New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5  GeV/c^{2}.

Abstract P5-01-02: Multimodality molecular imaging with dynamic 18F-fluorodeoxyglucose positron emission tomography (FDG PET) and MRI to evaluate response and resistance to neoadjuvant chemotherapy (NAC)

Background: Using quantitative FDG PET to measure glucose metabolism and perfusion, and dynamic contrast-enhanced (DCE) MRI to measure perfusion, we previously identified a metabolic signature for breast cancer resistant to NAC. This imaging signature is (1) persistent or increased tumor perfusion despite treatment, (2) an altered pattern of glucose kinetics in response to therapy, and (3) pre-therapy mismatch between tumor metabolism (MRFDG) and glucose delivery (K1) (high ratio of MRFDG/K1). These patterns predict poor response, early relapse and death independent of established prognostic factors, including pathologic response. Identification of factors associated with resistance or response to therapy is the translational goal of "Quantitative Dynamic PET and MRI in Breast Cancer Therapy," part of the Seattle Breast SPORE (1P50CA138293).

Methods: Patients (Pts) undergoing NAC for histologically confirmed breast cancer (stage II-III) were approached for this trial (CCIRB# 7587). FDG PET and DCE-MRI were obtained pre-therapy, 2-12 weeks after start of NAC (mid-therapy) and after completion of NAC. Breast biopsies were obtained pre-therapy and post-NAC. FDG PET included a dynamic scan with kinetic analysis. PET measures included SUVmax, MRFDG, K1, Ki, and Patlak. 3T DCE-MRI measurements included semi-quantitative vascular parameters of peak enhancement (PE), signal enhancement ratio (SER), washout fraction, functional tumor volume, and apparent diffusion coefficient (ADC) from diffusion-weighted MRI (DWI). Breast biopsies were assayed by immunohistochemistry and gene expression profiling. NAC was per physician's choice with most pts receiving weekly paclitaxel (with trastuzumab if HER2+) followed by doxorubicin/cyclophosphamide.

Results: 32 pts have completed the study. Pathologic complete response (pCR), defined as absence of invasive cancer in the breast, was observed in 9 (28%); near pCR defined as only microscopic residual invasive cancer in 3 (9%) more pts. Mid-therapy decline in SUVmax and K1 was associated with near pCR; (p-value 0.06, 0.04, respectively). Pre-therapy PET measures of MRFDG and K1 were not predictive of pCR. On MRI, pre-therapy PE (p=0.009), SER (p=0.01), washout fraction (p=0.02), ADC (p=0.08, trend) and mid-therapy change in volume (p=0.05) were each predictive of pCR. Gene profiling of pre-therapy biopsies showed correlation between high MRFDG/K1 ratio in basal and luminal B tumors.

Conclusions: Assessment of serial changes in tumor metabolism and perfusion by FDG PET and DCE-MRI is feasible in the clinic. Mid-therapy decline in metabolism and glucose delivery was predictive of pCR; consistent with prior retrospective series. Baseline DCE-MRI and DWI measures show promise to predict response, and associations of mid-therapy change in MR functional tumor volume with pCR agree with findings of another multisite clinical trial (ISPY). These imaging parameters may serve as useful biomarkers to inform future neoadjuvant trials. Integration of imaging data with gene expression profiling revealed that the pattern of metabolism in luminal B tumors was closer to that of the basal subtype compared to other ER-positive tumors.

Citation Format: Specht JM, Partridge S, Chai X, Novakova A, Peterson L, Shields A, Guenthoer J, Linden HM, Gralow JR, Gadi V, Korde L, Hills D, Hsu L, Hockenbery DM, Kinahan P, Mankoff DA, Porter PL. Multimodality molecular imaging with dynamic 18F-fluorodeoxyglucose positron emission tomography (FDG PET) and MRI to evaluate response and resistance to neoadjuvant chemotherapy (NAC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-02.

Validation of multisociety combined task force definitions of abnormal disk morphology

BACKGROUND AND PURPOSE

The multisociety task force descriptively defined abnormal lumbar disk morphology. We aimed to use their definitions to provide a higher level of evidence for the validation of MR imaging in the evaluation of this pathology in patients who have undergone diskectomy by retrospectively classifying their preoperative MRI.

MATERIALS AND METHODS

This retrospective, institutional review board-approved study included 54 of 86 consecutive patients (47 men; average age, 44 years) enrolled in an ongoing prospective trial of surgically treated lumbar disk herniation who had preoperative MRI and documented intraoperative classification of the abnormal disk as protrusion, extrusion, or sequestration by the treating surgeon. Preoperative MRI was classified by 2 blinded radiologists; discrepancies were resolved by a third reader. Statistical analysis of interobserver agreement and imaging compared with surgical findings was performed.

RESULTS

The readers disagreed on only 1 of the 54 cases. The third reader resolved the disagreement. Eight protrusions and 46 extrusions were found on imaging, with no sequestrations. At surgery, there were 13 protrusions and 40 extrusions, with 2 of the extrusions also containing sequestrations; the remaining case had only sequestration. There were 16 discrepancies between imaging and surgery, resulting in 70% agreement.

CONCLUSIONS

This study, which was intended to validate the multisociety combined task force definitions of abnormal disk morphology by using MR imaging with a surgical criterion standard, found 70% agreement between imaging diagnosis and surgical findings. Although reasonable, this finding highlights differences that often exist between intraoperative and preoperative imaging findings of lumbar disk herniation.

First direct limits on lightly ionizing particles with electric charge less than e/6

While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.

Search for low-mass weakly interacting massive particles with SuperCDMS

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30  GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42)  cm(2) at 8  GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6  GeV/c(2).

Search for low-mass weakly interacting massive particles using voltage-assisted calorimetric ionization detection in the SuperCDMS experiment

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170  eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6  GeV/c2.

Silicon detector dark matter results from the final exposure of CDMS II

We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10  GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6  GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41)  cm2.

Long-term treatment efficacy in primary inflammatory breast cancer by hormonal receptor- and HER2-defined subtypes

BACKGROUND

Subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied in inflammatory breast cancer (IBC). We characterized clinical parameters and long-term outcomes, and compared pathological complete response (pCR) rates by HR/HER2 subtype in a large IBC patient population. We also compared disease-free survival (DFS) and overall survival (OS) between IBC patients who received targeted therapies (anti-hormonal, anti-HER2) and those who did not.

PATIENTS AND METHODS

We retrospectively reviewed the records of patients diagnosed with IBC and treated at MD Anderson Cancer Center from January 1989 to January 2011. Of those, 527 patients had received neoadjuvant chemotherapy and had available information on estrogen receptor (ER), progesterone receptor (PR), and HER2 status. HR status was considered positive if either ER or PR status was positive. Using the Kaplan-Meier method, we estimated median DFS and OS durations from the time of definitive surgery. Using the Cox proportional hazards regression model, we determined the effect of prognostic factors on DFS and OS. Results were compared by subtype.

RESULTS

The overall pCR rate in stage III IBC was 15.2%, with the HR-positive/HER2-negative subtype showing the lowest rate (7.5%) and the HR-negative/HER2-positive subtype, the highest (30.6%). The HR-negative, HER2-negative subtype (triple-negative breast cancer, TNBC) had the worst survival rate. HR-positive disease, irrespective of HER2 status, had poor prognosis that did not differ from that of the HR-negative/HER2-positive subtype with regard to OS or DFS. Achieving pCR, no evidence of vascular invasion, non-TNBC, adjuvant hormonal therapy, and radiotherapy were associated with longer DFS and OS.

CONCLUSIONS

Hormone receptor and HER2 molecular subtypes had limited predictive and prognostic power in our IBC population. All molecular subtypes of IBC had a poor prognosis. HR-positive status did not necessarily confer a good prognosis. For all IBC subtypes, novel, specific treatment strategies are needed in the neoadjuvant and adjuvant settings.

Effect of pulsed light treatments on the growth and resistance behavior of Listeria monocytogenes 10403S, Listeria innocua, and Escherichia coli ATCC 25922 in a liquid substrate

Pulsed light (PL) treatment can effectively inactivate a large proportion of contaminating bacteria on surfaces and in clear solutions. An important issue that needs to be investigated is whether repeated exposure to PL treatment causes any changes to the growth and resistance behavior of the bacteria surviving the treatment. To test this, three challenge microorganisms were used: Listeria monocytogenes, Listeria innocua, and Escherichia coli. Cells of the challenge bacteria were treated with either low or high PL doses. Survivors of the PL treatment were enumerated, isolated, regrown, and exposed again to PL treatment. PL inactivation curves were generated for the survivors of each exposure cycle (as well as controls) to examine possible differences induced by repeated treatments. Growth curves of L. monocytogenes, L. innocua, and E. coli isolates recovered from exposure to either 1.1 or 10.1 J/cm(2) were not significantly different from the growth curves of untreated cells. Reduction levels of up to 4 and up to 6 log CFU were obtained after exposure to 1.1 and 10.1 J/cm(2), respectively, both for the controls and the repeatedly treated and recovered isolates. These results show that PL did not significantly change the growth kinetics or resistance to PL of the target microorganisms after up to 10 exposures. These findings have significance for the practical application of PL treatment, as they indicate that this technology does not select for microorganisms with increased resistance.

Abstract P3-10-05: Response to neoadjuvant systemic therapy (NST) in inflammatory breast cancer (IBC) according to estrogen receptor (ER) and HER2 expression

Background: Inflammatory breast cancer (IBC) is the most aggressive form breast cancer. NST, followed by local therapy (surgery and radiation therapy), is considered the current standard therapy for IBC. Among noninflammatory breast cancers, sensitivity to NST differs based on ER and HER2 status. However, whether the sensitivity to NST also differs in primary IBC based on ER status or other prognostic factors has not been studied in a large cohort.

Methods: We retrospectively reviewed 1078 patients (pts) newly diagnosed with IBC from April 1989 to January 2011. Of these, 838 pts met our inclusion criterion of stage III disease at diagnosis, and 713 of these pts had received NST and surgery. Among this population, 545 pts had information available on both ER and HER2 status. We compared pathological complete response (pCR) rates (defined as no evidence of invasive disease in the breast and ipsilateral axillary limph nodes) and clinical characteristics between ER and HER2-status subgroups and analyzed their clinical outcome. We used the Kaplan-Meier method to estimate the median recurrence-free survival (RFS) after surgery and overall survival (OS), and the Cox proportional hazards regression model to test the statistical significance of potential prognostic factors in each group.

Results: Overall 177 pts had ER+HER2− tumors; 75, ER+HER2+; 134, ER-HER2+; and 159, ER-HER2−. NST consisted of anthracycline-based [A] alone, a taxane [T] alone or with A+T; HER2 targeting therapies (H) were administered to 117 patients with HER2-positive breast cancer after 1998. Overall pCR rate was 14.7%. pCR rates are shown by marker subtype and NST received in the table below. pCR rate, nuclear grade, vascular invasion, clinical response to NST, adjuvant treatment, radiation therapy, and adjuvant hormonal therapy differed significantly among subgroups.

The median RFS and OS for all patients was 19.2 and 33.2 months, respectively. In multivariate analysis, BMI, ER status, lymphatic invasion, radiation therapy, and pCR rate were associated with RFS, and ER status, vascular invasion, radiation therapy, and pCR rate were associated with OS. Except in the ER+HER2− group, pCR was associated with better prognosis compared to non-pCR. Adjuvant hormonal therapy improved RFS both in ER+HER2+ and ER+HER2− groups, but did not improve OS in the ER+HER2+ group. Among 209 patients with HER2+ IBC, 134 received HER2 targeting therapies in neoadjuvant or adjuvant chemotherapy, and had a trend to improvement in RFS compared to chemotherapy alone (p = 0.082). The ER-HER2− group showed poorest outcome compared to other subgroups (P &lt; 0.001).

Conclusions: Sensitivity to NST differs depending on the ER and HER2 status in IBC pts. pCR rates based on these subgroups appear to be low. There is a need more effective treatments in the neoadjuvant and adjuvant therapies for all subgroups of IBC.

Multifocality and multicentricity in breast cancer and survival outcomes

BACKGROUND

The clinicopathological characteristics and the prognostic significance of multifocal (MF) and multicentric (MC) breast cancers are not well established.

PATIENTS AND METHODS

MF and MC were defined as more than one lesion in the same quadrant or in separate quadrants, respectively. The Kaplan-Meier product limit was used to calculate recurrence-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes.

RESULTS

Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n = 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P < 0.001), grade 3 disease (44% versus 38.2%, P < 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P < 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P = 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS.

CONCLUSIONS

MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.

Ki67 expression in the primary tumor predicts for clinical benefit and time to progression on first-line endocrine therapy in estrogen receptor-positive metastatic breast cancer

We examined whether baseline Ki67 expression in estrogen receptor-positive (ER+) primary breast cancer correlates with clinical benefit and time to progression on first-line endocrine therapy and survival in metastatic disease. Ki67 values and outcome information were retrieved from a prospectively maintained clinical database and validated against the medical records; 241 patients with metastatic breast cancer were included--who had ER+ primary cancer with known Ki67 expression level--and received first-line endocrine therapy for metastatic disease. Patients were assigned to low (<10 %), intermediate (10-25 %), or high (>25 %) Ki67 expression groups. Kaplan-Meier survival curves were plotted and multivariate analysis was performed to assess association between clinical and immunohistochemical variables and outcome. The clinical benefit rates were 81, 65, and 55 % in the low (n = 32), intermediate (n = 103), and high (n = 106) Ki67 expression groups (P = 0.001). The median times to progression on first-line endocrine therapy were 20.3 (95 % CI, 17.5-38.5), 10.8 (95 % CI, 8.9-18.8), and 8 (95 % CI, 6.1-11.1) months, respectively (P = 0.0002). The median survival times after diagnosis of metastatic disease were also longer for the low/intermediate compared to the high Ki67 group, 52 versus 30 months (P < 0.0001). In multivariate analysis, high Ki67 expression in the primary tumor remained an independent adverse prognostic factor in metastatic disease (P = 0.001). Low Ki67 expression in the primary tumor is associated with higher clinical benefit and longer time to progression on first-line endocrine therapy and longer survival after metastatic recurrence.

P2-12-06: Nomogram To Predict Subsequent Bone Metastasis in Patients with Non Metastatic Breast Carcinomas

Background

Bone metastasis (BM) is one of the most common sites of distant metastasis for breast cancer. We hypothesized that its occurrence can be predicted if a clinical nomogram can be developed, thus allowing for selection of patients at high risk for BM.

Patients and Methods

Medical records of patients with non metastatic breast cancer were prospectively collected for the period between January 1997 and February 2007 at the M.D. Anderson Cancer Center (Texas, USA). A multivariate logistic regression analysis of selected prognostic features was done. Based on Cox proportional hazards regression model, a nomogram to predict BM was constructed and validated in an independent cohort of 579 patients with non metastatic breast cancer at time of diagnosis treated at the Tenon Hospital (Paris, France) between January 2003 and December 2005.

Results: Of 4175 patients with non metastatic breast cancer, 314 developed subsequent BM. Age, T stage, lymph node status, lymphovascular space invasion, breast cancer molecular subtype, adjuvant hormonotherapy were significantly and independently associated with subsequent BM. The nomogram had a concordance index of 0.69 (95% CI, 0.68 to 0.70) in the training set. The validation set showed a good discrimination with a concordance index of 0.65 (95% CI, 0.57 to 0.72). At 3, 5 and 7 years, the nomogram was well calibrated.

Conclusion: We have developed a robust tool that is able to predict subsequent BM in patients with non metastatic breast cancer. Selection of an enriched patient population at high risk for BM will allow to practice individualized therapeutic strategies, an adapted medical supervision and will facilitate the design of trials aiming at its prevention with the use of biphosphonate treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-06.

Comparison of assay methods for detection of circulating tumor cells in metastatic breast cancer: AdnaGen AdnaTest BreastCancer Select/Detect™ versus Veridex CellSearch™ system

The detection of CTCs prior to and during therapy is an independent and strong prognostic marker, and it is predictive of poor treatment outcome. A major challenge is that different technologies are available for isolation and characterization of CTCs in peripheral blood (PB). We compare the CellSearch system and AdnaTest BreastCancer Select/Detect, to evaluate the extent that these assays differ in their ability to detect CTCs in the PB of MBC patients. CTCs in 7.5 ml of PB were isolated and enumerated using the CellSearch, before new treatment. Two cutoff values of ≥2 and ≥5 CTCs/7.5 ml were used. AdnaTest requires 5 ml of PB to detect gene transcripts of tumor markers (GA733-2, MUC-1, and HER2) by RT-PCR. AdnaTest was scored positive if ≥1 of the transcript PCR products for the 3 markers were detected at a concentration ≥0.15 ng/μl. A total of 55 MBC patients were enrolled. 26 (47%) patients were positive for CTCs by the CellSearch (≥2 cutoff), while 20 (36%) were positive (≥5 cutoff). AdnaTest was positive in 29 (53%) with the individual markers being positive in 18% (GA733-2), 44% (MUC-1), and 35% (HER2). Overall positive agreement was 73% for CTC≥2 and 69% for CTC≥5. These preliminary data suggest that the AdnaTest has equivalent sensitivity to that of the CellSearch system in detecting 2 or more CTCs. While there is concordance between these 2 methods, the AdnaTest complements the CellSearch system by improving the overall CTC detection rate and permitting the assessment of genomic markers in CTCs.

Results from a low-energy analysis of the CDMS II germanium data

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below ∼10  GeV/c(2). This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9  GeV/c(2) and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.

In vitro activity of doripenem and other carbapenems against contemporary Gram-negative pathogens isolated from hospitalised patients in the Asia-Pacific region: results of the COMPACT Asia-Pacific Study

The Comparative Activity of Carbapenems Testing (COMPACT) Study was designed to determine the in vitro potency of doripenem compared with imipenem and meropenem against a large number of contemporary Gram-negative pathogens from more than 100 centres across Europe and the Asia-Pacific region and to assess the reliability of Etest methodology for doripenem minimum inhibitory concentration (MIC) determination against these pathogens. Data from eight countries within the Asia-Pacific region, which collected 1612 bacterial isolates, are presented here. Etest methodology was found to be a reliable method for MIC determination. Doripenem showed in vitro activity similar to or better than meropenem and at least four-fold better than imipenem against Enterobacteriaceae. Against Pseudomonas aeruginosa, doripenem was also the most active of the three carbapenems in vitro. However, in vitro results do not necessarily correlate with clinical outcome.

Magnetostrictive Composite Material Systems Analytical/Experimental

Experimental and theoretical results are presented for a composite magnetostrictive material system. This material system contains Terfenol-D particles blended with a binder resin and cured in the presence of a magnetic field to form a 1–3 composite. Test data indicates that the magnetostrictive material can be preloaded in-situ with the binder matrix resulting in orientation of domains that facilitate strain responses comparable to monolithic Terfenol-D. Two constitutive equations for the monolithic material are described and a concentric cylinders model is used to predict the response of the composite structure. Experimental data obtained from the composite systems coincide with the analytical models within 10%. Particle size, resin system, and volume fraction are shown to significantly influence the response of the fabricated composite system.

Abstract P1-11-22: Bisphosphonates and Pathologic Complete Response to Neoadjuvant Chemotherapy in Patients with Breast Cancer

Purpose: Several studies have suggested that bisphosphonates have antitumor effects and that their use may have a potential benefit on recurrence and survival in patients with primary breast cancer. In a retrospective study, we sought to evaluate whether the use of bisphosphonates increased the rates of pathological complete response (pCR) in breast cancer patients receiving taxane and anthracycline-based neoadjuvant chemotherapy. Methods: We identified from our database 1449 breast cancer patients receiving taxane and anthracycline-based neoadjuvant chemotherapy between 1995 and 2007 at M.D. Anderson Cancer Center. Among the entire cohort, we identified by chart review those patients that while receiving chemotherapy also received bisphosphonates for a different indication (osteopenia or osteoporosis). Primary outcome was the proportion of patients achieving a pCR. Groups were compared using the chi-squared test. A multivariable logistic regression model was fit to examine the relationship between the use of bisphosphonates and pCR. An exploratory survival analysis using the Kaplan-Meier method was performed; groups were compared using the log-rank test.

Results: From the 1449 patients included, 39 (2.7%) received bisphosphonates at the time of neoadjuvant chemotherapy.66.7% received alendronate, 28.2% risedronate and 5.1% ibandronate. Those receiving bisphosphonates were older (P&lt;.001) and less likely to be obese (P=.04). The pCR rate was 26% in the bisphosphonate group and 16% in the non- bisphosphonate group (P=.11). After adjusting for potential confounding variables, patients treated with bisphosphonates tended to have higher rates of pCR (OR 2.16 95% CI 0.89-5.25); however the difference did not reach statistical significance. With a median follow up of 55 months (3-145) there were 412 recurrences and 359 deaths. There were no differences on 5-year PFS (71% vs 80%; P=.28) or 5-year OS (77% vs 82%; P=.42) between the two groups.

Conclusions: In this cohort of patients, the concurrent use of bisphosphonates at the time of neoadjuvant chemotherapy was not associated with significant increased rates of pCR. The observed estimates suggest a positive effect; however, it is possible that the small proportion of patients receiving bisphosphonates affected the power to detect a statistically significant difference. To fully test the hypothesis, additional, well-powered prospective studies to evaluate the potential use of bisphosphonates as antitumor agents used in the neoadjuvant setting are warranted.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-11-22.

Gene expression array testing of FFPE archival breast tumor samples: an optimized protocol for WG-DASL sample preparation

Archived formalin-fixed, paraffin embedded (FFPE) tissues constitute a vast, well-annotated, but underexploited resource for the molecular study of cancer progression, largely because degradation, chemical modification, and cross-linking, render FFPE RNA a suboptimal substrate for conventional analytical methods. We report here a modified protocol for RNA extraction from FFPE tissues which maximized the success rate (with 100% of samples) in the expression profiling of a set of 60 breast cancer samples on the WG-DASL platform; yielding data of sufficient quality such that in hierarchical clustering (a) 12/12 (100%) replicates correctly identified their respective counterparts, with a high self-correlation (r = 0.979), and (b) the overall sample set grouped with high specificity into ER+ (38/40; 95%) and ER- (18/20; 90%) subtypes. These results indicate that a large fraction of decade-old FFPE samples, of diverse institutional origins and processing histories, can yield RNA suitable for gene expression profiling experiments.