Cancer in childhood is rare. The most recent SEER Cancer Statistics Review, released in April 2018 and covering 2011–2015, shows that for ages 0–14 the incidence of all cancer sites was 16.4 per 100,000 children, with mortality 2.1 per 100,000. Five-year relative survival for the same age group was 83.8% for years 2008–2014 [1]. (Rates from the European Cancer Information System are similar but are currently available only to 2012.) As of 2015, 1 in 750 of the adult population of the United States was a long-term survivor of childhood cancer [1, 2]. Cancer is more common after puberty, with incidence rising from 12.9 for ages 5–9 to 23.3 for ages 15–19 in the United States for years 2011–2015 [1], and many of these patients will be cured by combination treatment, with surgery, chemotherapy, and radiotherapy. Long-term survivors are nevertheless at risk of developing a number of late sequelae [3], including impaired fertility, adverse pregnancy outcomes, and health problems in offspring [4–6].

Introduction

Survival from childhood cancer has markedly improved over recent decades following major advances in available treatments and supportive care, such that now around 75%–80% of children with cancer will be alive 5 years from diagnosis. The number of long-term survivors is therefore increasing, and it has been estimated that, by the year 2010, about one in 715 of the adult population will have been treated for cancer in childhood. Because of this, the emphasis in the management of childhood cancer has changed, from “cure at any cost” to one in which quality of life after treatment has become increasingly important. Thus, whilst continuing to strive for improved survival, attention must be directed towards minimizing the late effects of treatment.

Adverse late effects of childhood cancer treatment are diverse and include growth impairment, disorders of the endocrine system, infertility, abnormalities of cardiac and pulmonary function, renal and hepatic impairment, second malignancies, and cognitive and psychosocial difficulties. This chapter focuses on these consequences of childhood cancer treatment. Long-term follow-up of these patients is essential, in order that adverse effects are diagnosed early and appropriate counselling and therapeutic intervention instituted. Awareness of the etiology and prevalence of late complications will allow modifications of treatment that will improve the quality of life for long-term survivors of childhood cancer.

Endocrine disorders and growth impairment

Collectively, disorders of the endocrine system represent the commonest long-term complication of cancer treatment, with one study demonstrating endocrine abnormalities in up to 40% of such patients at follow-up.

Introduction

Tremendous therapeutic advances in the management of childhood malignancies mean that the majority of children can realistically hope for long-term survival. Cancer in childhood is rare, with about 1400 new cases per year in the UK and a cumulative risk of 1 in 650 by the age of 15 years (Stiller, 1997; Wallace, 1997). With survival rates in excess of 70%, it is estimated that by the year 2010, 1 in 250 of the young adult population will be a long-term survivor of childhood cancer (Fig. 32.1) (Bleyer, 1990). However, the successful treatment of cancer in childhood with chemotherapy and or radiotherapy is associated with a number of unwanted side effects in later life (Wallace et al., 2001). Therefore, the major challenge faced by paediatric oncologists today is to sustain the excellent survival rates while striving to improve the quality of life of the survivors.

One of the most important issues for the survivors of childhood cancer is the impact of their disease and its treatment on reproductive function and the implications for the health of their offspring. In the female, chemotherapy and radiotherapy may damage the ovary and hasten oocyte depletion, resulting in loss of hormone production, truncated fecundity and a premature menopause (Meirow, 2000; Thomson et al., 2002). Infertility is one of the most commonly encountered and psychologically traumatic late complications of treatment for childhood cancer, and consequently, strategies to preserve fertile potential are being pursued.