Study Findings Highlight Need for Monitoring of Pediatric Cancer Survivors

While treatment of various cancers has improved survival outcomes in many patients, it appears that evolving approaches are associated with improved life expectancy among childhood cancer survivors — particularly for those who received chemotherapy alone, according to study results published in JAMA Oncology.

However, pediatric cancer survivors are still at risk for shorter lifespans, especially when radiotherapy was involved in their treatment regimen.

“Advances in pediatric cancer therapy during the past few decades have been associated with remarkable increases in five-year survival rates, with more than 80% of children and adolescents who receive a diagnosis today expected to live at least five years. By 2020, the population of childhood cancer survivors is projected to grow to more than 500,000 individuals,” the researchers explained.

“As adults, childhood cancer survivors face substantially elevated risks of serious long-term morbidity and premature death, with nearly one in three survivors reporting a severe or life-threatening condition 20 years after diagnosis,” they added. “However, the association of childhood cancer with life expectancy after more modern therapy, often chosen based on concerns of late toxic effects, is not known.”

Therefore, the researchers conducted a microsimulation model using mortality risks from the Childhood Cancer Survivor Study — designed to evaluate five-year survivors of pediatric cancer who were diagnosed between 1970 and 1999. With this, they aimed to project long-term survival among childhood cancer survivors and to assess whether life expectancy will improve among adult survivors of childhood cancer who were treated in more recent decades.

The model included late recurrence, treatment-related late effects, and US background mortality rates.

The majority of patients in the hypothetical cohort of five-year survivors of childhood cancer representatives from the study, the majority were male (56%) at an average age of 7.3 years at diagnosis of their childhood cancer.

The cohort’s conditional life expectancy was 48.5 years for those who survived five years after their diagnosis in 1970-1979, 53.7 years for those diagnosed in 1980-1989 and 57.1 years for those diagnosed in 1990-1999.

The researchers compared these results to those without a history of having cancer, and they noted that these results represented a gap in life expectancy of 25%, or 16.5 years, for those diagnosed in 1970-1979; 19%, or 12.3 years, for those diagnosed in 1980-1989; and 14%, or 9.2 years, for those diagnosed in 1990-1999.

Over these three decades, the proportion of survivors who were treated with chemotherapy alone increased from 18% to 54%, while the life expectancy gap decreased from 11 years to six years. On the other hand, survivors treated with radiotherapy only saw modest improvements during the same time frame, improving the life expectancy gap from 21 years to 17.6 years. Similarly, those treated with a combination of radiotherapy and chemotherapy saw limited improvements (17.9 years to 14.8 years).

“Our findings highlight the need for new therapeutic approaches for cancer diagnoses for which radiotherapy remains an integral component of local control of the disease and for the vigilant care of survivors who received radiotherapy as children,” the researchers wrote. “Our findings highlight the need for continued monitoring of survivors’ health to manage late mortality risks and underscore the need for new therapeutic approaches to minimize early mortality risks, especially for cancer diagnoses for which radiotherapy remains a key component of therapy.”