Averbook, Bruce J.

9013 Background: Pediatric melanoma (PM) care has been extrapolated from adult melanoma data. PM and atypical melanocytic neoplasms (AMNs) appear to have different biology. An international database (DB) was developed to clarify their behavior. Methods: IRB approval was obtained at 12 institutions. An SQL-DB was developed for web entry of de-identified demographic and pathologic data for PM and AMN patients (pts) < 21yr through an honest broker system at the University of Pittsburgh. Institutions retained a key of pts entered with assigned numbers for quality assurance and updates. Statistical analysis used Kaplan-Meier survival curves, univariate linear trends and log rank tests. In situ melanoma was excluded from PM survival analysis. Results: 828 pts were registered as of 31 Oct 2008 (ages 11mo-23; median 15yr). 34 pts 21–23yr entered were left in the DB for statistical comparison. Diagnosis years ranged from 1936–2008. 455 pts had complete follow-up. Too few AMN pts had complete follow-up for analysis (18/208). After excluding 32 in situ and 40 with other incomplete data, 365 PM out of 415 total PM were evaluable for OS and 351 for DFS (Stage IV removed). Mean/median age for evaluable PM pts was 16.44/17-yrs (range 1–21yr). 591 pts were age 10–20 while 203 were < 10. Sentinel lymph node (SLN) biopsy showed spread in 30.1 % PM pts (compared to 50% [4/8] of AMN SLN pts). 10-yr PM OS was 80.6%, and pts 0–10 yr had 100% 10-yr OS compared to 69.6% for pts age 10–15 and 79.49% for age 15–20 (p= 0.1473). OS did not differ significantly by gender. Stage predicted OS (p<0.0001). 10-yr OS was 94.13% for Stage I (n=174), 79.62% for stage II (n=67) & 77.14% for stage III (n=75). Thickness affected 10-yr OS: 0–1mm=97% (n=147), 1.1–2mm 70% (n=84), 2.01–4mm 78% (n=71) & >4mm 81% (n=25), p= 0.0099. Survival was similar for pts with PM > 1mm of the several T stage groupings. Ulceration adversely affected OS (p=0.022). Mitosis, defined as present/absent did not alter survival. Nodal metastasis correlated with worse OS (p= 0.170). Conclusions: Stage, thickness, ulceration, and nodal status are significant predictors of OS for PM. Further study will focus on multivariable analysis of PM and AMNs after updating pts, increasing accrual, and cleaning data. No significant financial relationships to disclose.

BACKGROUNDThe management of pediatric melanoma (PM) has largely been extrapolated from adult data. However, the behavior of PM appears to differ from its adult counterparts. Therefore, an international PM registry was created and analyzed.METHODSTwelve institutions contributed deidentified clinicopathologic and outcome data for patients diagnosed with PM from 1953 through 2008.RESULTSOverall survival (OS) data were reported for 365 patients with invasive PM who had adequate follow‐up data. The mean age of the patients was 16 years (range 1 year‐21 years). The 10‐year OS rate, 80.6%, tended to vary by patient age: 100% for those aged birth to 10 years, 69.7% for those aged > 10 years to 15 years, and 79.5% for those aged > 15 years to 20 years (P = .147). Patients with melanomas measuring ≤ 1 mm had a favorable prognosis (10‐year OS rate of 97%), whereas survival was lower but similar for patients with melanomas measuring > 1 mm to 2 mm, > 2 mm to 4 mm, and > 4 mm (70%, 78%, and 80%, respectively; P = .0077). Ulceration and lymph node metastasis were found to be correlated with worse survival (P = .022 and P = .017, respectively). The 10‐year OS rate was 94.1% for patients with American Joint Committee on Cancer stage I disease, 79.6% for those with stage II disease, and 77.1% for patients with stage III disease (P < .001).CONCLUSIONSTumor thickness, ulceration, lymph node status, and stage were found to be significant predictors of survival in patients with PM, similar to adult melanoma. There is a trend toward increased survival in children aged ≤ 10 years versus adolescents aged > 10 years. Further analyses are needed to probe for potential biological and behavioral differences in pediatric versus adult melanoma. Cancer 2013;119:4012–4019. © 2013 American Cancer Society.