Early Diagnosis of Neuroblastoma by a Screening Program

Results of screening tests using urinary catecholamine determinations suggest that the majority of infants identified by a mass screening program have low-risk neuroblastoma by stage (stages I, II, IV in 70-90% of cases) and biological tumor marker studies, favorable histology (93%), hyperdiploid (75-100%) with a normal MYCN copy number, chromosome 1p abnormality (13%), and Ha-ras p21 expression (60-80%). Only a few patients with unfavorable biologic features have been identified and they have had an unfavorable outcome. It remains to be determined if a mass screening program at 1, 1.5, and 2 years of age would identify patients with and without high-risk biologic features at the earliest possible time and if early treatment of these patients would improve their prognosis. This is illustrated in patients by false negativity for screening at 6 months of age who then develop aggressive neu-roblastoma after 1 year of age. Widespread screening for neuroblastoma at or before the age of 6 months and perhaps even at later ages remains controversial.

If a screening test at or before 6 months of age is positive, then a search for a primary tumor is recommended. If a primary tumor is found, then studies for metasta-tic evaluation (CT scan, bone marrow aspiration and biopsy, and MIBG scan) should be performed. Patients with stage I and II disease should be followed periodically with urinary catecholamine determinations, CT scan, and MIBG scan. Assessment with urinary catecholamines and abdominal sonogram is needed once a month for 1 year and every 3 months thereafter.

For mediastinal tumors, urinary catecholamines and CT should be obtained at least once every 3 months. Patients with progressive disease or advanced-stage neuroblastoma diagnosed by screening at <6 months should always be resected and tumor samples tested for biologic features of prognosis. Intensity of treatment is then determined accordingly.

Table 18-4 shows the recommended studies for the assessment of extent of disease.

Table 18-4. Recommended Studies for Assessment of Extent of Disease

Tumor site

Recommended tests

Primary site Metastatic sitesb Bone marrow

CT and/or MRI scana with 3-D measurements; MIBG scan.b

Bilateral posterior iliac crest marrow aspirates and trephine (core) bone marrow biopsies required to exclude marrow involvement. A single positive site documents marrow involvement. Core biopsies must contain at least 1 cm of marrow (excluding cartilage) to be considered adequate.

Bone MIBG scan; 99Tc scan required if MIBG scan negative or unavailable. Plain radiographs of positive lesions.

Lymph nodes Clinical examination (palpable nodes), confirmed histologically.

CT scan for nonpalpable nodes (3-D measurements).

Abdomen/liver CT and/or MRI scana with 3-D measurements.

Chest AP and lateral chest radiographs. CT/MRI necessary if chest radiograph positive, or if abdominal mass/nodes extend into chest.

Abbreviation: AP, anteroposterior.

"Ultrasound considered suboptimal for accurate 3-D measurements.

bThe MIBG scan is applicable to all sites of disease.

From Brodeur GM, Pritchard J, Bethold F, et al. Revisions of the International Criteria for Neuroblastoma Diagnosis, Staging, and Response to Treatment. J Clin Oncol 1993;11:1466, with permission.

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