Background

Question 1

What is locally advanced breast cancer (LABC)?

Answer 1

Typically, the term refers to stage III Dz (T3N1, N2–3, or T4). However, stage IIB pts with T3N0 Dz may be included. IBC is included, but metastatic Dz is not. LABC can be separated into those cancers that are operable and those that are not.

Question 2

What are the epidemiologic trends and incidence of LABC?

Answer 2

The incidence of T3–4 Dz decreased by 27% from 1980 to 1987 (coincident with the institution of mammography). Analysis of the SEER database from 1992 to 1999 indicated that LABC (stage III other than IBC) and IBC made up 4.6% and 1.3% of all female breast carcinomas, respectively.

Question 3

What are the diagnostic criteria for inflammatory breast cancer (IBC)?

Answer 3

The consensus min diagnostic criteria for a Dx of IBC are (Dawood et al., Ann Oncol 2011):

1. Rapid onset of breast erythema, edema, and/or peau d’orange, and/or warm breast, with or without an underlying palpable mass
2. Duration of Hx of no more than 6 mos
3. Erythema occupying at least one-third of the breast
4. Pathologic confirmation of invasive carcinoma

Question 4

What is the pathognomonic feature that is more characteristic of IBC than other forms of LABC?

Answer 4

Presence of tumor emboli (aka dermal lymphatic invasion [DLI]) in the dermis of the skin overlying the breast; however, DLI is not necessary for the Dx of IBC.

Question 5

What is the prevalence of IBC?

Answer 5

1%–4% of breast cancer (BC) cases are IBC. 70% present with regional Dz and 30% with distant Dz.

Question 6

What are the histologic subtypes of LABC?

Answer 6

The histologic subtypes are the same for LABC as for earlier-stage Dz. Invasive ductal carcinoma is still the most common, but FHs, such as tubular, medullary, and mucinous, are less frequently represented.

Question 7

Are there genetic/molecular factors associated with LABC?

Answer 7

No. There are no molecular markers that define LABC. However, tumors with avian erythroblastic leukemia viral oncogene homolog 2/human epidermal growth factor receptor 2 (HER2) positivity, BRCA1 mutation, and triple-negative status (ER–, PgR–, HER2–) are associated with aggressive phenotypes. The basal-like and HER2 molecular subtypes are associated with a poor prognosis as well, though outcomes for pts with HER2+ Dz have been dramatically improved with trastuzumab.