Evaluation of the eighth American Joint Committee on Cancer staging system for malignant melanoma of the skin

Prognostic impact of Breslow thickness in acral melanoma: A retrospective analysis

BACKGROUND

Evidence for the prognostic importance of tumor thickness in acral melanoma (AM) patients is limited.

OBJECTIVE

The objective of the study was to determine the prognostic impact of Breslow thickness in AM.

METHODS

This multicenter study enrolled patients diagnosed with localized AM between January 1, 2000 and December 31, 2017. Melanoma-specific survival (MSS) in different tumor thickness strata (T1-T4: ≤1, >1-2, >2-4, >4 mm, respectively) was estimated by the Kaplan-Meier method. Comparisons were performed by the log-rank test and multivariable Cox regression.

RESULTS

A total of 853 patients with clinical N0 (cN0) AM were included in the analysis. The median follow-up time was 60.1 months. The median MSS in patients with T1-T4 disease was not reached, 111.0, 92.8, and 67.1 months, respectively. MSS differed significantly among cN0 patients with T1-T3 AM (log-rank P = .004, .012, <0.001 for T1 vs T2, T2 vs T3, and T1 vs T3, respectively); however, there was no significant difference between T3 and T4 AM (hazard ratio = 0.82, 95% CI, 0.62-1.09). Six-subgroup analyses confirmed that survival outcomes were similar between different subgroups with tumor thickness >2 mm.

LIMITATIONS

The limitations were retrospective design and some missing variables.

CONCLUSIONS

There was no association between tumor thickness and survival in AM patients with a Breslow thickness >2 mm.

Prognostic value of ulceration varies across Breslow thicknesses and clinical stages in acral melanoma: a retrospective study

BACKGROUND

Ulceration is regarded as an adverse prognostic factor and is used together with tumour thickness to subcategorize patients with cutaneous melanoma. However, the prognostic impact of ulceration in acral melanoma (AM) is controversial.

OBJECTIVES

To assess the prognostic impact of ulceration in AM and the variability across different Breslow thicknesses and clinical stages.

METHODS

A multicentre retrospective study of patients diagnosed with AM between January 2000 and December 2017. Differences in melanoma-specific survival (MSS) between patients with and without ulceration were assessed using the multivariable Cox proportional hazards model and log-rank test.

RESULTS

Among 1053 enrolled patients, 62.6% had ulceration. After a median follow-up of 61 months, patients with ulceration had a lower median MSS than those without: 66.1 months, 95% confidence interval (CI) 60.0-86.0 vs. not reached; hazard ratio 1.41, 95% CI 1.09-1.82; P = 0.012. Among patients with thin (≤ 1 mm) melanoma, the survival curves of patients with vs. without ulceration clearly separated over time (P < 0.001). No association between ulceration and MSS was observed for melanomas of thickness > 1 mm (subgroups of T2, T3 and T4; all P-values > 0.05) or patients with stage III disease (hazard ratio 1.09, 95% CI 0.71-1.68, P = 0.39).

CONCLUSIONS

Ulceration is an independent negative prognostic factor for patients with AM, but the impact varies across Breslow thicknesses and clinical stages. Ulceration has a significant effect on prognosis for patients with thin (≤ 1 mm) melanoma, but there was no association between ulceration and survival in intermediate/thick AM or stage III AM. What is already known about this topic? Ulceration status is used together with Breslow tumour thickness to subcategorize patients into different stages according to the America Joint Committee on Cancer melanoma staging system. As one distinctive subtype of cutaneous melanoma, acral melanoma (AM) is characterized by poor survival outcomes due to delayed diagnosis and a high prevalence of negative prognostic and genetic features. The prognostic impact of ulceration in AM is still controversial. What does this study add? This was the first large-scale study to assess the prognostic and staging values of ulceration in patients with AM. Ulceration has a significant effect on prognosis for patients with thin (≤1 mm) melanoma, but no association between ulceration and survival was found in intermediate/thick or stage III AM. These findings should be considered when using ulceration-based staging systems.

External validation of the American Joint Committee on Cancer melanoma staging system eighth edition using the surveillance, epidemiology, and end results program

AIM

The American Joint Committee on Cancer (AJCC) melanoma staging system eighth edition (AJCC-8) was recently released to provide accurate staging reflecting advances in the treatment of melanoma. Using population registry data, this study independently validates and compares the prognostic performance of AJCC-8 to the seventh edition (AJCC-7).

METHODS

We extracted patient-, tumor-related, and survival data from the SEER-18 registry between 2010 and 2015. To assess overall survival (OS) and cancer-specific survival (CSS) for AJCC-7 and AJCC-8, we performed Kaplan-Meier analysis and computed cumulative hazard functions using Nelson-Aalen function.

RESULTS

Of 126,408 individuals, 59,989 (47%) and 60,411 (48%) had available data for pathological and clinical-stage OS analysis, respectively. The 3-year OS for AJCC-7 among pathologically staged patients was: stage IA 97%, stage IB 95%, stage IIA 87%, stage IIB 76%, stage IIC 57%, stage IIIA 86%, stage IIIB 69%, stage IIIC 50%, and stage IV 24%. The 3-year OS for AJCC-8 patients was similar but was 56% for stage IIIC and 30% for stage IIID. Stage IV individuals with an elevated LDH had worse OS and CSS at all measured time-points up to 60 months compared to those with a normal LDH.

CONCLUSION

The discriminatory ability of AJCC-8 and AJCC-7 appear comparable. Changes in AJCC-8 identified stage IIID as a poor prognostic subgroup among stage III patients and elevated LDH in stage IV. However, patients with advanced T-stage, node-negative tumors experienced worse survival compared to those with earlier T-stage, node-positive tumors, and the results of ongoing trials should inform adjuvant therapy in this subset of patients.

Integrating additional factors into the TNM staging for cutaneous melanoma by machine learning

BACKGROUND

Integrating additional factors into the TNM staging system is needed for more accurate risk classification and survival prediction for patients with cutaneous melanoma. In the present study, we introduce machine learning as a novel tool that incorporates additional prognostic factors to improve the current TNM staging system.

METHODS AND FINDINGS

Cancer-specific survival data for cutaneous melanoma with at least a 5 years follow-up were extracted from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute and split into the training set (40,781 cases) and validation set (5,390 cases). Five factors were studied: the primary tumor (T), regional lymph nodes (N), distant metastasis (M), age (A), and sex (S). The Ensemble Algorithm for Clustering Cancer Data (EACCD) was applied to the training set to generate prognostic groups. Utilizing only T, N, and M, a basic prognostic system was built where patients were stratified into 10 prognostic groups with well-separated survival curves, similar to 10 AJCC stages. These 10 groups had a significantly higher accuracy in survival prediction than 10 stages (C-index = 0.7682 vs 0.7643; increase in C-index = 0.0039, 95% CI = (0.0032, 0.0047); p-value = 7.2×10-23). Nevertheless, a positive association remained between the EACCD grouping and the AJCC staging (Spearman's rank correlation coefficient = 0.8316; p-value = 4.5×10-13). With additional information from A and S, a more advanced prognostic system was established using the training data that stratified patients into 10 groups and further improved the prediction accuracy (C-index = 0.7865 vs 0.7643; increase in C-index = 0.0222, 95% CI = (0.0191, 0.0254); p-value = 8.8×10-43). Both internal validation using the training set and temporal validation using the validation set showed good stratification and a high predictive accuracy of the prognostic systems.

CONCLUSIONS

The EACCD allows additional factors to be integrated into the TNM to create a prognostic system that improves patient stratification and survival prediction for cutaneous melanoma. This integration separates favorable from unfavorable clinical outcomes for patients and improves both cohort selection for clinical trials and treatment management.

Characteristics of circRNA and its approach as diagnostic tool in melanoma

One of the most common types of cancer in the world is skin cancer, which has been divided into two groups: non-melanoma and melanoma skin cancer. Different external and internal agents are considered as risk factors for melanoma skin cancer pathogenesis but the exact mechanisms are not yet confirmed. Genetic and epigenetic changes, UV exposure, arsenic compounds, and chemical substances are contributory factors to the development of melanoma. A correlation has emerged between new therapies and the discovery of a basic molecular pattern for skin cancer patients. Circular RNAs (circRNAs) are described as a unique group of extensively expressed endogenous regulatory RNAs with closed-loop structure bonds connecting the 5' and 3' ends, which are commonly expressed in mammalian cells. In this review, we describe the biogenesis of circular RNAs and its function in cancerous conditions focusing on the crosstalk between different circRNAs and melanoma. Increasing evidence suggests that circRNAs appears to be relative to the origin and development of skin-related diseases like malignant melanoma. Different circular RNAs like hsa_circ_0025039, hsa_circRNA006612, circRNA005537, and circANRIL, by targeting different cellular and molecular targets (e.g., CDK4, DAB2IP, ZEB1, miR-889, and let-7 c-3p), can participate in melanoma cancer progression.

Differences in cutaneous melanoma survival between the 7th and 8th edition of the American Joint Committee on Cancer (AJCC). A multicentric population-based study

BACKGROUND

The 8th edition of the AJCC manual for melanoma includes many changes leading to major substage migrations, which could lead to important clinical reassessments.

OBJECTIVES

To evaluate the differences and prognostic value of the 8th AJCC classification in comparison with the 7th edition.

METHODS

Clinical and histopathological data were retrieved from five melanoma referral centers including 7815 melanoma patients diagnosed between January 1998 and December 2018. All patients were reclassified and compared using the 7th and 8th classifications of the AJCC. Sankey plots were used to evaluate the migration of patients between the different versions. The primary outcome was overall survival (OS), and curves based on the Kaplan-Meier method were used to investigate survival differences between the 7th and 8th editions.

RESULTS

The number of patients classified as stages IB, IIIA, and IIIB decreased while the patients classified as stages IA and IIIC increased notably. Migration analysis showed that many patients in group I were understaged whereas a significant percentage of patients in group III were upstaged. Indirect OS analysis showed a loss in the linearity in the AJCC 8th edition and the groups tended to overlap. Direct OS analysis between groups and versions of the AJCC showed a better prognosis within the new stage III patients, with no effect on those in stages I and II.

CONCLUSION

The 8th AJCC edition represents an important change in the classification of patients. We observe that the main migratory changes occur in stage I and III, that severity linearity is lost and groups overlap, and that a more advanced stage does not mean a worse prognosis.

Population-based validation of the National Cancer Comprehensive Network recommendations for baseline imaging workup of cutaneous melanoma

The aim of the current study is to assess the performance of some of the imaging scans recommended in the National Comprehensive Cancer Network Guidelines as part of baseline staging for cutaneous melanoma, regarding the detection of lung, brain, bone, and liver metastases. Surveillance, Epidemiology and End Results database (2010-2015) was used to extract the data, and cases with cutaneous melanoma and complete information about TN stages and sites of distant metastases were explored. Performance parameters assessed in the current study included positive predictive value (PPV), negative predictive value, sensitivity, specificity, number needed to investigate (NNI), and accuracy. A total of 109 971 patients were included in the analysis. If all stage III patients in the study cohort are to be staged through routine imaging, PPV (for the recognition of lung metastases) will be 2.9% and NNI to detect one case of lung metastasis will be 34. Likewise, PPV (for the recognition of bone metastases) will be 1.8% and NNI to detect one case of bone metastasis will be 55. Moreover, PPV (for the recognition of liver metastases) will be 1.8% and NNI to detect one case of liver metastasis will be 55. Excluding stage III patients with clinically node-negative/sentinel node-positive disease would improve PPV and decrease NNI for the three metastatic sites. Adherence to current National Comprehensive Cancer Network guidelines for cutaneous melanoma imaging for baseline staging results in low rates of failure to detect asymptomatic lung, liver, brain, or bone metastases.

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.

Novel circular RNA, hsa_circ_0025039 promotes cell growth, invasion and glucose metabolism in malignant melanoma via the miR-198/CDK4 axis

Malignant melanoma, a tumor derived from melanocytes, shows severe drug resistance and prompt metastasis, causing a serious threat to human health. Circular RNAs (circRNAs) are widely expressed in mammals and have been indicated to play important roles in tumorigenesis. In the present study, we analyzed the variability of circRNAs in malignant melanoma by microarray and identified six differentially expressed circRNAs. In particular, we found that hsa_circ_0025039, which is formed by FOXM1 exons, is significantly upregulated in melanoma. In vitro, the knockdown of circ_0025039 inhibited cell proliferation, colony formation ability, invasion and glucose metabolism in melanoma cells. Additionally, we identified miR-198 as a direct target of hsa_circ_0025039. Furthermore, we demonstrated that hsa_circ_0025039 regulates CDK4 expression by sponging miR-198. In vivo study indicated that the silencing of hsa_circ_0025039 inhibits melanoma tumor formation and downregulates miR-198 and CDK4 expression. Taken together, our data showed that circ_0025039 promotes cell growth, invasion and glucose metabolism in malignant melanoma by sponging miR-198 and regulating CDK4.