Work-up & Staging

Question 1

List the general workup for RMS.

Answer 1

RMS workup: H&P, basic labs (CMP, CBC, LDH), EUA, CT/MRI primary, CT chest/abdomen, bone scan, bilat BM Bx, and primary site core Bx/incisional Bx; PET/CT may be useful in determining extent of Dz

Question 2

What specific workup studies are needed for PM RMS?

Answer 2

PM RMS workup: MRI brain, CSF cytology (neuroaxial MRI if +)

Question 3

What specific workup studies are needed for bladder RMS?

Answer 3

Bladder RMS workup: EUA and cystoscopy

Question 4

Summarize the TNM criteria for RMS.

Answer 4

T1: confined to anatomic site of origin

T1a: ≤5 cm

T1b: >5 cm

T2: extension or fixed to adjacent tissue

T2a: ≤5 cm

T2b: >5 cm

N0: no regional LN involvement

N1: regional node involvement

M0: no DM

M1: DM

Question 5

Summarize the preop staging of RMS.

Answer 5

Stage 1: favorable site (any T, any N, M0)

Stage 2: unfavorable site, T1a or T2a (≤5 cm), N0, M0

Stage 3: unfavorable site, T1b or T2b (>5 cm), and/or N1, M0

Stage 4: M1

Question 6

Summarize the postop grouping for RMS.

Answer 6

Group I: R0 resected, localized Dz

Group II: R1 resected and/or resected +LN

Group III: R2 (residual primary Dz or LN) or Bx only

Group IV: M1

Question 7

What proportion of RMS pts end up with Group III Dz?

Answer 7

Most (∼50%) RMS end up with group III Dz.

Question 8

Define the risk groups for RMS (based on IRS-VI).

Answer 8

Low risk: all favorable embryonal and Group I–II unfavorable embryonal

Intermediate risk: any alveolar and Group III unfavorable embryonal

High risk: all metastatic Dz

Question 9

What is the staging system for rhabdomyosarcoma?

Answer 9

The pretreatment TNM staging system stratifies patients into four different categories based on the site of the primary tumor, tumor size, presence or absence of nodal and distant disease, and invasiveness.

T1: Confined to anatomic site of origin

T1a: ≤5 cm

T1b: >5 cm

T2: Extension or fixed to adjacent tissue

T2a: ≤5 cm

T2b: >5 cm

N1: Regional node involvement

M1: Distant mets

Stage I: Favorable site (any T, any N)

Stage II: Unfavorable site, T1a–T2a (<5 cm), N0

Stage III: Unfavorable site, T1b–T2b (>5 cm), and/or N1

Stage IV: Any M1

The grouping and staging systems, in addition to histologic subtype, should be used to stage patients with pediatric rhabdomyosarcoma because therapy and outcome closely depend on the variables outlined by each system.

Question 10

What factors define the risk groups and what is the expected outcome for each risk group for rhabdomyosarcoma?

Answer 10

Low risk (5-year OS 90%–95%): nonmetastatic, embryonal, and

Favorable site (group I–III) or

Unfavorable site groups I–II

Intermediate risk

Nonmetastatic, group III embryonal, unfavorable site (5-year OS 70%–85%) or

Nonmetastatic unfavorable histology, any site (5-year OS 55%–60%)

Metastatic embryonal (stage IV group IV), age 2 to 10

High risk (5-year OS 25%–35%): all other metastatic disease