«We paediatric oncologists set the course for the later quality of life of our patients»

Tamara Diesch (MD), senior physician in pediatric oncology and hematology at the University Children’s Hospital Basel (UKBB), specialises in fertility treatments for children and adolescents with cancer

Ms Diesch, why is fertility counselling a routine part of cancer treatment for children and adolescents at the UKBB?
Over the years, we have seen just how much suffering there can be for survivors when late effects occur due to cancer therapy. In our area, these range from the delayed onset of puberty, which can affect psychosocial health, to fertility problems with subsequent childlessness. Female patients also have an increased risk of reaching the menopause prematurely. For example, this can lead to an 18-year-old survivor suffering from symptoms of the menopause and then discovering she can’t actually have children of her own. To avoid such painful experiences as far as possible, it is important to address and take fertility-preserving measures at an early stage. That is why we conduct fertility counselling for parents and – if possible – children before we start any cancer treatment. We tell them about the risks and discuss how fertility can be preserved for the future.
 

Why is it not yet standard to have fertility counselling sessions before therapy?
We are all becoming aware of the importance of this topic in paediatric oncology. There are also more and more possibilities for preventive intervention because reproductive medicine is constantly making progress. Some procedures are still in the experimental stage, but others have already been officially recognised. In Switzerland, fertility-preserving measures for children and adolescents with cancer are not prescribed by law, unlike in other countries, and until 2019 those affected had to foot the bill themselves. But the situation is more positive when it comes to follow-up care. On the one hand, fertility counselling is a fixed standard here because we work on the basis of international guidelines in this area, and, on the other, the topic is much more relevant in this age group. For toddlers and infants, on the other hand, where sexual maturity is still a long way off, the issue does not seem quite so urgent. Here we have to think further ahead and ask ourselves what will happen when our patients reach adulthood. Then it will also become clearer why it is essential to focus on fertility at such a young age and, together with reproductive specialists who have the necessary expertise, to establish counselling services as an integral part of cancer therapy.
 

What specific options are there to preserve fertility in young cancer patients before therapy?
If the risk of infertility later in life is particularly great, various measures can be taken. These vary according to age and gender. For example, in the case of girls who have not yet reached puberty, ovaries can be partially or completely removed, frozen and then re-implanted at a later date. Re-implantation can then stimulate hormone production again. This procedure has already been used successfully for several years with post-pubertal patients. It is still at an experimental stage with pre-pubertal girls, but there is reason to believe that they too will be able to have children naturally later on using this method. The same is true for boys who have not yet reached puberty. In this case, testicular tissue is removed, frozen and later re-implanted. These advances in reproductive medicine are particularly important for us because up to two thirds of our patients have not even reached puberty yet. The established method after puberty is to freeze sperm or remove testicular tissue from which sperm are extracted. These can be used later in an IVF procedure. With girls, it is a little more complex: here, the production of the eggs has to be stimulated with hormones before they can be retrieved. This takes about two weeks, a period of time that is not always available when cancer treatment is needed urgently. Then ovarian tissue can be frozen as an alternative.
 

Can cancer therapy harm genetic material and do children of survivors have an increased risk of developing cancer themselves?
Based on numerous long-term studies, we know that this is not the case. Neither the disease nor the therapy have a damaging effect on the genetic material. Former childhood cancer patients can give birth to healthy children just like other parents. So the risk is not higher unless there is already a hereditary predisposition to cancer in the family.

Together with other partners in the health sector, you have successfully campaigned for the costs of certain fertility-preserving measures to be covered by the health insurance companies. What exactly are we talking about here?
Since 1 July 2019, the costs for the collection and storage of gametes have automatically been covered from puberty onwards and for a period of five years. This arrangement exists until a survivor has reached the age of 40 and must be renewed every five years. The costs of measures for pre-pubertal children are still not covered because they are still experimental. This is where we are pleased to be able to rely mostly on the support of foundations. Since costs incurred later, such as for IVF, are not yet covered by health insurance companies, we are planning to push in this direction. We simply can’t allow the socio-economic background of those affected by cancer to dictate anyone’s desire to have children. A political rethink is needed here to prevent young people who have survived cancer from suffering any more.
 

What exactly do you feel should be improved?
In addition to the health insurance companies covering all the costs, people should talk more openly about fertility and sexuality in general, especially during follow-up care. Often our patients have less trouble with the subject than we doctors do. Therefore, it would be equally important not only to acquire more expertise in this field, but also to improve communication and cooperation with other disciplines, such as reproductive medicine. We paediatric oncologists set the course for the later quality of life of our patients. So we should ask ourselves more often: what will happen to them when they are adults? And how can we use the methods available to us today to prevent them from experiencing suffering later? So basically I hope that we become more aware of this responsibility and act accordingly.