2012 EDUCATIONAL BOOK - American Society of Clinical Oncology

MANAGEMENT OF T1 BREAST CANCERS
the group]). Of the 307 T1abN0 HER2-negative BCs, 10-year
RFS was approximately 94%. Of the 21 T1abN0 HER2positive
BCs, the 10-year RFS was approximately 85%. T1b
fared a bit worse than T1a.
Gonzalez-Angulo et al analyzed a University of Texas
M. D. Anderson Cancer Center (MDACC) dataset (later
reported by Theriault et al 9 ) plus a confirmatory dataset
from the Institutes Bordet and Leoben. 22 Nine hundred and
sixty five patients from MDACC and 350 patients from the
other two institutions with T1abN0 were included. Endocrine
therapy was given to 55% of the MDACC patients;
treatment details were sparse from the other group. Overall
5-year RFS was 92% and 96% for the two groups but only
77% and 87% for the HER2-positive subset. Adverse prognostic
factors included HER2-positivity, ER-negativity, age
younger than 50, and grade 3 tumor. Tumor size was not a
factor. The TN group had a 5-year RFS of 83% at MDACC,
but it was substantially better (95%) at the other institutions.
It is uncertain whether this was a result of differences
in treatment.
Theriault et al summarized the MDACC experience for
1,012 patients with T1abN0 BC in 1990 to 2002. 9 Median
follow-up was roughly 60 months. Patients who had received
chemotherapy or trastuzumab were excluded from this article.
Of the 771 patients with ER-positive BC, 61% received
endocrine therapy. Of the 98 and 143 patients with HER2positive
and TN BC, endocrine therapy was given to 46%
and 21%, respectively. Five-year DDFS was 97.5%, 86.9%,
and 96.3% for the patients with HR-positive, HER2-positive,
and TN disease, respectively. Five-year RFS was 94.5%,
77.2%, and 84.9%, respectively. Adverse prognostic factors
included age younger than 35, HER2 positivity, and less so
TN BC.
Cancello et al reported on the European Institute of
Oncology experience for patients with T1mic/a/bN0 BC
treated in 1997 to 2005. 8 It is not clear how these patients
overlap with a prior report from Curigliano et al. 23 Median
follow-up was 76 months for the 1,691 patients. Overall
treatment consisted of endocrine therapy in 35% (93% of all
ER�) and chemotherapy in 10% (54% and 71% of HER2�
and TN BC). No trastuzumab was administered. Using
cutoffs of 1% for ER/PR and 14% for Ki67, patients were
categorized by IHC to have BCs that were luminal A (881,
52%), luminal B (532, 31%), luminal B HER2 positive (101,
6%), HER2 positive/ER negative (82, 5%), and TN (95, 6%).
Five-year BC-specific survival was approximately 98%, 97%,
95%, 91%, and 91%, respectively. Adverse prognostic factors
included age younger than 35, HER2 positivity, TN, and
LVI.
KEY POINTS
● T1ab N0 breast cancer generally has excellent prognosis.
● Adverse prognostic factors include HER2� disease,
ER� disease, high-grade histology, T1b, and younger
age.
● Vague treatment guidelines exist.
● No prospective trials have yet been reported.
● For the HER2� population, there is almost no trastuzumab
experience in the absence of chemotherapy.
Rouanet et al reported the outcomes of 703 French patients
with T1abN0 BC treated in 1999 to 2004. 10 Only 6%
had HER2-positive disease. Of these, 50% had dual positive
disease. Treatment consisted of endocrine therapy in 41%,
chemotherapy in 10%, and observation in 55%, which
achieved a 5-year DFS of only 74%. For the 661 patients
with HER2-negative disease, 10% had TN disease and 90%
ER-positive disease. Treatment for this group was endocrine
for 80%, chemotherapy for 5%, and observation for 17%,
which achieved a 5-year DFS of 95%. Adverse prognostic
factors included HER2-positivity, ER-negativity, age
younger than 50, no adjuvant therapy, and grade 3 disease.
Five-year DFS for the TN cohort was 91%.
Livi et al presented 704 Florentines with T1abN0 BC
treated in 2002 to 2008. 2,24 Median follow-up was 59
months. No chemotherapy or trastuzumab was given; endocrine
therapy was given in 64%. Five hundred and fifty-nine
had ER-positive/HER2-negative disease, 75 had HER2positive
disease—of whom 55% had ER-positive disease—
and 70 had TN BC. 24 Five-year DDFS was 97.8%, 92%, and
91.8%, respectively. Overall 5-year DFS was 96.5%. Adverse
prognostic factors included age 50 or younger and ERnegative
and HER2-positive disease.
Studies in Which >10% Patients Received Adjuvant Chemotherapy,
but No Trastuzumab
Colleoni et al reported on a cohort of patients with T1mic/
a/b N0 disease from the European Institute of Oncology
treated in 1997 to 2001. 14 Median follow-up was only 43
months. Of the 425 patients, 358 had ER-positive BC (11%
HER2�), and 60 had ER-negative BC (40% HER2�, 60%
TN). Most received adjuvant therapy. Of the patients who
were ER positive, only six relapsed following treatment
(endocrine 88%, chemotherapy 12%, observation 11%). Of
the patients who were ER negative, only three relapsed
following treatment (chemotherapy 60%, observation 40%).
Adverse prognostic factors included Ki67 greater than 20%,
age younger than 35, and PR-negative disease.
Hanrahan et al analyzed the outcomes of patients with
T1abN0 disease in the SEER registry from 1988 to 2001. 26
Treatment details are not available. By 10 years, only
approximately 4% died of BC, whereas an additional 20%
died of other causes, mostly cardiovascular. For OS, prognostic
factors included black race, T1b, and PR-negative
disease. For each mm tumor size, the HR for OS was 1.02.
Prognostic factors for BC-specific mortality were age
younger than 50, grade 3, ER negativity, PR negativity, and
fewer than six lymph nodes in the axillary lymph node
dissection (ALND).
Curigliano et al reviewed 2,130 patients with T1abN0 BC
treated at the European Institute of Oncology in 1999 to
2006. 23 The extent of overlap with Cancello’s presentation is
not clear. Median follow-up was 55 months. A subset had
immunohistochemical (IHC) testing: 79 with HER2-positive/
ER-positive disease and 71 with HER2-positive/ER-negative
disease; 158 patients with ER-positive/HER2-negative BC
were matched by HR status, age, and year of surgery.
Treatment for the ER-positive/HER2-negative group was
endocrine in 93%, chemotherapy in 1% and observation in
6% resulting in a 5-year DFS of 99%. Treatment for the dual
positive group was endocrine in 66% and chemotherapy in
25%, resulting in a 5-year DFS of 92%. Treatment for the
HER2-positive/ER-negative group was endocrine in 3%, che-
11