Review - Haymarket Media Group

Commentary
Inflammatory Breast Cancer: Still a Challenge
Nancy U. Lin, MD
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
Inflammatory breast cancer (IBC) is a relatively
rare disease, comprising less than 3% of breast
cancer cases in the United States. 1 Compared
with locally advanced, noninflammatory breast cancer,
IBC appears to be a distinct entity with a unique
mode of presentation and underlying biology.
Unfortunately, even with multimodality therapy, the
prognosis for patients with IBC remains poor. 2
Overexpression and/or amplification of HER2 is
present in 25% to 30% of primary breast carcinomas. 3
In contrast, HER2 is overexpressed in approximately
half of IBC cases. 4,5 In all patients with breast cancer,
Inflammatory breast cancer
appears to be a distinct entity with
a unique mode of presentation
and underlying biology.
overexpression of HER2 is associated with a higher
risk of relapse and worse overall survival (OS) 3 ; however,
the contribution of HER2 overexpression to the
prognosis of patients with IBC is not well defined.
Dawood and colleagues therefore set out to examine
the prognostic significance of HER2 status in
women with IBC diagnosed between 1989 and 2005
20 The American Journal of Hematology/Oncology
at the University of Texas M.D. Anderson Cancer
Center. 6 In all, 179 patients fulfilled the inclusion/
exclusion criteria for this retrospective analysis. A
strength of the study is the relatively uniform treatment
of the patients: all patients received an anthracycline,
and nearly 80% received a taxane as part of
their primary systemic chemotherapy. In addition,
the exclusion of patients who received trastuzumab
in the neoadjuvant or adjuvant setting allowed the
authors to describe the impact of HER2 upon relapsefree
survival (RFS) independent of an effective targeted
therapy. Chemotherapy was followed by mastectomy
and comprehensive radiotherapy in all patients,
and hormonal therapy was given to patients with
hormone receptor–positive disease. There was no difference
in the rate of pathologic complete response
(pCR) by HER2 status. After a median follow-up of 35
months, 56% of patients with HER2-negative disease
and 62% of patients with HER2-positive disease
developed a disease recurrence, a difference that was
not statistically significant.
What could account for the lack of prognostic significance
of HER2 for RFS described in this study
compared with the reproducible influence of HER2
status on prognosis in all-comers with breast cancer?
One possibility relates to common characteristics of
IBC present across breast cancer subtypes that lead to
a more aggressive clinical phenotype. Using expression
profiling, Bertucci and colleagues identified the
same five molecular subtypes (luminal A and B,
basal, HER2 positive, and normal breast-like) in IBC
as have been observed in non-IBC. 7 At the same time,
a single 109-gene set was able to distinguish between
IBC and non-IBC within each subtype. These genes
Dr Nancy U. Lin was invited to provide commentary on the following article: Dawood S, Broglio K, Gong Y, et al. Prognostic significance of
HER-2 status in women with inflammatory breast cancer. Cancer. 2008;112:1905-1911.