Vertical Growth Phase as a Prognostic Factor for Sentinel Lymph Node Positivity in Thin Melanomas: A Systematic Review and Meta-Analysis

Melanoma in situ and low risk pT1a melanoma: Need for new diagnostic terminology

Melanoma incidence has risen rapidly, at least until recently, while mortality has changed only a little, a phenomenon suggestive of overdiagnosis, which can be defined as the diagnosis as "melanoma" of a lesion that would not have had the competence to cause death or symptoms even if it had not been excised. Overdiagnosis has been attributed to efforts at early diagnosis ("overdetection"), and to changes in criteria resulting in diagnosis as melanoma of lesions previously termed nevi ("overdefinition"). In terms of overdefinition, there is evidence that criteria for the histopathologic diagnosis of melanoma has changed over a period of approximately two decades. Specialization may play a role in overdefinition; research has shown that when pathologists interpret the same lesion, dermatopathologists are more likely to diagnose low stage (AJCC T1a) melanomas and general/surgical pathologists are more likely to diagnose atypical nevi. An important subset that contributes to overdiagnosis is those melanomas that lack the property of tumorigenic vertical growth phase, thus lacking metastatic competence, and perhaps not warranting diagnosis as overt melanomas. Studies have defined subsets of patients with very low stage lesions diagnosed as melanomas in which observed survival has been 100%. In the past, many of these lesions would have been diagnosed as nevi, constituting overdefinition. Other key characteristics for very low risk (or no risk) lesions that are currently termed invasive "melanomas" include low Breslow thickness, Clark's level II invasion, absence of mitoses, and clinically, lack of observed or experienced dynamic changes. We propose a provisional terminology for diagnosing extremely low risk subgroups as "Melanocytic neoplasms of low malignant potential", aimed at reducing the negative personal and social effects of a cancer diagnosis for patients whose health and wellbeing are in reality not affected by an overdiagnosed "melanoma". With additional confirmation and appropriate consensus, it is likely that some of these subgroups can be reclassified as atypical or dysplastic nevi.

Invasive Cutaneous Melanoma: Evaluating the Prognostic Significance of Some Parameters Associated with Lymph Node Metastases

Background and Objectives: This study aimed to assess the clinical-pathological profile of patients with invasive cutaneous melanomas and to identify the parameters with a prognostic role in the lymph nodal spread of this malignant tumor. Materials and Methods: We performed a retrospective study on patients with invasive cutaneous melanomas who underwent surgery in the "Pius Brînzeu" County Clinical Emergency Hospital from Timișoara, Romania, and were evaluated for the status of loco-regional lymph nodes. We selected and analyzed some parameters searching for their relationship with lymph node metastases. Results: We identified 79 patients with invasive cutaneous melanomas (29 men and 50 women, mean age 59.36 years). A percentage of 58.3% of melanomas had Breslow tumor thickness >2 mm; 69.6% of melanomas showed a Clark level IV-V. Tumor ulceration was present in 59.5% of melanomas. A mitotic rate of ≥5 mitoses/mm² was observed in 48.1% of melanomas. Tumor-infiltrating lymphocytes (TILs), non-brisk, were present in 59.5% of cases and 22.8% of patients had satellite/in-transit metastasis (SINTM). Tumor regression was identified in 44.3% of cases. Lymph nodes metastases were found in 43.1% of patients. Statistical analysis showed that lymph node metastases were more frequent in melanomas with Breslow thickness >2 mm (p = 0.0002), high Clark level (p = 0.0026), mitotic rate >5 mitoses/mm² (p = 0.0044), ulceration (p = 0.0107), lymphovascular invasion (p = 0.0182), SINTM (p = 0.0302), and non-brisk TILs (p = 0.0302). Conclusions: The Breslow thickness >2 mm, high Clark level, high mitotic rate and ulceration are the most important prognostic factors for lymph nodal spread in cutaneous melanomas. However, some melanomas without these clinical-pathological features can have an unexpected, aggressive evolution, which entails the necessity of close and prolonged clinical follow-up of patients, including those with lesions considered without risk.

Prognostic modeling of cutaneous melanoma stage I patients using cancer registry data identifies subsets with very-low melanoma mortality

BACKGROUND

Evidence exists that escalating melanoma incidence is due in part to overdiagnosis, the diagnosis of lesions that will not lead to symptoms or death. The authors aimed to characterize subsets of melanoma patients with very-low risk of death that may be contributing to overdiagnosis.

METHODS

Melanoma patients diagnosed in 2010 and 2011 with stage I lesions ≤1.0 mm thick and negative clinical lymph nodes from the Surveillance, Epidemiology, and End Results database were selected. Classification and regression tree and logistic regression models were developed and validated to identify patients with very-low risk of death from melanoma within 7 years. Logistic models were also used to identify patients at higher risk of death among this group of stage I patients.

RESULTS

Compared to an overall 7-year mortality from melanoma of 2.5% in these patients, a subset comprising 25% had a risk below 1%. Younger age at diagnosis and Clark level II were associated with low risk of death in all models. Breslow thickness below 0.4 mm, absence of mitogenicity, absence of ulceration, and female sex were also associated with lower mortality. A small subset of high-risk patients with >20% risk of death was also identified.

CONCLUSION

Patients with very-low risk of dying from melanoma within 7 years of diagnosis were identified. Such cases warrant further study and consensus discussion to develop classification criteria, with the potential to be categorized using an alternative term such as "melanocytic neoplasms of low malignant potential."

LAY SUMMARY

Although melanoma is the most serious skin cancer, most melanoma patients have high chances of survival. There is evidence that some lesions diagnosed as melanoma would never have caused symptoms or death, a phenomenon known as overdiagnosis. In this study, we used cancer registry data to identify a subset of early-stage melanoma patients with almost no melanoma deaths. Using two statistical approaches, we identified patients with <1% risk of dying from melanoma in 7 years. Such patients tended to be younger with minimal invasion into the skin. We also identified a very small patient subset with higher mortality risk.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma, a Clinical Point of View

Sentinel lymph node biopsy (SLNB) is a surgical procedure that has been used in patients with cutaneous melanoma for nearly 30 years. It is used for both staging and regional disease control with minimum morbidity, as proven by numerous worldwide prospective studies. It has been incorporated in the recommendations of national and professional guidelines. In this article, we provide a summary of the general information on SLNB in the clinical guidelines for the management of cutaneous malignant melanoma (American Association of Dermatology, European Society of Medical Oncology, National Comprehensive Cancer Network, and Cancer Council Australia) and review the most relevant literature to provide an update on the existing recommendations for SLNB.

Efficacy of different sentinel lymph node biopsy protocols in oral squamous cell carcinoma: Systematic review and meta-analysis

The sentinel node biopsy (SNB) is highly protocolized in other cancers, however, this is not the case for oral squamous cell carcinoma patients, hence our objective was to evaluate the different protocols published. A specific study protocol was designed and subsequently registered on PROSPERO (Ref. CRD42021279217). Twenty‐three articles were included in the meta‐analysis. The grouped sensitivity of the SNB was 82% (95% CI: 0.74–0.88), and the grouped specificity was 100% (95% CI: 0.99–1.00). The use of other radiotracers other than pre‐operative lopamidol showed higher values of sensitivity of 82.80% (95% CI: 76.90%–87.50%; p < 0.001). The use of the blue dye stain showed higher sensitivity values of 85.60% (95% CI: 71.90%–93.20%), compared to sensitivity values of 77.50% when it was not used (95% CI: 69.10%–84.20%) (p < 0.001). Diagnostic rates are variable and they were significantly better when 99mTc was used in all its variations and accompanied by the blue dye staining.

Predictive Values of Pathological and Clinical Risk Factors for Positivity of Sentinel Lymph Node Biopsy in Thin Melanoma: A Systematic Review and Meta-Analysis

Background

The indications for sentinel lymph node biopsy (SLNB) for thin melanoma are still unclear. This meta-analysis aims to determine the positive rate of SLNB in thin melanoma and to summarize the predictive value of different high-risk features for positive results of SLNB.

Methods

Four databases were searched for literature on SLNB performed in patients with thin melanoma published between January 2000 and December 2020. The overall positive rate and positive rate of each high-risk feature were calculated and obtained with 95% confidence intervals (CIs). Both unadjusted odds ratios (ORs) and adjusted ORs (AORs) of high-risk features were analyzed. Pooled effects were estimated using random-effects model meta-analyses.

Results

Sixty-six studies reporting 38,844 patients with thin melanoma who underwent SLNB met the inclusion criteria. The pooled positive rate of SLNB was 5.1% [95% confidence interval (CI) 4.9%-5.3%]. Features significantly predicted a positive result of SLNB were thickness≥0.8 mm [AOR 1.94 (95%CI 1.28-2.95); positive rate 7.0% (95%CI 6.0-8.0%)]; ulceration [AOR 3.09 (95%CI 1.75-5.44); positive rate 4.2% (95%CI 1.8-7.2%)]; mitosis rate >0/mm2 [AOR 1.63 (95%CI 1.13-2.36); positive rate 7.7% (95%CI 6.3-9.1%)]; microsatellites [OR 3.8 (95%CI 1.38-10.47); positive rate 16.6% (95%CI 2.4-36.6%)]; and vertical growth phase [OR 2.76 (95%CI 1.72-4.43); positive rate 8.1% (95%CI 6.3-10.1%)].

Conclusions

The overall positive rate of SLNB in thin melanoma was 5.1%. The strongest predictor for SLN positivity identified was microsatellites on unadjusted analysis and ulceration on adjusted analysis. Breslow thickness ≥0.8 mm and mitosis rate >0/mm² both predict SLN positivity in adjusted analysis and increase the positive rate to 7.0% and 7.7%. We suggest patients with thin melanoma with the above high-risk features should be considered for giving an SLNB.

RIPK3 and AXL Expression Study in Primary Cutaneous Melanoma Unmasks AXL as Predictor of Sentinel Node Metastasis: A Pilot Study

Malignant melanoma (MM) is the most lethal skin cancer. AXL is a tyrosine kinase receptor involved in several oncogenic processes and might play a role in blocking necroptosis (a regulated cell death mechanism) in MM through the downregulation of the necroptotic-related driver RIPK3. The aim of this study was to evaluate the clinical impact of the expression of AXL and RIPK3 in 108 primary cutaneous MMs. Association between AXL and RIPK3 immunoreactivity and clinical-pathological variables, sentinel lymph node status, and tumor-infiltrating lymphocytes (TILs) was assessed. Immunoreaction in tumor cells was detected in 30 cases (28%; range, 5%-80%) and in 17 cases (16%; range, 5%-50%) for AXL and RIPK3, respectively. Metastases in the sentinel lymph nodes were detected in 14 out of 61 patients, and these were associated with AXL-positive immunoreactivity in the primary tumor (p < 0.0001). No association between AXL and TILs was found. RIPK3 immunoreactivity was not associated with any variables. A final logistic regression analysis showed Breslow and AXL-positive immunoreactivity as the stronger predictor for positive sentinel node status [area under the receiver operating characteristic curve (AUC) of 0.96]. AXL could be a potential new biomarker for MM risk assessment, and it deserves to be further investigated in larger studies.

High Mitotic Rate Predicts Sentinel Lymph Node Involvement in Thin Melanomas

BACKGROUND

Indications for sentinel lymph node (SLN) biopsy in the population with thin melanoma have frequently changed over time. The objective of our study was to evaluate T1 melanoma pathologic features predictive of SLN positivity with a primary focus on identifying a specific mitotic value that is most predictive of lymph node disease. Further detailed predictive features would help physicians select patients with thin melanoma for SLN biopsy.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for all patients diagnosed with trunk or extremity cutaneous melanoma with ≤1 mm depth who underwent SLN biopsy between the years of 2010 and 2013. Patient demographics and tumor characteristics including depth, mitotic rate (MR), ulceration, and tumor location were evaluated. MR was dichotomized at multiple cut points to identify the ideal number of mitosis for MR as a predictor of SLN status. Multivariable logistic regression analyses were performed to identify the factors affecting nodal positivity and the impact of MR threshold. Kaplan-Meir curves were used for overall survival (OS) analysis.

RESULTS

Factors significantly associated with SLN positivity in the entire cohort included MR (P < 0.001, OR 1.24, 95% CI 1.18-1.31), tumor location (P = 0.017, OR 1.48, 95% CI 1.07-2.05), and ulceration (P < 0.001, OR 2.01, 95% CI 1.39-2.93,). An MR ≥ 4 was significant for SLN positivity (P = 0.049, OR 1.08, 95% CI 1.01-1.38). Mean OS was 46.7 mo for MR < 4 compared with 43.2 mo for MR ≥ 4 (P < 0.001).

CONCLUSIONS

MR ≥ 4 was significant and associated with SLN positivity in thin melanomas and asulceration. Thus, MR ≥ 4 should be considered as an indication for SLN biopsy in thin melanoma.

Differences in direct costs of patients with stage I cutaneous melanoma: A real-world data analysis

BACKGROUND

Clinical factors, such as tumor thickness, ulceration and growth phase have a role as prognostic factors for stage I melanoma. However, it is still under debate whether these variables influence the related direct costs. We aimed to investigate which clinical factors represent direct health care "cost drivers" for stage I melanoma.

MATERIALS AND METHOD

Analyses were conducted on a cohort of patients diagnosed with stage I melanoma. Differences in the costs incurred by different groups of patients were examined using Mann-Whitney or Kruskal-Wallis non-parametric tests. Log linear multivariate analysis was used to identify the clinical drivers of the total direct costs one and two years after diagnosis. The study was conducted from the perspective of Italy's National Health care System.

RESULTS

One year after diagnosis, patients whose melanomas had a Breslow thickness ≥0.8 mmin (compared with those with lower thickness) and a vertical growth phase (compared with those with radial growth) incurred higher costs for hospitalization, as well as higher overall costs. One year after their diagnosis, treatment of patients with stage I melanoma in the vertical growth phase costs 50% more (95% CI: 22-85%) than their counterparts with a radial growth pattern, resulting in an estimated absolute increase of € 256.23. Having a tumor thicker than 0.8 mm prompted an increase of 91% (95% CI: 43-155%) in the costs (€955.24 in absolute terms).

CONCLUSION

Our data indicate a heterogeneity in the direct costs of stage I melanoma patients during the first year after diagnosis, which can be partly explained by clinical prognostic factors, like tumor thickness and growth pattern.

Impact of American Joint Committee on Cancer 8th edition classification on staging and survival of patients with melanoma

OBJECTIVE

The American Joint Committee on Cancer (AJCC) 8th staging system introduced several revisions. To assess the impact of the 8th edition American Joint Committee on Cancer (AJCC8) staging system on subgrouping and survival, patients with melanoma from two tertiary skin cancer centres were classified according to both the 7th edition American Joint Committee on Cancer (AJCC7) and AJCC8.

METHODS

A total of 1948 patients aged ≥18 years with cutaneous melanoma stage II-IV were included. The impact of sex and age on reclassification was assessed by log binomial models. The inverse probability of censoring weighting method was used to compute ROC curves from time-to-event data to assess the discriminatory ability of AJCC7 and AJCC8. Melanoma-specific survival (MSS) and overall survival (OS) were calculated, and age- and sex-adjusted MSS hazard ratios were estimated using Cox proportional hazards models.

RESULTS

Of all, 23.5% of patients were assigned a different subgroup when classified according to AJCC8. Owing to upshifting to stage IIIC (AJCC7 24.8% vs. AJCC8 50.8%), patient numbers of stages IIIA and IIIB decreased from 28.7% to 16.2% and 46.5% to 28.3%. The prediction accuracy for AJCC7 and AJCC8 was comparable (integrated time-dependent area under the curve [AUC] of 0.75 and 0.74, respectively). Five-year MSS of IIB and IIC AJCC8 was poor and lower than that of IIIA AJCC8 (80%, 67% and 89%, respectively). Compared to results of the International Melanoma Database and Discovery Platform, 5-year MSS was 10-15% points lower for stages IIC, IIIB and IIIC.

CONCLUSIONS

Upshifting affects primarily stage III subgroups, while effects in stage II are minor. Stage IIB/C (AJCC8) patients have 67-80% MSS and should be considered for adjuvant treatment, while in stage IIIA, the indication of adjuvant treatment is questionable.

Identification of risk in cutaneous melanoma patients: Prognostic and predictive markers

New therapeutic modalities for melanoma promise benefit in selected individuals. Efficacy appears greater in patients with lower tumor burden, suggesting an important role for risk-stratified surveillance. Robust predictive markers might permit optimization of agent to patient, while low-risk prognostic markers might guide more conservative management. This review evaluates protein, gene, and multiplexed marker panels that may contribute to better risk assessment and improved management of patients with cutaneous melanoma.