Cranial irradiation and early puberty

Response to GH Treatment After Radiation Therapy Depends on Location of Irradiation

OBJECTIVES

Cancer survivors with GH deficiency (GHD) receive GH therapy (GHT) after 1+ year observation to ensure stable tumor status/resolution.

HYPOTHESIS

Radiation therapy (RT) to brain, spine, or extremities alters growth response to GHT.

AIM

Identify differences in growth response to GHT according to type/location of RT.

METHODS

The Pfizer International Growth Database was searched for cancer survivors on GHT for ≥5 years. Patient data, grouped by tumor type, were analyzed for therapy (surgery, chemotherapy, RT of the focal central nervous system, cranial, craniospinal, or total body irradiation [TBI] as part of bone marrow transplantation), sex, peak stimulated GH, age at GHT start, and duration from RT to GHT start. Kruskal-Wallis test and quantile regression modeling were performed.

RESULTS

Of 1149 GHD survivors on GHT for ≥5 years (male 733; median age 8.4 years; GH peak 2.8 ng/mL), 431 had craniopharyngioma (251, cranial RT), 224 medulloblastoma (craniospinal RT), 134 leukemia (72 TBI), and 360 other tumors. Median age differed by tumor group (P < 0.001). Five-year delta height SD score (SDS) (5-year ∆HtSDS; median [10th-90th percentile]) was greatest for craniopharyngioma, 1.6 (0.3-3.0); for medulloblastoma, 5-year ∆HtSDS 0.9 (0.0-1.9); for leukemia 5-year ∆HtSDS, after TBI (0.3, 0-0.7) versus without RT (0.5, 0-0.9), direct comparison P < 0.001. Adverse events included 40 treatment-related, but none unexpected.

CONCLUSIONS

TBI for leukemia had significant impact on growth response to GHT. Medulloblastoma survivors had intermediate GHT response, whereas craniopharyngioma cranial RT did not alter GHT response. Both craniospinal and epiphyseal irradiation negatively affect growth response to GH therapy compared with only cranial RT or no RT.

Undernutrition and Pubertal Timing in Female Survivors of Medulloblastoma and Other Embryonal Tumors

CONTEXT

Children with brain tumors may have pubertal onset at an inappropriately young chronologic age. Hypothalamic-pituitary irradiation ≥18Gy has been found to be a risk factor; age at irradiation is associated with pubertal timing. However, the underlying mechanisms are unknown.

OBJECTIVE

To determine the impact of body mass index (BMI) and catch-up growth on pubertal timing in females treated for medulloblastoma and other embryonal tumors.

DESIGN, SETTING, AND PATIENTS

Retrospective cohort analysis of 90 female patients treated for medulloblastoma and other embryonal tumors at Dana-Farber Cancer Institute/Boston Children's Hospital from 1996 to 2016. Eighteen individuals met inclusion criteria, with a mean ± SD follow-up period of 11.9 ± 3.4 years.

MAIN OUTCOME MEASURES

Multiple linear regression models for age at pubertal onset and bone age discrepancy from chronologic age at pubertal onset assessed the joint influences of age at irradiation, hypothalamic irradiation dose, undernutrition duration, BMI standard deviation score (SDS) at pubertal onset, and catch-up BMI SDS.

RESULTS

The mean ± SD age of pubertal onset was 9.2 ± 1.3 years and hypothalamic radiation dose was 31.9 ± 9.9 Gy. There was a direct relationship between age at irradiation and age at pubertal onset (β = 0.323 ± 0.144 [standard error] year per year; P = 0.04) that was significantly attenuated after adjusting for BMI SDS at pubertal onset (P = 0.5) and catch-up BMI SDS (P = 0.08), suggesting that BMI is a mediator.

CONCLUSIONS

Both absolute and catch-up BMI SDS at pubertal onset are significant mediators of pubertal timing and bone age discrepancy in pediatric medulloblastoma and other embryonal tumors, and thus, are targetable risk factors to optimize pubertal timing.

Radiations and female fertility

Hundreds of thousands of young women are diagnosed with cancer each year, and due to recent advances in screening programs, diagnostic methods and treatment options, survival rates have significantly improved. Radiation therapy plays an important role in cancer treatment and in some cases it constitutes the first therapy proposed to the patient. However, ionizing radiations have a gonadotoxic action with long-term effects that include ovarian insufficiency, pubertal arrest and subsequent infertility. Cranial irradiation may lead to disruption of the hypothalamic-pituitary-gonadal axis, with consequent dysregulation of the normal hormonal secretion. The uterus might be damaged by radiotherapy, as well. In fact, exposure to radiation during childhood leads to altered uterine vascularization, decreased uterine volume and elasticity, myometrial fibrosis and necrosis, endometrial atrophy and insufficiency. As radiations have a relevant impact on reproductive potential, fertility preservation procedures should be carried out before and/or during anticancer treatments. Fertility preservation strategies have been employed for some years now and have recently been diversified thanks to advances in reproductive biology. Aim of this paper is to give an overview of the various effects of radiotherapy on female reproductive function and to describe the current fertility preservation options.

Late Effects of Therapy in Childhood Acute Lymphoblastic Leukemia Survivors

Over the last 50 years, the survival rates in children with acute lymphoblastic leukemia (ALL) have increased remarkably. The optimal use of antileukemic agents in cooperative group protocols, central nervous system-directed treatment, improvements in supportive care, and recognition of biological, clinical, and treatment response characteristics that predict patients with a higher or a lower risk of treatment failure have improved 5-year event-free survival rates, reaching more than 85%, and 5-year overall survival rates, reaching more than 90%. Consequently, it has become increasingly important to characterize the occurrence of long-term late effects. ALL treatments have been associated with increased risks for adverse outcomes such as late mortality, secondary malignancies, and neurological, cardiac, endocrine, and social/psychological disorders. In recent decades, cooperative groups in Europe and in the United States have provided essential information about the long-term effects of ALL therapy, giving recommendations for screening as well as facilitating new approaches for reducing late-term morbidity and mortality. Current frontline protocols continue to examine ways to lower the intensity and amount of therapy to reduce late effects, whereas survivorship studies attempt to predict such adverse effects precisely and develop targeted prevention and treatment strategies.

Pubertal development and primary ovarian insufficiency in female survivors of embryonal brain tumors following risk-adapted craniospinal irradiation and adjuvant chemotherapy

BACKGROUND

Female survivors of central nervous system (CNS) tumors are at an increased risk for gonadal damage and variations in the timing of puberty following radiotherapy and alkylating agent-based chemotherapy.

PROCEDURE

Clinical and laboratory data were obtained from 30 evaluable female patients with newly diagnosed embryonal CNS tumors treated on a prospective protocol (SJMB 96) at St. Jude Children's Research Hospital (SJCRH). Pubertal development was evaluated by Tanner staging. Primary ovarian insufficiency (POI) was determined by Tanner staging and FSH level. Females with Tanner stage I-II and FSH > 15 mIU/ml, or Tanner stage III-V, FSH > 25 mIU/ml and FSH greater than LH were defined to have ovarian insufficiency. Recovery of ovarian function was defined as normalization of FSH without therapeutic intervention.

RESULTS

Median length of follow-up post completion of therapy was 7.2 years (4.0-10.8 years). The cumulative incidence of pubertal onset was 75.6% by the age of 13. Precocious puberty was observed in 11.1% and delayed puberty in 11.8%. The cumulative incidence of POI was 82.8%, though recovery was observed in 38.5%.

CONCLUSIONS

Treatment for primary CNS embryonal tumors may cause variations in the timing of pubertal development, impacting physical and psychosocial development. Female survivors are at risk for POI, a subset of whom will recover function over time. Further refinement of therapies is needed in order to reduce late ovarian insufficiency. Pediatr Blood Cancer 2015;62:329-334. © 2014 Wiley Periodicals, Inc.

Fertility Preservation for Prepubertal Girls: Update and Current Challenges

With increasing rates of diagnosis of childhood cancers and the evolution of more effective treatment options resulting in prolonged life spans, fertility preservation counseling is an integral component of the discussion at the time of diagnosis of childhood cancers. The primary fertility preservation option that exists for prepubertal girls is ovarian tissue cryopreservation. Although ovarian tissue cryopreservation is still considered to be experimental in nature, live births have resulted from orthotopic tissue transplantation. Fertility preservation should be offered to all prepubertal girls at high-risk for premature ovarian failure as a result of gonadotoxic treatment. Ethical and legal questions surrounding these issues must be considered as more and more pediatric patients pursue fertility preservation.

Female reproductive health after childhood, adolescent, and young adult cancers: guidelines for the assessment and management of female reproductive complications

PURPOSE

As more young female patients with cancer survive their primary disease, concerns about reproductive health related to primary therapy gain relevance. Cancer therapy can often affect reproductive organs, leading to impaired pubertal development, hormonal regulation, fertility, and sexual function, affecting quality of life.

METHODS

The Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancer (COG-LTFU Guidelines) are evidence-based recommendations for screening and management of late effects of therapeutic exposures. The guidelines are updated every 2 years by a multidisciplinary panel based on current literature review and expert consensus.

RESULTS

This review summarizes the current task force recommendations for the assessment and management of female reproductive complications after treatment for childhood, adolescent, and young adult cancers. Experimental pretreatment as well as post-treatment fertility preservation strategies, including barriers and ethical considerations, which are not included in the COG-LTFU Guidelines, are also discussed.

CONCLUSION

Ongoing research will continue to inform COG-LTFU Guideline recommendations for follow-up care of female survivors of childhood cancer to improve their health and quality of life.

Male reproductive health after childhood, adolescent, and young adult cancers: a report from the Children's Oncology Group

The majority of children, adolescents, and young adults diagnosed with cancer will become long-term survivors. Although cancer therapy is associated with many adverse effects, one of the primary concerns of young male cancer survivors is reproductive health. Future fertility is often the focus of concern; however, it must be recognized that all aspects of male health, including pubertal development, testosterone production, and sexual function, can be impaired by cancer therapy. Although pretreatment strategies to preserve reproductive health have been beneficial to some male patients, many survivors remain at risk for long-term reproductive complications. Understanding risk factors and monitoring the reproductive health of young male survivors are important aspects of follow-up care. The Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancer (COG-LTFU Guidelines) were created by the COG to provide recommendations for follow-up care of survivors at risk for long-term complications. The male health task force of the COG-LTFU Guidelines, composed of pediatric oncologists, endocrinologists, nurse practitioners, a urologist, and a radiation oncologist, is responsible for updating the COG-LTFU Guidelines every 2 years based on literature review and expert consensus. This review summarizes current task force recommendations for the assessment and management of male reproductive complications after treatment for childhood, adolescent, and young adult cancers. Issues related to male health that are being investigated, but currently not included in the COG-LTFU Guidelines, are also discussed. Ongoing investigation will inform future COG-LTFU Guideline recommendations for follow-up care to improve health and quality of life for male survivors.

Endocrine effects of Fukushima: Radiation-induced endocrinopathy

The unfortunate accidents of Chernobyl and Fukushima have led to an enormous amount of radioactive material being released into the atmosphere. Radiation exposure to the human body may be as a result of accidents, such as those in Chernobyl and Fukushima, or due to occupational hazards, such as in the employees of nuclear plants, or due to therapeutic or diagnostic procedures. These different sources of radiations may affect the human body as a whole or may cause localized damage to a certain area of the body, depending upon the extent and dosage of the irradiation. More or less every organ is affected by radiation exposure. Some require a higher dose to be affected while others may be affected at a lower dose. All the endocrine glands are susceptible to damage by radiation exposure; however, pituitary, thyroid and gonads are most likely to be affected. In addition to the endocrine effects, the rates of birth defects and carcinomas may also be increased in the population exposed to excessive radiation.

Gonadotropin-dependent precocious puberty: neoplastic causes and endocrine considerations

Premature activation of the hypothalamic-pituitary-gonadal (HPG) axis manifests as gonadotropin-dependent precocious puberty. The mechanisms behind HPG activation are complex and a clear etiology for early activation is often not elucidated. Though collectively uncommon, the neoplastic and developmental causes of gonadotropin-dependent precocious puberty are very important to consider, as a delay in diagnosis may lead to adverse patient outcomes. The intent of the current paper is to review the neoplastic and developmental causes of gonadotropin-dependent precocious puberty. We discuss the common CNS lesions and human chorionic gonadotropin-secreting tumors that cause sexual precocity, review the relationship between therapeutic radiation and gonadotropin-dependent precocious puberty, and finally, provide an overview of the therapies available for height preservation in this unique patient population.

Abnormal timing of menarche in survivors of central nervous system tumors: A report from the Childhood Cancer Survivor Study

BACKGROUND

Children who receive high-dose radiotherapy to the hypothalamic-pituitary (H-P) axis may be at risk for both early and late puberty. To the authors' knowledge, data regarding the risk of altered timing of menarche after higher dose radiotherapy (RT), as used in the treatment of central nervous system (CNS) tumors, are limited.

METHODS

The authors evaluated 235 female survivors of CNS tumors, diagnosed between 1970 and 1986, and >1000 sibling controls who were participants in the Childhood Cancer Survivor Study, and provided self-reported data concerning age at menarche.

RESULTS

Survivors of CNS tumors were more likely to have onset of menarche before age 10 years compared with their siblings (11.9% vs 1.0%) (odds ratio [OR], 14.1; 95% confidence interval [95% CI], 7.0-30.9). Of the 138 survivors who received RT to the H-P axis, 20 (14.5%) had onset of menarche before age 10 years, compared with 4.3% of those who did not receive RT (OR, 3.8; 95% CI, 1.2-16.5). Age <or=4 years at the time of diagnosis was associated with an increased risk (OR, 4.0; 95% CI, 1.7-10.0) of early menarche. In addition, survivors of CNS tumors were more likely than siblings to have onset of menarche after age 16 years (10.6% vs 1.9%) (OR, 6.6; 95% CI, 3.4-11.4). Doses of RT to the H-P axis >50 gray OR, 9.0; 95% CI, 2.3-59.5) and spinal RT conferred an increased risk of late menarche, as did older age (>10 years) at the time of diagnosis (OR, 3.0; 95% CI, 1.3-7.0).

CONCLUSIONS

Survivors of CNS tumors are at a significantly increased risk of both early and late menarche associated with RT exposure and age at treatment.

Impact of radiotherapy on fertility, pregnancy, and neonatal outcomes in female cancer patients

PURPOSE

Radiation has many potential long-term effects on cancer survivors. Female cancer patients may experience decreased fertility depending on the site irradiated. Oncologists should be aware of these consequences and discuss options for fertility preservation before initiating therapy.

METHODS AND MATERIALS

A comprehensive review of the existing literature was conducted. Studies reporting the outcomes for female patients treated with cranio-spinal, abdominal, or pelvic radiation reporting fertility, pregnancy, or neonatal-related outcomes were reviewed.

RESULTS

Cranio-spinal irradiation elicited significant hormonal changes in women that affected their ability to become pregnant later in life. Women treated with abdomino-pelvic radiation have an increased rate of uterine dysfunction leading to miscarriage, preterm labor, low birth weight, and placental abnormalities. Early menopause results from low-dose ovarian radiation. Ovarian transposition may decrease the rates of ovarian dysfunction.

CONCLUSIONS

There is a dose-dependent relationship between ovarian radiation therapy (RT) and premature menopause. Patients treated with RT must be aware of the impact of treatment on fertility and explore appropriate options.

Hypopituitarism following radiotherapy

Deficiencies in anterior pituitary hormones secretion ranging from subtle to complete occur following radiation damage to the hypothalamic-pituitary (h-p) axis, the severity and frequency of which correlate with the total radiation dose delivered to the h-p axis and the length of follow up. Selective radiosensitivity of the neuroendocrine axes, with the GH axis being the most vulnerable, accounts for the high frequency of GH deficiency, which usually occurs in isolation following irradiation of the h-p axis with doses less than 30 Gy. With higher radiation doses (30-50 Gy), however, the frequency of GH insufficiency substantially increases and can be as high as 50-100%. Compensatory hyperstimulation of a partially damaged h-p axis may restore normality of spontaneous GH secretion in the context of reduced but normal stimulated responses; at its extreme, endogenous hyperstimulation may limit further stimulation by insulin-induced hypoglycaemia resulting in subnormal GH responses despite normality of spontaneous GH secretion in adults. In children, failure of the hyperstimulated partially damaged h-p axis to meet the increased demands for GH during growth and puberty may explain what has previously been described as radiation-induced GH neurosecretory dysfunction and, unlike in adults, the ITT remains the gold standard for assessing h-p functional reserve. Thyroid-stimulating hormone (TSH) and ACTH deficiency occur after intensive irradiation only (>50 Gy) with a long-term cumulative frequency of 3-6%. Abnormalities in gonadotrophin secretion are dose-dependent; precocious puberty can occur after radiation dose less than 30 Gy in girls only, and in both sexes equally with a radiation dose of 30-50 Gy. Gonadotrophin deficiency occurs infrequently and is usually a long-term complication following a minimum radiation dose of 30 Gy. Hyperprolactinemia, due to hypothalamic damage leading to reduced dopamine release, has been described in both sexes and all ages but is mostly seen in young women after intensive irradiation and is usually subclinical. A much higher incidence of gonadotrophin, ACTH and TSH deficiencies (30-60% after 10 years) occur after more intensive irradiation (>60 Gy) used for nasopharyngeal carcinomas and tumors of the skull base, and following conventional irradiation (30-50 Gy) for pituitary tumors. The frequency of hypopituitarism following stereotactic radiotherapy for pituitary tumors is mostly seen after long-term follow up and is similar to that following conventional irradiation. Radiation-induced anterior pituitary hormone deficiencies are irreversible and progressive. Regular testing is mandatory to ensure timely diagnosis and early hormone replacement therapy.

Long-Term Health Status Among Survivors of Childhood Cancer: Does Sex Matter?

Increasing numbers of children diagnosed with cancer will survive their primary malignancy. Within this growing population of long-term survivors, considerable effort has been put forth to identify treatment-related risks for adverse health-related outcomes, such as exposure to alkylating agents, anthracyclines, radiotherapy, and surgery. Patient sex has been identified as a risk factor for numerous long-term adverse outcomes, with female sex more commonly associated with higher risks. In this article, we review the literature, which generally supports associations between female sex and cognitive dysfunction after cranial irradiation, cardiovascular outcomes, obesity, radiation-associated differences in pubertal timing, development of primary hypothyroidism, breast cancer as a second malignant neoplasm and suggests an increased prevalence for the development of osteonecrosis among females. Results of this review support future investigations to further define sex as a risk factor for other common treatment-specific exposures and outcomes. Additionally, research should focus on understanding the underlying biologic and physiological basis of these sex-specific risks. Historically, evidence from both basic science and clinical research has been used to develop risk-stratified therapy, allowing reduction of toxic therapies to low-risk patients without compromising overall survival. With greater knowledge of sex-specific risks, the potential application of sex-specific therapy designed to avoid poor long-term adverse outcomes may become a viable strategy.

Hypopituitarism as a consequence of brain tumours and radiotherapy

Radiation-induced damage to the hypothalamic-pituitary (h-p) axis is associated with a wide spectrum of subtle and frank abnormalities in anterior pituitary hormones secretion. The frequency, rapidity of onset and the severity of these abnormalities correlate with the total radiation dose delivered to the h-p axis, as well as the fraction size, younger age at irradiation, prior pituitary compromise by tumour and/or surgery and the length of follow up. Whilst, the hypothalamus is the primary site of radiation-induced damage, secondary pituitary atrophy evolves with time due to impaired secretion of hypothalamic trophic factors and/or time-dependent direct radiation-induced damage. Selective radiosensitivity in the neuroendocrine axes with the GH axis being the most vulnerable to radiation damage accounts for the high frequency of GH deficiency, which usually occurs in isolation following irradiation of the h-p axis with doses less than 30 Gy. With higher radiation doses (30-50 Gy), however, the frequency of GH insufficiency substantially increases and can be as high as 50-100%, and TSH and ACTH deficiency start to occur with a long-term cumulative frequency of 3-6%. Abnormalities in gonadotrophin secretion are dose-dependent; precocious puberty can occur after radiation dose less than 30 Gy in girls only, and in both sexes equally with a radiation dose of 30-50 Gy. Gonadotrophin deficiency occurs infrequently and is usually a long-term complication following a minimum radiation dose of 30 Gy. Hyperprolactinemia, due to hypothalamic damage leading to reduced dopamine release, has been described in both sexes and all ages but is mostly seen in young women after intensive irradiation and is usually subclinical. A much higher incidence of gonadotrophin, ACTH and TSH deficiencies (30-60% after 10 years) occur after more intensive irradiation (>70 Gy) used for nasopharyngeal carcinomas and tumours of the skull base and following conventional irradiation (30-50 Gy) for pituitary tumours. Radiation-induced anterior pituitary hormone deficiencies are irreversible and progressive. Regular testing is mandatory to ensure timely diagnosis and early hormone replacement therapy to improve linear growth and prevent short stature in children cured from cancer, and in adults preserve sexual function, prevent ill health and osteoporosis and improve the quality of life.

Endocrine dysfunctions in patients treated for brain tumors: incidence and guidelines for management

Endocrine alterations are frequently found in patients undergoing treatment for CNS tumors. Careful follow-up aimed at the early detection of recurrences, with life-long monitor of hypothalamus-pituitary (HP) function, will also reveal any endocrine dysfunctions; indeed, their appropriate diagnosis and treatment may determine a significant improvement in the quality of life of these patients.

Growth and puberty after growth hormone treatment after irradiation for brain tumours

The impact of treatment with either cranial or craniospinal irradiation with or without cytotoxic chemotherapy for a brain tumour distant from the hypothalamic-pituitary axis was assessed in 29 children who had reached final height. All had received growth hormone treatment for radiation induced growth hormone deficiency. Final height, segmental growth during puberty, and duration of puberty were studied. Both craniospinal irradiation and the use of chemotherapy resulted in a significant and equal reduction in final height; this effect in those children who received both craniospinal irradiation and chemotherapy was additive. The degree of height loss was related to the age at irradiation, the most profound effect on final height occurring in the youngest at irradiation. The mean duration of puberty from G2-G4/B2-B4 (1.97 years) was not significantly different from the duration of puberty in normal children. Growth hormone increases growth velocity in children with radiation induced growth hormone deficiency but their final height is significantly less than their mid-parental height. The use of spinal irradiation and chemotherapy in the original treatment of brain tumours has a marked effect on growth which is not overcome with the use of growth hormone treatment in current doses. Early puberty of normal duration contributes to poor growth.