Workup/Staging

Question 1

What view(s) comprise a screening mammogram?

Answer 1

1. Mediolateral oblique: allows localization of tumor in sup–inf dimensions
2. Craniocaudal: allows localization of tumor in medial–lat dimensions

Question 2

What is the workup for a breast lesion detected on screening mammogram?

Answer 2

Breast lesion workup: H&P (family Hx of breast and ovarian cancer, prior abnl mammograms, Hx of atypical ductal or lobular hyperplasia), diagnostic bilat mammogram (additional views including spot compression and magnification), and Bx of lesion (if mass nonpalpable, a stereotactic Bx should be performed).

Question 3

What is the rate of axillary nodal positivity by T stage for breast cancer pts undergoing axillary dissection? What if the primary tumor is palpable vs. nonpalpable on exam?

Answer 3

ALL (nonpalpable/palpable)

Overall: 30% - (8%/40%)

Tis: 0.8% - (0.7%/1.1%)

T1a: 5% - (3%/7%)

T1b: 16% - (8%/22%)

T1c: 28% - (18%/32%)

T2: 47% - (23%/50%)

T3: 68% - (46%/69%)

T4: 86% - (−/86%)

(Silverstein M et al., World J Surg 2001)

Question 4

What are the 5 regional LN stations in breast cancer?

Answer 4

Regional LN stations in breast cancer:

Infraclavicular (ICV) nodes typically refer to the level III axillary nodes in radiation oncology.

Station I: nodes inf/lat to pectoralis minor muscle

Station II: nodes deep to pectoralis minor and the interpectoral Rotter nodes

Station III: nodes sup/med to pectoralis minor

Station IV: supraclavicular nodes

Station V: IM nodes

Question 5

What is the T staging for invasive breast cancer according to the AJCC 8th edition (2017)?

Answer 5

(Note: T classification is the same whether it is based on clinical judgment or pathologic assessment. In general, pathologic determination should take precedence for determination of T size.)

Tis: in situ (ductal carcinoma in situ* or isolated Paget)

T1mi: microinvasion ≤1 mm

T1a: >1 mm but ≤5 mm

T1b: >5 mm but ≤1 cm

T1c: >1 cm but ≤2 cm

T2: >2 cm but ≤5 cm

T3: >5 cm

T4a: extension to CW, not including only pectoralis muscle invasion/adherence

T4b: edema (including peau d’orange) but not meeting T4d criteria and/or ulceration of skin of breast, and/or ipsi satellite nodules

T4c: both T4a and T4b

T4d: inflammatory carcinoma (erythema and edema over at least one-third of the breast, present for less than 6 mos, in conjunction with Bx proof of invasive carcinoma)

*In AJCC 8th edition, LCIS is considered a benign process and is not classified as Tis

Question 6

Does involvement of the dermis alone qualify as T4 Dz?

Answer 6

No. Involvement of the skin by breast cancer qualifies as T4 only if there is edema, ulceration, or skin nodules.

Question 7

What is the clinical N staging for invasive breast cancer according to the AJCC 8th edition (2017)?

Answer 7

N1: movable ipsi level I/II axillary LN

N2a: ipsi level I/II axillary LNs fixed/matted

N2b: clinically apparent IM node in absence of clinically evident axillary nodes

N3a: ipsi ICV LNs

N3b: ipsi IM and axillary nodes

N3c: ipsi SCV nodes

Question 8

What is the pathologic N staging for invasive breast cancer according to the AJCC 8th edition (2017)?

Answer 8

pN0(i-): no isolated tumor cells (ITCs) by immunohistochemistry (IHC)

pN0(i+): ITCs only, but no cluster >0.2 mm (also called ITC clusters)

pN0(mol-): negative by reverse-transcriptase polymerase chain reaction (RT-PCR)

pN0(mol+): positive by RT-PCR, but no ITCs detected on IHC

pN1mi: micrometastases (∼200 cells, larger than 0.2 mm, but ≤2 mm)

pN1a: 1–3 axillary LNs involved, at least 1 mets >2 mm

pN1b: positive IM node by sentinel LND, excluding ITCs

pN1c: pN1a and pN1b

pN2a: 4–9 axillary LNs involved, at least 1 mets >2 mm

pN2b: clinically detectable IM node (± microscopic confirmation) with pN0 axilla

pN3a: ≥10 axillary LNs or mets to ICV (axillary level III) LNs

pN3b: clinically detected IM node (± microscopic confirmation) with pN1a or pN2a axilla, or positive IM node by sentinel LND and pN2a axilla

pN3c: ipsi SCV node

Question 9

What is the M staging for invasive breast cancer according to the AJCC 8th edition (2017)?

Answer 9

M0: no clinical or radiographic evidence of DM

cM0(i+): no clinical or radiographic evidence of DM in the presence of tumor cells or deposits no greater than 0.2 mm detected microscopically or using molecular techniques in circulating blood, BM, or nonregional LN tissue in a patient without signs or Sx of metastatic Dz.

M1: DM detected by clinical and/or radiographic means and/or histologic demonstration of a mets larger than 0.2 mm.

Question 10

Define the AJCC 8th edition (2017) breast cancer stage groupings using TNM status.

Answer 10

Stage 0: TisN0

Stage IA: T1N0

Stage IB: T0–T1, N1mic

Stage IIA: T0–T1, N1 or T2N0

Stage IIB: T2N1 or T3N0

Stage IIIA: T3N1 or T0–T3, N2

Stage IIIB: T4, N0–N2

Stage IIIC: any T, N3

Stage IV: any T, any N, M1

Question 11

What factors were incorporated into AJCC 8th edition (2017) to generate a breast cancer prognostic stage grouping?

Answer 11

1. Grade
2. HER2 status
3. ER status
4. PgR status
5. Oncotype DX (for patients with T1–2, N0 ER+/HER2– Dz; score <11 qualifies as most favorable prognostic stage, regardless of tumor size and grade. If score ≥11, not used in prognostication.)

Question 12

What are the 5-yr relative survival rates for breast cancer?

Answer 12

The 5-yr relative survival rates (observed survival in women with breast cancer vs. expected survival in women without breast cancer) according to the ACS Cancer Facts & Figures 2017 and the NCI SEER database:

Localized (confined to primary site): 99%

Regional (spread to LNs): 85%

Distant (cancer has metastasized): 26%