Annual Meeting Proceedings Part 1 - American Society of Clinical ...
Annual Meeting Proceedings Part 1 - American Society of Clinical ...
Annual Meeting Proceedings Part 1 - American Society of Clinical ...
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565 General Poster Session (Board #4H), Sat, 8:00 AM-12:00 PM<br />
Prognostic factor Ki67 for breast cancer patients in each subgroup.<br />
Presenting Author: Naoki Niikura, Tokai University School <strong>of</strong> Medicine,<br />
Isehara Kanagawa, Japan<br />
Background: Immunohistochemical (IHC) Ki67 has described it as a<br />
prognostic and predictive marker for breast cancer. The St. Gallen<br />
Consensus <strong>Meeting</strong> determined that Ki67 labeling index is chiefly important<br />
for distinguishing between “Luminal A” and “Luminal B (HER2<br />
negative)” subtypes and is a predictive marker for chemotherapeutic<br />
efficacy. However, the high and low cut<strong>of</strong>f points remain controversial. Our<br />
objective is to compare survival in patients with low, intermediate, and high<br />
Ki67 levels in each subgroup. Methods: We retrospectively identified all the<br />
patients in the Tokai University breast cancer database for whom IHC Ki67<br />
data were available between January 1, 2000, and December 31, 2010.<br />
Ki67 was defined as low if �10% Ki67 was detected, as Intermediate if<br />
10–20% Ki67 was detected, and as high if �20% Ki67 was detected. To<br />
assess Ki67 levels and survival outcomes, survival curves were calculated<br />
using the Kaplan–Meier method and compared using the log-rank test.<br />
Results: We identified 1331 primary breast cancer patients without<br />
metastasis, <strong>of</strong> whom 686 received neoadjuvant or adjuvant chemotherapy.<br />
Patients with high Ki67 had poorer relapse-free survival (RFS) than<br />
patients with intermediate (p � 0.009) and low Ki67 (p � 0.001). Patients<br />
with intermediate Ki67 had poorer RFS than patients with low Ki67 (p �<br />
0.001). In ER-positive cases (n � 1059), patients with high and intermediate<br />
Ki67 had poorer RFS than patients with low Ki67 (p � 0.001 and p �<br />
0.002, respectively). In HER2-positive and ER-negative cases (n � 103),<br />
patients with high Ki67 had poorer RFS than patients with low Ki67 (p �<br />
0.002). In triple-negative cases (n � 164), patients with high Ki67 tended<br />
to have poorer RFS than patients with low Ki67 (p � 0.064). Conclusions:<br />
Our data demonstrated that low, intermediate, and high Ki67 levels may be<br />
used to differentiate prognosis in ER-positive cancer patients as well as<br />
HER2-positive and triple-negative cancer patients.<br />
567 General Poster Session (Board #5B), Sat, 8:00 AM-12:00 PM<br />
Characterization <strong>of</strong> the overall survival benefit in ENCORE 301, a randomized<br />
placebo-controlled phase II study <strong>of</strong> exemestane with and without<br />
entinostat in ER� postmenopausal women with metastatic breast cancer.<br />
Presenting Author: Pamela Klein, PMK Consulting, San Mateo, CA<br />
Background: Histone deacetylase inhibitors (HDACi) prevent the emergence<br />
<strong>of</strong> drug tolerant clones and sensitize cells to a variety <strong>of</strong> anti-cancer<br />
therapies. We previously reported ENCORE 301, a randomized placebo<br />
controlled phase 2 study comparing exemestane with (EE) and without (EP)<br />
the HDACi entinostat met its primary endpoint <strong>of</strong> prolonging progression<br />
free survival (PFS) (4.3 months vs 2.3 months) and extending overall<br />
survival (OS) benefit (26.9 vs 19.8 months). In order to characterize and<br />
better understand the OS benefit, exploratory analyses were conducted.<br />
Methods: Hazard ratios (HR) for treatment were estimated from the Cox<br />
proportional hazards model, with EP serving as the reference treatment in<br />
the calculations. Inferential comparisons between treatment groups were<br />
made using the log-rank test. Results: Analysis <strong>of</strong> OS across multiple<br />
subsets <strong>of</strong> interest demonstrated a consistent benefit in EE group versus<br />
EP. Sensitivity analysis <strong>of</strong> baseline characteristics potentially impacting<br />
OS did not identify any factors that influenced the effect <strong>of</strong> EE on OS.<br />
Examination <strong>of</strong> treatments received during follow-up after discontinuation<br />
<strong>of</strong> EE and EP demonstrated balance between treatment group for patients<br />
receiving chemotherapy (48% EE: 44% EP), hormone therapy (37% EE:<br />
35% EP), bisphosphonates (2% EE; 0% EP), radiation (6% EE; 5%EP),<br />
and surgery (0% EE: 2% EP). Compared to EP, OS was longer in EE group<br />
for patients whose first subsequent treatment was a hormone therapy (EE<br />
median not reached vs EP median 20.5 months; HR 0.65 [95% CI 0.26,<br />
1.58]) or chemotherapy (EE median 26.9 months vs EP median 17.6<br />
months; HR 0.51 [95% CI 0.25, 1.04]). Updated PFS and OS data will<br />
also be presented along with correlation analysis <strong>of</strong> PFS and OS. Conclusions:<br />
Analyses <strong>of</strong> baseline characteristics, subsequent treatment and subsets <strong>of</strong><br />
prognostic factors in ENCORE 301 did not identify any contributing factors<br />
that account for the extended OS benefit in the EE treatment group. Long<br />
lasting effects <strong>of</strong> entinostat on progenitor cells, emergence <strong>of</strong> drug tolerant<br />
cells and or priming to subsequent therapies cannot be ruled out.<br />
Breast Cancer—HER2/ER<br />
23s<br />
566 General Poster Session (Board #5A), Sat, 8:00 AM-12:00 PM<br />
Prognostic significance <strong>of</strong> PI3K pathway (PI3Kp) dysregulation in metastatic<br />
breast cancer (MBC) patients (pts). Presenting Author: Alejandro Navarro,<br />
Medical Oncology Department, Vall d’Hebron University Hospital, Barcelona,<br />
Spain<br />
Background: PI3Kp dysregulation represents a potential target for therapies that<br />
are currently being tested in clinical trials. This observational retrospective study<br />
aims to evaluate the prognostic implications <strong>of</strong> PI3Kp dysregulation in MBC.<br />
Methods: MBC pts with PI3Kp status assessment from Sep09 to Sep11 were<br />
reviewed. PIK3CA mutation status analyzed in paraffin-embedded tissue by DxS<br />
PI3K Mutation Test Kit or Sequenom MassARRAY. PTEN status determined by<br />
IHC. PI3Kp status: (a) No dysregulation: PIK3CA wt and PTEN normal; (b)<br />
PI3Kp dysregulation: PIK3CA mutation (PIK3CAmut) or PTEN low (HScore�50).<br />
Results: 232 MBC pts screened, median age 49.8 (22.9-83.1) and median MBC<br />
lines 4 (1-15). Distribution: HR�/HER2- 99 (43%), HER2� 52 (22%), triple<br />
negative 35 (15%), unclassified 46 (20%). Sites <strong>of</strong> metastasis: visceral 173<br />
(75%), only skin 10 (4%), only bone 49 (21%). PIK3CA status assessed in 174<br />
pts, 53 (22.8%) bearing a mutation (21 exon9, 32 exon20). PTEN status<br />
assessed in 229 pts, PTEN low 61 (26.6%). PI3Kp dysregulation in 103/185<br />
pts (55.6%). Time to progression to first line MBC treatment (TTP) and overall<br />
survival after MBC diagnosis (OS) are shown. Disease free survival (DFS) and<br />
distant-disease free survival (DDFS) in pts initially diagnosed with early breast<br />
cancer (n�193) has also been calculated. Conclusions: These results suggest<br />
that PI3Kp dysregulation, either by PIK3CA mutation or PTEN low, does not<br />
seem to have impact on disease recurrence, response to first line MBC treatment<br />
or overall MBC survival.<br />
PIK3CA PTEN PI3Kp dysregulation<br />
Median (95%CI) WT Mut Normal Low No Yes<br />
n�174 n�229 n�185<br />
n�121 n�53 n�168 n�61 n�82 n�103<br />
TTP (m) 12.0<br />
11.8<br />
13.0<br />
11.5<br />
12.3<br />
11.8<br />
(10.3-13.8) (9.6-14.0) (11.4-14.6) (7.4-15.6) (10.0-14.5) (9.1-14.5)<br />
p�0.780 p�0.891 p�0.516<br />
OS (y) 5.5<br />
5.0<br />
5.6<br />
5.1<br />
5.5<br />
5.0<br />
(4.1-6.9) (3.3-6.7) (4.9-6.3) (3.0-7.3) (3.9-7.1) (3.5-6.5)<br />
p�0.882 p� 0.460 p�0.443<br />
n�158 n�189 n�167<br />
n�107 n�51 n�132 n�57 n�69 n�98<br />
DFS (m) 45.0<br />
36.6<br />
38.6<br />
49.6<br />
36.0<br />
46.0<br />
(35.6-54.4) (28.6-44.6) (32.2-45.1) (42.6-56.5) (24.3-47.7) (38.5-53.4)<br />
p� 0.476 p�0.071 p�0.163<br />
DDFS (m) 51.0<br />
44.6<br />
46.3<br />
57.1<br />
40.0<br />
49.6<br />
(43.1-58.8) (32.5-56.7) (35.8-56.8) (44.3-69.9) (22.5-57.5) (39.7-59.4)<br />
p� 0.505 p� 0.289 p� 0.254<br />
568^ General Poster Session (Board #5C), Sat, 8:00 AM-12:00 PM<br />
Prospective study <strong>of</strong> the impact <strong>of</strong> using the 21-gene recurrence score<br />
assay on clinical decision making in women with estrogen receptorpositive,<br />
HER2-negative, early-stage breast cancer in France. Presenting<br />
Author: Joseph Gligorov, APHP Tenon APREC, CancerEst, University Paris<br />
VI, Paris, France<br />
Background: The 21-gene Oncotype DX Recurrence Score (RS) is a<br />
validated assay to help inform the appropriate treatment <strong>of</strong> estrogen<br />
receptor-positive (ER�), early stage breast cancer in the adjuvant setting.<br />
Treatment traditions regarding choice <strong>of</strong> adjuvant treatment vary significantly<br />
in different countries. This prospective multicenter study is the first<br />
to assess the impact <strong>of</strong> using the Oncotype DX assay in the French clinical<br />
setting. Methods: A total <strong>of</strong> 100 consecutive patients with ER�, HER2negative,<br />
node negative or pN1 (mi) breast cancer were enrolled. Overall<br />
treatment recommendation change, change from chemoendocrine to<br />
endocrine alone and change from endocrine alone to chemoendocrine<br />
treatment were recorded. Medical oncologists completed questionnaires<br />
regarding their confidence in their recommendation before and after<br />
knowing the patient’s RS. A preliminary analysis was conducted on the first<br />
92 evaluable patients with data available at the time <strong>of</strong> abstract submission.<br />
Final data will be presented at the meeting. Results: Prior to Oncotype<br />
DX 49% <strong>of</strong> patients were recommended chemoendocrine treatment and<br />
51% endocrine treatment alone. After having the RS, 26% were recommended<br />
chemoendocrine treatment and 74% endocrine treatment alone.<br />
The overall reduction in chemotherapy recommendation from 49% to 26%<br />
was significant (p�0.001). Of patients originally recommended chemoendocrine<br />
treatment, 58% were changed to endocrine treatment alone after<br />
having the RS. Of patients originally recommended endocrine treatment,<br />
11% were changed to chemoendocrine treatment after receiving the RS.<br />
There was a significant improvement in physician confidence in treatment<br />
recommendations (p�0.002) when using Oncotype DX. Conclusions: These<br />
are the first prospective data regarding the impact <strong>of</strong> using Oncotype DX in<br />
France. Using Oncotype DX was associated with a significant change in<br />
treatment decisions and an overall reduction in chemotherapy use. The<br />
data are consistent with those presented from Germany, Spain, the UK and<br />
the US.<br />
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