Background: In Thailand, a national treatment protocol for childhood leukemia and lymphoma (LL) was
implemented in 2006. Access to treatment has also improved with the National Health Security system. Since
these innovations, survival of childhood LL has not been fully described. Materials and Methods: Trends and
survival of children under 15 with childhood cancers diagnosed between 1993 and 2012 were investigated using the
hospital-based data from the Khon Kaen Cancer Registry, Srinagarind Hospital, Faculty of Medicine, Khon Kaen
University, Thailand. Childhood cancers were classified into 12 diagnostic groups, according to the ICCC based
on the histology of the cancer. Survival rates were described by period, depending on the treatment protocol. For
leukemias and lymphomas, survival was assessed for 3 periods (1993-99, 2000-5, 2006-12) while for solid tumors
it was for 2 periods (before and after 2000). The impacts of sex, age, use of the national protocol, and catchment
area on leukemia and lymphoma were evaluated. Overall survival was calculated using the Kaplan-Meier method
while the Cox proportional hazard model was used for multivariate analysis. Trends were calculated using the
R program. Results: A total of 2,343 childhood cancer cases were included. Survival for acute lymphoblastic
leukemia (ALL) from 1993-9, 2000-5, and 2006-12 improved significantly (43.7%, 64.6%, and 69.9%). This
was to a lesser extent true for acute non-lymphoblastic leukemia (ANLL) (28.1%, 42.0%, and 42.2%). Survival
of non-Hodgkin lymphoma (NHL) also improved significantly (44%, 65.5%, and 86.8%) but not for Hodgkin
disease (HD) (30.1%, 66.1%, and 70.6%). According to multivariate analysis, significant risk factors associated
with poor survival in the ALL group were age under 1 and over 10 years, while not using the national protocol
had hazard ratios (HR) of 1.6, 1.3, and 2.3 respectively. In NHL, only non-use of national protocols was a risk
factor (HR 3.9). In ANLL and HD, none of the factors influenced survival. Survival of solid tumors (liver tumors,
retinoblastomas) were significantly increased compared to after and before 2000 while survival for CNS tumors,
neuroblastoma and bone tumors was not changed. Conclusions: The survival of childhood cancer in Thailand
has markedly improved. Since implementation of national protocols, this is particularly the case for ALL and
NHL. These results may be generalizable for the whole country.