Researchers identified clinical, radiologic and molecular factors associated with survival among children and young adults with diffuse intrinsic pontine glioma, according to results of an international study published in Journal of Clinical Oncology.
“Diffuse intrinsic pontine glioma (DIPG) is a malignant brainstem tumor of childhood for which median survival is less than 1 year,” Maryam Fouladi, MD, medical director of the Neuro-Oncology Program at Cincinnati Children’s Hospital Medical Center, and colleagues wrote.
“The rarity and inconsistent classication of DIPG, an imaging-based diagnosis, have long hampered cross-cohort comparisons,” they added.
The researchers reviewed data from registries in North America, Australia, Germany, Austria, Switzerland, the Netherlands, Italy, France, the UK and Croatia to identify 1,008 children and young adults (median age, 6.8 years; range 0-26.8) with DIPG. Researchers compared histomolecular, radiologic and clinical characteristics between short-term survivors (OS of less than 24 months), long-term survivors (OS of 24 months or longer) and very long-term survivors (OS of 60 months or longer).
Overall median survival was 11 months; 10% (n = 101) of patients were long-term survivors.
Researchers observed survival rates of 42.3% (95% CI, 38.1-44.1) at 1 year, 9.6% (95% CI, 7.8-11.3) at 2 years, 4.3% (95% CI, 3.2-5.8) at 3 years, 3.2% (95% CI, 2.4-4.6) at 4 years and 2.2% (95% CI, 1.4-3.4) at 5 years.
Long-term survivors more frequently presented with disease at ages younger than 3 years (11% vs. 3%) or older than 10 years (33% vs. 23%; P < .001 for both) compared with short-term survivors. Long-term survivors also had longer duration of symptoms (P < .001).
Short-term survivors more frequently experienced cranial nerve palsy (83% vs. 73%; P = .008), and they more frequently presented with ring enhancement (38% vs 23%; P = .007), necrosis (42% vs. 26%; P = .009) and extra pontine extension (92% vs. 86%; P = .04).
A greater proportion of long-term survivors received systemic therapy at the time of diagnosis (88% vs. 75%; P = .005).
Long-term survivors also had a greater likelihood to harbor a HIST1H3B mutation (OR = 1.28; 95% CI, 1.1-1.5).
Researchers acknowledged that the study was limited by the use of disease-specific registry information, which was vulnerable to enrollment bias.
“To our knowledge, this study represents the largest, most comprehensively annotated cohort of radiographically conrmed DIPG reported, offering the most accurate rates of long- and very long-term survival for this rare tumor,” the researchers wrote. “Identication of robust survival-associated factors in this study is vital for development of prognostic subgroups and emphasizes patient subsets from whom the most could be learned from analyzing pretreatment biopsy tissue. Understanding biologic differences that confer survival advantage in DIPG paves the road toward development of subgroup-specic therapies that, when implemented in the context of clinical trials, may improve outcomes for this devastating disease.” – by Andy Polhamus
Fouladi reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.