrence. Lentigo maligna melanomas were the largest tumors at presentation and, despite being thinner, were a greater surgical challenge. This type of melanoma is almost certainly underdiagnosed by ophthalmologists.

High proliferative activity may predict early metastasis of thin melanomas

Metastasis of thin melanomas is uncommon and unpredictable. We prospectively investigated the clinical course of 167 thin melanomas (<1 mm thickness) over a median observation period of 4 years (18 to 87 months). In addition to Breslow thickness, Clark level, and growth phase characteristics, we assessed cellular proliferation by counting mitoses and immunohistochemically using the monoclonal antibody Ki-S5 (Ki-67). Mitotic and Ki-S5 indices were correlated to tumor thickness, Clarks level, and radial/vertical growth phase (RGP/VGP). However, 5 tumors had proliferation indices above 25% (outside the range of a theoretical normal distribution). Four of these tumors metastasized, and none of the melanomas with lower proliferative activity progressed during the observation period. The metastatic behavior was independent of tumor thickness and Clark level and did not unconditionally coincide with VGP or high mitotic counts. It is concluded that the immunohistochemical proliferation index may be a powerful predictor of early systemic progression in thin melanomas, which may be helpful in making therapeutic decisions. Further investigations are needed to determine the value of proliferation measurements for the long-term prognosis of thin melanomas.

Clinical and histologic features of level 2 cutaneous malignant melanoma associated with metastasis

BACKGROUND

Metastatic melanoma developing in patients with a level 2 primary cutaneous malignant melanoma (CMM) is rare but has been reported in studies with follow-up periods ranging up to 15 years. The objective of this study was to investigate level 2 CMM associated with metastasis in a population-based retrospective study.

METHODS

In this retrospective population-based study, all level 2 CMMs associated with metastases were identified in Western Australia during 1982-1989 and were followed up to the end of 1996.

RESULTS

Pathology reports of 2834 patients were examined. Of these, 1716 had a CMM of maximum tumor thickness 1 mm or less recorded on the pathology report. Of these, 67 had a metastatic melanoma reported on follow-up. Histologic review of these 67 cases under blind conditions identified 5 cases with a level 2 primary CMM followed by metastasis without another primary CMM. All these level 2 CMM showed established regression. Eight other patients were identified with a level 2 CMM, metastatic melanoma, and another primary CMM of at least level 3 invasion. These subsequent primaries occurred before the metastasis had been reported.

CONCLUSIONS

These findings suggest that metastasis from level 2 CMM without regression is very rare, if it occurs at all.

Pathologic and Clinical Features Influencing Outcome of Thin Cutaneous Melanoma: Correlation with Newly Proposed Staging System

The incidence of malignant melanoma is increasing. Because of increased awareness, early recognition of malignant melanoma has become more common. In 1997, a new staging system for cutaneous melanoma was proposed, with reclassification of thin melanoma < 1 mm, with and without ulceration. This report evaluates the pathologic and clinical features of thin melanomas influencing recurrence and survival from a tertiary cancer center in an attempt to correlate findings with the proposed staging system. A review of the Roswell Park Cancer Institute tumor registry identified 352 patients with thin cutaneous melanomas (< 1.0 mm) seen during an 18-year period ending August 30, 1998. Overall survival was 93 and 87 per cent at 5 and 10 years, respectively. Disease-free survival was 94 and 93 per cent at 5 and 10 years, respectively. Local recurrence occurred in 3 per cent of patients, regional recurrence in 3 per cent, and metastatic disease in 3 per cent, for an overall recurrence of 7 per cent, with a median follow-up of 118 months. Only the presence of ulceration was a significant prognostic factor for recurrence by both univariate and multivariate analysis. Failure rates (any recurrence) by Clark levels I, II, and III/IV were 3, 5, and 10 per cent, respectively ( P = 0.14). Failure rates by tumor thickness (mm), for 0.0–0.24, 0.25–0.49, 0.50–0.74, and 0.75–0.99 were 3, 4, 7, and 10 per cent, respectively ( P = 0.49). Ten-year disease-free survival for ulceration versus no ulceration was 40 and 94 per cent, respectively ( P < 0.0001). We conclude that thin cutaneous melanoma carries an excellent prognosis with appropriate treatment. Our findings support inclusion of ulceration in a new staging system. Lesions 0.76 to 0.99 mm and Clark level III and IV may warrant close observation as a separate subgroup.

Thin cutaneous malignant melanomas (< or =1.5 mm): identification of risk factors indicative of progression

BACKGROUND

Although thin cutaneous melanomas generally have a favorable prognosis, in some cases they may undergo progression. The current study was undertaken to identify variables that may predict a more aggressive clinical outcome in these patients. In addition to classic clinicopathologic features, the authors tested the prognostic impact of three new morphometric quantitative parameters: 1) tumor thickness plus regression thickness (T+R), 2) percentage of skin thickness infiltrated by tumor cells (T/S ratio), and 3) percentage of skin thickness infiltrated by tumor cells and regression ([T+R]/S ratio).

METHODS

The authors retrospectively evaluated 287 patients with invasive cutaneous melanoma < or = 1.5 mm in thickness. Disease free survival rates (Kaplan-Meier method) were compared by using the log rank test. A multivariate analysis (Cox proportional hazards model) was used to determine the independent effect of each variable on progression. Progression was defined as any documented cutaneous local and/or distant metastasis.

RESULTS

Thirty-two of the 287 patients (11.1%) underwent disease progression. The overall 5-year and 10-year disease free survival rates were 89.3% and 84.6%, respectively. In the univariate analysis, the following factors were found to be significant predictors of progression: male gender (P = 0.01), acral-lentiginous histotype (P = 0.02), tumor thickness (P = 0.005), T+R (P = 0.001), T/S ratio > or = 50% (P = 0.03), (T+R)/S ratio > or = 50% (P = 0.006), vertical growth phase (P = 0.04), and absence of inflammatory response (P < 0.0001). Conversely, age, site, and Clark's level did not affect the risk of recurrences and/or metastases significantly. In the multivariate analysis, only T+R (P = 0.009) and inflammatory response (P < 0.0001) were found to be independent predictors of progression. Five-year disease free survival rates according to presence versus absence of inflammatory response were 93.4% and 63.8%, respectively (P < 0.0001).

CONCLUSIONS

In the current study, peritumoral and intratumoral inflammatory infiltrate and T+R were found to be strong independent predictors of progression in thin cutaneous melanomas.

Pathologic parameters in the diagnosis and prognosis of primary cutaneous melanoma

Significant progress has been made in the last 10 years on the identification of histologic parameters that are independent predictors of melanoma prognosis, immunohistochemical markers of cells of melanocytic origin and changes in adhesion molecules, cytoskeletal proteins, growth factor receptors, cell signaling, and nuclear proliferation proteins associated with tumor progression. Histologic criteria may never be completely sufficient to predict behavior accurately, because the fundamental change that renders a cell aggressive may not be morphologically reflected and may require immunohistochemical or other molecular markers to establish behavior. To date, it is humbling that no immunohistochemical or molecular marker provides a greater predictable value for aggressive behavior than does the simple calibrated ocular micrometer to measure tumor thickness. Nevertheless, development of multiple histologic parameters with the concept of nontumorigenic RGP and tumorigenic VGP provides a reliable statistical model to predict metastases. Fortunately, nontumorigenic RGP melanomas with greater than 75% regression are rare. Thus, individual patients with melanoma without regression and without the tumorigenic VGP can be given reasonable assurance of 100% survival. Nevertheless, this assurance is based on a statistical model with a finite population studied. Additional studies are needed to confirm this model, as well as more definitive markers to precisely predict outcome for those individuals with tumorigenic VGP melanoma.

Expression of c-myc oncoprotein represents a new prognostic marker in cutaneous melanoma

BACKGROUND

Overexpression of the c-myc oncoprotein has been observed to be of prognostic significance in several human cancers. This study was undertaken to establish whether c-myc has any prognostic significance in melanoma.

METHODS

Expression of c-myc oncoprotein was studied in a prospective series of primary and secondary malignant melanomas. Ethanol-fixed tissue was digested into nuclei and stained for flow cytometric analysis using a pan-myc antibody.

RESULTS

Overexpression of the c-myc oncoprotein was prevalent in both disease stages. In primary disease, overexpression was associated with tumour thickness and with the presence of ulceration, age and reduced disease-free interval. Of most importance, high expression of c-myc predicted poor outcome in both primary and metastatic disease. In addition, c-myc was able to discriminate prognosis in melanomas uniformly stratified as thick (greater than 3 mm) lesions.

CONCLUSION

These results indicate an important role for c-myc in melanoma which may lead to better prognostic information and identification of new therapeutic strategies.

Malignant melanoma: prognostic indicators

The incidence of cutaneous malignant melanoma in the Caucasian population has continued to increase at an alarming rate and is expected to be 1 in 75 by the year 2000. Within the medical community, these trends have prompted an interest in factors that potentially influence the biologic activity of such lesions. Several clinical and pathologic variables have been identified that affect the progression and behavior of melanoma. On the basis of multivariate analysis, the most important factors for predicting survival in patients with stage I and II melanomas are tumor thickness, presence of ulceration, and anatomic site of the primary tumor (the prognosis is poorer with head and neck lesions than with extremity lesions). For patients with stage III melanomas, all the foregoing factors plus the extent of nodal disease are of prognostic importance. For patients with stage IV melanomas, the main prognostic factors are the number of metastatic lesions and the site of metastatic involvement (visceral lesions portend a poor outcome).

Prognosis of thin cutaneous head and neck melanoma (<1mm)

Thin malignant melanomas, i.e. tumours less than 1 mm, are generally considered to have a good prognosis. The records of 148 patients with thin invasive melanomas located to the head and neck region were reviewed. All patients were followed for the excision of the primary tumour until death, or the closing date of this study (31 December 1989). Follow-up was median 9.6 years, (range: 3 months to 26.5 years). Increasing tumour thickness led to an increasing number of recurrences. However, there was no statistically significant difference in the length of recurrence-free survival or total survival between patients with tumours less than 0.76 mm and patients with tumours measuring between 0.76 mm and 0.99 mm (P>0.08). Tumours located in the scalp, neck and ears did relapse more often than tumours located to the face (P<0.03). No difference in prognosis was found in tumours that were excised with a free margin of <2.0 cm or of > or = 2.0 cm (P>0.29). Sixteen of the patients (11%) developed recurrences, 12 of these 16 patients (75%) died of disseminated melanoma. We conclude that thin head and neck melanomas do not necessarily carry an excellent prognosis. Prognosis is not dependent upon tumour thickness when less than 1.00 mm.

A study of thin (< 1.5 mm) malignant melanomas with poor prognosis

555 cases of malignant melanoma less than 1.5 mm in depth were studied. 30 recurred locally or metastasised during follow-up. The width and depth of excision was similar in those with and without recurrence. There were no local recurrences in tumours < 1.0 mm which had been completely excised, irrespective of the width of excision. Other variables, the size of the primary tumour (p < 0.03), the depth of uninvolved dermis deep to the lesion (p < 0.01), the Clark level (p < 0.03) and the presence of lesional regression (p < 0.001), identify a sub-group of thin melanomas which have a poor prognosis irrespective of local treatment.

Pathology of APUDomas

The pathology of APUDomas involves two main areas. The first is the biochemical aspects of these tumours and the use of biochemical tests to investigate a patient suspected of having an APUDoma, and the other is the histopathology of these tumours. This review is devoted to the histopathological considerations.

Malignant melanoma excision margins: plastic surgery audit in Britain and Ireland, 1991, and a review

In 1991, 146 consultant plastic surgeons in Britain and Ireland were sent a short questionnaire about their policies for excision margins for primary cutaneous malignant melanoma. 106/146 (73%) replied. 39/106 (37%) considered narrow margin (2-3 mm) excision biopsies adequate in certain cases. The minimum tumour thickness for a margin of more than 1 cm was 1 mm or more for 67/106 (63%) on the leg and for 57/106 (54%) on the back. The maximum margin was specified as 4 cm or more on the leg by 37/106 (35%) and on the back by 42/106 (40%). Other sub-groups of results were analysed. A review of the literature is presented.