Rhabdoid tumour of the kidney is one of the most aggressive and fast-growing childhood cancers, primarily affecting infants and toddlers. Treatment strategies combine intensive surgery, powerful chemotherapy, and radiation therapy, while researchers worldwide are exploring innovative approaches in clinical trials to improve outcomes for these youngest patients.

Understanding Treatment Goals for This Aggressive Childhood Cancer

When a child is diagnosed with a rhabdoid tumour of the kidney, the main focus of treatment is to remove the cancer as completely as possible, prevent it from spreading further, and give the child the best chance of survival. This type of cancer grows and spreads extremely quickly, which means that medical teams must act fast and use very strong treatments. Because rhabdoid tumours are so rare—affecting fewer than 1 in every million children—doctors don’t yet have a single “standard” treatment plan that works for everyone. Instead, treatment is carefully tailored to each child’s specific situation, taking into account the size and location of the tumour, whether the cancer has already spread to other parts of the body, the child’s age, and overall health.^[1][2]

The treatment approach usually involves a combination of several methods working together. Surgery is typically the first step, where doctors try to remove as much of the tumour as they can. After that, powerful medications called chemotherapy (drugs that kill fast-growing cancer cells) are given to destroy any remaining cancer cells. In some cases, radiation therapy (high-energy beams that target and kill cancer cells) may also be used, especially for children older than six months. The overall goal is not just to eliminate the cancer, but also to manage symptoms, reduce suffering, and support the child’s quality of life throughout this challenging journey.^[2][11]

Medical societies and expert groups have established guidelines based on years of experience treating children with kidney cancers, but because rhabdoid tumours are so aggressive and rare, there is no universally agreed-upon protocol. This has led researchers and doctors around the world to conduct ongoing studies and clinical trials, testing new drugs and treatment combinations that might work better. These trials are exploring innovative therapies that target the specific biological mechanisms driving this cancer, offering hope for improved survival rates in the future.^[4][12]

Standard Treatment Approaches: Surgery, Chemotherapy, and Radiation

The cornerstone of treating rhabdoid tumour of the kidney is surgery. In most cases, the first and most critical step is an operation to remove the entire tumour along with the affected kidney. This procedure is called a radical nephrectomy, which involves taking out the whole kidney, the surrounding tissue, and often nearby lymph nodes to check if cancer has spread. Surgeons aim to remove as much of the cancer as possible because leaving even small amounts of tumour behind can allow the disease to regrow and spread. Depending on where the tumour is located and how large it has become, the surgical team may also remove parts of nearby organs if the cancer has grown into them.^[2][11]

After surgery, the next phase is chemotherapy. Because rhabdoid tumours grow and spread so aggressively, doctors use very intensive chemotherapy regimens—these are combinations of several powerful drugs given at high doses. The goal of chemotherapy is to kill any cancer cells that might have been left behind after surgery or that have already spread to other parts of the body. The specific drugs used can vary, but treatment protocols often include medications that target rapidly dividing cells. These drugs are usually given through a vein over several weeks or months, in cycles that allow the child’s body some time to recover between doses.^[2][12]

Chemotherapy for rhabdoid tumours is much more aggressive than for many other childhood cancers. This intensity is necessary because the cancer cells grow so fast, but it also means that side effects can be significant. Common side effects include nausea and vomiting, loss of appetite, hair loss, increased risk of infections because the immune system is weakened, fatigue, and low blood cell counts. Children receiving this treatment need very close monitoring, often requiring hospital stays and supportive care such as blood transfusions, medications to prevent infections, and nutritional support. Families should expect that treatment will be demanding and that the child will need a lot of rest and comfort during this time.^[2][13]

Radiation therapy may also be part of the treatment plan, especially for children who are older than six months. Radiation uses high-energy X-rays or other types of radiation to destroy cancer cells or stop them from growing. It is typically aimed at the area where the tumour was located or at areas where cancer has spread. The decision to use radiation depends on several factors, including the child’s age, the extent of the disease, and how well the cancer responded to surgery and chemotherapy. Radiation can help control the disease, but it also carries risks, especially in very young children, because it can affect normal growth and development of surrounding tissues and organs.^[11][13]

In some cases, doctors may recommend a stem cell transplant (also called a bone marrow transplant). This procedure involves collecting healthy blood-forming stem cells from the child’s own body before giving very high doses of chemotherapy. After the intensive chemotherapy has destroyed both cancer cells and the child’s bone marrow (which produces blood cells), the collected stem cells are returned to the child’s body to help rebuild the bone marrow and restore normal blood cell production. This approach allows doctors to use even higher doses of chemotherapy than would otherwise be safe, but it is a complex and risky procedure that requires specialized care and a long recovery period.^[13][19]

The duration of treatment varies depending on the stage of the disease and how well the cancer responds, but families should be prepared for several months of intensive therapy. Throughout this period, the child will need frequent hospital visits for chemotherapy sessions, blood tests, imaging scans to monitor the tumour, and supportive care to manage side effects. The medical team will also watch carefully for signs that the cancer is coming back, which unfortunately happens frequently with rhabdoid tumours. Regular follow-up appointments and scans will continue for years after treatment ends to catch any recurrence as early as possible.^[2][12]

Innovative Treatments Being Tested in Clinical Trials

Because standard treatments for rhabdoid tumour of the kidney have not been as successful as doctors would like, researchers around the world are actively working on new and experimental therapies. Clinical trials are research studies that test new treatments to see if they are safe and effective before they become widely available. For children with rhabdoid tumours, especially those at high risk or whose cancer has come back after initial treatment, participating in a clinical trial may offer access to promising new therapies that are not yet part of routine care.^[4][12]

One important area of research focuses on understanding the genetic cause of rhabdoid tumours. Scientists have discovered that nearly all these tumours have a problem with a gene called SMARCB1 (sometimes also referred to by other names like INI1, SNF5, or BAF47). This gene normally helps control how cells grow and divide. When the SMARCB1 gene is missing or not working properly, cells can grow out of control and form tumours. Understanding this genetic change has opened up new possibilities for developing treatments that specifically target the underlying cause of the cancer rather than just trying to kill rapidly dividing cells.^[2][4][11]

Current research suggests that rhabdoid tumours are driven by problems with how genes are turned on and off—a process controlled by epigenetic regulation. Instead of having mutations in many different genes like some other cancers, rhabdoid tumours seem to result from widespread disruption of normal gene regulation caused by the loss of SMARCB1. This understanding has led scientists to explore drugs that can correct or compensate for these epigenetic problems. Several experimental treatments targeting these mechanisms are now being tested in clinical trials.^[4][12]

One promising approach involves drugs called histone deacetylase inhibitors (or HDAC inhibitors). These medications work by affecting how tightly DNA is packaged inside cells, which in turn affects which genes are active. By changing this packaging, HDAC inhibitors can potentially restore normal gene activity patterns and slow down or stop cancer growth. Another class of experimental drugs being studied are EZH2 inhibitors, which target a specific protein involved in gene regulation that is often overactive in rhabdoid tumours. These drugs aim to correct the abnormal gene expression patterns that drive the cancer.^[12]

Researchers are also exploring immunotherapy approaches for rhabdoid tumours. Immunotherapy is a type of treatment that helps the body’s own immune system recognize and attack cancer cells. Some experimental immunotherapy strategies being tested include checkpoint inhibitors, which remove the “brakes” that cancer cells put on the immune system, and CAR-T cell therapy, which involves engineering a patient’s own immune cells to specifically target and kill cancer cells. While these approaches have shown promise in other types of cancer, they are still in early stages of testing for rhabdoid tumours.^[12]

Clinical trials for rhabdoid tumours are conducted in different phases. Phase I trials are the first step and focus primarily on determining whether a new drug is safe and finding the right dose. These trials usually involve small numbers of patients. Phase II trials test whether the drug actually works against the cancer and continue to monitor safety. Phase II trials include more patients and provide important information about how effective the treatment might be. Phase III trials compare the new treatment directly with current standard treatments to determine if it works better. These are large studies that can definitively show whether a new approach should become the new standard of care.^[4][12]

Clinical trials for rhabdoid tumours are being conducted at specialized pediatric cancer centers in the United States, Europe (including countries like Germany, where there is a dedicated EU-RHAB Registry), and other parts of the world. To participate in a clinical trial, children typically need to meet certain eligibility criteria, which might include their age, the stage of their disease, whether they have received previous treatment, and their overall health status. Doctors carefully screen potential participants to ensure that the trial is appropriate for each child and that the potential benefits outweigh the risks.^[12]

Some clinical trials are also investigating combinations of existing drugs in new ways, or pairing standard chemotherapy with experimental agents to see if the combination works better than either approach alone. Other studies are looking at whether very intensive treatment approaches, including high-dose chemotherapy followed by stem cell rescue, can improve survival rates for children with this devastating disease. While results from these studies are still emerging, early findings have shown that some children respond to these intensive strategies, though the toxicity and side effects remain significant challenges.^[12][24]

Most common treatment methods

• Surgery (Radical Nephrectomy)
  • Complete removal of the affected kidney, surrounding tissue, and nearby lymph nodes
  • Often the first step in treatment to remove as much tumour as possible
  • May include removal of parts of nearby organs if cancer has spread
• Chemotherapy
  • Intensive combination of multiple powerful drugs given at high doses
  • Administered in cycles through a vein over several weeks or months
  • Aims to kill remaining cancer cells after surgery or cells that have spread
  • Common side effects include nausea, hair loss, infection risk, and low blood counts
• Radiation Therapy
  • High-energy beams targeted at the tumour site or areas where cancer has spread
  • Typically used for children older than six months
  • Helps control disease and destroy remaining cancer cells
  • Can affect normal tissue growth in very young children
• Stem Cell Transplantation
  • Collection of healthy stem cells before very high-dose chemotherapy
  • Stem cells returned to the body after intensive treatment to rebuild bone marrow
  • Allows use of higher chemotherapy doses than would otherwise be safe
  • Complex procedure requiring specialized care and long recovery
• Experimental Therapies in Clinical Trials
  • HDAC inhibitors targeting epigenetic regulation of genes
  • EZH2 inhibitors affecting protein involved in gene expression
  • Immunotherapy approaches including checkpoint inhibitors
  • CAR-T cell therapy using engineered immune cells
  • Novel drug combinations and intensive treatment protocols