Second Malignant Neoplasms Following Treatment for Childhood Cancer: A Population-Based Registry Study

Area of Science:

• Oncology
• Cancer Epidemiology
• Survivorship Research

Background:

• Improved survival rates for childhood cancer have increased the number of individuals at risk for secondary cancers.
• Second malignant neoplasms (SMNs) represent a significant long-term adverse outcome for childhood cancer survivors.

Purpose of the Study:

• To assess the risk and temporal trends of SMNs among childhood cancer survivors in Finland.
• To identify specific subgroups of survivors with elevated SMN risk.

Main Methods:

• Utilized data from the Finnish Cancer Registry for 10,941 patients diagnosed with cancer before age 20 (1970-2020).
• Calculated standardized incidence ratios (SIRs) and absolute excess risks (AERs) with a mean follow-up of 14.5 years.
• Compared SMN risk between two diagnostic eras: 1970-1990 and 1991-2020.

Main Results:

• A total of 498 (4.6%) survivors developed an SMN, with an overall SIR of 4.41.
• Survivors diagnosed before age 10 had a substantially higher SMN risk (SIR 6.79) compared to older patients (SIR 3.47).
• Survivors of central nervous system (CNS) and solid tumors diagnosed from 1991-2020 showed more than double the SMN risk compared to those diagnosed 1970-1990.

Conclusions:

• The risk of SMNs remains a significant concern for childhood cancer survivors.
• Survivors of CNS and solid tumors require particular attention due to their elevated risk.
• Tailored surveillance strategies and further research are crucial to mitigate long-term adverse outcomes in this population.