Evaluation of the Gonadotoxicity of Cancer Therapies to Improve Counseling of Patients About Fertility and Fertility Preservation Measures: Protocol for a Retrospective Systematic Data Analysis and a Prospective Cohort Study

BACKGROUND

Cytotoxic treatments such as chemo- and radiotherapy and immune therapies are required in cancer diseases. These therapies have the potential to cure patients but may also have an impact on gonadal function and, therefore, on fertility. Consequently, fertility preservation treatments such as freezing of gametes and gonadal tissue might be required. However, as detailed data about the necessity to perform fertility preservation treatment are very limited, this study was designed to fill this data gap.

OBJECTIVE

Primary objective of this study is to analyze the impact of cancer therapies and chemotherapies on the ovarian reserve and sperm quality. Secondary objectives are to analyze the (1) impact of cancer therapies and chemotherapies on other fertility parameters and (2) probability of undergoing fertility preservation treatments in relation to specific cancer diseases and treatment protocols and the probability to use the frozen gametes and gonadal tissue to achieve pregnancies.

METHODS

First, previously published studies on the gonadotoxicity of chemo- and radiotherapies among patients with cancer will be systematically analyzed. Second, a prospective cohort study set up by approximately 70 centers in Germany, Switzerland, and Austria will collect the following data: ovarian function by analyzing anti-Müllerian hormone (AMH) concentrations and testicular function by analyzing sperm parameters and total testosterone immediately before and around 1 year after gonadotoxic therapies (short-term fertility). A follow-up of these fertility parameters, including history of conceptions, will be performed 5 and 10 years after gonadotoxic therapies (long-term fertility). Additionally, the proportion of patients undergoing fertility-preserving procedures, their satisfaction with these procedures, and the amount of gametes and gonadal tissue and the children achieved by using the frozen material will be analyzed. Third, the data will be merged to create the internet-based data platform FertiTOX. The platform will be structured in accordance with the ICD (International Classification of Diseases) classification of cancer diseases and will be easily be accessible using a specific App.

RESULTS

Several funding bodies have funded this study. Ten systematic reviews are in progress and the first one has been accepted for publication. All Swiss and many German and Austrian ethics committees have provided their approval for the prospective cohort study. The study registry has been set up, and a study website has been created. In total, 50 infertility centers have already been prepared for data collection, which started on December 1, 2023.

CONCLUSIONS

The study can be expected to bridge the data gap regarding the gonadotoxicity of cancer therapies to better counsel patients about their infertility risk and their need to undergo fertility preservation procedures. Initial data are expected to be uploaded on the FertiTOX platform in 2026.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05885048; https://clinicaltrials.gov/study/NCT05885048.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51145.

Learning Chronobiology by Improving Wikipedia

Although chronobiology is of growing interest to scientists, physicians, and the general public, access to recent discoveries and historical perspectives is limited. Wikipedia is an online, user-written encyclopedia that could enhance public access to current understanding in chronobiology. However, Wikipedia is lacking important information and is not universally trusted. Here, 46 students in a university course edited Wikipedia to enhance public access to important discoveries in chronobiology. Students worked for an average of 9 h each to evaluate the primary literature and available Wikipedia information, nominated sites for editing, and, after voting, edited the 15 Wikipedia pages they determined to be highest priorities. This assignment ( http://www.nslc.wustl.edu/courses/Bio4030/wikipedia_project.html ) was easy to implement, required relatively short time commitments from the professor and students, and had measurable impacts on Wikipedia and the students. Students created 3 new Wikipedia sites, edited 12 additional sites, and cited 347 peer-reviewed articles. The targeted sites all became top hits in online search engines. Because their writing was and will be read by a worldwide audience, students found the experience rewarding. Students reported significantly increased comfort with reading, critiquing, and summarizing primary literature and benefited from seeing their work edited by other scientists and editors of Wikipedia. We conclude that, in a short project, students can assist in making chronobiology widely accessible and learn from the editorial process.

Simultaneous impedimetric and amperometric interrogation of renal cells exposed to a calculus-forming salt

The complexity of the cellular response, induced even by the simplest experimental stimulus, requires an increased number of cellular parameters to be simultaneously monitored. An all electrochemical system allowing the simultaneous and real-time monitoring of both cell adherence and superoxide release into the extracellular space was developed to address this challenge. Cell adherence (to neighboring cells and to substrate) was monitored using non-faradaic impedance spectroscopy while the superoxide release was monitored using a cytochrome c-based amperometric biosensor. The system was used to observe for the first time how these two cellular parameters are changing in real-time for renal cells exposed to calcium oxalate, a calculus-forming salt. It was discovered that calcium oxalate crystals decrease cell adherence and in the same time induce oxidative stress by an overproduction of superoxide. Subconfluent cells, without fully developed tight junctions, appear to be more vulnerable than confluent cells with tight junctions indicating the important protective role of these junctions.

Effect of calcium oxalate on renal cells as revealed by real-time measurement of extracellular oxidative burst

Calcium oxalate is one of the main constituents of kidney stones and has a proved deleterious effect on renal cells that is mediated by oxidative stress. However, the subcellular source of this oxidative stress, and whether it is extending to the extracellular space or not, is still disputed. Therefore, an electrochemical superoxide biosensor was constructed, positioned above A6 renal cells, and used to measure in real-time the extracellular oxidative burst following addition of calcium oxalate crystals. It was observed that A6 cells do secrete superoxide into their extracellular space in few minutes after encountering calcium oxalate crystals. The amount of released superoxide peaks at about 20 min. Superoxide is cleared away from the extracellular space after approximately 3h. Superoxide secretion depends on the presence of superoxide-scavenging enzyme superoxide dismutase, the age of the cells, the amount of calcium oxalate crystals, and the temperature. Moreover, the effect of calcium oxalate crystals was mimicked by phorbol 12-myristate 13-acetate. The developed sensing system can be a useful tool for biologists investigating nephrolithiasis at cellular level.

Clinical manifestations in the West Nile virus outbreak

During the summer of 1996 an unusual clustering of meningoencephalitis cases was recorded in the Capital City, Bucharest, and in some areas from South-East Romania. After an initial suspicion of an enteroviral etiology was discarded, the West Nile etiology was confirmed by specific antibodies demonstration through hemagglutination-inhibition and ELISA tests. This study included 251 patients with the diagnoses of West Nile acute encephalitis (166 cases), acute meningitis (57 cases) and acute febrile disease (33 cases). The patients' age ranged from 1 to 89 years (mean 51.1 years). The most frequent clinical manifestations were: fever (95.7% of cases), cephalalgia (92.6%), stiffness of the neck (89.1%), vomiting (62.5%), marked asthenia (46.5%), myalgia (28.9%). In addition, patients with encephalitis exhibited: alteration of consciousness (89.2% of cases), tremor of extremities (40.4%), ataxia (44%), paralysis (15.1%). The fatality rate was 15.1% in acute encephalitis, 1.8% in acute meningitis and 0% in the acute febrile disease.

Chlorpromazine-induced decrease of red cell aggregability

Starting from the assumption that binding of chlorpromazine to the erythrocyte membrane might influence th rheology of these cells, the authors studied erythrocyte aggregability and deformability by means of a filtrability test in 42 neurotics and 16 patients with personality disorders, all males, aged 20 to 27 years, clinically healthy from the somatic view point. Determinations were carried out before and 30 min after a single i.m. dose of 1 mg/kg b.w. chlorpromazine (14 patients) and before and after a 5-day oral treatment with 3 mg/day haloperidol (11 patients) or 75 mg/day chlorpromazine (33 patients). Chlorpromazine induced a significant decrease of erythrocyte aggregability after 5 days of oral treatment (p less than 0.02) the effect being more marked in the patients with relatively high initial values (p less than 0.01). The mechanism of this phenomenon and its possible implications of ESR determination and in the therapy of occlusive vascular diseases are discussed.

Erythrocyte rheology in acute cerebral thrombosis. Effects of ABO blood groups

Within a few hours after a cerebral thrombosis in 220 patients, the flow-properties of the red blood cells (RBC) were analyzed by a filtration test that expresses quantitatively the deformability and aggregability of the RBC by the filtration indexes pT. Abnormal deformability of the RBC washed clean of plasma was found in 27.5% of the patients. Aggregability disorders, caused by the plasma trapped between the unwashed RBC, were found in 78.6% of the patients: computation of correlation coefficients between pT indexes and fibrinogen, which was found abnormally high in 88.2% of cases, demonstrated significantly that in the patients with A and B blood groups these aggregability disorders were due to fibrinogen and that they were caused by other components of plasma in patients with O and AB blood groups. All these disorders can account for blood hyperviscosity.

Two cases of choreatic syndrome caused by polycythemia vera

Two patients with choreatic syndromes caused by polycythemia vera recovered after treatment of the polycythemia by only two venesections: this proves that the syndrome is due to reversible alterations. Investigations of the cerebral circulation in one of the patients showed that blood flow was lowest in the grey matter at the basal region of the brain: this suggests that the alterations might mainly occur there. However, investigation of erythrocyte rheology, glucose-6-phosphate dehydrogenase, serum concentrations of caeruloplasmin and serotonin, and urinary excretion of epinephrine, norepinephrine and vanillylmandelic acid gave normal results in both patients. There are therefore no indications as to the possible pathophysiology of these alterations. There are now 24 cases reported, including our 2 patients, which suggests that the association of these two diseases may not be so rare as supposed.

Radioisotope investigations in some hemolytic disorders of children

Ferrokinetics and life-span of erythrocytes were investigated with 59Fe and 51Cr respectively, in 15 children with thalassemia major, aged between 18 months and 15 years (five of which had been splenectomized), and in 8 children with hereditary spherocytosis aged between 12 and 14 years. In all cases studied with 59Fe there was low tracer incorporation in erythrocytes, but no correlation of this parameter to the amount of Hb F. The use of radioisotopes in studies of hemolytic disorders of children is stressed, primarily when splenectomy is considered. Investigation of ferrokinetics in thalassemic children is useful for monitoring advanced stages of the disease.

Cerebral thrombosis, cerebral haemorrhage, and ABO blood-groups

The ABO blood-group distributions of 1460 patients who had died from a stroke were compared with those of a control group of 20 705 controls selected at random from the healthy population at risk (i.e., over thirty-five years of age and matched for age and sex ratio). The cause of death was certified as cerebral thrombosis in 329 cases and as cerebral haemorrhage in 482 cases, these diagnoses being established in neurological hospitals; the remaining 649 cases had an unspecified type of stroke, the diagnosis being made by general practitioners. In the group with unspecified type of stroke the blood-group distribution was practically the same as the distribution in the controls. In the thrombosis cases there was an excess of blood-groups A and AB and a deficiency of O and B; in cerebral haemorrhage this situation was reversed. However, these were only trends; the differences were not significant at the 5% level. A statistically significant difference did emerge when the A+AB excess in thrombosis was contrasted with the O+B excess in haemorrhage, suggesting that this difference might be accounted for the major A subgroup (A1) and, consequently, A1B.