What is the BWS CDKN1C Neuroblastoma Screening Protocol?

If your child has Beckwith-Wiedemann syndrome (BWS) caused by a CDKN1C mutation, their tumor screening protocol should look different from the standard BWS guidelines.

The standard protocol—abdominal ultrasound every three months and alpha-fetoprotein (AFP) blood tests—is primarily designed to catch Wilms tumor (kidney cancer) and hepatoblastoma (liver cancer). However, children with CDKN1C mutations have a uniquely elevated risk for a different type of tumor called neuroblastoma, while their risk for Wilms tumor and hepatoblastoma is extremely low or absent ^[1][2][3].

Because cancer risks in BWS vary significantly depending on the underlying genetic cause (the molecular subtype), international consensus guidelines emphasize tailoring surveillance to the specific mutation ^[4][5]. For the CDKN1C subtype, screening is specifically adjusted to detect neuroblastoma early. When caught early through these tailored surveillance protocols, embryonal tumors are highly treatable.

How the CDKN1C Protocol Differs

Neuroblastoma is a cancer that develops from immature nerve cells. It most commonly arises in and around the adrenal glands (small hormone-producing glands sitting on top of the kidneys) or along the spine. The targeted screening protocol for a child with a CDKN1C mutation typically includes:

• Targeted Abdominal Ultrasounds (Every 3 Months): Standard BWS ultrasound orders often just say “abdominal ultrasound,” which focuses heavily on the kidneys and liver. For a child with a CDKN1C mutation, the radiologist must specifically look closely at the adrenal glands and paraspinal areas where neuroblastoma is most likely to develop ^[2][6]. Tip: Ask your doctor to explicitly write “Abdominal ultrasound with specific attention to the adrenal glands and paraspinal regions for neuroblastoma surveillance” on the imaging order.
• Skipping Urine Catecholamine Tests: In the past, doctors sometimes checked the urine for chemical markers called VMA and HVA to screen for neuroblastoma. However, current international consensus guidelines specifically recommend against routine urine testing for neuroblastoma ^[4]. Large studies showed that urine screening does not improve overall survival, but it does cause a high rate of “false alarms” (overdiagnosis) that lead to unnecessary stress and invasive medical procedures. Ultrasounds are the safest and most effective screening tool.
• Re-evaluating AFP Blood Tests: The standard BWS protocol includes AFP blood draws every three months until age 4 to monitor for hepatoblastoma. Because the risk of hepatoblastoma in the CDKN1C subgroup is negligible compared to other BWS subtypes, your child’s oncology team may decide that these routine blood draws are completely unnecessary, sparing your child from needless needle sticks ^[1][7].

Screening Timeline

For children with BWS, the general recommendation is to continue abdominal ultrasound surveillance every three months until the child reaches age 7 or 8 ^[8][9]. This timeline covers the highest-risk window for childhood embryonal tumors. As your child approaches this age, their risk drops significantly, and surveillance can typically safely stop.

No Chest X-Rays Required

Because neuroblastoma can occasionally occur in the chest, parents sometimes wonder if chest X-rays or full-body imaging are needed. Routine screening chest X-rays are not recommended as part of standard surveillance for asymptomatic children with BWS ^[2][4]. The risks of repeated radiation exposure in a young, growing child far outweigh any potential screening benefits.

What to Watch For Between Scans

While three-month ultrasounds are highly effective at catching tumors early, they are spaced apart. It is completely normal for parents to feel anxious during the “off months.” Between scans, you can monitor your child for clinical signs of neuroblastoma. Contact your pediatrician if you notice any of the following symptoms persisting without a clear explanation:

• A hard, palpable mass or unusual swelling in the abdomen
• Unexplained, lingering fevers
• Unexplained bruising or bleeding
• Localized back or bone pain (a young child might suddenly refuse to walk or show a limp)
• Chronic, unexplained diarrhea