Work-up & Staging Flashcards
Outline the workup for pts with suspected NB.
Suspected NB workup:
- H&P
- Labs: CBC, BUN/Cr, LFTs, serum markers, UA, urine catecholamines
- Imaging of primary: CT C/A/P, abdominal US, or MRI abdomen/liver/spine
- Workup of mets: bone scan, I-131 metaiodobenzylguanidine [MIBG] scan, bilat BM Bx, CT/MRI as needed
5, Pathology: DNA content, N-myc amplification, and cytogenetics
Why is a BM Bx important in the workup of NB?
BM Bx may obviate the need for primary site Sg if the testing is positive and the clinical picture is clear.
What % of NB pts have uptake on an I-131 MIBG scan?
∼90% of NB pts have uptake on an I-131 MIBG scan.
What are the currently used NB staging systems?
As of 2010, most cooperative group trials use the International Neuroblastoma Staging System (INSS), which involves the extent of surgical resection. However, a new staging system that uses only pre-Tx factors has been developed: the International Neuroblastoma Risk Group (INRG). These 2 staging systems will likely be used concurrently to allow for comparisons b/t trials. (Monclair T et al., JCO 2009)
Summarize the INSS staging system.
Stage 1: unilat localized tumor s/p GTR +/– microscopic residual Dz; ipsi LN–, though LNs attached and removed with the primary may be involved
Stage 2A: unilat localized tumor s/p STR only; ipsi LN–, though LNs attached and removed with the primary may be involved
Stage 2B: unilat localized tumor s/p GTR or STR with involved nonadherent ipsi LNs; enlarged contralat LN– microscopically
Stage 3: unresectable localized tumor extending across the midline +/– regional LN involvement; unilat localized tumor with contralat regional LN involvement; midline tumor with bilat involvement via LN or direct extension
Stage 4: distant Dz except as defined by stage 4S
Stage 4S: localized unilat primary as defined by stage 1, 2A, or 2B; distant Dz limited to the liver, skin, and/or <10% of BM in infants <1 yo
What are the prognostic factors in NB per INRG?
Age, stage, histologic category, grade, N-myc amplification, 11p or 11q aberration, DNA ploidy
Summarize the INRG staging system.
In the INRG system, locoregional tumors are staged L1 or L2 based on the absence or presence of 1 or more of 20 image-defined radiographic findings (IDRFs). These IDRFs generally affect whether or not a tumor is surgically resectable and to what degree, although resectability is ultimately surgeon-dependent. Metastatic tumors are defined as stage M, except for stage Ms, in which mets are confined to the skin, liver, and/or BM in pts <18 mos old. (Monclair T et al., JCO 2009)
What is the INRG stage of an 8-mo-old pt with metastatic Dz to bone only?
An 8-mo-old pt with metastatic Dz to bone only is INRG stage M (only BM, liver, and skin mets qualify for stage MS).
What is the INSS stage of a 14-mo-old pt with metastatic Dz to BM only?
A 14-mo-old pt with metastatic Dz to BM only is INSS stage 4 (only pts <12 mos old qualify for stage 4S).
What 2 clinical factors are most predictive of cure in NB?
The 2 clinical factors most predictive of cure are age and stage at Dx.
In children with metastatic Dz, what is the most important prognostic factor?
In children with metastatic Dz, age (<1 yo best) is the strongest prognostic factor, even more so than N-myc.
The Shimada classification system divides NB into what 2 categories? What 5 features are used to classify pts in this system?
The Shimada classification system divides NB into favorable histology (FH) and unfavorable histology (UH). Favorable factors:
Stroma-rich
Age
Differentiation
Mitotic/karyorrhectic index
Nodularity
(Mnemonic: Dr. Shimada has a SAD MiNd)
Favorable tumors:
- Age <1.5 yr: Poorly differentiated or differentiating NB, low/intermediate mitosis/karyorrhexis index
- Age b/t 1.5–5 yr: Differentiating NB and low mitosis/karyorrhexis index
- Ganglioneuroblastoma, intermixed (Schwannian stroma-rich) & ganglioneuroma histologies
What 5 factors are used to classify NB pts into low-, intermediate-, and high-risk groups per the COG?
5 factors used to classify NB in COG low-, intermediate-, and high-risk groups:
- Stage, INSS
- Age
- N-myc status
- DNA ploidy
- Shimada classification
(Mnemonic: SANDS, see Table 4-1)
An NB pt with stage I Dz and N-myc amplification is in what risk group?
All stage I NB pts are low risk.
Can a pt with N-myc amplification be classified as intermediate risk?
No. All NB pts with N-myc are either low risk or high risk.