Introduction:
Paediatric cancers are rare tumours, heterogeneous in location and biologically very different from adult cancers. Documented survival variation across European countries and Italian regions show that there is still room for further improvement by reducing inequalities. We aim to understand why there are differences in survival. The stage of the tumor is a determining factor in the likelihood of recovery and the intensity of treatment required by the cancer patient. The BENCHISTA-ITA project (National BENchmarking of CHIldhood Cancer Survival by STAge at diagnosis), that is the Italian twin project of the International BENCHISTA, collect stage at diagnosis of solid paediatric tumours, according to the Toronto Guidelines. We will compare how far the cancer has spread at diagnosis and test if differences in tumour stage explain any survival differences between Italian regions.

Materials and Methods:
The project study stage distribution and survival for 9 paediatric solid tumours diagnosed between 2014 and 2017 with 3 years of follow-up for life-stage definition. The study involves: • The identification of all new diagnoses. • Evaluation of the clinical documentation of cases eligible for research, extraction, ICCC-3 classification, coding (ICDO-3.2), clinical and pathological information useful for staging • Linkage of identified cases with clinical records • Stage assignment at tumour diagnosis using the Toronto staging guidelines using a two-tier system • Production of a database containing clinical information, stage, recurrence and other prognostic factors The registries will centralise the data at the National Cancer Institute in Milan. An initial comparative analysis will show stage distribution and 3-year survival by stage by area/country.

Results:
Data from 28 population-based cancer registries were collected covering about 84% of the Italian child population. In particular, data on: imaging/examination performed before any treatment; source used for staging; primary treatment defined as given within 1 year from diagnosis; relapse/ recurrence/ progression; follow up and status of life. The study tested the applicability of Toronto Guidelines as a tool to obtain population-level comparable stage information for childhood cancers. Difference in stage distribution and survival differences between regional grouping were presented.

Conclusions:
The Italian BENCHISTA project, improving the connection between pediatric cancer registries, aims to improve care of children with cancer in the national territory, reducing possible disparities. The wide adoption of Toronto Guidelines will facilitate international comparative incidence studies, strengthen the interpretation of survival data, and contribute to more appropriate solutions to improve childhood cancer outcomes.