Dexamethasone does not prevent malignant cell reintroduction in leukemia patients undergoing ovarian transplant: risk assessment of leukemic cell transmission by a xenograft model.

STUDY QUESTION: Does dexamethasone (DXM) incubation avoid the reintroduction of leukemic malignant cells after ovarian tissue retransplantation in vivo? SUMMARY ANSWER: DXM incubation prior to retransplantation of ovarian tissue does not prevent reintroduction of leukemic cells. WHAT IS KNOWN ALREADY: Retransplantation of cryopreserved ovarian cortex from patients diagnosed with acute lymphoblastic leukemia (ALL) involves a risk of reintroducing malignant cells. DXM treatment is effective at inducing leukemic cell death in vitro. STUDY DESIGN, SIZE, DURATION: This was an experimental study where ovarian cortex fragments from patients with ALL were randomly allocated to incubation with or without DXM (n = 11/group) and grafted to 22 immunodeficient mice for 6 months. In a parallel experiment, 22 immunodeficient mice were injected i.p. with varying amounts of RCH-ACV ALL cells (human leukemia cell line) and maintained for 4 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: Cryopreserved ovarian fragments from patients with ALL were exposed in vitro to 0.4 µM DXM or basal media (control) prior to xenograft into ovariectomized severe combined immunodeficiency (SCID) mice (experiment 1). After 6 months of monitoring, leukemia cell contamination was assessed in ovarian grafts and mouse organs by histology, PCR (presence of mouse mtDNA and absence of p53 were together considered a negative result for the presence of human cells) and detection of immunoglobulin monoclonality and specific ALL markers if present in the patient.In experiment 2, a series of 22 immunodeficient female mice was injected with specific doses of the leukemia cell line RCH-ACV (103 - 5 × 106, n = 4/group) to assess the engraftment competence of the SCID model. MAIN RESULTS AND THE ROLE OF CHANCE: ALL metastatic cells were detected, by PCR, in five DXM-treated and one control human ovarian tissue graft as well as in a control mouse liver, although malignant cell infiltration was not detected by histology in any sample after 6 months. In total, minimal residual disease was present in three DXM-treated and three control mice.RCH-ACV cells were detected in liver and spleen samples after the injection of as little as 103 cells, although only animals receiving 5 × 106 cells developed clinical signs of disease and metastases. LIMITATIONS, REASONS FOR CAUTION: This is an experimental study where the malignant potential of leukemic cells contained in human ovarian tissues has been assessed in immunodeficient mice. WIDER IMPLICATIONS OF THE FINDINGS: These results indicate that DXM incubation prior to retransplantation of ovarian tissue does not prevent reintroduction of leukemic cells. Therefore, caution should be taken in retransplanting ovarian tissue from patients with leukemia until safer systems are developed, as leukemic cells present in ovarian grafts were able to survive, proliferate and migrate after cryopreservation and xenograft. STUDY FUNDING/COMPETING INTEREST(S): Funded by the Regional Valencian Ministry of Education (PROMETEO/2018/137) and by the Spanish Ministry of Economy and Competitiveness (PI16/FIS PI16/01664 and PTQ-16-08222 for S.H. participation). There are no competing interests.

Personalized Medicine in Infant Population with Cancer: Pharmacogenetic Pilot Study of Polymorphisms Related to Toxicity and Response to Chemotherapy.

BACKGROUND: Pharmacogenetics is a personalized medicine tool that aims to optimize treatments by adapting them to each individual's genetics, maximizing their efficacy while minimizing their toxicity. Infants with cancer are especially vulnerable, and their co-morbidities have vital repercussions. The study of their pharmacogenetics is new in this clinical field. METHODS: A unicentric, ambispective study of a cohort of infants receiving chemotherapy (from January 2007 to August 2019). The genotypes of 64 patients under 18 months of age were correlated with severe drug toxicities and survival. A pharmacogenetics panel was configured based on PharmGKB, drug labels, and international experts' consortiums. RESULTS: Associations between SNPs and hematological toxicity were found. Most meaningful were: MTHFR rs1801131 GT increasing the anemia risk (OR 1.73); rs1517114 GC, XPC rs2228001 GT, increasing neutropenia risk (OR 1.50 and 4.63); ABCB1 rs1045642 AG, TNFRSF11B rs2073618 GG, CYP2B6 rs4802101 TC and SOD2 rs4880 GG increasing thrombocytopenia risk (OR 1.70, 1.77, 1.70, 1.73, respectively). Regarding survival, MTHFR rs1801133 GG, TNFRSF11B rs2073618 GG, XPC rs2228001 GT, CYP3A4 rs2740574 CT, CDA rs3215400 del.del, and SLC01B1 rs4149015 GA were associated with lower overall survival probabilities (HR 3.12, 1.84, 1.68, 2.92, 1.90, and 3.96, respectively). Lastly, for event-free survival, SLC19A1 rs1051266 TT and CDA rs3215400 del.del increased the relapse probability (HR 1.61 and 2.19, respectively). CONCLUSIONS: This pharmacogenetic study is a pioneer in dealing with infants under 18 months of age. Further studies are needed to confirm the utility of the findings in this work to be used as predictive genetic biomarkers of toxicity and therapeutic efficacy in the infant population. If confirmed, their use in therapeutic decisions could improve the quality of life and prognosis of these patients.

[Current state regarding fertility cryopreservation in pre-pubertal boys]. / Estado actual de la criopreservación de la fertilidad en varones prepúberes.

Some treatments for any cancer therapy and hematological diseases may have gonadotoxic side effects that can result in infertility, and thus sperm cryopreservation is routinely offered to patients as the strategy to preserve their fertility. However, there are many cases where sperm banking cannot be applied, as is the case of pre-pubertal cancer patients and others unable to produce mature gametes at the moment of diagnosis. Regarding this, recent breakthroughs have gained public attention to the fertility preservation options that Regenerative Medicine can offer to these patients. In this review, we tried to compile and discuss the latest updates about all these strategies from a critical point of view.

Basic and Clinical Approaches for Fertility Preservation and Restoration in Cancer Patients.

As gonadotoxic adverse effects of antineoplastic treatments can result in infertility, gamete cryopreservation is routinely offered to patients as the strategy to preserve their fertility. However, there are many cases where gold standards cannot be applied, as is the case for prepubertal cancer patients and others unable to produce gametes or their precursors at the moment of diagnosis. With an increasing number of cancer survivors in our society, strategies using either cryopreserved gonadal tissue or stem cells have been developed to allow cancer survivors to achieve fatherhood, and recent advances in the field have increased public interest. In this review, we discuss the latest updates in fertility preservation from a basic and a clinical point of view.