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

684s Tumor Biology
10614 General Poster Session (Board #51G), Mon, 1:15 PM-5:15 PM
Isolation and expansion of circulating tumor cells (CTC) from melanoma
patients using a novel cell culture technique. Presenting Author: John R.
McGregor, TrueCells, LLC, Las Vegas, NV
Background: Identification of rare (�2-5) circulating tumor cells (CTC) in
7.5 ml blood by immunofluorescence assay (IFA) correlates with a poor
prognosis in colon, breast, prostate and lung cancer. Changes in CTC count
during treatment also predict the eventual patient progression and survival
in these cancers. Existing assays do not detect melanoma CTC, however. In
addition, isolation of viable CTC remains problematic. To overcome these
limitations we attempted to develop novel melanoma CTC assays, using IFA
and cell culture approaches. Methods: Blood samples were obtained from
patients and controls following informed consent. The buffy coat (white
cells � tumor) was isolated by Ficoll/Hypaque centrifugation, and split into
6 replicate cultures in proprietary TrueCells medium. After 21 days in
culture, tumor colonies were counted, and stained for melanoma and
leukocyte markers. Buffy coat cells from parallel blood samples were
stained with a panel of CSPG4-specific mAb (a pan-melanoma marker) on
ultraclean glass slides for analysis by immunofluorescence microscopy.
Results: Blood samples were obtained from 16 melanoma patients, ages
28-87. Eight patients were men and 8 were women. CSPG4 � events (�2)
were detected in 8/16 patients by IFA (range 0-52). In contrast, tumor cell
colonies of �50 cells grew in 12 out of 16 patients with Stage 3 or 4
melanoma (range 0-1054), shown in Table. Cells isolated from CTC
colonies produced melanin, stained for CSPG4 and other melanoma
markers, but not for leukocyte markers. Control cultures grew no tumor
colonies. Conclusions: Our pilot study shows that melanoma CTC can be
identified by both IFA and cultured from blood in many patients with stage
3 or 4 melanoma. These CTC exhibited cytologic characteristics diagnostic
of melanoma. The culture assay may represent a useful means of enumerating,
isolating, and expanding viable melanoma CTC for further molecular
study.
Melanoma patients
IFA Culture
Pos assay Median Mean St dev Pos culture Median Mean St dev
Control 0 of 5 0.0 0.0 0.0 0 of 5 0.4* 0.4* 0.8
Stage 1-2 0 of 1 0.0 0.0 0.0 0 of 1 0.0 0.0 0.0
Stage 3 1 of 4 1.0 1.3 1.3 3 of 4 320.5 285.3 209.6
Stage 4 7 of 11 3.0 8.3 15.0 9 of 11 500.0 343.4 221.8
*Non-tumor.
10616 General Poster Session (Board #52A), Mon, 1:15 PM-5:15 PM
Role of proliferation in response to neoadjuvant chemotherapy in GEICAM/
2006-03 and GEICAM/2006-14 breast cancer patients. Presenting Author:
E. Alba, Hospital Clínico Universitario Virgen de la Victoria, Málaga,
Spain
Background: Ki67 proliferation biomarker determined by immunohistochemistry
(IHC) has been studied as a prognostic and predictive factor in
Operable Breast Cancer (OBC). Ki67 modifications after neoadjuvant
endocrine therapy have been correlated with long term outcome. However,
there is no robust data about its predictive role in Neoadjuvant Chemotherapy
(NC). In this study, we investigated Ki67 value as predictor of NC
efficacy. Methods: 193 patients (pts) from 2 GEICAM phase II randomized
trials (2006-03 and 2006-14) were included: 78 (40%) received epirubicine
plus cyclophosphamide followed by docetaxel (EC-D), 41 (21%) EC-D
plus carboplatin, and out of the 74 HER2� pts, 37 (19%) received EC-D
plus tratuzumab and 37 (19%) EC-D plus lapatinib. Median age was 49
years. From series, 87% were invasive ductal carcinoma, 58% premenopausal,
50% grade III, 23% luminal , 39% basal and 38% HER2�. Ki67
was centrally assessed by IHC (MIB1 clone) and median score was 40%
(range 1-100%). Pathological Complete Response (pCR), defined as
absence of invasive cells in breast and lymph nodes, was achieved in 56 pts
(29%). Univariate and multivariate logistic regression models were used to
study the association of each clinical-pathological variable with pCR. ROC
curves were used to determine the most accurate ki67 cut-off for predicting
NC response. Results: Ki67�50% was defined as the most accurate
threshold to select patients obtaining benefit from NC. In the univariate
analysis, histological grade (p�0.01), treatment (P�0.006), ER
(p�0.0001), PR (p�0.0001), HER2 (p�0.01), and Ki67�50%
(p�0.0003) were statistically associated with pCR. A multivariate logistic
regression showed that only Ki67� 50% (p�0.0003; OR�5.4 CI95%
2.1-13.4), ER (p�0.0001; OR�0.2 CI95% 0.1-0.4), and HER2 status
(p�0.0001; OR�8.8 CI95% 3.3-23.6) were predictive for pCR
(AUC�0.7812). Conclusions: These results suggest that a high proliferation
in breast cancer measured by Ki67 marker is an independent
predictive factor for pCR in an unclassified HER2 population of OBC
patients treated with NC.
10615 General Poster Session (Board #51H), Mon, 1:15 PM-5:15 PM
Zoledronic acid effect on circulating RANK/RANK-l/OPG axis in cancer
patients. Presenting Author: Toni Ibrahim, Osteoncology Center, Istituto
Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola, Italy
Background: Bone metastasis disrupts bone integrity through loss of the
balance between osteoclastic-mediated osteolysis and osteoblastic osteogenesis.
The RANK/RANK-L/OPG axis governs osteoclastogenesis and bone
resorption. We evaluated the trend of markers over time. Secondary aims
were to study the predictive role of different circulating markers in the
response to Zoledronic Acid (ZA) with respect to objective response and to
skeletal-related events (SREs). Methods: The study prospectively evaluated
levels of RANK, RANKL and OPG transcripts by Real-Time PCR and VEGF
and NTX expression by ELISA in the peripheral blood of 49 consecutive
patients with advanced breast, prostate or lung cancer (36, 7 and 6,
respectively). Enrolled patients were at first diagnosis of bone metastases
and had not previously undergone treatment with bisphosphonates. Patients
received the standard schedule of ZA (4 mg infusion every 28 days)
for about 12 months, undergoing blood tests and instrumental evaluation
before the first infusion of ZA and every 4 months thereafter. Results:
Median RANKL values after 12 infusions of ZA had decreased by 22% with
respect to baseline whereas OPG, had increased by about 96%, with a 56%
decrease in the RANKL/OPG ratio. NTX decreased over time (p�0.0001).
On the basis of ROC curve analysis, RANKL was the most accurate marker
for bone response with an AUC of 0.74 (95% CI 0.54-0.93). No
correlations were found between circulating markers and SREs. Conclusions:
The present work is one of the few prospective studies carried out on the
circulating markers that are potentially associated with bone metastases.
Our findings would seem to indicate that ZA decreases osteoclast activity
through RANK/RANKL/OPG pathway modulation and that RANKL may play
a role in the prediction of objective response to ZA. Confirmation of results
is needed in a larger case series.
10617 General Poster Session (Board #52B), Mon, 1:15 PM-5:15 PM
Predictive impact of RRM1 protein expression on vinorelbine efficacy in
NSCLC patients randomized in a chemotherapy phase III trial. Presenting
Author: Adam Vilmar, Department of Oncology, Finsen Centre, National
University Hospital, Copenhagen, Denmark
Background: Platinum based doublets remain the cornerstone of treatment
in non-small cell lung cancer (NSCLC) and often includes gemcitabine. A
biomarker predicting sensitivity to this antimetabolite would represent a
major step forward in the management of advanced disease. Ribonucleotide
reductase subunit M1 (RRM1) has been of some value in NSCLC but
evidence is not uniform. Accordingly, we explored the predictive role of
RRM1 in patients with advanced NSCLC. Methods: 443 patients with
advanced NSCLC were randomized in a phase III trial to regimen A
(paclitaxel and cisplatin with gemcitabine) or regimen B (cisplatin and
vinorelbine). Immunohistochemical evaluation of RRM1 was performed on
mainly bioptic material and correlated to response rates, progression free
survival (PFS) and overall survival (OS). Results: 261 (58.9%) patients had
representative tissue samples for RRM1 evaluation. Disease control rate,
PFS and OS were significantly improved in patients with RRM-negative
tumors receiving regimen B as compared to patients with RRM-positive
tumors (68.8% vs. 31.2%, P � 0.046 , 6.90 months (mths) (95% CI
5.83-7.96) vs. 3.93 mths (95% CI 3.11-4.76), P � 0.000 and 11.57
mths (95% CI 9.65-13.48) vs. 7.4 mths (95% CI 5.37-9.43), P � 0.002,
respectively). However, this was not the case for patients receiving regimen
A (67.6% vs. 32.4%, P � 0.366, 6.73 mths vs. 7.6 mths, P � 0.207,
11.07 mths vs. 12.37 mths, P � 0.103, respectively ). Together with
histological subtype, RRM1-positivity emerged as the only other significant
prognostic variable with a hazard ratio of 1.56 (95% CI 1.38-2.35, P �
0.033) in multivariate analysis for patients treated with regimen B.
Conclusions: RRM1 protein expression was without predictive impact in
patients treated with cisplatin, paclitaxel and gemcitabine. Surprisingly,
the predictive power proved robust in the cisplatin and vinorelbine arm
across classic endpoints confirmed by multivariate analysis. These findings
may suggest that RRM1 is involved in vinorelbine sensitivity and warrant
further research which will be presented shortly.
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