Annual Meeting Proceedings Part 1 - American Society of Clinical ...

1114 General Poster Session (Board #32G), Sat, 8:00 AM-12:00 PM
Prognostic impact of local therapy of the primary tumor in metastatic breast
cancer. Presenting Author: Isabelle Katrin Himsl, Ludwig Maximilians
University Munich, Munich, Germany
Background: MBC is an incurable disease and the treatment aims are
palliative. It is not known whether the difference in OS is the result of a
selection bias or caused by dissemination of tumor stem cells in pat.
without surgery. Methods: To identify the impact of surgical therapy of the
primary tumor, a mono-institutional retrospective review from 1990-2006
was done in primary MBC pts. Results: We identified 269 pts. with primary
MBC, 63 of whom had received no surgical local treatment. Mean follow up
is 65 m for pts., observed mortality 87%. Location of metastases were bone
only (36%), visceral or soft tissue (one organ only, 19%), multiple organs
(40%) and including CNS metastases (5%). 50% had G3 tumors, 25%
negative receptor status, 7% non-resectable local disease and 57%
symptomatic metastases. In univariate analysis, pat. without local treatment
had a median OS of 14.4m, pts. with local therapy 28.1m (p�0.001).
Pts. not receiving local treatment were significantly more likely to have
multiorgan or CNS involvement (p� 0.001), symptoms at diagnosis
(p�0.009), non-resectable tumor (p�0.001) and were more likely to die
within the first 30d after diagnosis (p� 0.001). In multivariate analysis,
local treatment had no significant impact on OS. The only significant
variables were: number of involved organs, symptoms at diagnosis, receptor
status, grading, and size of the local tumor. The effect of local treatment on
OS was not homogenous across subgroups. Local treatment was a significant
factor in tumors with only one involved organ or asymptomatic disease.
In all other groups, local treatment did not result in an OS benefit.
Conclusions: Our cohort showed significantly improved OS in univariate
analysis if the breast primary tumor had been removed in metastatic
disease. Yet, the decision for local treatment was biased by the extent and
presentation of metastatic disease. Pts. with more advanced MBC seem not
to benefit from removal of the primary tumor. However, we see significant
influence in pts. with limited and asymptomatic MBC. The potential
dissemination of tumor stem cells from the breast primary in metastatic but
locally untreated disease may only influence prognosis in pts. with limited
disease.
1116 General Poster Session (Board #33A), Sat, 8:00 AM-12:00 PM
Postmastectomy radiotherapy for patients with one to three positive lymph
nodes: Utilization and benefit. Presenting Author: Dezheng Huo, The
University of Chicago, Chicago, IL
Background: The use of postmastectomy radiotherapy (PMRT) for patients
with pT1-2pN1 tumors is controversial and ASCO guidelines indicate that
there is insufficient evidence to make recommendation. We hypothesized
that the use of PMRT in this patient group was low and has minimal impact
on survival. Methods: The study includes 83,742 invasive breast cancer
patients from the National Cancer Data Base who underwent mastectomy
with pT1-2 and pN1 disease from 1998-2007. Neoadjuvant cases were
excluded. We investigated factors related to PMRT use using cross tables
and logistic regression. Survival analysis was conducted using Cox models
in patients diagnosed from 1998-2002, with a median follow-up of 5.5
years. Results: The proportion of N1 patients undergoing PMRT remained
stable from 1998 to 2007, at approximately 20%. PMRT use increased
with larger tumor size (15.4% in T1N1 and 24.4% in T2N1), and with
increasing positive lymph nodes (14.6%, 23.7%, and 35.2% for patients
with one, two, or three positive nodes, respectively). Age was significantly
inversely correlated with PMRT use: the proportion of patients receiving
PMRT was 31.3% for age �40 years and 8.2% for 80� years (p�0.001).
Asians are more likely to receive PMRT (25.5%), compared to other races
(20.3% white, 20.7% black, and 20.6% Hispanic; p�0.001). PMRT also
varied considerably by facility location, the highest in the Northeast at
31.3%, and the lowest in the South at 15.8% (p�0.001). There was only
minor difference in PMRT use between different types of cancer centers.
Insurance status, income and education level were not associated with
PMRT use. After adjusting for prognostic factors in the Cox models, PMRT
use was associated with a reduced mortality (hazard ratio�0.87, 95% CI:
0.81-0.93; p�0.001). The multivariable-adjusted 5-year death rate was
16.1% in patients receiving PMRT and 18.1% in patients not receiving
PMRT. For pT1N1 tumors the absolute benefit was 1.3% compared to
2.7% for pT2N1 tumors. Conclusions: PMRT use varies with facility and
clinicopathologic factors, but not socioeconomic factors. The risks of
radiation need to be weighed against the 2% absolute survival benefit when
deciding on whether to use PMRT for pT1-2N1 patients.
Breast Cancer—Triple-Negative/Cytotoxics/Local Therapy
77s
1115 General Poster Session (Board #32H), Sat, 8:00 AM-12:00 PM
Role of breast surgery in T1-T3 breast cancer patients with synchronous
bone metastases. Presenting Author: Edoardo Botteri, European Institute
of Oncology, Division of Epidemiology and Biostatistics, Milan, Italy
Background: The role of breast surgery in advanced breast cancer (ABC) is
controversial. The main potential advantage of removing the primary tumor
is to eliminate the source of further metastatic spread. While previous
studies addressed the question in very heterogeneous populations (e.g.
patients with any local and distant extension), we have focused on a
homogeneous series of ABC patients. Methods: From our institutional
Tumor Registry we selected 191 consecutive women diagnosed between
2000 and 2008 with locally operable (T1-T3) ABC, synchronous bone
metastases and no other distant sites involved. The progression free
survival (PFS) was calculated from diagnosis to the date of progression,
defined as either a new site of metastatic disease or clinical/radiographic
evidence of increasing tumor burden at a previously known bone metastatic
site. Results: Median age was 51 years and 92% of the women had an
endocrine-responsive tumor. One-hundred and thirty patients out of 191
(68%) underwent surgery at the time of diagnosis, while 61 (32%) did not.
Twenty-six of the operated patients (20%) had previously undergone
neoadjuvant chemotherapy; 15 (12%) had positive or undetermined
surgical margins. Operated and non-operated patients were similar with
respect to age, tumor size, nodal involvement, estrogen and progesterone
receptor status, HER2 overexpression and Ki-67, but differed in terms of
number of bone metastatic sites: a single metastasis was detected in 34
(26%) operated and 7 (11%) non-operated cases (P�0.02). First-line
treatment strategies with endocrine therapy, chemotherapy and Trastuzumab
were similarly distributed between the two groups. The 5-year PFS
was 22.0% and 10.4% in operated and non-operated patients, respectively.
The multi-adjusted hazard ratio was 0.62 (95% confidence interval
0.39-0.98) in favor of surgery. The exclusion of the patients who had
received neoadjuvant chemotherapy and patients with positive or undetermined
surgical margins did not alter the results. Conclusions: In this large
and homogeneous series of ABC patients with synchronous bone metastases,
the role of breast surgery had a favorable impact on the progression of
the disease, indicating a potential survival benefit.
1117 General Poster Session (Board #33B), Sat, 8:00 AM-12:00 PM
Patient factors and satisfaction in the choice of contralateral prophylactic
mastectomy. Presenting Author: Amanda Kathleen Arrington, City of Hope,
Duarte, CA
Background: The percentage of women undergoing contralateral prophylactic
mastectomy (CPM) has more than doubled in recent years. The
underlying reasons patients choose CPM have not been fully evaluated. Our
objective was to survey patients who have undergone a unilateral mastectomy
with or without CPM to identify reasons surrounding their decisions.
Methods: After obtaining IRB approval, a 30-question cross-sectional
validated survey was mailed to 691 patients who underwent mastectomy
from 1972 to 2011 and are receiving treatment or surveillance at City of
Hope. The questionnaire queried the factors behind the choice of surgery
for each patient. Demographic questions were included and patient charts
were also reviewed. Results: The overall response rate was 53% (N�368).
Patients were classified into those who underwent mastectomy with CPM
(N�139, 38%) and those who underwent mastectomy without CPM
(no-CPM) (N�229, 62%). Of returned surveys, the median age was 50;
24% of patients reported a family history of breast cancer (42% CPM vs.
13% no-CPM, p�0.0001) and 80% of patients had education beyond the
high school level (87% CPM vs. 77% no-CPM, p�0.013). PM patients
reported being “very concerned” about breast cancer more often than
no-CPM patients (46% vs. 34%, p�0.033).The primary reasons for CPM
were: concern of recurrence (55%), cosmetic symmetry (27%), physician
recommendation (17%), and unclear pre-operative imaging (9%). When
questioned about regrets, the top response was decreased sensation
(26%). Although 81% of CPM patients were “very satisfied” with their
decision, 32% of no-CPM patients reported the same level of satisfaction
with their decision (p�0.0001). For no-CPM patients, the primary reasons
for the choice of no-CPM was physician advice and “monitoring is
sufficient”; with 18% of the responders still considering a CPM. Conclusions:
Patients’ perceived risk of contralateral breast cancer is the primary reason
for CPM. CPM patients tend to be more satisfied with their decision
compared to no-CPM patients. This may be related to the active decisionmaking
thought processes and education necessary to choose CPM. Further
patient education is warranted to minimize the risk of regret in making this
decision.
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