Risk of cancer among children of cancer patients - a nationwide study in Finland

Elucidating the Transcriptional States of Spermatogenesis-Joint Analysis of Germline and Supporting Cell, Mice and Human, Normal and Perturbed, Bulk and Single-Cell RNA-Seq

In studying the molecular underpinning of spermatogenesis, we expect to understand the fundamental biological processes better and potentially identify genes that may lead to novel diagnostic and therapeutic strategies toward precision medicine in male infertility. In this review, we emphasized our perspective that the path forward necessitates integrative studies that rely on complementary approaches and types of data. To comprehensively analyze spermatogenesis, this review proposes four axes of integration. First, spanning the analysis of spermatogenesis in the healthy state alongside pathologies. Second, the experimental analysis of model systems (in which we can deploy treatments and perturbations) alongside human data. Third, the phenotype is measured alongside its underlying molecular profiles using known markers augmented with unbiased profiles. Finally, the testicular cells are studied as ecosystems, analyzing the germ cells alongside the states observed in the supporting somatic cells. Recently, the study of spermatogenesis has been advancing using single-cell RNA sequencing, where scientists have uncovered the unique stages of germ cell development in mice, revealing new regulators of spermatogenesis and previously unknown cell subtypes in the testis. An in-depth analysis of meiotic and postmeiotic stages led to the discovery of marker genes for spermatogonia, Sertoli and Leydig cells and further elucidated all the other germline and somatic cells in the testis microenvironment in normal and pathogenic conditions. The outcome of an integrative analysis of spermatogenesis using advanced molecular profiling technologies such as scRNA-seq has already propelled our biological understanding, with additional studies expected to have clinical implications for the study of male fertility. By uncovering new genes and pathways involved in abnormal spermatogenesis, we may gain insights into subfertility or sterility.

Ovarian Insufficiency and Fertility Preservation During and After Childhood Cancer Treatment

Premature ovarian insufficiency (POI) is one of many potential long-term consequences of childhood cancer treatment in females. Causes of POI in this patient population can include chemotherapy, especially alkylating agents, and radiation therapy. Rarely, ovarian tumors lead to ovarian dysfunction. POI can manifest as delayed pubertal development, irregular menses or amenorrhea, and infertility. This diagnosis often negatively impacts emotional health due to the implications of impaired ovarian function after already enduring treatment for a primary malignancy. The emerging adult may be challenged by the impact on energy level, quality of life, and fertility potential. POI can also lead to low bone density and compromised skeletal strength. This review discusses the health consequences of POI in childhood cancer survivors (CCS). We also explore the role of fertility preservation for CCS, including ovarian tissue cryopreservation and other available options. Lastly, knowledge gaps are identified that will drive a future research agenda.

Perinatal and childhood outcomes of children born to female cancer survivors in South Korea

Despite the increasing number of female cancer survivors, uncertainty remains regarding potential adverse health outcomes for their offspring. Comprehensive population-based studies would be invaluable for female cancer survivors in making decisions about their future. This study uses the National Health Information Database to investigate perinatal and long-term outcomes of offspring born to mothers with a history of cancer. In a South Korean cohort of 95,264 women aged 15-40 diagnosed with cancer between 2007 and 2010, we evaluated the outcomes of 15,221 children born to 11,092, cancer survivors. We selected 147,727 women without a history of cancer and 201,444 children as a control group. Our study found that children of female cancer survivors have a significantly higher odds ratio of primary outcomes including preterm birth, low birth weight, neonatal intensive care unit admission, and death. While there was no difference in the rate of death within 1 year of birth between the two groups, the total death rate during the follow-up period was significantly higher in children born to mothers with cancer. After adjusting for gestational age and birth weight, there was no statistically significant increased hazard ratio of secondary outcomes including cancer, chromosomal abnormalities, cerebral palsy, delayed development, epilepsy, language disorder, or hearing impairment.

S1 Guideline: Impairment of gonadal function After Cancer in Childhood and Adolescence

A possible negative consequence of cancer treatment is the fertility impairment of young cancer survivors. However, most former patients express the wish to have biological children. Fertility-preserving measures are available and are - under certain circumstances - financed by health insurance. Separate information at the time of diagnosis and during follow-up care should be adapted to the individual risk and enable those affected to make a self-determined decision about cryopreservation of germ cells or germ cell tissue. Hyopgonadotropic hypogonadism can be treated by the pulsatile administration of gonadotropins. Affected individuals can be reassured. A health restriction of the offspring due to the cancer treatment is not to be expected, even after artificial insemination.

Long-Term Morbidity and Mortality in Children After In Utero Exposure to Maternal Cancer

PURPOSE

In utero exposure to maternal cancer and cancer treatment might influence the child's short- and long-term health and development. The objective of the study was to investigate short- and long-term somatic and psychiatric outcomes in children exposed to maternal cancer in utero.

METHODS

This nationwide cohort study identified all liveborn children in Denmark between January 1978 and December 2018. Exposure was defined as maternal cancer diagnosis during pregnancy, and in a subgroup analysis, exposure to chemotherapy in utero. The main outcomes of interest were overall mortality, somatic diagnoses, and psychiatric diagnoses identified in the National Health Registers. Follow-up started at birth and ended at an event, death, emigration, or end of 2018. Hazard ratios of end points adjusted for potential confounders were estimated using Cox regression analysis.

RESULTS

Of 2,526,163 included liveborn children, 690 (0.03%) were exposed to maternal cancer in utero. Compared with unexposed fetuses, children exposed in utero had no higher overall mortality, adjusted hazard ratio 0.8 (95% CI, 0.4 to 1.5), nor increased risk of congenital malformations, overall somatic or psychiatric disease. During the period 2002-2018, of 378 (0.03%) children exposed to cancer in utero, 42 (12.5%) were exposed to chemotherapy. Among these 42 children, in utero exposure to chemotherapy was not associated with selected somatic diseases nor to congenital malformations when compared with in utero exposure to maternal cancer without chemotherapy.

CONCLUSION

Overall, findings did not indicate excess risk of mortality or severe morbidity among children exposed to cancer in utero. Fetal exposure to chemotherapy was not associated with adverse health outcomes in childhood.

Familial aggregation of early-onset haematological malignancies

Population-based studies on familial aggregation of haematological malignancies (HM) have rarely focused specifically on early-onset HMs. We estimated standardized incidence ratios (SIR) and cumulative risks of relatives with Hodgkin lymphoma (HL), non-Hodgkin lymphomas (NHL), acute lymphoblastic leukaemia/lymphoma (ALL/LBL) and acute myeloid leukaemia (AML) when index persons and relatives were diagnosed with early-onset HM. A total of 8791 patients aged ≤40 years and diagnosed with primary HM in Finland from 1970 to 2012 were identified from the Finnish Cancer Registry and their 75 774 family members were retrieved from the population registry. SIRs for concordant HMs were elevated among first-degree relatives in all of the most common HMs of children and adolescents and young adults (AYA). The risk was highest among siblings with HL (SIR 9·09, 95% confidence interval 5·55-14·04) and AML (8·29, 1·00-29·96). HL also had the highest cumulative risk for siblings at ≤40 years of age (0·92% vs. 0·11% in the population). In conclusion, significantly elevated SIRs indicate a role of shared aetiological factors in some families, which should be noted in the clinical setting when caring for patients with early-onset HMs.

Socioeconomic consequences of parenting a child with cancer for fathers and mothers in Sweden: A population-based difference-in-difference study

Parents are the primary source of support for children with cancer. To inform clinical practice and health policies, the socioeconomic consequences of childhood cancer for fathers and mothers in Sweden were investigated. A total of 3865 mothers and 3865 fathers of 3865 children diagnosed with cancer in Sweden when 0 to 18 years were followed for 5 years before and 10 years after diagnosis. Socioeconomic consequences of the cancer diagnosis on earnings and employment, and mental health (number of inpatient diagnoses), were investigated exploiting variation in timing of cancer diagnosis. Data were obtained from the Swedish Childhood Cancer Registry, Intergenerational Registry and Inpatient Registry. Childhood cancer has a negative short-term effect on fathers' and mothers' earnings; a negative long-term effect on fathers' earnings; a positive long-term effect on mothers' earnings; negative short- and long-term effects on fathers' and mothers' employment; and no effect on the number of inpatient diagnosis of mental and behavioral disorders for fathers or mothers. Taken together, findings show that in Sweden childhood cancer has negative effects on parents' employment, a more negative impact on fathers' than mothers' earnings and no effect on inpatient diagnosis of mental and behavioral disorders. Future research should explore mechanisms possibly explaining, for example, mental health, social support and priorities regarding work and private life potentially resulting in changes from full-time to part-time work or vice versa. The novel findings should change clinical practice and help inform health policies for parents of children with cancer in Sweden and countries with a similar health and welfare system.

A narrative review of pregnancy after malignancies in young women that don't originate in the female genital organs or in the breast

While cancer during pregnancy and its treatment has grown to be a popular topic in recent years, little is known on how to advise patients looking to conceive or conceiving after cancer treatment. The aim of this paper is to review the available literature on the impact of pregnancy on survivors of the most common childhood cancers, brain cancer, haematological malignancies, thyroid cancer, melanomas and sarcomas. Its main objective is to be a source of information for clinicians looking to counsel patients in these delicate moments exploiting all the available literature, albeit scarce. Given the available literature, we conclude that the presence of a multidisciplinary team is of great importance in supporting the patient and her loved ones when facing pregnancy with a previous cancer diagnosis.

Risk of somatic diseases in offspring of survivors with childhood or adolescent central nervous system tumor in Sweden

With the improvement of treatments, a growing number of survivors with childhood or adolescent central nervous system (CNS) tumor are parenting their own children. We aimed to explore the risk of somatic diseases among children of these survivors compared to population controls. Children of survivors with CNS tumor below age of 20 were identified between 1973 and 2014 by combining the several Swedish registers. Five children without parental CNS tumor were matched randomly to generate the population comparisons. Relative risk (RR) and absolute excess risk (AER) were calculated for overall somatic diseases, and hazard ratio (HR) was calculated for specific type of somatic diseases. A total of 2231 somatic disease diagnoses were identified in children of survivors with a cumulative incidence rate of 94.77 per 1000 person‐years, whereas the rate was 92.79 in matched comparisons thus resulting in an overall RR of 1.02 (95% CI = 0.98‐1.07) and AER of 1.98 (95% CI = −2.06, 6.13). Specifically, five of 1364 children of survivors had CNS tumor with an incidence rate of 0.21 per 1000 person‐year, whereas the rate was 0.04 in children of matched children, generating a HR of 4.91 (95% CI = 1.42‐16.96). Children of male survivors were at a statistically increased risk of malignancy, as well as infectious and parasitic diseases. In conclusion, no significantly higher risk of overall somatic diseases was found in children of survivors with CNS tumor before the age of 20, but children with a paternal diagnosis of CNS tumor had significantly increased risk of malignancies and infectious and parasitic diseases.

What's new?

Survivors of central nervous system (CNS) tumors are at higher risk of experiencing late adverse effects on reproductive function. However, it remains unknown if the tumor or related treatments subsequently affect the physical health of their offspring. This population‐based study did not find an association of parental CNS tutors in childhood or adolescence with the risk of overall somatic diseases in the offspring. Nonetheless, an increased risk was observed in preterm born children, and children of male survivors had an increased risk of malignancies and infectious and parasitic diseases, calling for a tailored surveillance strategy.

Preterm birth, neonatal therapies and the risk of childhood cancer

Our aim was to study the impact of preterm birth and neonatal therapies on the risk of childhood cancer using a nationwide, registry-based, case-control design. Combining population-based data from Finnish Medical Birth Registry (MBR) and Finnish Cancer Registry, we identified a total of 2029 patients diagnosed with cancer under the age of 20 years and 10 103 age- and sex-matched controls over the years 1996 to 2014. Information on the prenatal and perinatal conditions was obtained from the MBR. Gestational age was categorized into early (<32) and late preterm (32-36) and term (≥37 weeks). Cancer risk among the preterm compared to term neonates was evaluated using conditional logistic regression. We identified 141 cancers among the preterm (20.8% of 678) vs 1888 cancers in the term children (16.5% of 11 454). The risk of any cancer was increased for the preterm (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.06-1.57), especially for the early preterm (OR 1.84, 95% CI 1.16-2.92). The risk of acute myeloid leukemia (AML; OR 2.33, 95% CI 1.25-4.37), retinoblastoma (OR 3.21, 95% CI 1.22-8.41) and germ cell tumors (OR 5.89, 95% CI 2.29-15.18) was increased among the preterm compared to term. Germ cell tumors were diagnosed at a significantly younger age among the preterm. Neonatal therapies, for example, mechanical ventilation, were associated with an increased risk of childhood cancer independent of gestational age. Preterm, especially early preterm birth, is associated with an increased risk of childhood cancer, especially germ cell tumors and AML. Respiratory distress requiring neonatal intervention also appears to be associated with an increased risk.

Familial aggregation of testicular cancer among early-onset cancer survivors. A prospective observational cohort data from Finland

Testicular cancer (TC) is the most common form of cancer in men aged 15-35 years. Familial risk for TC is among highest of all cancers.

MATERIAL AND METHODS

A prospective observational cohort of 9111 relatives in 2,188 families of early-onset TC patients, called probands, diagnosed at age ≤40 years in Finland between 1970 and 2012. Standardized incidence ratios (SIR) were used as measures of familial aggregation for early-onset (≤40 years) TC. Follow-up ended at diagnosis of TC, death or 31 December 2014 whichever earliest.

RESULTS

Among first-degree relatives of early-onset TCs, in all 12 early-onset TC cases (0.24%) were diagnosed over the follow-up; the SIR for any first-degree relative was 4.59 (95% confidence interval (CI): 2.37-8.01) and for brothers the SIR was 6.51 (95% CI 3.12-11.96).

DISCUSSION

Familial aggregation of TC shows substantial risk for early-onset TC among first-degree relatives of early-onset TC patients in Finland. This is important to acknowledge to avoid diagnostic delay especially of TC.

Linking population-based registries to identify familial cancer risk in childhood cancer

BACKGROUND

Linked population-based registries provide a unique source for identification of new family cancer syndromes and for elucidating risk of early-onset cancer in close relatives of cancer patients.

METHODS

Using the Finnish Cancer Registry, we identified 9078 probands who had been diagnosed with cancer at <21 years of age between 1970 and 2012. Siblings, offspring, parents, nephews, and nieces of probands were identified from the Population Registry. Childhood and young adult (ChYA) cancer diagnoses (age 0-39 years) in relatives were identified by linking to the Finnish Cancer Registry. The relative risk of ChYA cancer in family members of probands was estimated using standardized incidence ratios (SIRs).

RESULTS

Among 58,010 family members of the 9078 probands, 363 ChYA cancers were diagnosed, 324 of which were expected (SIR, 1.12; 95% CI, 1.01-1.24). The risk of ChYA cancer was elevated both in offspring (SIR, 2.25; 95% CI, 1.51-3.24) and in siblings (SIR, 1.17; 95% CI, 1.01-1.36). Offspring of probands with retinoblastoma were at highest risk (SIR, 75.85; 95% CI, 32.75-149.45); risks were also elevated for siblings of probands with lymphoma (SIR, 1.62; 95% CI, 1.14-2.25). Known cancer predisposition syndromes were observed in 29 (66%) of 44 sibling pairs with cancers diagnosed at <21 years of age and in 20% of the 135 families with a childhood cancer proband whose sibling was diagnosed with a young adult malignancy.

CONCLUSION

Linked population-based registry data indicate a modestly increased risk of ChYA in relatives of children with cancer. Some of the observed cancer clusters in the cohort suggest novel patterns and familial cancer syndromes.

Fertility Preservation for Pediatric and Adolescent Patients With Cancer: Medical and Ethical Considerations

Many cancers presenting in children and adolescents are curable with surgery, chemotherapy, and/or radiotherapy. Potential adverse consequences of treatment include sterility, infertility, or subfertility as a result of gonad removal, damage to germ cells as a result of adjuvant therapy, or damage to the pituitary and hypothalamus or uterus as a result of irradiation. In recent years, treatment of solid tumors and hematologic malignancies has been modified in an attempt to reduce damage to the gonadal axis. Simultaneously, advances in assisted reproductive technology have led to new possibilities for the prevention and treatment of infertility. This clinical report reviews the medical aspects and ethical considerations that arise when considering fertility preservation in pediatric and adolescent patients with cancer.

Genetics-related service and information needs of childhood cancer survivors and parents: a mixed-methods study

Genetics in paediatric oncology is becoming increasingly important in diagnostics, treatment and follow-up care. Genetic testing may offer a possibility to stratify survivors follow-up care. However, survivors' and parents' preferences and needs for genetics-related services are largely unknown. This mixed-methods study assessed genetics-related information and service needs of survivors and parents. Six hundred and twenty-two participants (404 survivors: mean age: 26.27 years; 218 parents of survivors: mean age of child: 13.05 years) completed questionnaires. Eighty-seven participants (52 survivors; 35 parents) also completed in-depth telephone interviews. We analysed data using multivariable logistic regression and qualitative thematic analyses. Thirty-six of 50 families who were offered cancer-related genetic testing chose to undergo testing. Of those not offered testing, 11% of survivors and 7.6% of parents indicated that they believed it was 'likely/very likely' that the survivor had inherited a gene fault. Twenty-nine percent of survivors and 36% of parents endorsed access to a genetics specialist as important in their care. Survivors (40.9%) and parents (43.7%) indicated an unmet need for information about genetics and childhood cancer. Parents indicated a higher unmet need for information related to the survivors' future offspring than survivors (p < 0.001). Many survivors and parents have unmet needs for genetics-related services and information. Greater access to services and information might allow survivors at high risk for late effects to detect and prevent side effects early and improve medical outcomes. Addressing families' needs and preferences during survivorship may increase satisfaction with survivorship care.

Consequences of chemotherapeutic agents on primordial follicles and future clinical applications

The ovarian reserve is necessary for female fertility and endocrine health. Commonly used cancer therapies diminish the ovarian reserve, thus, resulting in primary ovarian insufficiency, which clinically presents as infertility and endocrine dysfunction. Prepubertal children who have undergone cancer therapies often experience delayed puberty or cannot initiate puberty and require endocrine support to maintain a normal life. Thus, developing an effective intervention to prevent loss of the ovarian reserve is an unmet need for these cancer patients. The selection of adjuvant therapies to protect the ovarian reserve against cancer therapies underlies the mechanism of loss of primordial follicles (PFs). Several theories have been proposed to explain the loss of PFs. The "burn out" theory postulates that chemotherapeutic agents activate dormant PFs through an activation pathway. Another theory posits that chemotherapeutic agents destroy PFs through an "apoptotic pathway" due to high sensitivity to DNA damage. However, the mechanisms causing loss of the ovarian reserve remains largely speculative. Here, we review current literature in this area and consider the mechanisms of how gonadotoxic therapies deplete PFs in the ovarian reserve.

Familial aggregation of early-onset cancers

This registry‐linkage study evaluates familial aggregation of cancer among relatives of a population‐based series of early‐onset (≤40 years) cancer patients in Finland. A cohort of 376,762 relatives of early‐onset cancer patients diagnosed between 1970 and 2012 in 40,538 families was identified. Familial aggregation of early‐onset breast, colorectal, brain and other central nervous system (CNS) cancer and melanoma was explored by standardized incidence ratios (SIR), stratified by relatedness. Gender‐, age‐ and period‐specific population cancer incidences were used as reference. Cumulative risks for siblings and offspring of the proband up to age ≤40 years were also estimated. Almost all early‐onset cancers were sporadic (98% or more). Among first‐degree relatives, SIR was largest in colorectal cancer (14, 95% confidence interval 9.72–18), and lowest in melanoma (1.93, 1.05–3.23). Highest relative‐specific SIRs were observed for siblings in families, where also parent had concordant cancer, 90 (43–165) for colorectal cancer and 29 (11–64) for CNS cancer. In spouses, all SIRs were at population level. Cumulative risk of colorectal cancer by age 41 was 0.98% in siblings and 0.10% in population, while in breast cancer the corresponding risks were 2.05% and 0.56%. In conclusion, early‐onset cancers are mainly sporadic. Findings support high familial aggregation in early‐onset colorectal and CNS cancers. Familial aggregation in multiplex families with CNS cancers was mainly attributed to neurofibromatosis and in colorectal cancer to FAP‐ and HNPCC‐syndromes. The pattern of familial aggregation of early‐onset breast cancer could be seen to support very early exposure to environmental factors and/or rare genetic factors.

What's new?

The tendency for certain cancer types to cluster in families generally is explained by shared environmental exposures or inherited mutations. In particular, early‐onset cancer, diagnosed between ages 0 and 40, is considered indicative of familial factors. Here, investigation of cancer risk among more than 376,760 relatives of probands, or individuals with early‐onset cancer, shows that the likelihood of early‐onset cancer affecting even just one other relative in addition to the proband is exceedingly rare. Nearly all early‐onset cancers in the study population were sporadic. Estimated cumulative risks observed for specific cancers may prove useful in the context of genetic counseling.

Hospitalization rate in offspring of cancer survivors: a national cohort study

Purpose

The number of childbirths among cancer survivors continues to increase, but it is still largely unknown whether the children of cancer survivors might experience adverse health outcomes during the process of growing up.

Methods

We identified all individuals diagnosed with cancer between 1958 and 2015 from the Swedish Cancer Registry and linked them to the Swedish Medical Birth Register to identify their offspring born between 1997 and 2015. Up to 10 children, whose parents did not have a diagnosis of cancer, were matched with the study population according to date of birth and gender.

Results

By linking with the Swedish Hospital Discharge Register, we found that the hospitalization rate was 15% higher in offspring of female cancer survivors, and 16% higher in offspring of male cancer survivors as compared to matched controls. Besides an increased risk of hospitalization due to malignant neoplasms (relative risk (RR) = 1.86, 99% CI 1.70–2.04) and benign neoplasms (RR = 1.48, 99% CI 1.18–1.86), a non-significant increased risk was found for hospitalization due to infectious and parasitic disease (RR = 1.09, 99% CI 0.98–1.21), diseases of the blood and blood-forming organs and certain disorders involving the immune mechanisms (RR = 1.33, 99% CI 0.98–1.80), and diseases of the circulatory system (RR = 1.05, 99% CI 0.98–1.12).

Conclusion

Our study suggests that children of cancer survivors might experience a significantly increased rate of hospitalization, which calls for further studies.

Implications for Cancer Survivors

Cancer survivors might be aware that the risk of hospitalization due to various diseases might be higher in their children as compared to the normal population.

Reproductive Function and Outcomes in Female Survivors of Childhood, Adolescent, and Young Adult Cancer: A Review

Some survivors of childhood, adolescent, and young adult cancer are at increased risk of gonadal dysfunction and adverse pregnancy outcomes. We reviewed currently available literature that evaluated reproductive function and pregnancy outcomes of female cancer survivors diagnosed before the age of 25 years. High-dose alkylating agent chemotherapy and abdominal/pelvic radiotherapy adversely affect gonadal function in a dose-related fashion, with older age at exposure conferring greater risk as a result of the age-related decline in ovarian reserve. Gonadal injury clinically manifests as ovarian hormone insufficiency (delayed or arrested puberty, premature ovarian insufficiency, or premature menopause) and infertility. The effect of molecular-targeted agents on ovarian function has not been established. For female cancer survivors who maintain fertility, overall pregnancy (relative risk, 0.67 to 0.81) and live birth rates (hazard ratio, 0.79 to 0.82) are lower than those in the general public. Pregnancy in cancer survivors also may be associated with risks to both the mother and the fetus related to miscarriage; preterm birth; and, rarely, cardiomyopathy. Women at risk for these complications require preconception assessment and counseling from both obstetricians and oncology providers. The risk for inherited genetic disease in offspring conceived after cancer treatment exposure is not increased. The optimization of reproductive outcomes and minimization of risks of pregnancy complications in survivors requires informed, risk-based assessment and monitoring.

Best Practices in Counseling Young Female Cancer Survivors on Reproductive Health

In the United States, there are more than 400,000 girls and young women of reproductive-age with a history of cancer. Cancer treatments including surgery, chemotherapy, targeted therapy, and radiation can adversely impact their reproductive health. This review discusses infertility, contraception, and adverse pregnancy and child health outcomes in reproductive-aged cancer survivors, to increase awareness of these health risks for survivors and their health care providers. Infertility rates are modestly higher, while rates of using contraception and using highly effective contraceptive methods are lower in cancer survivors than in women without a history of cancer. During pregnancy, preterm births are also more common in survivors, resulting in more low-birth-weight offspring. Children of cancer survivors do not have more childhood cancers, birth defects, or chromosomal abnormalities than the general population, with the exception of families with hereditary cancer. Reproductive risks in survivors depend on cancer treatment exposures. For example, women with prior abdominal or pelvic radiation have additional risks of spontaneous abortions, small-for-gestational-age offspring and stillbirths, while those with prior chest radiation or anthracycline exposures have higher risks of cardiomyopathy. To help survivors achieve their reproductive goals safely, family planning and preconception counseling are central to survivorship care.

Pregnancy and child health outcomes in pediatric and young adult leukemia and lymphoma survivors: a systematic review

As long-term survival is high for children and young adults diagnosed with leukemia and lymphoma, delineating maternal, fetal and offspring health risks is important to their family planning. This systematic review examined data comparing these health risks between leukemia and lymphoma survivors and women without a history of cancer. Following a search of Embase, PubMed, CINAHL, Cochrane, and Web of Science, 142 articles were screened and 18 were included in this review. No higher risks of spontaneous abortion, maternal diabetes and anemia, stillbirth, birth defects, or childhood cancer in offspring were observed in survivors compared to controls. Important to counseling and clinical care, live birth rates were lower, while preterm birth and low birth weight risks were modestly higher in survivors compared to controls. Findings were largely reassuring but highlight the lack of data on maternal cardiopulmonary risks, differential risk by cancer treatment type, and interventions to decrease these risks.

Evidence relevant to untargeted and transgenerational effects in the offspring of irradiated parents

In this article we review health effects in offspring of human populations exposed as a result of radiotherapy and some groups exposed to chemotherapy. We also assess risks in offspring of other radiation-exposed groups, in particular those of the Japanese atomic bomb survivors and occupationally and environmentally exposed groups. Experimental findings are also briefly surveyed. Animal and cellular studies tend to suggest that the irradiation of males, at least at high doses (mostly 1Gy and above), can lead to observable effects (including both genetic and epigenetic) in the somatic cells of their offspring over several generations that are not attributable to the inheritance of a simple mutation through the parental germline. However, studies of disease in the offspring of irradiated humans have not identified any effects on health. The available evidence therefore suggests that human health has not been significantly affected by transgenerational effects of radiation. It is possible that transgenerational effects are restricted to relatively short times post-exposure and in humans conception at short times after exposure is likely to be rare. Further research that may help resolve the apparent discrepancies between cellular/animal studies and studies of human health are outlined.

A 10-year follow up of reproductive function in women treated for childhood cancer

Previously, this study group found that female childhood cancer survivors could be at risk of early cessation of fertility. The aim of the present study was to evaluate reproductive function in the same group of survivors 10 years after the initial study. Of the original cohort of 100, 71 were re-examined. Thirty-six survivors reported regular menstrual cycles. When they were compared with 210 controls, they differed significantly in antral follicle count (AFC) (median 15 versus 18, P=0.047) but not in anti-Müllerian hormone (AMH) (median 13.0 versus 17.8 pmol/l). Survivors cured with minimal gonadotoxic treatment had significantly higher AMH and AFC compared with survivors cured with either potentially gonadotoxic treatment or treatment including alkylating chemotherapy and ovarian irradiation (20.0, 5.8 and <3 pmol/l, P<0.001; and 15, 9 and 2, P=0.03, respectively). Thirty-eight survivors had achieved at least one live birth. Complicated second-trimester abortions (n=4) were observed primarily in survivors cured with radiotherapy affecting pelvic organs. In conclusion, childhood cancer survivors have signs of diminished ovarian reserve. However, if the ovarian function is preserved in the early to mid-twenties, it is likely to persist until the mid-thirties, giving a good chance of childbearing.

Preconception exposure to mutagens: medical and other exposures to radiation and chemicals

Contrary to intuition, no environmental exposure has been proved to cause human germ line mutations that manifest as heritable disease in the offspring, not among the children born to survivors of the American atomic bombs in Japan nor in survivors of cancer in childhood, adolescence, or young adulthood who receive intensive chemotherapy, radiotherapy, or both. Even the smallest of recent case series had sufficient statistical power to exclude, with the usual assumptions, an increase as small as 20 % over baseline rates. One positive epidemiologic study of a localized epidemic of Down syndrome in Hungary found an association with periconceptual exposure to a pesticide used in fish farming, trichlorfon. Current population and occupational guidelines to protect against genetic effects of ionizing radiation should continue, with the understanding they are based on extrapolations from mouse experiments and mostly on males. Presently, pre-conceptual counseling for possible germ cell mutation due to the environment can be very reassuring, at least based on, in a sense, the worst-case exposures of cancer survivors. Prudence demands further study. Future work will address the issue with total genomic sequencing and epigenomic analysis.

Embryo banking between induction and consolidation chemotherapy in women with leukemia

OBJECTIVE

To report the results of controlled ovarian hyperstimulation (COH) after long-acting GnRH agonist (GnRH-a) and chemotherapy for the purposes of embryo cryopreservation.

DESIGN

Case report.

SETTING

University medical center.

PATIENT(S)

Two premenopausal women with acute myelogenous leukemia with recent treatment with GnRH-a and induction chemotherapy for hematopoietic cell transplantation (HCT).

INTERVENTION(S)

COH with embryo cryopreservation.

MAIN OUTCOME MEASURE(S)

Numbers of oocytes and embryos cryopreserved.

RESULT(S)

Both patients responded to gonadotropin stimulation and cryopreserved embryos.

CONCLUSION(S)

Women who have received recent long-acting GnRH-a and chemotherapy may respond to gonadotropin stimulation. The option of embryo banking can be offered to leukemia patients who are preparing for HCT.

Genetic disease in the children of Danish survivors of childhood and adolescent cancer

PURPOSE

Preconception radiation and chemotherapy have the potential to produce germ cell mutations leading to genetic disease in the next generation. Dose-response relationships were evaluated between cancer treatments and untoward pregnancy outcomes.

PATIENTS AND METHODS

A case-cohort study was conducted involving 472 Danish survivors of childhood and adolescent cancer and their 1,037 pregnancies. Adverse outcomes included 159 congenital malformations, six chromosomal abnormalities, seven stillbirths, and nine neonatal deaths. Preconception radiation doses to the gonads, uterus, and pituitary gland and administered chemotherapy were quantified based on medical records and related to adverse outcomes using a generalized estimating equation model.

RESULTS

No statistically significant associations were found between genetic disease in children and parental treatment with alkylating drugs or preconception radiation doses to the testes in male and ovaries in female cancer survivors. Specifically, the risk of genetic disease was similar among the children of irradiated survivors when compared with nonirradiated survivors (relative risk [RR], 1.02; 95% CI, 0.59 to 1.44; P = .94). A statistically significant association between abdomino-pelvic irradiation and malformations, stillbirths, and neonatal deaths was not seen in the children of female survivors overall (P = .07) or in the children of mothers receiving high uterine doses (mean, 13.5 Gy; max, 100 Gy; RR, 2.3; 95% CI, 0.95 to 5.56).

CONCLUSION

Mutagenic chemotherapy and radiotherapy doses to the gonads were not associated with genetic defects in children of cancer survivors. However, larger studies need to be conducted to further explore potential associations between high-dose pelvic irradiation and specific adverse pregnancy outcomes.

Reproductive outcomes for survivors of childhood cancer

Because of remarkable progress in therapy, long-term survival is expected for 80% of children and adolescents diagnosed with cancer. Infertility remains one of the most common and life-altering complications experienced by adults treated for cancer during childhood. Surgery, radiation, or chemotherapy that negatively affects any component of the hypothalamic-pituitary-gonadal axis may compromise reproductive outcomes in childhood cancer survivors. The risk of infertility is generally related to the tissues or organs involved in cancer and the specific type, dose, and combination of cytotoxic therapy. In addition to anticancer therapy, age at treatment, sex, and likely genetic factors influence the risk of permanent infertility. When possible, contemporary protocols limit cumulative doses of cytotoxic therapy in an effort to optimize reproductive potential. If sterilizing therapy is required for cancer control, then fertility preservation measures should be explored before initiation of therapy. For childhood cancer survivors who maintain fertility, health risks to offspring resulting from their cancer treatment are major concerns. Radiation affecting ovarian and uterine function has been linked to pregnancy complications, including spontaneous abortion, preterm labor, fetal malposition, and low birth weight. The risk of congenital malformations, genetic disorders, and cancer appears to be low, with the exception of cancer risk in offspring born to survivors with germline cancer-predisposing mutations. This review summarizes research about cancer treatment factors affecting fertility and pregnancy outcomes of childhood cancer survivors. The data presented should facilitate the delivery of preventive counseling and age- and sex-appropriate interventions to optimize reproductive outcomes in childhood cancer survivors.

Germ cell mutagens: risk assessment challenges in the 21st century

Heritable mutations may result in a wide variety of detrimental outcomes, from embryonic lethality to genetic disease in the offspring. Despite this, today's commonly used test batteries do not include assays for germ cell mutation. Current challenges include a lack of practical assays and concrete evidence for human germline mutagens, and large data gaps that often impede risk assessment. Moreover, most regulatory assessments are based on the assumption that somatic cell mutation assays also protect the germline by default, which has not been adequately confirmed. The field is also faced with new challenges aimed at dramatically reducing animal testing, and attempts to rapidly classify thousands of chemicals using high throughput in vitro assays. These approaches may not adequately capture effects that may be particular to gametes, since many aspects of the germline are unique. In light of these challenges, an urgent need exists to develop new approaches to evaluate the potential of toxicants to cause germline mutation. The application of new technologies will greatly enhance our understanding of mutation in humans exposed to environmental mutagens. However, we must be poised to collect and interpret these data, and facilitate risk translation to regulators and the public. Genetic toxicologists must also become actively involved in the development of high-throughput tools to study germline mutation. Appropriate attention to these areas will result in the development of policies that prioritize the protection of the germline and future generations from DNA sequence mutations.