Clinicopathologic features correlated with paradoxical outcomes in stage IIC versus IIIA melanoma patients

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.

Defining the Criteria for Reflex Testing for BRAF Mutations in Cutaneous Melanoma Patients

Targeted therapy has been developed through an in-depth understanding of molecular pathways involved in the pathogenesis of melanoma. Approximately ~50% of patients with melanoma have tumors that harbor a mutation of the BRAF oncogene. Certain clinical features have been identified in BRAF-mutated melanomas (primary lesions located on the trunk, diagnosed in patients <50, visibly pigmented tumors and, at times, with ulceration or specific dermatoscopic features). While BRAF mutation testing is recommended for stage III-IV melanoma, guidelines differ in recommending mutation testing in stage II melanoma patients. To fully benefit from these treatment options and avoid delays in therapy initiation, advanced melanoma patients harboring a BRAF mutation must be identified accurately and quickly. To achieve this, clear definition and implementation of BRAF reflex testing criteria/methods in melanoma should be established so that patients with advanced melanoma can arrive to their first medical oncology appointment with a known biomarker status. Reflex testing has proven effective for a variety of cancers in selecting therapies and driving other medical decisions. We overview the pathophysiology, clinical presentation of BRAF-mutated melanoma, current guidelines, and present recommendations on BRAF mutation testing. We propose that reflex BRAF testing should be performed for every melanoma patient with stages ≥IIB.

Cost-Benefit Implication of Gene Expression Profiling and Adjuvant Therapy in Stage IIIA Melanoma

BACKGROUND

Indiscriminate use of adjuvant therapy in stage IIIA melanoma is controversial. We sought to model the clinical impact and cost of implementing a gene expression profile (GEP) test to guide adjuvant therapy.

STUDY DESIGN

A Markov decision-analysis model was created to represent resected stage IIIA melanoma with 3 treatment options: observation (OBS), adjuvant pembrolizumab for all patients (ALL), and selective adjuvant therapy (SEL). In the SEL option, only high-risk patients based on GEP stratification were treated with pembrolizumab. Cost of adjuvant therapy was normalized to reflect Medicare reimbursement schedules. The primary outcome was cost per mortality avoided at 10 years.

RESULTS

Model projections for 10-year overall survival were 68% for OBS, 73% for SEL, and 76% for ALL. The estimated incremental cost-per-mortality-avoided (compared to OBS) was $2.1 million for SEL and $2.4 million for ALL. These translate to costs of $583.0K and $697.1K per life-year for the SEL and ALL strategies, respectively.

CONCLUSIONS

Routine adjuvant pembrolizumab for stage IIIA melanoma is costly, and risk-stratification by GEP only marginally improves the value of therapy.

Epidemiology and survival outcomes in stages II and III cutaneous melanoma: a systematic review

Aim

Management of cutaneous melanoma (CM) is continually evolving with adjuvant treatment of earlier stage disease. The aim of this review was to identify published epidemiological data for stages II-III CM.

Materials & methods

Systematic searches of Medline and Embase were conducted to identify literature reporting country/region-specific incidence, prevalence, survival or mortality outcomes in stage II and/or III CM. Screening was carried out by two independent reviewers.

Results & conclusion

Of 41 publications, 14 described incidence outcomes (incidence rates per stage were only reported for US and Swedish studies), 33 reported survival or mortality outcomes and none reported prevalence data. This review summarizes relevant data from published literature and highlights an overall paucity of epidemiological data in stages II and III CM.