Leydig cell damage after testicular irradiation for lymphoblastic leukaemia

Impact of Radiation on Male Fertility

In today's time, environmental aspects, lifestyle changes, and person's health coalesce to form stupendous impact on the fertility. All of us are knowingly or unknowingly exposed to several types of radiation. These can lead to collection of early and delayed adverse effects of which infertility is one. A spurt in the number of cases of male infertility may be attributed to intense exposure to heat, pesticides, radiations, radioactivity, and other hazardous substances. Radiation both ionizing and non-ionizing can lead to adverse effects on spermatogenesis. Though thermal and non-thermal interactions of radiation with biological tissue can't be ruled out, most studies emphasize on the generation of reactive oxygen species (ROS). In addition, radiation pathophysiology also involves the role of kinases in cellular metabolism, endocrine system, genotoxicity, and genomic instability. In this study, we intend to describe a detailed literature on the impact of ionizing and non-ionizing radiation on male reproductive system and understand its consequences leading to the phenomenon of male infertility.

Androgens During Infancy, Childhood, and Adolescence: Physiology and Use in Clinical Practice

We provide an in-depth review of the role of androgens in male maturation and development, from the fetal stage through adolescence into emerging adulthood, and discuss the treatment of disorders of androgen production throughout these time periods. Testosterone, the primary androgen produced by males, has both anabolic and androgenic effects. Androgen exposure induces virilization and anabolic body composition changes during fetal development, influences growth and virilization during infancy, and stimulates development of secondary sexual characteristics, growth acceleration, bone mass accrual, and alterations of body composition during puberty. Disorders of androgen production may be subdivided into hypo- or hypergonadotropic hypogonadism. Hypogonadotropic hypogonadism may be either congenital or acquired (resulting from cranial radiation, trauma, or less common causes). Hypergonadotropic hypogonadism occurs in males with Klinefelter syndrome and may occur in response to pelvic radiation, certain chemotherapeutic agents, and less common causes. These disorders all require testosterone replacement therapy during pubertal maturation and many require lifelong replacement. Androgen (or gonadotropin) therapy is clearly beneficial in those with persistent hypogonadism and self-limited delayed puberty and is now widely used in transgender male adolescents. With more widespread use and newer formulations approved for adults, data from long-term randomized placebo-controlled trials are needed to enable pediatricians to identify the optimal age of initiation, route of administration, and dosing frequency to address the unique needs of their patients.

Leydig cell failure with testicular radiation doses <20Gy: The clinical effects of total body irradiation conditioned haematopoietic stem cell transplantation for childhood leukaemia during long-term follow-up

OBJECTIVE

Testosterone replacement is generally considered likely to be required only at testicular radiation doses in excess of 20Gy. Long-term data are not available for patients receiving 9-14.4Gy as part of Total Body Irradiation in childhood.

DESIGN

Retrospective cohort study.

DATA COLLECTION

notes review, laboratory results, prescription of testosterone.

PATIENTS

Forty-two of 96 boys who received Total Body Irradiation (9-14.4Gy) and Haematopoietic Stem Cell Transplantation for childhood leukaemia at Great Ormond Street Hospital between 1981-2011 and survived >5 years.

MEASUREMENTS

The serum concentrations of testosterone and gonadotrophins and the prescription of testosterone were recorded.

RESULTS

Of the 42 boys included, 37 (88%) entered puberty spontaneously and 5 required induction. Median length of follow-up was 19.4 years (range 5-33.1). At last follow-up, 23 of the 37 (62%) with spontaneous puberty were receiving testosterone replacement and 4 of the 5 (80%) with induced puberty.

CONCLUSION

This study with the benefit of long follow-up indicates that Leydig cell failure occurs with radiation doses <20Gy. It may occur many years after irradiation and mandates long-term screening for hypogonadism.

Leydig Cell Function in Male Survivors of Childhood Cancer: A Report From the St Jude Lifetime Cohort Study

PURPOSE

Direct assessment of Leydig cell function in childhood cancer survivors has been limited. The objectives of this study were to describe the prevalence of and risk factors for Leydig cell failure (LCF), Leydig cell dysfunction (LCD), and associated adverse health outcomes.

PATIENTS AND METHODS

In this retrospective study with cross-sectional health outcomes analysis, we evaluated 1,516 participants (median age, 30.8 years) at a median of 22.0 years after cancer diagnosis. LCF was defined as serum total testosterone less than 250 ng/dL (or 8.67 nmol/L) and luteinizing hormone greater than 9.85 IU/L, and LCD by testosterone as 250 ng/dL or greater and luteinizing hormone greater than 9.85 IU/L. Polytomous logistic regression evaluated associations with demographic and treatment-related risk factors. Log-binomial regression evaluated associations with adverse physical and psychosocial outcomes. Piecewise exponential models assessed the association with all-cause mortality.

RESULTS

The prevalence of LCF and LCD was 6.9% and 14.7%, respectively. Independent risk factors for LCF included an age of 26 years or older at assessment, testicular radiotherapy at any dose, and alkylating agents at cyclophosphamide equivalent doses of 4,000 mg/m² or greater. The risk increased with older age, higher doses of testicular radiotherapy, and cyclophosphamide equivalent doses. LCF was significantly associated with abdominal obesity, diabetes mellitus, erectile dysfunction, muscle weakness, and all-cause mortality. LCD was associated with unilateral orchiectomy and the same risk factors as LCF; no significant associations were found with adverse physical or psychosocial outcomes.

CONCLUSION

Older age, testicular radiotherapy, and exposure to alkylating agents were associated with LCF, which was associated with adverse physical and psychosexual outcomes. LCD, although having similar risk factors, was not associated with adverse health outcomes. Additional studies are needed to investigate the role of sex hormone replacement in mitigating the burden from adverse outcomes in survivors.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Fertility Issues in Pediatric Urology

Improved understanding of the pathogenesis and natural history of many urologic disorders, as well as advances in fertility preservation techniques, has increased the awareness of and options for management of fertility threats in pediatric patients. In children, fertility may be altered by oncologic conditions, by differences in sexual differentiation, by gonadotoxic drugs and other side effects of treatment for nonurologic disorders, and by urologic conditions, such as varicocele and cryptorchidism. Although fertility concerns are best addressed in a multidisciplinary setting, pediatric urologists should be aware of the underlying pathophysiology and management options to properly counsel and advocate for patients.

Isolated late testicular relapse of B-cell acute lymphoblastic leukemia treated with intensive systemic chemotherapy and response-based testicular radiation: A Children's Oncology Group study

BACKGROUND

The incidence of isolated testicular relapse (ITR) of acute lymphoblastic leukemia (ALL) has decreased with contemporary treatment strategies, but outcomes are suboptimal with a 58% 5-year overall survival (OS). This study aimed to improve outcome in patients with ITR of B-cell ALL (B-ALL) occurring after 18 months of first clinical remission using intensive systemic chemotherapy and to decrease long-term sequelae by limiting use of testicular radiation.

PROCEDURE

Forty patients in first ITR of B-ALL were enrolled. Induction (dexamethasone, vincristine, daunorubicin, and intrathecal triple therapy) was preceded by one dose of high-dose methotrexate (MTX, 5 g/m² ). Following induction, 25 of 26 patients who had persistent testicular enlargement underwent testicular biopsy. Eleven had biopsy-proven disease and received bilateral testicular radiation (24 Gy), whereas twenty-nine did not.

RESULTS

Overall 5-year event-free survival (EFS)/OS was 65.0 ± 8.8%/73.1 ± 8.3%, with 5-year EFS 62.1 ± 11.0% vs. 72.7 ± 14.4% for patients who did not receive radiation therapy (XRT) (n = 29) compared with those who did (n = 11), respectively (P = 0.64). There were six second bone marrow relapses and six second ITRs. The proportion of second relapses was similar in the patients that received testicular radiation and those who did not. However, the 5-year OS was similar for patients who did not receive XRT (72.6 ± 10.2%) compared with those who did (72.7 ± 14.4%) (P = 0.85).

CONCLUSIONS

A 5-year OS rate of 73.1 ± 8.3% was obtained in children with first ITR of B-ALL occurring after 18 months of CR1 (length of first clinical remission) using intensive chemotherapy and limiting testicular radiation.

Testicular damage in children and adolescents treated for malignancy: a short review

Significant advances have been made over recent decades in the treatment of childhood malignancies. These advances had an incredible cost, as an increasing number of young survivors suffer subfertility or infertility, because of the high sensitivity of testicular cells, especially the rapidly dividing germ cells, to cytotoxic drugs and irradiation. Therefore, the impact of treatment on future fertility is of significant concern, both to parents and patients. Assessment of fertility damage in childhood remains problematic. For post-pubertal males, semen analysis represents a good indicator of spermatogenesis and testicular function, and allows for sperm cryopreservation. The available method for prepubertal children is only gonadal tissue cryopreservation. This method is still experimental and raises ethical concerns. Ideally, a multidisciplinary team approach needs to be used in addressing the needs of fertility preservation for this population. Precise knowledge of these issues would help pediatric oncologists and endocrinologists to counsel their patients and inform them for factors and resources that may protect or preserve parenthood options in the future. (www.actabiomedica.it)

Approaches to reduce the long-term burden of treatment-related complications in survivors of childhood cancer

Advances in diagnostics, treatment strategies, and supportive care have contributed to a marked improvement in outcomes for children with cancer. This has resulted in a growing number of long-term childhood cancer survivors. Currently there are over 360,000 individuals who are survivors of childhood cancer in the United States. However, treatment for patients with childhood cancer with chemotherapy, radiation, and/or hematopoietic stem cell transplantation can result in health-related complications that may not become evident until years after completion of treatment. As a result, several initiatives have been established to help standardize the surveillance for treatment-related late effects in childhood cancer survivors. This review highlights emerging concepts related to commonly reported late effects, such as subsequent malignant neoplasms, cardiovascular disease, and endocrinopathies. It also discusses relevant population-based screening strategies to mitigate the long-term health-related burden in vulnerable populations of survivors.

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.

Fertility of male survivors of childhood cancer: a report from the Childhood Cancer Survivor Study

PURPOSE

This study was undertaken to determine the effect of treatment for childhood cancer on male fertility.

PATIENTS AND METHODS

We reviewed the fertility of male Childhood Cancer Survivor Study survivor and sibling cohorts who completed a questionnaire. We abstracted the chemotherapeutic agents administered, the cumulative dose of drug administered for selected drugs, and the doses and volumes of all radiation therapy from medical records. Risk factors for siring a pregnancy were evaluated using Cox proportional hazards models.

RESULTS

The 6,224 survivors age 15 to 44 years who were not surgically sterile were less likely to sire a pregnancy than siblings (hazard ratio [HR], 0.56; 95% CI, -0.49 to 0.63). Among survivors, the HR of siring a pregnancy was decreased by radiation therapy of more than 7.5 Gy to the testes (HR, 0.12; 95% CI, -0.02 to 0.64), higher cumulative alkylating agent dose (AAD) score or treatment with cyclophosphamide (third tertile HR, 0.42; 95% CI, -0.31 to 0.57) or procarbazine (second tertile HR, 0.48; 95% CI, -0.26 to 0.87; third tertile HR, 0.17; 95% CI, -0.07 to 0.41). Compared with siblings, the HR for ever siring a pregnancy for survivors who had an AAD score = 0, a hypothalamic/pituitary radiation dose = 0 Gy, and a testes radiation dose = 0 Gy was 0.91 (95% CI, 0.73 to 1.14; P = .41).

CONCLUSION

This large study identified risk factors for decreased fertility that may be used for counseling male cancer patients.

Evaluating Survivors of Pediatric Cancer

The past 3 decades have seen tremendous improvements in the survival of children diagnosed with cancer, with the 5-year survival rate approaching 80%. This improvement in survival has resulted in a growing population of childhood cancer survivors. Use of cancer therapy at an early age can produce complications that may not become apparent until years later. Approximately two thirds of the survivors of childhood cancer experience at least one late effect and about one fourth experience a late effect that is severe or life-threatening, although psychosocial issues in survivors and family members are often underestimated and may be more prevalent. Long-term complications in childhood cancer survivors, such as impairment in growth and development, neurocognitive dysfunction, cardiopulmonary compromise, endocrine dysfunction, renal impairment, gastrointestinal dysfunction, musculoskeletal sequelae, and subsequent malignancies, are related not only to the specific therapy used but also may be determined by individual host characteristics. We review the known late effects in survivors of childhood in order to suggest reasonable starting points for the evaluation of specific long-term problems in this unique but growing population.

Long-term endocrine effects of cancer treatment: experience of the Royal Children's Hospital, Melbourne

OBJECTIVES

To evaluate the frequency and degree of severity of endocrine late effects in patients treated for childhood cancer and to assess the value of the late effects clinic for continued monitoring of these patients.

METHOD

Data was collected on all patients who attended the late effects clinic at the Royal Children's Hospital (RCH) between 1998-2003. Endocrine function was assessed by clinical and biochemical evaluation at the time of presentation and at ongoing intervals of 3-12 months as clinically indicated.

RESULTS

A total of 249 children attended the late effects clinic. Two hundred and thirty five endocrine diagnoses were made in 155 (62%) patients, of whom 63 patients had multiple endocrinopathies.

CONCLUSION

Our audit supports the need for ongoing prospective surveillance in survivors of childhood cancer. Appropriate and timely interventions in such patients can help to reduce morbidity and improve quality of life.

The incidence of testicular recurrence in boys with acute leukemia treated with total body and testicular irradiation and stem cell transplantation

BACKGROUND

The incidence of testicular recurrence of childhood acute leukemia after total body irradiation (TBI) in conjunction with stem cell transplantation (SCT) has been reported to be as high as 24%. The authors studied the incidence of testicular failure in a large series of male patients who underwent SCT using either TBI and a testicular irradiation boost or chemotherapy alone.

METHODS

One hundred thirty-one boys with either acute myeloid leukemia (AML) or acute lymphocytic leukemia (ALL) were treated with SCT with either TBI with testicular boost (n = 94 patients), TBI without testicular boost (n = 1 patient), or chemotherapy alone (n = 36 patients) between 1991 and 1999.

RESULTS

The median follow-up was 26.5 months (range, 0.6-99.5 months) from the date of bone marrow infusion. Two patients in the study had a primary testicular failure after TBI with testicular boost followed by an umbilical cord blood transplantation. The first patient had ALL, did not engraft, and was rescued with autologous cells. He developed disease in the testicle 15 months afterward and subsequently died. The second patient had Philadelphia chromosome-positive ALL and developed a testicular recurrence 26 months after SCT. He was treated with orchiectomy, further testicular irradiation, and chemotherapy and remained in complete remission > 3 year after his failure. The incidence of testicular failure in boys who received TBI and testicular irradiation who survived > or = 1 year was 4.2%. There were no primary testicular failures reported in boys who received chemotherapy alone.

CONCLUSIONS

Boys with AML or ALL had a low incidence of primary testicular failure when they were treated with TBI plus a testicular boost or with chemotherapy alone.

Late effects among survivors of leukemia during childhood and adolescence

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, accounting for one-third of all cancers occurring in childhood and adolescents. Over the last 3 decades there has been a marked improvement in survival, with 5-year survival rates approaching 80%. With this improvement in survival, increasing attention is now being focused on issues relating to long-term morbidity and mortality associated with the treatments responsible for that increased survival. Because of the young age of these cancer survivors, and thus the potential longevity, the delayed consequences of therapy may have a significant impact on their lives. Long-term sequelae of treatment, such as impaired intellectual and psychomotor functioning, neuroendocrine abnormalities, impaired reproductive capacity, cardiotoxicity, and second malignant neoplasms, are now being reported with increasing frequency in this growing cohort of survivors and knowledge of the late -effects associated with cancer in children and adolescents continues to increase through ongoing research efforts. However, much of the available information relates to outcomes within the first decade following treatment, although information about the longer term outcomes that may occur later in adulthood is emerging as a result of well-conducted, large cohort studies. Through a multi-disciplinary approach to the diagnosis, treatment, and long-term follow-up of pediatric leukemia patients, we can achieve the goal of cure while minimizing the occurrence of long-term adverse outcomes. This review summarizes some of the well-described long-term consequences of therapy among children and adolescents treated for ALL.

Long-term effects of irradiation before adulthood on reproductive function in the male rhesus monkey

Today, many patients, who are often young, undergo total body irradiation (TBI) followed by bone marrow transplantation. This procedure can have serious consequences for fertility, but the long-term intratesticular effects of this treatment in primates have not yet been studied. Testes and epididymides of rhesus monkeys that received doses of 4-8.5 Gy of TBI at 2-4 yr of age were studied 3-8 yr after irradiation. In all irradiated monkeys, at least some seminiferous tubule cross-sections lacked germ cells, indicating extensive stem cell killing that was not completely repaired by enhanced stem cell renewal, even after many years. Testes totally devoid of germ cells were only found in monkeys receiving doses of 8 Gy or higher and in both monkeys that received two fractions of 6 Gy each. By correlating the percentage of repopulated tubules (repopulation index) with testicular weight, it could be deduced that considerable numbers of proliferating immature Sertoli cells were killed by the irradiation. Because of their finite period of proliferation, Sertoli cell numbers did not recover, and potential adult testis size decreased from approximately 23 to 13 g. Most testes showed some dilated seminiferous tubules, indicating obstructed flow of the tubular fluid at some time after irradiation. Also, in 8 of the 29 irradiated monkeys, aberrant, densely packed Sertoli cells were found. The irradiation did not induce stable chromosomal translocations in spermatogonial stem cells. No apparent changes were seen in the epididymides of the irradiated monkeys, and the size of the epididymis adjusted itself to the size of the testis. In the irradiated monkeys, testosterone and estradiol levels were normal, whereas FSH levels were higher and inhibin levels lower when testicular weight and spermatogenic repopulation were low. It is concluded that irradiation before adulthood has considerable long-term effects on the testis. Potential testis size is reduced, repopulation of the seminiferous epithelium is generally not complete, and aberrant Sertoli cells and dilated tubules are formed. The latter two phenomena may have further consequences at still longer intervals after irradiation.

Gonadal and sexual function in men treated for childhood cancer

BACKGROUND

Insofar as a majority of children with malignant diseases are cured, the late effects of treatment are of major importance.

PROCEDURE

A retrospective study was conducted of gonadal and sexual function of 77 adult male survivors of childhood malignancies treated and cured at a single center from 1970 to 1989 and followed for a median of 13 years. The study included an interview, physical examination, sperm test, and hormonal analyses.

RESULTS

One-third of the patients were treated for hematological malignancies, one-third for CNS tumors, and one-third for other malignancies. Eleven patients required androgen substitution after treatment for tumors of the pituitary-hypothalamic region or acute lymphoblastic leukemia including testicular irradiation and/or orchiectomy. In three patients the testicles were removed. The other eight had small testicles, and those providing sperm samples had azoospermia, and sexual function was disturbed in most of them. Most of the remaining 66 patients had small testicles. Normozoospermia was found in 63%, oligozoospermia in 20%, and azoospermia in 17%. Although there was a highly significant correlation between testicular volume and sperm test, 25% of patients with testicles of <10 ml had normozoospermia. Sexual function was normal in 46 patients, and they were married at a frequency comparable to the normal population. Twenty-one patients had no signs of gonadal dysfunction.

CONCLUSIONS

Patients treated for tumors in the hypothalamic-pituitary region or treated with testicular irradiation or with high doses of alkylating agents had severe gonadal and sexual dysfunction. Most of the other patients had good prospects for preserved gonadal and sexual function.

Survival and endocrine outcome after testicular relapse in acute lymphoblastic leukaemia

Survival and endocrine status in a cohort of boys with acute lymphoblastic leukaemia (ALL) who started treatment between 1972 and 1987 and subsequently developed a testicular relapse were analysed. During this period there was a significant improvement in the overall event free survival for boys, but no significant decrease in the testicular relapse rate. Thirty three boys had an apparently isolated testicular relapse, whereas 21 boys had a combined relapse. The event free survival for boys with an isolated testicular relapse was 59% at six years (95% confidence interval (CI) 42 to 74%). The event free survival for the 16 patients with a combined relapse who received a second course of treatment was 32% (95% CI 17 to 60%). Those patients receiving adequate second line treatment for an isolated testicular relapse whose first remission was longer than or equal to two years had an event free survival of 82% (95% CI 63 to 93%) at six years. No boy relapsing within two years from diagnosis has survived. Endocrine late effects are significant, with 82% of the boys requiring hormonal treatment at some stage for induction of puberty or continuing pubertal maturation, or both. It is concluded that, despite the increasing intensity of initial treatment for ALL, isolated testicular relapse is treatable by conventional means in most patients. Careful endocrine follow up of these patients is essential as most will require hormone replacement treatment.

Gonadal function of young adults after therapy of malignancies during childhood or adolescence

As the survival rate of children with malignancies has increased over past decades, the follow up of adult long-term survivors (LTS) of childhood cancer should focus on late effects of disease and treatment. Gonadal function was therefore studied in 54 LTS (aged 17-29 years; 33 male, 21 female) 2-18 years after treatment for malignancies during childhood or adolescence. To analyse the sensitivity of different diagnostic methods, tests of endocrine function (n = 52), spermiograms (n = 14), gynaecological status (n = 20) and ultrasonography of the gonads (n = 53) were compared with the results of equivalent tests in 23 age-matched normal controls (12 male, 11 female). There were no differences between male and female LTS concerning age at diagnosis, gonadal dose of irradiation (XRT) and doses of applied chemotherapeutic agents. Whereas male LTS had elevated levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) before (P < 0.05; P < 0.001) and after (P < 0.01; P < 0.001) stimulation with gonadotropin releasing hormone, female LTS exhibited normal endocrine function. Accordingly, male patients exhibited lower testicular volumes than normal controls, as measured with a Prader orchidometer (P < 0.01) or by ultrasonography (P < 0.001). Gynaecological status and ultrasonography of the gonads were normal in female LTS and controls. Whereas all spermiograms of normal controls (n = 8) showed a normal sperm cell density (SCD), only 2 of 14 male LTS exhibited a normal SCD (P < 0.001). Azoospermic LTS (n = 9) had been treated more often with alkylating agents and had received higher (P < 0.05) gonadal doses of XRT. All male LTS with testicular volumes below the normal range (< 13 ml) and basal FSH levels above the normal range (> 10 IU/l) exhibited azoospermia, whereas LTS with normal values for testicular volume and basal FSH had a normal SCD.

CONCLUSION

A sex-specific susceptibility for gonadal damage after treatment for malignancies might be responsible, in part, for the impaired gonadal function of male LTS. Therapy with alkylating agents and/or high gonadal doses of XRT were important risk factors for azoospermia. A simple method to estimate potential fertility in individual LTS is to measure testicular volume, using a Prader orchidometer, and basal FSH serum levels.

Efficacy and toxicity of radiation in preparative regimens for pediatric stem cell transplantation. II: Deleterious consequences

There has been a dramatic improvement in the treatment of both allogeneic and autologous stem cell transplants, especially in children and young adults. However, attempts to apply more intensive conditioning treatments to the more refractory pediatric malignancies have also increased the risks of deleterious consequences. This review examines the risks, and reports important variations in the toxic effects of using different conditioning techniques.

Pubertal growth in response to testosterone replacement therapy for radiation-induced Leydig cell failure

The adolescent growth pattern of eight boys, who had puberty induced with androgen replacement therapy following radiation-induced Leydig cell failure, was studied from induction of puberty at a mean age of 13.1 years (range 11.6-14.5) to final height at mean age of 18.8 years (range 17.7-20.3). The mean gains during puberty (SD) for standing height, sitting height, and sub-ischial leg length were 18.56 cm (3.98), 10.46 cm (2.39), and 8.1 cm (2.01) respectively, which were significantly reduced compared with normal Tanner standards (P < .001). The peak velocity for each parameter occurred in the 1st year of induced puberty in contrast to the pattern in normal adolescence, although the mean peak velocity for each auxological parameter was not significantly different from the normal Tanner standards. The mean adult standing height (SD), 167.5 cm (9.88), and mean adult leg length (SD), 80.8 cm (6.19), were not significantly different from the normal Tanner standards, whereas the mean adult sitting height (SD), 86.7 cm (4.78), was shorter (P < .001). Three of the eight patients had a leg length standard deviation score less sitting height standard deviation score in excess of +2.96 suggesting the presence of significant skeletal disproportion. Seven of the eight boys reached target genetic height, though in six, the final height was below mid-parental height (P < .05). The modest loss in height potential was mainly due to radiation-induced skeletal dysplasia attenuating the growth of the spine. The families of boys with radiation-induced Leydig cell failure requiring androgen replacement therapy can be reasonably optimistic about height prognosis as seven of the eight boys reached target genetic height.

Fertility and pregnancy after treatment for cancer during childhood or adolescence

Because most children and adolescents with cancer now survive, issues regarding the late effects of therapy, including fertility and the health of offspring, are increasingly important. This article summarizes the literature regarding issues related to fertility in survivors of cancer, including actual fertility, gonadal function, menarche, menopause, and birth defects and cancer in the offspring. Radiation therapy to the gonads and alkylating agent chemotherapy, either alone or in combination, impair actual fertility in survivors of childhood and adolescent cancer. Males are particularly affected by alkylating agents, and females who have had radiation therapy to the abdomen have decreased fertility and an increased risk of adverse pregnancy outcomes. Consequently, these women should be followed up as high-risk obstetrical patients. Offspring of survivors of cancer appear to have little risk of childhood cancer or birth defects. Thus, in most instances, survivors of cancer should not be discouraged from having children and can expect a good outcome of pregnancy. This article concludes with advice to survivors and clinicians who counsel survivors.

Male fertility in long-term survivors of childhood acute lymphoblastic leukaemia

To study long-term testicular function following the treatment of acute lymphoblastic leukaemia (ALL) in childhood, 37 young adult males were assessed at two separate time points. The initial assessment was made by a wedge testicular biopsy after completion of treatment (median 9.7 years; range 4.1-16.3 years) and the subsequent assessment (median 18.6 years; range 15.4-26.8 years) consisted of the clinical examination of pubertal stage, measurement of serum gonadotrophins and testosterone and, in 19 patients, semen analysis. All 37 men completed pubertal development normally and had a testosterone concentration within the normal adult range. Six men showed evidence of severe damage to the seminiferous epithelium, five were azoospermic and one, who did not provide semen for analysis, had a reduced mean testicular volume (11 mls; normal greater than or equal to 15 mls) and a raised basal FSH level (13 UI 1-1; normal less than or equal to 6 IU 1-1). All six men with germ-cell damage had received either cyclophosphamide or both cyclophosphamide and cytosine arabinoside as part of their chemotherapy regimen. Approximately 10.7 years earlier all 37 men had undergone a testicular biopsy after completion of their chemotherapy. Morphological damage to the seminiferous epithelium had been calculated by estimating the tubular fertility index (TFI), which is the percentage of seminiferous tubules containing identifiable spermatogonia (age-matched normal = 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Gonadal function after 12-Gy testicular irradiation in childhood acute lymphoblastic leukaemia

Gonadal function was assessed in 15 boys with acute lymphoblastic leukaemia (ALL) who had received testicular irradiation. The dose to the testes was 12 Gy in 12, 15 Gy in 1, and 24 Gy in 2 cases. All of those who had received 12 or 15 Gy had normal Leydig cell function, although high levels of gonadotropins suggest subclinical Leydig cell damage. The 2 who had 24 Gy had Leydig cell failure. All who were old enough to produce a semen specimen were azoospermic.

Delayed effects of doxorubicin on spermatogenesis and endocrine function in rats

Doxorubicin was administered to adult male Wistar rats (1 mg/kg body weight, three times per week, for one, two, three, or four weeks) in order to examine testicular and reproductive endocrine toxicity 56 days after treatment. Doxorubicin treatment produced persistent dose-related reductions in testis, epididymis, and seminal vesicle weights, but did not alter ventral prostate weight. Testis and serum testosterone levels were not significantly affected by treatment, but serum LH was increased after treatment, and binding of iodinated hCG to testicular LH receptors was reduced. Serum FSH was elevated by the two lower total administered doses, but was not different from controls after treatment with the two higher total doses. There was clear histologic evidence of dose-dependent damage to the seminiferous tubules, which was reflected by decreased testicular and epididymal sperm content and by reductions in the stem-cell survival index. These results indicate that doxorubicin produces significant and persistent damage to the endocrine and spermatogenic compartments of the testis.

The effect of total body irradiation and bone marrow transplantation during childhood and adolescence on growth and endocrine function

Seventeen children (11 M, 6 F) with acute leukaemia and myeloproliferative disorders were investigated for growth and endocrine dysfunction. All had undergone bone marrow transplantation prepared with cyclophosphamide and single fraction total body irradiation (900-1000 cGy) between 1.5 and 3.8 (mean 2.2) years previously. The majority of children exhibited growth failure, which was of multiple aetiology. Ten patients, of whom eight had had previous prophylactic cranial irradiation, had evidence of growth hormone deficiency based on the reduced growth hormone response to insulin induced hypoglycaemia. Three patients had evidence of hypothalamic damage as shown by their growth hormone response to 200 micrograms GHRH (1-29) NH2 intravenously. Gonadal failure was common, assessed clinically, and biochemically by basal gonadotrophin and sex steroid concentrations. All four girls of adolescent age (10.6-14.1 years) had ovarian failure requiring sex steroid replacement. Of the eight boys of adolescent age (12.3-18.3 years), two had testicular failure requiring sex steroid supplements. Both of these had had previous testicular irradiation. Five others had compensated gonadal failure, and one had normal Leydig cell function. Abnormalities of the TSH response to TRH occurred in 10 patients but only three had overt hypothyroidism. Unlike growth hormone deficiency, gonadal and thyroid dysfunction showed no correlation with previous cranial radiotherapy.

Leydig cell function in the pubertal rat following local testicular irradiation

Dose- and time-response relationships were measured after irradiation of the pubertal rat testis with between 1 and 20 Gy of 300 kVp X-rays. The threshold dose for Leydig cell dysfunction was about 5 Gy. Dysfunction after higher doses was observed by 2 weeks post-irradiation as a dose-dependent decrease in serum testosterone (T) concentrations, and the levels were undetectable after 15 or 20 Gy. Despite the recovery of serum T by 24 and 36 weeks, dysfunction of the Leydig cell population was still observed as an increase in luteinizing hormone (LH) secretion (1.5 to 2-fold increase after 15 or 20 Gy at 24 weeks; 2 to 3-fold increase after 10 or 20 Gy at 36 weeks). The endocrine changes were probably due to the observed loss of Leydig cells following irradiation. These results indicate that the Leydig cells of pubertal rats are more radioresponsive than those of the adult.

Seminiferous epithelial function in the pubertal rat following local testicular irradiation

The dose- and time-related responses of the irradiated seminiferous epithelium in the pubertal rat have been investigated. The threshold dose for Sertoli cell dysfunction, as assessed by serum androgen binding protein (ABP) concentrations, was estimated to be 5 Gy. A significant reduction (to less than 50% of control levels) in serum ABP was observed at 8 weeks post-irradiation, with further reductions at later times (24 and 36 weeks). Serum follicle-stimulating hormone (FSH) was elevated to between 130 and 175% of control at only 2 weeks post-irradiation, but recovered with time. Normal FSH levels seemed to be related to recovery of spermatogenesis, as assessed by counts of regenerating tubule cross-sections. The results indicate that the clonogenic spermatogonia and Sertoli cells of the pubertal rat testis are less sensitive to radiation than those of the adult.

Dose and time related responses of the irradiated prepubertal rat testis. II. Seminiferous epithelial function

Dose-related effects of radiation upon the seminiferous epithelium were examined in the prepubertal rat. Marked damage to the spermatogenic cell populations was produced by doses of 5 Gy and above. As a result serum levels of FSH were increased, maximum changes being observed at 2 weeks, but levels remaining high even at 36 weeks after irradiation. Serum levels of androgen binding protein (ABP) were inversely related to serum FSH. Above a threshold dose of 5 Gy, serum ABP levels were reduced to between 30-50% of control values, possibly indicating damage to the Sertoli cells. Progression in the degree of testicular failure was indicated at 36 weeks after a dose of 15 Gy by further increases in serum gonadotrophins when compared to earlier times and by the absence of spermatogenesis.

Dose and time related responses of the irradiated prepubertal rat testis. I. Leydig cell function

The testes of prepubertal rats were locally irradiated with 300 kVp x-rays to doses of between 1 and 15 Gy. Leydig cell function was assessed between 2 and 36 weeks post-irradiation. Dysfunction was observed at two weeks as evidenced by a reduction in serum levels of testosterone to between 40 and 70% of control, with a threshold dose of about 5 Gy. Endocrine deficiencies in the Leydig cell population were indicated at later times by increased serum levels of LH, although serum testosterone concentrations recovered to control levels. The elevations in serum LH increased with time suggesting progressive Leydig cell failure.