By way of context, Daniel Green highlighted that survival for children with cancer has increased as a result of treatment improvements driven by trial derived research. As a result, the aggregate overall five-year survival rate in so-called resource-rich Western nations is approximately 85%, with steady improvement over the past few decades.
As a result of improving survival, the issue of survivorship is increasingly large. As of 2005, there was an estimated 330,000 survival of or with cancer diagnosed before age 19 years. Assuming continuing trends, extrapolation suggests more than 500,000 survivors of childhood cancers by the end of this year, 2020.
In order to better understand the long-term outcomes for these patients, Dr. Green described a survivorship cohort study of patients diagnosed between 1970 and 1986.
Initial data from this study showed that survivors of childhood cancers had increased mortality compared to the general population.
The original childhood cancer remains a major cause of late mortality, up until 30 years following diagnosis. However, overall survival is but one metric which is important for these individuals. The morbidity of treatment may have significant health-related and quality-of-life effects. These, in turn, are influenced by a variety of factors including underlying disease characteristics, provider characteristics, patient characteristics, and health system factors.
Chronic and/or debilitating conditions are relatively common among survivors of childhood cancer (62%) and these conditions occur at rates which are much higher than among their siblings. Further, severe or life-threatening conditions current in 27.5%.
Of particular note is the development of the cardiac disease. This is notably related to exposure to systemic anthracyclines with the incidence rising in association with cumulative dose. Rates of cardiac disease are also related to cardiac radiation doses.
Infertility is a perhaps underrecognized and under-addressed consequence of childhood cancer treatment. Those who have undergone cancer treatment in childhood are much less likely to have ever gotten pregnant. This applies to both men and women, though the magnitude of the effect is greater among men, potentially as a result of the gonadotoxic effect of cyclophosphamide.
Just as cardiac toxicity is associated with anthracycline and radiation dosages, infertility risk is associated with the cumulative exposure to cyclophosphamide.
Among women, survivors of childhood cancer are at significantly increased risk of premature menopause with a relative risk exceeding 13, and strongly statistically significant.
Finally, one of the most daunting consequences of childhood cancer treatment is treatment-induced malignancy. A large portion of the excess risk among patients with a history of pediatric cancer treatment is attributable to prior radiotherapy, though underlying genetic causes may also contribute.
As a result of each of the aforementioned issues, the Children’s Oncology Group has developed Long-Term Follow-Up Guidelines for survivors of Childhood, Adolescent, and Young Adult Cancers. These guidelines provide direction regarding the potential late effects of each category of therapy along with suggested periodic evaluation and health counseling.
Presented by: Daniel Green, MD, Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN
Written by: Christopher J.D. Wallis, Urologic Oncology Fellow, Vanderbilt University Medical Center, @WallisCJD on Twitter at the 2020 American Urological Association (AUA) Annual Meeting, Virtual Experience #AUA20, June 27- 28, 2020