Fertility Preservation in Leukemia

Endocrine Late Effects in Childhood Cancer Survivors

Simple Summary

Recent advances in cancer treatment have led to improved survival, with an exponential increase in sequelae among survivors. Around 50% of survivors will experience at least one hormonal disorder, with radiotherapy, hematopoietic stem cell transplantation, and alkylating chemotherapy being the most frequently related. Therefore, lifelong monitoring of childhood cancer survivors at risk is paramount. With this review, we describe in detail the most prevalent endocrine sequelae, considering new approaches such as proton beam therapy and immune-related endocrinopathies with the advent of precision oncology treatment. We hope to encourage oncologists and endocrinologists to develop early detection guidelines that minimize sequelae and have a positive impact on their quality of life.

Abstract

Childhood cancer management has improved considerably over the years, leading to a significant improvement in survival of up to 80%. However, childhood cancer survivors are at the highest risk of developing sequelae resulting from treatment, with endocrine complications being frequently observed among survivors. Multiple predisposing factors for endocrine sequelae have been identified, including age at diagnosis, treatment received, radiation, tumor type, and genetic polymorphisms, which could explain the individual predisposition to develop drug toxicity. Novel agents targeting tumor growth and immune checkpoint inhibitors have recently become the cornerstone for the treatment of different cancers, triggering a myriad of immune-related endocrinopathies. Endocrine sequelae of cancer therapy will have an impact on not only childhood but also on the survival and quality of life of these highly complex patients. Therefore, lifelong monitoring of childhood cancer survivors at risk of endocrine diseases is paramount. Encouraging oncologists and endocrinologists to develop new follow-up and early detection guidelines that minimize sequelae among these patients has become a priority, promoting integration between pediatric and adult units since many sequelae may manifest only after years to decades of follow-up.

Fertility Preservation Using GnRH Agonists: Rationale, Possible Mechanisms, and Explanation of Controversy

The only clinically accepted method of fertility preservation in young women facing gonadotoxic chemo- and/or radiotherapy for malignant or autoimmune diseases is cryopreservation of embryos or unfertilized ova, whereas cryopreservation of ovarian tissue for future reimplantation, or in vitro maturation of follicles, and the use of gonadotropin-releasing hormone agonists (GnRHa) are still considered investigational, by several authorities. Whereas previous publications have raised the fear of GnRHa's possible detrimental effects in patients with hormone receptor-positive breast cancers, recent randomized controlled trials (RCTs) have shown that it either improves or does not affect disease-free survival (DFS) in such patients. This review summarizes the pros and cons of GnRHa co-treatment for fertility preservation, suggesting 5 theoretical mechanisms for GnRHa action: (1) simulating the prepubertal hypogonadotropic milieu, (2) direct effect on GnRH receptors, (3) decreased ovarian perfusion, (4) upregulation of an ovarian-protecting molecule such as sphingosine-1-phosphate, and (5) protecting a possible germinative stem cell. We try to explain the reasons for the discrepancy between most publications that support the use of GnRHa for fertility preservation and the minority of publications that did not support its efficiency.