Rhabdoid tumours of the kidneys and soft tissues (RTK, eMRT) – Brief information

Author:  Maria Yiallouros, Editor:  Maria Yiallouros, Reviewer:  Prof. Dr. Dr. med. Michael C. Frühwald, English Translation:  Dr. med. Gesche Riabowol (geb. Tallen), Last modification: 2026/08/27 https://kinderkrebsinfo.de/doi/e217648

General information on the disease

Rhabdoid tumours are rare, very aggressively growing tumour‎s, which mostly occur in infants and toddlers during the first two years of life. They are embryonal‎ tumours, which means that they originate from extremely immature (undifferentiated‎) cells. Rhabdoid tumours can develop in any tissue of the body. Most frequently (with about 65 %), however, they affect brain‎ and spinal cord‎ (hence the central nervous system‎, CNS).

Rhabdoid tumours outside the CNS (extracranial MRT) account for about 35 % and occur in particular in the kidneys and other soft tissue‎, such as liver, chestwall and the abdominal and pelvic region (see also chapter “Site and spread”). Soft tissue includes tissues like the muscles, fat and connective tissue as well as the tissue of peripheral nerves (peripheral nervous system‎).

Rhabdoid tumours of the kidney are also referred to as "RTK“ for short (from "rhabdoid tumour of the kidney“), whilst those of other extracranial soft tissues are referred to as "eMRT“ (from "extrarenal malignant rhabdoid tumour“). Rhabdoid tumours of the central nervous system (CNS) are known as “atypical teratoid rhabdoid tumours” – briefly AT/RT.

The following information is on extracranial rhabdoid tumours only. Information on rhabdoid tumours of the central nervous system (AT/RT) can be found here.

Site and spread

Rhabdoid tumors of the kidney (RTK) are usually large tumours in the area of the renal pelvis and the renal hilum, which is the intended slit on the inner side of the kidney, where blood vessels, nerves and the ureter pass into and out of the organ. Via the bloodstream, the tumour can infiltrate additional regions in the kidney and also form multiple metastases (satellite knots) in the entire organ [see metastasis‎]. Spread to the lungs at the timepoint of diagnosis is also common. In 10–15 % of patients with RTK, a tumour in the central nervous system‎ (AT/RT) is also detected at the time of diagnosis. In this case, the disease is called (multifocal) synchronous rhabdoid tumour.

Rhabdoid tunours of other soft tissue (eMRT) can arise in various regions of the body. Liver and head and neck muscles are affected most frequently, but abdominal tissues and the thighs, genitals and many other organ tissue (such as heart, bladder, skin, pancreas, adrenals, collarbones and peripheral nervous system‎) may develop these tumours as well. They are all fast-growing with strong tendency to spread.

Incidence

Rhabdoid tumours are overall rare. According to the German Childhood Cancer Registry (Mainz), extracranial rhabdoid tumours account for about 0.4 % of all malignant diseases in children and adolescents under 18 years of age in Germany (0.1 % of these involve the kidney, 0.3 % involve other soft tissues). According to the latest data from the European Registry for Rhabdoid Tumours (EU-RHAB), a total of 30–40 patients with rhabdoid tumours of all sites are registered in Germany each year, around eight of whom have a soft-tissue rhabdoid tumour and two to three of whom have a rhabdoid tumour of the kidney(s). One or two of the patients have tumours in different parts of the body (known as synchronous rhabdoid tumours).

The actual incidence of new diagnoses is probably a bit higher based on estimates by experts. In some countries, rhabdoid tumours are still not documented as their own entity, but registered with other entities such as Wilms tumour‎s (nephroblastoma) and sarcoma‎s due to histological‎ similarities. Because of their overall rarity, determining the exact number of cases per year and country remains challenging.

Rhabdoide Tumoren der Nieren oder Weichgewebe können in fast allen Altersgruppen vorkommen, am häufigsten betroffen (mit circa 80 %) sind Säuglinge und Kleinkinder in den ersten beiden Lebensjahren.

Rhabdoid tumours of the kidneys or other soft tissue can occur in almost every age group, infants and toddlers are the most affected (with about 80 %). The average age for rhabdoid tumours of the kidneys is between 10 and 13 months at diagnosis. Patients with soft tissue rhabdoid tumours are usually a bit older at diagnosis, however, most of them (at least 60 %) are under 10 years of age and toddlers. Synchronous, multifocal tumours are usually diagnosed significantly earlier (due to a hereditary component), the average age of these patients is a few months (also see chapter “Causes“). Overall, boys are affected a bit more frequently than girls (gender ratio: 1.1:1).

Causes

The causes leading to the development of a rhabdoid tumour are not fully understood yet. A known fact, however, is that almost all (meaning over 90–95 % of) rhabdoid tumours – regardless of their localisation in the body – harbour a structural (epigenetic‎) alteration of a certain gene‎ on chromosome‎ 22. The affected gene is the SMARCB1 gene (also known as INI1), which encodes the protein‎ SMARCB1/INI1. This protein plays a major role in controlling cellular mechanisms such as cell growth and differentiation‎. The genetic defect (mutation) leads to loss of protein function and subsequently to predisposition to malignant transformation and tumour development.

Most of the time, the mutated SMARCB1 gene is only found in the tumour cells following spontaneous malignant transformation of a somatic cell. Less frequently (in 25–30 % of patients), the germline‎ (germ cells‎) and thus all cells in the body are affected (germline mutation). Both a spontaneous genetic‎ change in the patient’s germline during embryonal development‎ and (very rarely) a defect inherited from a parent are considered as causes. In both cases the disease is hereditary, meaning that the mutated gene and thus the predisposition to develop a rhabdoid tumour can be passed on to the offspring. Experts communicate this as “Rhabdoid Tumour Predisposition Syndrome" (RTPS). However, not all individuals harbouring a SMARCB1 mutation will develop a rhabdoid tumour.

Aside from SMARCB1 mutations, SMARCA4 mutations (also known as BRG1) on chromosome 19 very rarely cause the tumour disease as well. This mutation is frequently inherited from a parent. Depending on which type of mutation has been found (SMARCB1 oder SMARCA4), the syndrome is either called RTPS1 or RTPS2.

Good to know: In case of rhabdoid tumour predisposition syndrome (RTPS1 oder 2), thus a germline mutation‎, the patient’s siblings may also be at an increased risk of developing the disease. For both kinds of the syndrome are inherited in an autosomal dominant‎ manner, which means that each child of a parent with RTPS has a 50 % risk of carrying the familial germline mutation as well. Therefore, genetic councelling for the patient’s whole family is recommended when a rhabdoid tumour is suspected (see chapter “Diagnosis”).

Symptoms

Symptoms of a rhabdoid tumour of the kidneys or other soft tissue usually develop within a few weeks or months due to the rapid tumour growth. They don’t differ from those caused by other tumour types in the affected regions.

A rhabdoid tumour of the kidneys can, in particular in young infants, present as a distended abdomen. Pain may exist as well, which, in infants and toddlers, may be associated with behavioural changes (such as crying a lot, fuzziness, irritability, sleep disturbances, refusal to feeding). Typical additional symptom‎s are fever and blood in the urine (haematuria‎); impaired bowel movements (such as constipation or diarrhea), weight loss and hypertension may also occur. Bloodwork often shows a reduced number of red blood cells (anaemia‎) and elevated serum calcium levels (hypercalcaemia). A persistent cough may be suggestive of spread to the lungs.

The symptoms of rhabdoid tumours arising from other soft tissues depend on the site and size of the tumour and may vary. Tumours closer to the body surface often present as a visible lump with or without local pain. Other symptoms are weight loss and behavioural changes, for example.

Tumours of the extremities can result in swelling and impaired circulation, even in infants. In case the eye socket is affected, patients may present with impaired eye movements/strabism. I addition, certain concomitant deformities or hereditary syndromes (rhabdoid tumour disposition syndrome) require to be checked for (see chapter “Causes“).

Good to know: Not all patients presenting with one or more of the symptoms mentioned above do have a rhabdoid tumour. Many of these symptoms may also occur with other, rather harmless diseases that are not associated with such a tumour at all. However, if certain symptoms persist or get worse, a doctor should be seen to find the underlying reason. In case it is a rhabdoid tumour, treatment should be started as soon as possible.

Diagnosis

If the paediatrician thinks that the young patient’s history (anamnesis‎) and physical examination‎ are suspicious of a malignant tumour of the kidney or soft tissue‎, the child should immediately be referred to a hospital with a childhood cancer program (paediatric oncology unit), where further diagnostics can be initiated and performed by childhood cancer professionals.

Very close collaboration between various specialists (such as paediatric oncologists, paediatric neurosurgeons, paediatric radiologists, to name a few) is required, both to find out, whether the patient really suffers from a malignant kidney or soft tissue tumour and, if so, to determine the tumour type and the extension of the disease. Knowing these details is absolutely essential for optimal treatment and prognosis‎.

Imaging tests to confirm tumour existence

The initial diagnostic procedures for a young patient presenting with a suspected rhabdoid tumour of the kidney(s) (RTK) or other soft tissues (eMRT) at a childhood cancer centre include another assessment of the patient’s history, a thorough physical exam and imaging‎ diagnostics, such as sonography‎ and magnetic resonance imaging‎ (MRI). Rapid clarification may require computed tomography‎ (emergency CT). These tests help to find out exactly whether the patient has a kidney or soft tissue tumour. Also, location and extent of the tumour as well as its demarcation regarding adjacent tissue can be diagnosed by these imaging techniques. To rule out synchronous tumours or metastases, a whole-body MRI scan is usually indicated at least once (see below, the section on tumour staging).

Tissue extraction (biopsy) and analysis to secure diagnosis

Final diagnosis of a rhabdoid tumour requieres the removal of tumour tissue (biopsy‎). This usually requires surgery. The obtained tissue will be analysed under the microscope (histologically) as well as with immunohistochemical‎, cytogenetic‎ and molecular genetic‎ methods. In particular, proof of SMARCB1 or SMARCA4 mutation‎ secures establishing the diagnosis of a rhabdoid tumour (see chapter “Causes”). In the context of immunohistochemical analysis, loss of the SMARCB1 or SMARCA4 protein as a result of the mutation can be determined by specific staining of the tumour cells. Cytogenetic and molecular genetic testing provides direct proof of the genetic defect.

Once a SMARCB1 or SMARCA4 mutation has been confirmed for the tumour tissue, blood cells (or any other tumour-free tissue) will be tested for the mutation as well in order to rule out a germline mutation‎ and rhabdoid tumour predisposition syndrome (RTPS), since in case of a germline mutation, the blood cells (or other tissue cells) do contain the mutation as well. The germline mutation is particularly suspected in children under two years of age, in patients with tumours at multiple sites (synchrone tumours) or in case of a family history of tumour diseases, respectively.

In case a family history of rhabdoid tumour predisposition syndrome (RTPS1 or RTPS2) is known prior to biopsy, testing only the patient’s blood for mutation can – in very rare situations (for example, if the child is too ill to be operated) – be sufficient to confirm diagnosis. This is because a malignant tumour revealed by diagnostic imaging and with SMARCB1 or SMARCA4 mutation in the patient’s blood cells is most likely a rhabdoid tumour.

Aside from the examination of tumour tissue for a SMARCB1 or SMARCA4 mutation, the determination of the DNA methylation‎ profile is becoming increasingly important. With the help of this molecular genetic method, AT/RT can be divided into three different molecular‎ (epigenetic‎) subtypes (ATRT-MYC, ATRT-SHH, ATRT-TYR), some of which also behave differently regarding their growth pattern (see chapter "Therapy planning").

Good to know: Diagnosis of a germline mutation not only affects a patient’s prognosis, but also other family members, especially regarding the need for subsequent screening tests (see recommendations in case of a rhabdoid tumour predisposition syndrome below).

Tests to assess spread of disease (tumour staging)

Once the diagnosis of a rhabdoid tumour has been confirmed, additional tests are required to assess the extent of the disease within the body (stage of disease). Since rhabdoid tumours are known to metastasise frequently and also may be found at multiple sites already at diagnosis, for example in the kidneys and simultaneously in the central nervous system‎ (CNS) (multiple, synchronous rhabdoid tumour), the initial finding of a single tumour is always followed by diagnostic imaging of the whole body.

Usually, this involves at least one whole-body MRI‎ scan and one MRI scan of the central nervous system (CNS). If a tumour in CNS is suspected, the cerebrospinal fluid‎ (CSF) is microscopically checked for tumour cells in the spinal cord (which are not visible by MRI scan). Cerebrospinal fluid is mostly obtained from the spine in the lower back (lumbar puncture‎), since the risk of the puncture needle damaging the spinal cord is lowest at the lower back level.

Tests before treatment begins

In preparation for the intensive treatment of the brain tumour, further investigations are performed, such as electrocardiography‎ (ECG) and/orechocardiography‎ to check cardio function or electroencephalography‎ (EEG) to test brain function. Furthermore, blood tests are needed to assess the patient’s general health condition and to check whether the function of certain organs (such as liver and kidneys) is affected by the disease and whether there are any metabolic disorders to be considered prior or during therapy. Any changes that may occur during the course of treatment can be identified at an early stage and assessed more effectively on the basis of such initial findings.

Recommendations if a rhabdoid tumour predisposition syndrome is suspected

If a patient is diagnosed with a SMARCB1 germline mutation‎ – and, subsequently, is at an increased risk for developing a rhabdoid tumour (rhabdoid tumour predisposition syndrom, RTPS) –, one possible reason may be that the disease has been inherited by one parent. In most of the cases, however, it is more likely that the genetic defect is a result of a new SMARCB1 mutation‎.

If inheritance is the case, both the patient’s parents and siblings are at a higher risk to develop a rhabdoid tumour as well (see chapter „Causes“). In order to rule out this risk or to diagnose it as early as possible, certain blood tests will be recommended to both parents first. If those come back positive for a germline mutation in one of the parents, the patient’s siblings should also be tested. These tests are usually done in human genetics laboratories. Also, genetic councelling is recommended.

If a rhabdoid tumour predesposition syndrome is known in the family and a germline mutation is found in a so far healthy family member, it is recommended that the affected child(ren) is (are) closely monitored from birth by regular physical/neurological‎ examinations, magnetic resonance imaging‎ and ultrasound‎ (of the head, abdomen and chest).

Treatment planning

After the diagnosis has been confirmed, therapy is planned. In order to design a highly individual, risk-adapted treatment regimen for the patient, certain individual factors influencing the patient’s prognosis‎ (called risk factors or prognostic factors‎) are being considered during treatment planning (risk-adapted treatment strategy).

One important prognostic factor is the patient‘s age at diagnosis: it determines treatment intensity and, therefore, has an impact on the patient’s chances of survival. For example, radiotherapy – a very efficient treatment method for rhabdoid tumours – must always be carefully considered in children under 3 years of age or under 12–18 months, depending on the location of the tumour. Radiotherapy for lung metastases presents a real challenge in very young children. Also, the tolerance of this treatment is significantly reduced in very young children when compared to other methods (such as surgery, chemotherapy).

Whether the condition is hereditary or not, as well as the location and extent of the rhabdoid tumour, are further factors that influence the patient’s prognosis. Hereditary disease (germline mutation‎), that is, a rhabdoid tumour predisposition syndrome (RTPS), is known as an unfavourable prognostic factor and so is metastasis‎ at the timepoint of tumour diagnosis. Both scenarios are associated with a lower probability of eliminating all tumour manifestations (which is known to promote favourable prognosis). Response of the disease to chemotherapy is also an important prognostic factor.

All these factors are included in treatment planning in order to achieve the best outcome possible for each patient by selecting the most appropriate therapy in each case.

Good to know: As part of treatment planning, patients are assigned to one of two different risk groups depending on their prognosis: a standard-risk group and a high-risk group. The standard-risk group comprises patients with a locally confined, non-hereditary tumour that has been completely removed or is removable. High-risk patients are characterised by being under 1 year of age at diagnosis, the presence of distant metastases, incomplete tumour removal and/or the detection of a germline mutation.

Treatment

Treatment of children and adolescents with rhabdoid tumour should take place in a children's hospital with a paediatric oncology program. Only such a childhood cancer centre provides highly experienced and qualified staff (doctors, nurses and many more), since they are specialised and focussed on the diagnostics and treatment of children and teenagers with cancer according to the most advanced treatment concepts. The doctors in these centres collaborate closely with each other. Together, they treat their patients according to treatment plans (protocols) that are continuously optimised.

The goal of the treatment is to achieve high cure rates while avoiding side effects as much as possible. Considering the usually very young age of patients with a rhabdoid tumour, this is a huge challenge. Infants and toddlers are highly vulnerable; they suffer severely of acute side effects and long-term sequelae of the aggressive therapy and are therefore hard to treat. Hence, the most important step prior to or during therapy is to decide whether treatment should be initiated or continued, respectively, and if so, whether the goal is cure (curative approach) or managing symptoms (palliative therapy‎).

Since 2007, patients with rhabdoid tumour have received treatment according to a standardised therapy protocol under the roof of the EU-RHAB Registry (so-called consensus treatment strategy, see chapter „Therapy optimising trials and registries”). The following information on therapy is based on this consensus treatment strategy.

Treatment methods

Treatment options for patients with rhabdoid tumour include surgery, chemotherapy and radiotherapy. For very few patients, high-dose chemotherapy followed by autologous stem cell transplantion may be an option, too. The individual treatment choice is based on the patient’s age and general health status as well as on the tumour type and its extent at diagnosis and after surgery.

Surgery and radiotherapy‎ are the most promising therapy methods and of highest impact in the treatment of patients with a rhabdoid tumour. Yet, surgery‎ or radiation cannot be performed in every child. Radiotherapy, for example, is only possible from a certain age. Chemotherapy (and, for some patients, high-dose chemotherapy‎ followed by stem cell transplantation‎) can help improve prognosis and – particularly in very young children – delay or even completely avoid radiotherapy.

Surgery

First step when treating a patient with rhabdoid tumour is maximal surgical tumour removal [see surgery‎], if possible, since the extent of tumour resection seems to have a major impact on the subsequent course of the disease. The more radically the tumour can be resected, the higher are the chances of long-term survival. If the tumour is localised and has not spread, second look surgery to achieve gross total removal is an option. In some cases, it is not possible to remove the tumour completely. This is related to the frequently unfavourable tumour location, the patient’s young age as well as the frequent presence of metastases [see metastasis‎] at the timepoint of tumour diagnosis.

Chemotherapy

Surgery is followed by intensive chemotherapy‎ in order to improve the patient’s chances of cure. Chemotherapy uses drugs (so-called cytostatic agents or cytostatics‎) that can kill fast-dividing cells, such as cancer cells, or inhibit their growth, respectively. In order to optimise treatment efficacy, combinations of different cytostatics are given in different treatment blocks.

Standard therapy according to the current guideline consists of two phases, an induction and a consolidation phase, and currently includes twelve chemotherapy blocks for all patients. Induction therapy aims at a maximum possible control of the tumour and/or the tumour cell count, while the aim of consolidation therapy is to maintain (consolidate) the results gained by induction. The therapy includes the agents doxorubicine (DOX) and combinations of ifosfamide, carboplatin and etoposide (briefly: ICE) or vincristine, cyclophosphamide and actinomycin D (briefly: VCA), respectively, which are given intravenös‎intravenously in alternation. By the intravenous route, they get distributed in the blood system and can, thus, eliminate tumour cells throughout the whole body (systemic‎ chemotherapy).

If the tumour also affects the brain (synchronous tumour), some chemotherapy (methotrexate, MTX) is additionally given directly into the cerebrospinal fluid‎, which surrounds both brain and spinal cord. This intraventricular or intrathecal chemotherapy‎ is necessary, because most chemotherapeutic agents cannot pass the barrier between blood and brain (blood-brain barrier‎). For more information on the treatment of rhabdoid tumours of the central nervous system (AT/RT), please see our patient information on AT/RT.

Radiation therapy

Depending on the patient’s age at the timepoint of treatment, radiotherapy‎ may be recommended during or after chemotherapy. Radiotherapy is carried out using energy-rich, electromagnetic‎ radiation, given through the skin to the tumour region. Radiation causes DNA‎ damage in tumour cells, thereby leading to cell death.

Aside from complete surgical tumour removal, radiotherapy is one of the most important and successful measures for treatment of a rhabdoid tumour. It has been shown to lead to a significantly better treatment outcome (long-term survival) compared with treatment without radiotherapy, particularly in slightly more advanced stages of the disease. However, its application is limited due to treatment-induced late effects. This applies in particular to young children and infants under the age of three or under 12–18 months, for whom radiotherapy (depending on the location of the tumour and the size of the radiation field) can lead to serious physical consequences.

For example, administering radiotherapy too early to tumours near the spine or in the extremities (such as the thigh) can cause severe growth disorders, whilst radiotherapy to the developing brain can cause serious impairment of normal cognitive‎ development. Therefore, chemotherapy and, if applicable, even high-dose chemotherapy‎ are used to delay radiotherapy as long as possible. For children under 12 months, radiotherapy is always a case-by-case decision and must be discussed with the radiotherapy team.

If radiotherapy is an option, timing, volume and type (photon‎s versus proton‎s) are determined based on the patient’s age, the vulnerability of the tissue and prognostic factors.

Modern radiation techniques, such as intensity-modulated radiotherapy‎ (IMRT), help minimise the damage of healthy tissue. For some patients, radiotherapy with protons instead of conventional radiotherapy (with photons) may be an option, for example for very young children or in case proton therapy‎ is expected to have a clear advantage compared to conventional radiotherapy. This type of radiotherapy allows to reduce the effects of radiation in healthy tissue even better and is, therefore, gaining an increasing importance in the treatment of children and teenagers with solid tumours.

High-dose chemotherapy and autologous stem cell transplantation

For some patients, high-dose chemotherapy‎ as a consolidation treatment followed by autologous stem cell transplantation‎ may be an option instead of the conventional chemotherapy described above. In this case, the patient receives treatment with carboplatin and thiotepa (CARBO/TT) after six cycles of standard chemotherapy (induction therapy, see chapter “chemotherapy”). The chemotherapy doses of this regimen are considered high enough to also eliminate otherwise treatment-resistant tumour cells in the body.

However, high-dose chemotherapy is only considered in isolated cases at most. This treatment option will therefore not be discussed further here. For general information on stem cell transplantation please see here.

New treatment approaches

Despite the currently available intensive treatment modalities, cure rates for chil-dren with RTK or eMRT are unsatisfying. This particularly applies to high-risk patients (young age at diagnosis, germline mutation‎ and/or metastasised tumour). In addition, the intensive treatment does not only cause acute side effects, but also long-term sequelae (such as hormonal deficits, which are associated with certain developmental delays, or impaired organ function (for example, loss of a kidney, loss of muscle mass or loss of an eye). This may seriously impair the patients’ quality of life.

Scientists keep studying these tumours intensely to find new agents and treatment modalities. The current research focuses on the molecular‎ mechanisms leading to the developments and growth of rhabdoid tumours. The analysis of cellular signalling pathways that are altered in rhabdoid tumours have helped identifying different agents, which may be of benefit in the treatment of rhabdoid tumours. Promising new treatment strategies will be examined in the framework of clinical studies.

For patients with a relapse of an RTK or eMRT, various approaches apply to individual treatment attempts. These include epigenetic‎ally active agents like decitabine on the one hand, but also the drug ribociclib and so-called checkpoint inhibitor‎. Another therapy option is a metronomic therapy‎s, for example within the framework of the MEMMAT protocol.

Unfortunately, there are no phase I/II studies open for children. The researchers at the EU-RHAB-Registry are working hard to find new drugs and get them approved for clinical use. This should always be carried out as clinical studies (see also next chapter).

Therapy optimising trials and registries

In the large paediatric treatment centres, children and teenagers with rhabdoid tumour receive therapy according to guidelines and/or standardized treatment plans (protocols). These protocols are designed by experts with the goal to im-prove the patient’s prognosis‎ and are usually applied within therapy optimising trials‎ or registries. Therapy optimising trials are standardised and controlled clinical trials that aim at steadily developing and improving treatment concepts for sick patients based on the current scientific knowledge.

Patients who cannot participate in any study, for example because none is available or open for them at that time, or since they do not meet the required inclusion criteria, respectively, are often included in a so-called registry. Such a registry primarily serves to acquire all clinical, molecular genetic‎ and treatment-associated patient data in order to gain a better understanding oft he tumour biology. Furthermore, the registry center supports the doctors at site with (non-commital) treatment recommendations based on the most recent data on best treatment options, in order to provide the patient with optimal therapy even without the framework of a clinical study.

Currently available for patients with RTK or eMRT is the EU-RHAB registry.

European Rhabdoid Registry (EU-RHAB Registry)

Since rhabdoid tumours are very rare, experts of the Society of Paediatric Oncology and Haematology (GPOH‎) initiated during a consensus conference in Italy in 2007 that all patients with rhabdoid tumours in a part of Europe should be registered with the European Rhabdoid Registry (EU-RHAB Registry) and treated according to a standardised strategy (consensus strategy). The treatment regimen was designed by an international competence network and is outlined in the chapter “Treatment”. It has been validated as standard therapy for all rhabdoid tumours (regardless of their location in the body), unless the patient is not treated within the experimental arm of a trial, and requires adjustment to the individual patient.

Numerous countries worldwide are currently registering their patients with this EU-RHAB Registry. Treatment centres in Germany, where children and adoles-cents with cancer are being treated, are legally obliged to register their patients with the appropriate studies or registries. The decision on whether treatment will be according to the registry’s recommendations, is made locally by the individual treatment group. As parents, you are encouraged, however, to ask for treatment for your child according to the EU-RHAB recommendations. The European Registry headquarters are located at the University Hospital in Augsburg, Germany, and the principal investigator is Prof. Dr. Dr. med. Michael C. Frühwald. Please note: The new EU RHAB 2.0 registry has recently been opened.

New trials

Within the framework of EU-RHAB, new studies are also being developed based on previously acquired data. A phase I/II study is currently under development to test a new substance that is presumably effective in rhabdoid tumours. In addition, a new treatment protocol is being developed for the treatment of patients with disease relapse.

Prognosis

The chances of cure (prognosis‎) for children with a rhabdoid tumour of the kidney(s) or other soft tissues have significantly improved thanks to standardised, multimodal treatment concepts within the framework of EU-RHAB. Patients treated in the most favourable risk (therapy) group meanwhile present with 5-year-survival rates of more than 7.2 %. For patients with unfavourable prognostic factors‎, however, prognosis is still not favourable, despite the intensive therapy. According to data of the EU-RHAB Registry, the average overall 5-year-survival rate (for all risk groups taken together) is about 40–51 %.

Important prognostic factors are the patient’s age at diagnosis, tumour type (hereditary or non-hereditary, molecular‎ subtype) as well as tumour size, site and extent and, thus, possibility of complete tumour removal (see chapter “Treatment planning”). Survival rates are thus different in individual patients:

• patients with localised, non-metastasised, non-synchronous, surgically remov-able and non-hereditary rhabdoid tumour, who are older than three years of age at diagnosis, usually have favourable probabilities of cure, given that the tumour can be completely removed, early radiotherapy is possible and the tumour responds well to chemotherapy.
• children between their first and third birthday with the same co-factors have a comparably higher risk of relapse.
• Prognosis is particularly unfavourable for infants and toddlers under one year of age, especially if they present with metastases [see metastasis‎], a synchronous tumor or germline mutation‎.
• Patients with a rhabdoid tumour of the kidney (RTK) generally have a poorer prognosis than patients with rhabdoid tumours of other soft tissues (eMRT). This is partly due to the fact that RTK patients are often younger than eMRT patients and are more likely to have synchronous and/or advanced/metastatic disease at the time of diagnosis. Furthermore, probably due to a higher proportion of germline mutations, relapses occur more frequently, and the response to chemotherapy is also poorer than in patients with eMRT.

However, there are patients who do benefit from treatment (surgery, chemotherapy, in some cases high-dose chemotherapy and radiotherapy) despite of unfavourable prognostic factors, so that long-term survival may be possible. New molecular treatment approaches are currently being analysed in the framework of therapy optimising trials. The goal is to optimise cure rates also for high-risk patients.

Note: The survival rates mentioned in the text above are statistical values. Therefore, they only provide information on the total cohort of patients with rhabdoid tumours. They do not predict individual outcomes.