Wilms Tumor: Diagnosis and Therapy

A blood test provides evidence of an inflammatory process at most in late stages. In addition, it may be possible to exclude another type of tumor (neuroblastoma).

By far the most important diagnostic tools are imaging techniques, especially ultrasound and magnetic resonance imaging. These can then also be used to determine the size and spread and to detect whether other organs are affected. Since the tumor particularly often spreads to the lungs, an X-ray is also taken of these. The function of the kidneys is assessed with a scintigraphy.

Further examinations depend on the tumor and the therapy. Since nephroblastoma can be diagnosed fairly reliably by these means, tissue removal (fine-needle biopsy), which carries the risk of tumor spread to the abdomen, is necessary only in very few exceptional cases. Depending on whether the tumor is confined to only one kidney, has grown into surrounding tissue, has spread to metastases, has affected both kidneys, and can be surgically removed, it is assigned to one of five stages that differ not only in treatment but also in prognosis.

What is the therapy?

Treatment is a combination of chemotherapy (given as tablets or injected into the vein or muscle), surgery, and-in some cases-radiation. It depends on the type of tumor, its spread (staging), and the age of the child.

Worldwide, there are two main treatment guidelines. They differ in that chemotherapy is administered only after surgery in one case and before in the other. In Germany, the second approach is common.

With chemotherapy before surgery (preoperative), the tumor can be reduced in size and thus slide into a group with a better prognosis. It also reduces the risk of tumor rupture with spread of cancer cells or bleeding during surgery. The duration of preoperative chemotherapy ranges from 4 to 40 weeks, depending on the tumor.

During surgery, either the affected kidney can be removed with or without surrounding tissue and lymph nodes, or, for example, if only one kidney is left, only the tumor can be excised. Whether additional radiation or renewed chemotherapy is needed afterward depends on the surgical findings and on how the removed tissue looks under the microscope.