Late mortality in survivors of childhood cancer in Hungary

Possible Mechanisms of Subsequent Neoplasia Development in Childhood Cancer Survivors: A Review

Advances in medicine have improved outcomes in children diagnosed with cancer, with overall 5-year survival rates for these children now exceeding 80%. Two-thirds of childhood cancer survivors have at least one late effect of cancer therapy, with one-third having serious or even life-threatening effects. One of the most serious late effects is a development of subsequent malignant neoplasms (histologically different cancers, which appear after the treatment for primary cancer), which occur in about 3-10% of survivors and are associated with high mortality. In cancers with a very good prognosis, subsequent malignant neoplasms significantly affect long-term survival. Therefore, there is an effort to reduce particularly hazardous treatments. This review discusses the importance of individual factors (gender, genetic factors, cytostatic drugs, radiotherapy) in the development of subsequent malignant neoplasms and the possibilities of their prediction and prevention in the future.

Late mortality from other diseases following childhood cancer in Australia and the impact of intensity of treatment

BACKGROUND

People who receive treatment for cancer during childhood often experience subsequent complications of therapy, known as late effects, which can lead to an increased risk of death.

PROCEDURE

Using deidentified population-based data from the Australian Childhood Cancer Registry for children aged 0-14 diagnosed with cancer during the period 1983-2011 and who survived for a minimum of 5 years, we examined disease-related deaths (other than cancer recurrence or second primary cancers) that occurred up to 31 December 2016. Risk of death relative to the general population was approximated using standardised mortality ratios (SMRs). Treatment received was stratified according to the intensity of treatment rating, version 3 (ITR-3).

RESULTS

During the study period, 82 noncancer disease-related deaths were recorded among 13 432 childhood cancer survivors, four times higher than expected (SMR = 4.43, 95% CI = 3.57-5.50). A clear link to treatment intensity was observed, with the relative risk of noncancer disease-related mortality being twice as high for children who underwent 'most intensive' treatment (SMR = 5.94, 95% CI = 3.69-9.55) compared to the 'least intensive' treatment group (SMR = 2.98, 95% CI = 1.42-6.24; P_trend  = .01). Thirty-year cumulative mortality from noncancer disease-related deaths was estimated at 1.4% (95% CI = 1.1-1.9) after adjusting for competing causes of death such as cancer, accidents, or injuries.

CONCLUSIONS

Although childhood cancer survivors are at increased relative risk of death from noncancer diseases, particularly those who undergo more intensive treatment, the cumulative mortality within 30 years of diagnosis remains small. Knowledge of late effects can guide surveillance of survivors and treatment modification, without wanting to compromise the high rates of survival.