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16697

A Comparison of Pediatric and Adolescent Testicular Germ Cell Malignancy

Saturday, October 20, 2012
Grand Ballroom A/B (Hilton Riverside)
Nicholas G. Cost, M.D.1, Jessica D. Lubahn, M.D.2, Mehrad Adibi, M.D.2, Adam Romman, M.D.2, Jonathan E. Wickiser, M.D.3, Ganesh V. Raj, M.D., Ph.D.2, Arthur I. Sagalowsky, M.D.2 and Vitaly Margulis, M.D.2, (1)Division of Urology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, (2)Urology, University of Texas Southwestern Medical School, Dallas, TX, (3)Pediatric Hematology and Oncology, University of Texas Southwestern Medical School, Dallas, TX

Purpose:

Testicular Germ Cell Tumors (T-GCTs) can occur from infancy to adulthood.  However, they are more frequently diagnosed in adolescents and young adults and are the most common solid tumor in males between 15-19yr.  Recent investigation has emphasized the unique characteristics of adolescent cancer patients and how they can be caught between pediatric and adult specialists and they generally suffer from worse outcomes than their pediatric counterparts.  In terms of testicular cancer, pre-pubertal T-GCTs are typically thought to be more benign than post-pubertal, adolescent T-GCTs.  However, there are few studies comparing these groups in terms of oncologic outcomes. 

Methods:

We retrospectively reviewed an institutional database of all available patients with an ICD-9 diagnosis of T-GCT.  We organized these patients into pediatric (0-12yr), and adolescent (13-19yr) cohorts.  Next, we compared them in terms of demographics, tumor characteristics, disease stage, treatment type, recurrence-free survival (RFS) and overall survival (OS).

Results:

We identified 59 such patients (20 pediatric and 39 adolescent) followed-up for a median of 1.8yr (0.01-15.6) after diagnosis.  The median age at diagnosis was 1.4yr (0.29-7.5) in the pediatric group and 17.3yr (13.0-19.9) in the adolescent group.  We observed that adolescent patients had more mixed non-seminomatous GCTs, while pediatric patients were more likely to harbor pure yolk sac or teratoma.  The adolescent patients had significantly more advanced primary tumor stage (p=0.033), clinical nodal stage (p=0.036), and American Joint Committee on Cancer Group Stage at presentation (p=0.006).  Statistically fewer adolescent patients were managed with observation, p<0.0001, and more treated with chemotherapy, p<0.0001.

In terms of RFS, there were more recurrences in the adolescents (13, 33.3%) than in the pediatric group (1, 5.0%).  The 3yr RFS was 92.3% for the pediatric group and 61.1% for the adolescent group, p=0.016 (Figure 1).  5yr OS was 100% in the pediatric group and 84.8% in the adolescents, p=0.243.

Lastly, we retrospectively investigated the potential for a risk-adapted strategy in managing Stage Ia/b disease in this population.  We analyzed the impact of lymphovascular invasion (LVI) or higher percentage of Embryonal Carcinoma (EC) in the orchiectomy specimen on either positive nodes at primary RPLND or recurrence after initial observation in 23 such patients.  We assigned those with LVI or ≥40% EC as high-risk and observed recurrence in 3 of 6 (50.0%) high-risk patients compared to 1 of 16 (6.2%) without high risk features, Hazard Ratio = 10.03 (95%CI 1.035-97.213), p=0.047.

Conclusion:

Our data on Adolescent T-GCTs support the larger movement to establish a distinct focus on adolescent cancer patients.  We recommend managing these patients more aggressively than pediatric T-GCT patients.  Also, we believe that the use of a risk-adapted strategy, utilizing LVI and the %EC, can be helpful in such patients with Stage Ia/b disease. 

Figure 1: Recurrence Free Survival in Pediatric and Adolescent T-GCT Patients