436P - Clinicopathological characteristics and outcomes of adolescent and young adult (AYA) melanoma: Results from an Asian perspective

Background

AYA melanomas (diagnosed 16-39 years) are rare but rising in incidence. It is not well-understood how they differ from adult melanomas. We aim to describe the demographics, clinic-molecular characteristics and outcomes from our institution.

Methods

We retrospectively reviewed all melanoma patients diagnosed between 16 and 39 years old (y) who presented to the National Cancer Centre Singapore from 1 January 2000 to 31 March 2019.

Results

There were 74 patients (41 females, 33 males). 51.4% (n=38) were Chinese, 9.5% Caucasians, 6.8% Malays and the rest of other ethnicity. Across age groups, 9 patients were 16-23 y (12.2%); 26 between 24-31y (35.1%) and 39 between 32-39y (52.7%). The most common subtype was cutaneous melanoma (46%, n=34). 31 (41.9%) patients had BRAF testing. 46.4% (n=13) had BRAF V600E mutation and 1 had BRAF V600K. 20 (27.0%) were tested for cKIT, with none having mutations. 51.4% (n=38) had stage I/II disease (American Joint Committee on Cancer 7^th Edition), 16 with stage III and 10 had stage IV. Common metastatic sites were lungs, lymph nodes and liver. 25 (33.8%) patients had sentinel lymph node biopsy (SLNBx), with 5 having lymph node dissection. Among those with SLNBx, 4, 13 and 5 patients had Breslow depths of <1mm, 1-4mm and >4mm respectively. The median depth was 2.7mm (range 0.25–9mm). 7 (9.5%) had first-line systemic therapy, with 5 (2 stage IV; 2 stage III and 1 unknown) receiving immunotherapy. 2 (stage IV) had combination chemotherapy (Dacarbazine/Cisplatin and Paclitaxel/Bevacizumab/Caroboplatin). None received BRAF inhibitors. The median overall survival (OS) is 2.7y (range 0.1–17.7y) for all and 1y for metastatic disease. The 5y OS is 34.5%. The breakdown is shown in the table. Table: 436P

Survival by age and stage

Conclusions

Routine BRAF/cKIT testing commenced in 2010 and immunotherapy started only in 2017, contributing to outcomes we see. Poorer survival is associated with higher stage (p<0.001). Further studies are needed to elucidate potential biological and cancer-specific differences between AYAs and adult melanoma population.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.