Childhood Kidney Cancer Treatment Questions

A kidney tumor in a child is not the same disease as kidney cancer in an adult. The type, the treatment, and the outlook are all different. This page explains the words on the pathology and staging reports, and lists the exact questions worth asking at each step.

Wilms tumor is the most common kidney cancer in children. NCI reports that about 650 children in the United States are diagnosed with it each year. Most are between the ages of 2 and 5 years.

The rate is 9.7 cases for every 1 million children younger than 15 years. Among infants it is higher, at 13.5 cases per 1 million.

The mean age at diagnosis is 44 months when one kidney is involved. It is 31 months when both are. NCI reports that 5% to 10% of children with Wilms tumor have bilateral or multicentric tumors. Bilateral means both kidneys. Multicentric means more than one tumor.

Older teenagers sometimes have renal cell carcinoma instead. That is the usual adult kidney cancer. NCI reports a 5-year relative survival rate of 76% for patients aged 15 to 19 with renal cell carcinoma.

Histology means what the tumor cells look like under a microscope. Wilms tumor is sorted into two groups, and the difference changes treatment.

NCI states that favorable histology tumors "have a better prognosis and respond better to chemotherapy and radiation therapy than anaplastic tumors."

Anaplastic cells "divide quickly and do not look like the type of cells they came from when viewed under a microscope." NCI adds that "anaplastic tumors are harder to treat with chemotherapy than other Wilms tumors at the same stage."

Ask for the exact word in the pathology report. Favorable and anaplastic are not general impressions. They are specific findings that set the plan.

NCI describes five stages.

• Stage I: the tumor was only in the kidney and was removed completely. No lymph nodes were involved and the tumor did not rupture.
• Stage II: the tumor was removed completely, but cancer had reached the renal sinus or blood vessels outside the kidney. No lymph node spread.
• Stage III: cancer is left in the abdomen after surgery. This covers lymph node involvement, spread across the peritoneum, a biopsy before removal, tumor rupture, or a tumor that could not be fully removed.
• Stage IV: cancer has spread to the lungs, liver, bone, brain, or distant lymph nodes.
• Stage V: there are tumors in both kidneys at diagnosis. Each kidney is staged separately from I to IV.

Read stage III again. It includes tumor rupture and a biopsy taken before removal. Ask the surgeon directly whether either happened. Both raise the stage and change the treatment.

NCI describes nephrectomy, surgery to remove the whole kidney, as the most common treatment for Wilms tumor. Lymph nodes are removed at the same time so a pathologist can check them.

Partial nephrectomy removes the tumor with a small amount of normal tissue around it. NCI also calls this renal-sparing surgery.

Chemotherapy follows surgery in every stage. Radiation is added at different points. For stage I anaplastic disease, NCI describes nephrectomy plus chemotherapy and flank radiation. For stage II anaplastic and for stage III favorable histology, it describes nephrectomy, abdominal radiation, and chemotherapy. Stage IV treatment may include nephrectomy, chemotherapy, and radiation to the sites where the cancer has spread.

Sometimes surgery comes second. NCI explains that chemotherapy is given first when a tumor "cannot be removed because [it is] too close to important organs or blood vessels or is growing in important blood vessels."

The drugs NCI lists for Wilms tumor are dactinomycin, vincristine, doxorubicin, carboplatin, cyclophosphamide, etoposide, ifosfamide, and irinotecan. No child receives all of them. Ask which ones are in your child's plan and why.

Stage V is treated differently. NCI describes chemotherapy first to shrink the tumors, then repeat imaging to reassess, then either partial nephrectomy on the parts that can be saved or continued systemic therapy.

Ask how much kidney tissue the team expects to preserve. Ask what happens if the tumors do not shrink enough. Ask who will follow blood pressure and kidney function afterward, and for how long.

NCI names three syndromes linked to Wilms tumor.

• WAGR syndrome includes Wilms tumor, aniridia (a missing or partly missing iris), an abnormal genitourinary system, and developmental delay.
• Beckwith-Wiedemann syndrome includes overgrowth of one or more body parts, a large tongue, an umbilical hernia at birth, and an abnormal genitourinary system.
• Denys-Drash syndrome is also listed.

Family history is a risk factor. So is a mother being exposed to pesticides while pregnant.

Ask whether a genetics referral is indicated, and what a positive result would change.

Beyond histology and stage, labs look for specific chromosome changes.

Gain of chromosome 1q is found in about 30% of Wilms tumors, and it is linked to worse outcomes. In the data NCI cites, the 8-year event-free survival rate was 77% for patients with 1q gain and 90% for those without it. The 8-year overall survival rate was 88% with 1q gain and 96% without.

Loss of heterozygosity (LOH) means one of the two copies of a chromosome region is missing. NCI reports LOH at 16q in 17% of Wilms tumor cases and at 1p in 11%.

Ask whether these tests were run, and whether the results changed the regimen.

NCI reports a 5-year relative survival rate of 93% for children younger than 20 years with Wilms tumor.

That figure describes a whole group. It does not predict one child. A stage I favorable histology tumor and a stage IV anaplastic tumor sit inside the same 93%, and their outlooks are not alike.

NCI states plainly that "newly diagnosed Wilms tumor with favorable histology can often be cured."

Ask your oncologist for the estimate that matches your child's exact stage, histology, and tumor biology. Ask what data that estimate comes from.

NCI lists the late effects followed after Wilms tumor treatment: heart, lung, and kidney dysfunction; infertility; second cancers including leukemia, thyroid cancer, and breast cancer; and neurological symptoms.

Some of these trace back to specific parts of the plan. NCI names anthracyclines, including doxorubicin, as a cause of cardiovascular damage. It notes that high-dose chest radiation increases breast cancer risk. And a child who has had a kidney removed is left with one kidney doing the work of two.

Ask for a written survivorship care plan before treatment ends, not years later.

• Does the pathology report say favorable or anaplastic histology?
• What stage is it, and exactly what made it that stage?
• Did the tumor rupture, and was a biopsy taken before removal?
• Is one kidney involved or both?
• Which drugs, how many cycles, and what is the total planned dose of each?
• Is radiation part of the plan, to which area, and at what dose?
• Were 1q gain and LOH at 1p and 16q tested, and did results change anything?
• Should we see a geneticist, and what would that change?
• What is the survival estimate for this exact stage and histology?
• Which late effects will be monitored, by whom, and starting when?
• Who do we call at night or on a weekend, and for what?

• Wilms Tumor and Other Childhood Kidney Tumors Treatment (PDQ) Patient Version — National Cancer Institute.
• Wilms Tumor and Other Childhood Kidney Tumors Treatment (PDQ) Health Professional Version — National Cancer Institute.
• Late Effects of Treatment for Childhood Cancer (PDQ) Patient Version — National Cancer Institute.