The first population-wide picture of the distribution and outcomes for childhood blood cancers in Australia by stage at diagnosis shows five-year survival is about 85–90%, even in ALL and NHL patients presenting with higher stage disease.
The study applied the Toronto Paediatric Cancer Staging Guidelines to more than 2,000 leukaemia and lymphoma cases from the Australian Childhood Cancer Registry.
It found 91% of patients with ALL had CNS1 disease using the Children’s Oncology Group (COG) staging system, 6.9% staged as CNS2 and 2.1% as CNS3. Respective five-year survival rates were 94.1%, 89.0% and 90.3%.
The overall difference in survival by stage at diagnosis was not statistically significant (p=0.07-0.91) or borderline when comparing CNS1 with CNS2 (p=0.05).
Almost two thirds of AML cases (65.6%) were CNS- and 34.4% CNS+. Survival estimates were similar irrespective of CNS involvement (77% vs 78%, P=0.94).
“This similarity in survival irrespective of CNS involvement is at least in part because intrathecal chemotherapy has proven to be effective in the treatment of CNS disease associated with AML, but the optimal regime is yet to be determined,” the study authors said.
“Prognosis for AML is instead primarily dictated by cytogenetic and molecular characteristics at diagnosis, raising the question of whether an alternative definition of stage for children with AML that incorporates these characteristics may be of more benefit.”
The proportions of Hodgkin lymphoma patients staged by the Ann Arbor system was 16.2% IA/IB, 35.1% IIA/IIB, 19.9% IIIA/IIIB and 28.8% IVA/IVB. Respective five-year survival rates were 100%, 100%, 97.1% and 100% with no difference by stage (p=0.30).
Non-Hodgkin lymphoma staging using the St Judes-Murphy’s system showed most cases (56.1%) were stage III versus stage 1 (12.0%), II (9.6%) and IV (22.3%).
“Although the overall effect of disparities in survival by stage was not statistically significant for children with NHL (P=0.22), there was evidence of a decreasing trend in survival as stage became higher, with survival of 97% for stage I compared with 85% for stage IV (P trend = 0.04).”
Co-author Professor Joanne Aitken, from Cancer Council Queensland, told the limbic cancer registries around the world had not routinely collected staging details.