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

1122 General Poster Session (Board #33G), Sat, 8:00 AM-12:00 PM
Association of pathologic complete response following neoadjuvant chemotherapy
with survival among young women with breast cancer. Presenting
Author: Rachel Adams Greenup, Massachusetts General Hospital, Boston,
MA
Background: Neoadjuvant chemotherapy is increasingly being used in the
treatment of breast cancer, yet data on efficacy and significance of
pathologic complete response (pCR) is limited among young women. We
sought to determine whether timing of chemotherapy impacted diseasefree
(DFS) or overall survival (OS), and whether pCR is associated with
improved prognosis among young women with breast cancer. Methods: We
performed an IRB-approved review of women �40 years old who received
treatment for stage I-III breast cancer during 1996-2008 at our institution.
DFS and OS were determined through use of state tumor registry, death
certificate data, and Social Security Master Death Index. Tumor biology was
categorized as hormone receptor positive (HR�), HER-2�, or triple
negative (TN) breast cancer. pCR was defined as lack of invasive cancer in
the breast and axilla on final pathologic review. Cox regression analyses
were conducted to evaluate the hazard ratios (HRs) of the association
between chemotherapy and outcomes. Results: 370 women �40 years old
(median age � 36.5, range: 22-40) were treated with systemic therapy for
stage I-III breast cancer. 54.7% of tumors were HR�, 20.9% were
HER-2�, and 24.4% were TN. After adjusting for stage, there was no
difference in DFS or OS among women who received neoadjuvant versus
adjuvant chemotherapy (p�0.6 and 0.5 respectively). pCR following
neoadjuvant chemotherapy was higher among HER-2� (50%) and TN
(28.6%) tumors when compared to HR� tumors (17.6%). Among women
who received neoadjuvant chemotherapy, 10-year DFS and OS rates were
significantly higher when pCR was achieved when compared to lack of pCR
(HR�0.20, p value�0.01 and HR�0.13, p�0.05). pCR with neoadjuvant
chemotherapy trended towards higher 10-year DFS and OS when compared
to women who received adjuvant chemotherapy (HR�0.30, p value�0.08
and HR�0.20, p�0.1). Conclusions: pCR after neo-adjuvant chemotherapy
is associated with improved disease-free and overall survival in
young women with breast cancer. Pathologic complete response may be a
valuable surrogate marker for survival, and aid in the evaluation of
therapeutic efficacy in young breast cancer patients.
1124 General Poster Session (Board #34A), Sat, 8:00 AM-12:00 PM
Clinical findings and outcomes from MRI staging of breast cancers in
women. Presenting Author: Akshara Raghavendra, University of Southern
California Norris Comprehensive Cancer Center, Los Angeles, CA
Background: For patients diagnosed with breast cancer, case series have
shown that staging MRI can detect occult breast cancers in 1-10% of
cases. Prevalence and risk factors in underserved populations remain
unclear. Methods: We performed a retrospective analysis of all patients,
newly diagnosed, with breast cancer who had a preoperative staging MRI
seen at Norris Comprehensive Cancer Center and LAC �USC, that cares for
an underserved and minority population, from 2006 to 2011. Demographic,
clinicopathologic and imaging data were obtained through a review
of electronic records. Non index lesions were defined as those not known to
be malignant, not presenting with clinical, mammographic or ultrasound
findings, in a different quadrant and given an MRI BIRADS score of 4 or 5.
Results: A total of 718 patients were analyzed and 148 patients (21%) had
a total of 187 non index lesions; 63% were ipsilateral, 26% contralateral
and 11% bilateral. As initial evaluation of non-index ipsilateral lesions, 71
(38%) had biopsy, 24 (13%) had excision and 34 (18%) had mastectomy.
For contralateral non-index lesions, 41 (22%) had contralateral biopsy, 6
(3%) had excision and 11(6%) had mastectomy. Among all non index
lesions, 111 (59%) were benign, 14 (7%) DCIS and 62 (33%) invasive
cancer. Occult ipsilateral cancer was detected in 50 (6.9%) of patients and
contralateral in 10 (1.4%) and bilateral in 6 (0.8%). Conclusions: The
occult cancer detection rate with staging MRI was in this 9.2% of this
diverse population. No clear risk factors were identified, with detailed
factors, including BRCA status to be updated and reanalyzed.
Variable Total series Non index lesions Occult cancers
Total 718 148 66
Hispanic (304/631) 48% (63/125) 50% (18/55) 33%
African American (50/631) 8% (10/125) 8% (3/55) 5%
Caucasian (193/631) 31% (36/125) 29% (25/55) 45%
Asian (66/631) 10% (11/125) 9% (6/55) 11%
Others (17/631) 3% (4/125) 3% (3/55) 5%
Age: 50 (422/718) 59% (82/148) 55% (45/66) 68%
Hormone receptor�/HER2– (288/513) 56% (56/94) 60% (25/39) 64%
HER2� (105/478) 22% (24/92) 26% (10/39) 26%
Triple negative (75/569) 13% (10/108) 9% (3/43) 7%
Breast Cancer—Triple-Negative/Cytotoxics/Local Therapy
79s
1123 General Poster Session (Board #33H), Sat, 8:00 AM-12:00 PM
Long-term rates of breast cancer in a population of women with ductal
carcinoma in situ treated by breast-conserving surgery. Presenting Author:
Eileen Rakovitch, Institute for Clinical Evaluative Sciences, Sunnybrook
Health Sciences Centre, Toronto, ON, Canada
Background: Ductal Carcinoma in Situ (DCIS) is a non-invasive form of
breast cancer which is often treated by breast-conserving surgery. The
addition of radiotherapy to surgery has been shown to reduce the risk of
local recurrence (LR), but use of radiotherapy varies. It is not known to what
extent women with DCIS are at risk for recurrent cancer due to the omission
of radiation therapy. We studied a large provincial cohort of women with
DCIS who were treated with breast-conserving surgery for factors which
predict local recurrence and estimate the impact of radiotherapy on local
recurrence and long-term rates of breast preservation. Methods: All women
diagnosed with DCIS in Ontario from 1994 to 2003 were identified.
Treatments and outcomes were identified through administrative databases
and validated by chart review. Women treated with breast-conserving
surgery, alone or with radiotherapy, were included. Survival analyses were
used to study local recurrence (DCIS or invasive) in relation to patient
characteristics, tumour characteristics and treatment. Results: The cohort
included 3975 women who were treated with breast-conserving therapy; of
these, 1949 (49%) received radiation. At 10 years median follow-up, 736
developed LR(19%). LR developed in 259 of 1949 women who received
radiotherapy (13%) and in 477 of 2026 women who did not (24%;
p�0.001). The differences were significant for both invasive LR (7% vs.
14%; p�0.001) and DCIS recurrence (6% vs.9%; p�0.001). The 10-year
cumulative rate of mastectomy was 13% for women who received radiotherapy
compared to 17% for those who did not (p�0.01).We estimate that
29% (N�214) of all local recurrences diagnosed in Ontario in women
treated for DCIS between 1994 and 2003 would be prevented if all
patients received radiotherapy. Conclusions: The omission of radiation
therapy after breast-conserving surgery in women with DCIS resulted in a
substantial number of local recurrences that might have been avoided and
lower rates of breast preservation. Improvements in guidelines that facilitate
the selection of women in whom radiotherapy can be avoided are
needed.
1125 General Poster Session (Board #34B), Sat, 8:00 AM-12:00 PM
Overuse of sentinel lymph node biopsy with breast conserving surgery for
clinical DCIS. Presenting Author: Natalie Beckman Jones, The Ohio State
University Medical Center, Columbus, OH
Background: The National Comprehensive Cancer Network (NCCN) guidelines
recommend against sentinel lymph node biopsy (SLNB) for ductal
carcinoma in-situ (DCIS) treated with breast conservation surgery (BCS).
SLNB is appropriate with mastectomy because it precludes subsequent
SLNB if invasive cancer is identified. However, SLNB is commonly
performed with BCS for DCIS. We hypothesize SLNB use in the setting of
BCS for DCIS varies and may be over used in some cancer centers. Methods:
We examined 6,070 cases with initial biopsy showing DCIS presenting to
13 institutions participating in the NCCN Breast Outcomes Database from
1998-2009. Receipt of SLNB was defined as SLNB performed at any point
in primary treatment for those with a final diagnosis of DCIS or at the first
surgical procedure for those upstaged to invasive cancer. Characteristics of
patients who did and did not have SLNB were compared using Chi-square
tests. Logistic models adjusting for clinical and pathologic variables were
performed to assess factors associated with use of SLNB. Results: Of 3,725
treated with BCS, 778 (20.9%) had SLNB. Among 2,345 treated with
mastectomy, 1,484 (63.3%) had SLNB. Within BCS, patients presenting
with clinical symptoms (vs. screening detected) were more likely to have
SLNB (p�0.0006, OR: 1.76; 95% CI 1.31-2.36). For both groups,
presence of comedo necrosis, year of diagnosis, and treating institution
were predictors of SLNB (p�0.0001). 1,171 (19.3%) were upstaged from
DCIS at initial biopsy to invasive cancer on final pathology. 212 (18.1%
invasive cancer group) had positive nodes. Use of SLNB increased over
time from 1998-2009 in mastectomy group. Among BCS group, SNLB use
decreased over the first half of the study period and then remained stable at
approximately 15% across all centers. Conclusions: Although use of SNLB
has decreased over time, a substantial percentage of patients undergoing
BCS for DCIS receive SNLB. Practices vary considerably across centers.
SLNB can be performed as a second procedure for those treated with BCS
and identified with invasive cancer, thereby avoiding unnecessary risk of
significant morbidity. Breast programs should review their practices to
curtail the use of unnecessary surgery for women with DCIS.
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