Fetal outcome after prenatal exposure to chemotherapy and mechanisms of teratogenicity compared to alcohol and smoking

Pregnancy and neonatal outcomes following malignancy in pregnancy at a tertiary care Canadian center: a retrospective chart review

Objective: Data on pregnancy-associated cancers (PACs) are lacking. The objectives of this study were to determine the incidence of PACs and describe the characteristics and outcomes of pregnancies affected by malignancy at a single tertiary care center in Ottawa, Canada.Methods: This was a retrospective chart review of individuals with PAC at The Ottawa Hospital (TOH) between 2011-2022. Eligible cases were identified from the TOH Data Warehouse, the TOH instance of the Better Outcomes Registry & Network Ontario, and the TOH Division of Maternal Fetal Medicine's Perinates database. Chart reviews were conducted to confirm case eligibility and to extract demographic, oncologic, obstetrical, and neonatal measures. The annual incidence of PAC over the 11-year period was reported per 1000 deliveries. Descriptive statistics were used to describe the sample, including frequency (n) and proportions (%) for categorical variables and mean and standard deviation (SD) for continuous variables.Results: The final cohort included 59 individuals with PAC at TOH between 2011-2022. The annual incidence of PAC ranged from 0.47 to 1.54 per 1000 deliveries. The most common PACs were breast cancer (28.8%), Hodgkin lymphoma (10.2%), and thyroid cancer (8.5%). Common interventions during pregnancy included chemotherapy (33.9%) and surgical intervention (32.2%). A total of 19 individuals (32.2%) did not undergo PAC-related treatment during pregnancy. There were 55 livebirths (91.7%), 2 spontaneous abortions (3.3%), 3 induced abortions (5.0%), and no stillbirths. Among livebirths, the mean gestational age was 37.4 ± 2.8 weeks and the mean birthweight was 2920.3 ± 650.0 g. All neonates had reassuring 5-minute Apgar scores, 18 (32.7%) were admitted to the Neonatal Intensive Care Unit/Special Care Nursery (NICU/SCN), and 8 (14.5%) were noted to have a mild congenital abnormality.Conclusion: This study shows promising perinatal outcomes for patients with PAC and their neonates. Ongoing surveillance of PAC is needed to better inform care for this patient population.

Chemotherapy against cancer during pregnancy: A systematic review on neonatal outcomes

BACKGROUND

The concomitant incidence of cancer and pregnancy has increased in recent years because of the increase in maternal age at the time of the 1st pregnancy. The diagnosis of cancer in a pregnant woman causes ethical and therapeutic problems for both the patient and the physician. The main aim of this paper is to describe the available evidence concerning the short- and long-term neonatal impact of chemotherapy given to pregnant women.

METHODS

The relevant publications in English were identified by a systematic review of MEDLINE and PubMed for the last 15 years. The search strategy included "cancer[Title/Abstract] OR tumor[Title/Abstract] AND pregnancy[Title/Abstract] OR pregnant[Title/Abstract] AND embryo[Title/Abstract] or fetus[Title/Abstract] or neonate[Title/Abstract] or newborn[Title/Abstract] or pediatric[Title/Abstract] or child[Title/Abstract] AND English[lang]."

RESULTS

An analysis of the literature showed that only the administration of chemotherapy during the embryonic stage of conceptus is dangerous and can lead to the termination of the pregnancy. When the disease is diagnosed in the 2nd or 3rd trimester of gestation or when it is possible to delay the initiation of chemotherapy beyond the 14th week, the risk of severe problems for the fetus are low, and pregnancy termination is not required.

CONCLUSION

Data regarding the final outcome of children who have received in utero chemotherapy seem reassuring. Only the administration in the embryonal stage of conceptus is dangerous and can lead to the termination of pregnancy. When the disease is diagnosed in the 2nd or 3rd trimester of gestation or when it is possible to delay the initiation of chemotherapy beyond the 14th week, the risk of severe problems for the fetus are low and pregnancy termination is not needed. Increased knowledge of how to minimize the risks of chemotherapy can reduce improper management including unnecessary termination of pregnancy, delayed maternal treatment, and iatrogenic preterm delivery.

Etoposide damages female germ cells in the developing ovary

BACKGROUND

As with many anti-cancer drugs, the topoisomerase II inhibitor etoposide is considered safe for administration to women in the second and third trimesters of pregnancy, but assessment of effects on the developing fetus have been limited. The purpose of this research was to examine the effect of etoposide on germ cells in the developing ovary. Mouse ovary tissue culture was used as the experimental model, thus allowing us to examine effects of etoposide on all stages of germ cell development in the same way, in vitro.

RESULTS

Fetal ovaries from embryonic day 13.5 CD1 mice or neonatal ovaries from postnatal day 0 CD1 mice were cultured with 50-150 ng ml(-1) or 50-200 ng ml(-1) etoposide respectively, concentrations that are low relative to that in patient serum. When fetal ovaries were treated prior to follicle formation, etoposide resulted in dose-dependent damage, with 150 ng ml(-1) inducing a near-complete absence of healthy follicles. In contrast, treatment of neonatal ovaries, after follicle formation, had no effect on follicle numbers and only a minor effect on follicle health, even at 200 ng ml(-1). The sensitivity of female germ cells to etoposide coincided with topoisomerase IIα expression: in the developing ovary of both mouse and human, topoisomerase IIα was expressed in germ cells only prior to follicle formation.

CONCLUSIONS

Exposure of pre-follicular ovaries, in which topoisomerase IIα expression was germ cell-specific, resulted in a near-complete elimination of germ cells prior to follicle formation, with the remaining germ cells going on to form unhealthy follicles by the end of culture. In contrast, exposure to follicle-enclosed oocytes, which no longer expressed topoisomerase IIα in the germ cells, had no effect on total follicle numbers or health, the only effect seen specific to transitional follicles. Results indicate the potential for adverse effects on fetal ovarian development if etoposide is administered to pregnant women when germ cells are not yet enclosed within ovarian follicles, a process that starts at approximately 17 weeks gestation and is only complete towards the end of pregnancy.

Unintended pregnancy during the first year after breast cancer diagnosis

OBJECTIVES

Young women experience high levels of anxiety and distress during cancer diagnosis and therapy, and it can be devastating to become pregnant in this vulnerable state. Pregnancy during cancer treatment is strongly discouraged, as radiotherapy and chemotherapy administered during the first trimester of pregnancy result in increased congenital malformations.

METHODS

In this study, we analysed an unselected, consecutive cohort of young breast cancer (BC) patients with regard to unintended pregnancy during the first year after BC diagnosis. We analysed all patients who were ≤40 years of age at initial BC diagnosis (n = 100, mean age at diagnosis: 35.9 years), according to data from the Basel Breast Cancer Database. The frequency of unintended pregnancy was assessed, and particular attention was given to patients' obstetric and reproductive history.

RESULTS

Forty-two percent of the cohort (mean age 36.5 years) were identified as not at risk of unintended pregnancy during the first year after BC diagnosis. However, 58% of the cohort (mean age 35.6 years) were using an ineffective contraceptive method and thus were at risk of unintended pregnancy. The rate of unintended pregnancy was 3.5% in this group (two patients). Oncologists should be aware that the use of reliable contraception should be discussed before starting, and also during, adjuvant therapy.

CONCLUSIONS

Oncologists should consider actively referring young BC patients to a gynaecologist to ensure proper contraceptive counselling.

Effects of prenatal exposure to cancer treatment on neurocognitive development, a review

Due to the increasing incidence of cancer during pregnancy, the need to better understand long-term outcome after prenatal exposure to chemo- and/or radiotherapy has become more urgent. This manuscript focuses on the neurocognitive development after prenatal exposure to cancer treatment. We will review possible pathways for brain damage that could explain the subtle changes in neurocognition and behavior found after in utero exposure to cancer treatment. Contrary to radiation, which has a direct effect on the developing nervous system, chemotherapy has to pass the placental and blood brain barrier to reach the fetal brain. However, there are also indirect effects such as inflammation and oxidative stress. Furthermore, the indirect effects of the cancer itself and its treatment, e.g., poor maternal nutrition and high maternal stress, as well as prematurity, can be related to cognitive impairment. Although the available evidence suggests that cancer treatment can be administered during pregnancy without jeopardizing the fetal chances, larger numbers and longer follow up of these children are needed.