Abstract 309P
Background
Most pediatric patients with MB that experience recurrence present with distant dissemination within the neuroaxis and rarely benefit from local rescue strategies such as surgery and radiotherapy. However, adult MB has important biological differences that impact clinical behavior and patient outcomes.
Methods
Adult patients with MB included in the GEINO-GETHI National CNS tumor register were analyzed. Patients alive at inclusion provided informed consent.
Results
From a total of 81 registered pts, 24 cases of relapse were identified for analysis. The median age at diagnosis was 28.4y(30.2 excluding 5 pediatric patients relapsed>18y) 37% were female, 87% caucasic. Patients with nonSHH-nonWNT MB are overrepresented in this cohort(4/7 cases)over SHH MB(3/7). Histologic subtype distribution was: 5 desmoplasic/4 classic/2 anaplasic/1extensive nodularity. All patients had initially received surgery(75% complete resection) and radiation(all including the tumor bed and 41% the neuroaxis) at diagnosis, and 87% systemic treatment(52% sequential, 38% concomitant, 14% neoadyuvant). Relapses ocurred after a median of 3.74 years(range 0.32 to 9.7). First relapse was usually local(65%), neuroaxis(20%), both(10%) or other SNC localizations(5%). Initial strategy after 1st relapse was: 4,1% only surgery, 12,5% only rdt 20,8% only chemotherapy, 20,8% surgery followed by radiotherapy and chemotherapy, 12,5% radiotherapy and chemotherapy, 16,6% surgery and adjuvant chemotherapy, 12,5% only palliative treatment. Patients went to receive up to 6 lines of treatment. Only 2 patients were treated with high dose chemotherapy followed by BM trasplant. 2 pts, including 1 pt treated with BMO, died as a consequence of toxicity. Median OS after relapse was 2,04 y.
Conclusions
Although the majority of relapses ocurred in the first 5 years of follow-up this study seems to confirm that adult meduloblastoma tends to recurr later(3.74y vs 1 year in pediatric patients), have a higher likelihood of presenting isolated local recurrence(65% vs 30% in other series), and therefore have a better median OS. This can have implications for follow-up strategies.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
GEINO/GETHI Group.
Funding
GEINO/GETHI Group.
Disclosure
All authors have declared no conflicts of interest.