# ANBL00P2: expectant observation as primary therapy for neuroblastoma in young infants

Source: https://onco.cc/key-papers/paper-anbl00p2-expectant-observation-nuchtern-ann-surg-2012/  
OnCo record `paper-anbl00p2-expectant-observation-nuchtern-ann-surg-2012` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Small adrenal masses found in infants under six months could safely be watched rather than operated on: nearly half shrank or disappeared and the rest were removed later without any child dying of neuroblastoma.

## Summary

Children's Oncology Group prospective study of 87 infants under six months with small (under 3.1 cm solid or 5 cm cystic) adrenal masses managed by observation with serial ultrasound and urinary catecholamines, with surgery for growth or progression.

Eighty-one percent avoided surgery; among those observed, 45 percent had complete or partial spontaneous resolution, and three-year event-free and overall survival were 97.7 and 100 percent.

## Fields

- Kind: Key paper
- Last checked: 2026-09-17
- Journal: Annals of Surgery
- Year: 2012
- DOI: 10.1097/SLA.0b013e31826cbbbd
- Authors: Nuchtern JG, London WB, Barnewolt CE, et al.
- Findings: Surgery avoided in 81 percent of infants.; Three-year overall survival 100 percent.
- What it means: Observation without biopsy is standard for small adrenal masses in young infants, sparing them surgery for tumours that often regress.
- Caveats: Applies only to small localised masses in infants under six months with defined imaging criteria.

## Sources

- Ann Surg 2012: https://doi.org/10.1097/SLA.0b013e31826cbbbd
- PubMed: https://pubmed.ncbi.nlm.nih.gov/22964741/

## Connected records

- cancers: [Low-risk neuroblastoma (INRG very low and low risk, including stage MS)](https://onco.cc/cancers/neuroblastoma-low-risk/)

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