Wilms’ tumour, or nephroblastoma, is a rare type of kidney cancer that generally affects children. It is a type of blastoma, which are cancers that develop from precursor cells in the body. It is generally found in only one kidney, however in rare instances in can be found in both kidneys.
The kidneys are a pair of bean-shaped organs that sit in the middle of your back on each side of your spine. They are responsible for filtering excess water and waste products from the blood, and converting them into urine to be removed from the body. The kidneys also produce and secrete certain hormones that regulate blood pressure and initiate the production of red blood cells.
Wilms’ tumours are slightly more common in girls, and are generally diagnosed in children under five years of age. However, anyone can develop this disease.
Treatment
If a Wilms’ tumour is detected, it will be staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (node) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, age, stage of disease and overall health.
Treatment options for Wilms’ tumour may include:
- Surgery, potentially including a nephrectomycomplete or partial removal of affected kidney(s).
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Targeted therapymedication that targets specific molecular features of cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of Wilms’ tumour remains unknown, the following factors may increase the likelihood of developing the disease.
- Genetic mutations.
- Having certain conditions, such as:
- WAGR syndrome (Wilms’ tumour, aniridia, abnormal genitourinary system, and mental instability).
- Denys-Drash syndrome.
- Beckwith-Wiedemann syndrome.
- A family history of Wilms’ tumour.
- Aniridia.
- Isolated Hemihyperplasia.
- Hemihypertrophy.
- Urinary tract problems, potentially including:
- Cryptorchidism.
- Hypospadias.
- Exposure to pesticides in utero.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Some of the information regarding risk factors was obtained from the Wilms Tumor and Other Childhood Kidney Tumors Treatment (PDQ) page published by the National Cancer Institute.
Symptoms
Many children may appear asymptomatic in the early stages of disease. As the cancer progresses, some of the following symptoms may occur:
- An abdominal mass.
- Abdominal swelling and/or pain.
- Fever.
- Haematuriathe presence of blood in urine.
- Nausea and/or vomiting.
- Constipation.
- Unexplained weight loss/loss of appetite.
- Dyspnea.
- Hypertensionhigh blood pressure.
- Fatigue.
- Weakness.
- Anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have Wilms’ tumour, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imaging tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- X-raya type of medical imaging that uses x-ray beams to create detailed images of the body .
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Urine tests.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Cytoscopyexamination of the bladder and urethra.
- Ureteroscopyexamination of the bladder and ureters using a small, flexible instrument called a ureteroscope .
- Biopsyremoval of a section of tissue to analyse for cancer cells.