Clinical and pathological features of paediatric malignant rhabdoid tumours

Malignant rhabdoid tumours (MRT) and their central nervous system (CNS) counterparts atypical teratoid/rhabdoid tumours (ATRT) are rare, highly aggressive malignant neoplasms of childhood. Although there are isolated reports of long-term survival with intensive, multimodal therapy, outcomes are generally poor.

We conducted a retrospective review of all patients diagnosed with MRT/ATRT at Great Ormond Street Hospital over the 20 years from 1989 to 2009. All cases were subjected to expert pathological review including INI-1 immunostaining.

In a final cohort of 34 cases, overall survival was 17.4%, with median survival 10.1 months. Outcome in patients aged <3 years was significantly worse (median survival 6.2 months vs. 19.2 months). Data demonstrated a statistically significant benefit of radiotherapy (median survival 14.9 months vs. 6.6 months), although this analysis is confounded by the impact of patient age. There were four long-term survivors (>30 months), all of whom received chemotherapy with or without surgical resection or radiotherapy. In the present study, immunohistochemistry revealed no significant staining for either c-Erb or c-Met in any case, suggesting that targeting these molecules is unlikely to be of benefit in treating MRT/ATRT.

In view of poor outcomes, there is a clear need for new treatment strategies and the identification of novel molecular targets for MRT/ATRT.