Preparation of highly pure zeaxanthin particles from sea water-cultivated microalgae using supercritical anti-solvent recrystallization

Xanthophylls, including zeaxanthin, are considered dietary supplements with a potentially positive impact on age-related macular degeneration. Using pilot-scale column fractionation coupled with supercritical anti-solvent (SAS) recrystallization, highly pure zeaxanthin particulates were prepared from ultrasonic extracts of the microalgae, Nannochloropsis oculata, grown in sea water. Column partition chromatography increased the concentration of zeaxanthin from 36.2 mg/g of the ultrasonic extracts to 425.6 mg/g of the collected column fractions. A response surface methodology was systematically designed for the SAS process by changing feed concentration, CO(2) flow rate and anti-solvent pressure. Zeaxanthin-rich particles with a purity of 84.2% and a recovery of 85.3% were produced using supercritical anti-solvent recrystallization from the column eluate at a feed concentration of 1.5 mg/mL, CO(2) flow rate of 48.6 g/min and pressure of 135 bar.

P2-09-15: Functional Measurements of Tumor Response during Neoadjuvant Chemotherapy Infusion and Early during Treatment Using Diffuse Optical Spectroscopic Imaging

Background: Non-invasive markers of neoadjuvant chemotherapy response early during treatment would provide physicians a valuable tool to make evidence-based changes to treatment strategies. In a retrospective study of 23 patients presented at SABCS 2011 we demonstrated that Diffuse Optical Spectroscopic Imaging (DOSI) can discriminate non-responding from responding subjects on the first day after the start therapy based on the presence or absence of an oxyhemoglobin flare. Here we present results of an ongoing prospective study designed to confirm the predictive nature and biological origins of oxyhemoglobin flare and to determine if similar functional changes occur at even earlier timepoints such as during infusion.

Methods: DOSI was used to measure hemodynamic and metabolic information from tumors and surrounding normal tissue in patients prior to neoadjuvant chemotherapy, during chemotherapy infusion, and daily for the first week of treatment. DOSI uses temporally modulated near-infrared light to determine absolute tissue concentrations of oxyhemoglobin, deoxyhemoglobin, water and lipid content and requires no exogenous contrast agent. Measurements are made using a simple handheld probe placed on the skin. Blood samples were also collected at baseline and daily for seven days after the first infusion and tested for a panel inflammatory cytokines. Patients received paclitaxel + carboplatin + bevacizumab. Overall response to therapy was determined by the decrease in anatomic tumor size.

Results: To date three subjects have been measured, two of which have completed neoadjuvant chemotherapy and undergone surgery. One subject was a pathologic complete responder (pCR) and the other a non-responder (NR). In both the pCR subject and the subject still undergoing therapy there were significant functional changes measured in the tumor during infusion. A decrease in oxyhemoglobin and oxygen saturation occurred after paclitaxel infusion (saturation changes: −4.8% and −9.7% for each subject respectively), followed by an increase in these quantities after carboplatin infusion (saturation: 3.8% and 5.9% respectively). In the NR subject both oxyhemoglobin and oxygen saturation had only small fluctuations during infusion (saturation: 1.1%). Oxyhemoglobin flare was also observed 24 hours after infusion for each of the patients. Plasma levels of several inflammatory cytokines including G-CSF, MIP-1α, and C-reactive protein increased 24 hours after infusion for the first two subjects and subsequently decreased at 48 hours.

Discussion: We have confirmed the presence of oxyhemoglobin flare on day one after infusion in this small prospective patient cohort. Increased plasma levels of inflammatory cytokines were correlated in time with the presence of oxyhemoglobin flare suggesting a possible link between optical measurements and inflammatory processes induced by chemotherapy. Additionally, we report for the first time significant changes in tumoral oxyhemoglobin and oxygen saturation during chemotherapy infusion. These changes may be of prognostic significance. DOSI allows functional measurements of tumor response at timepoints unachievable with current functional medical imaging modalities.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-09-15.

Abstract P5-01-10: Tumor Optic Properties Measured Using Diffuse Optic Spectroscopy Imaging Correlate with Proliferation and Glucose Metabolism in Breast Cancer Patients

(Background) Diffuse Optic Spectroscopy Imaging (DOSI) is non-invasive imaging technology that employs near-infrared (NIR) light to quantitatively characterize the hemodynamic and metabolic properties of breast cancer tumors.

(Methods) We utilized DOSI to measure baseline tumor concentrations of oxy-hemoglobin (ctO2Hb), deoxy-hemoglobin (ctHHb), total hemoglobin (ctTHb), oxygen saturation (stO2), as well as water and lipid content of tumors from sixteen patients with primary breast cancer prior to neoadjuvant chemotherapy. Core-needle biopsy specimens were also collected from these patients and analyzed for Ki67, Glut-1, and Fatty acid synthese (FAS), biomarkers of cancer proliferation, glucose metabolism and fatty acid metabolism, respectively. These optic and biological biomarkers were statistically compared to each other and to overall therapy response. (Results) Ki67 score was positively correlated with baseline levels of ctO2Hb (µM) (r = 0.51, p = 0.04), ctTHb (µM) (r = 0.51, p = 0.05), and stO2 (%) (r = 0.57, p = 0.02), and negatively correlated with lipid content (%) (r = -0.52, p = 0.04). Tumors with positive Glut-1 status (n=8) showed significantly higher baseline levels of ctO2Hb (26.2±12.5 v.s 19.9±10.1, p = 0.04), ctTHb (41±13.3 v.s 27.5±11.7, p = 0.05), and stO2 (81.1±6.6 v.s 70.2±9.9, p = 0.02) and lower baseline levels of lipid (49±17.1 v.s 66.2±10.4, p = 0.03) compared to those with negative Glut-1 status (n = 8). There were no correlation between FAS and the optic properties. Five (31.3%) of 16 tumors achieved pathologic complete response (pCR) after completion of chemotherapy followed by surgery. Tumors with pCR showed higher stO2, higher Ki67 score and higher likelihood of Glut-1 expression than those with non-pCR (p = 0.009, 0.01, 0.03, respectively).

Only p-values with statistical significance were described.

(Conclusion) Higher tumoral expression levels of Ki67 and Glut-1 were correlated with higher oxygenation and lower lipid concentration and associated with a pathologic complete response to chemotherapy. Non-invasive optic properties measured using DOSI are potential surrogate markers for tumor proliferation and glucose metabolism.

HER2 FISH ratio cut-points and pathologic complete response (pCR), residual tumor (RT), HER2 status, and survival prediction in HER2-positive breast cancer (BC)

e22033

Background: We demonstrated that pCR is correlated with increasing HER2-FISH ratio, while disease-free survival (DFS) with pCR and ER-positivity in HER2-positive breast cancer treated with trastuzumab (SABCS 2008). It is known that quantitative HER2-FISH ratio correlates with ER levels and HER2-positivity imparts a higher grade in ER-positive BC. Collectively, we hypothesized that combined ER (≥10) and a HER2 ratio cut-point may subdivide HER2-positive BC into pCR predictive subtypes.Methods: Of the 80 HER2-positive (IHC3+/FISH+) BC, quantitative HER2 FISH ratio (widely spread over 1–18.3) and ER correlation was noted (r=0.34, p=0.002). Moreover, HER2 ratio (>4) correlated with higher Ki-67 (r= 0.5, p=0.01) and grade (p trend=0.05) in ER-positive subtype, inferring a biologic cut-point. Results: Of patients with stage I-IV BC treated neoadjuvantly (92% trastuzumab-based), pCR was 0% (0/13) in ER-positive-low-HER2 compared to 77% (10/13, p=0.0001), 75% (24/32, p<0.0001) and 37.5% (3/8, p=0.043) in ER-positive-high-HER2, ER-negative-high-HER2 and ER-negative-low-HER2, respectively. DFS was 100, 90, 80% and 60% (logrank-trend p<0.05) in these 4 subtypes (excluding stage IV), respectively, at a median follow-up of 38 months (range 6–72). In ER-negative subtypes, DFS was 97% and 29% (logrank p=0.0001) in patients with or without pCR; of the six with RT, 0% DFS was noted in four with HER2-negative/HER2-reduced (HER2-R) RT, compared to 100% in the two with unchanged HER2 (p=<0.05, logrank test). In ER-positive subtypes, DFS is 95% overall, and 100% in patients with RT; 7 of 10 tested RT were HER2- R. Conclusions: pCR is crucial and high in ER-negative-high-HER2 and is crucial (but low) in ER-negative-low-HER2-positive BC for improved outcome. Improved DFS is associated with high pCR in ER-positive-high-HER2 BC, but is independent of the low pCR in ER-positive-low-HER2-subtype. Thus, combined HER2 and ER offer improved prediction. In hypothesis generating analysis, HER2-R may underlie relapse in ER-negative subtypes (HER2-basal-transitional-residual), while it may be beneficial in ER-positive subtypes (luminal-B- A-transitional) by reducing HER2-pathway mediated endocrine resistance.

[Table: see text]

Non-invasive detection and monitoring of tumor pathological grade during neoadjuvant chemotherapy by measuring tissue water state using diffuse optical spectroscopic imaging

Abstract #803

Background: Changes of tissue water state are related to physiological and pathological properties of breast tissues. For instance, MRI has measured water mobility in order to monitor local micro-structural changes in breast cancer tissues during chemotherapy. Diffuse Optical Spectroscopic Imaging (DOSI) measures water molecular vibrational states associated with macro-molecular complexes in tissues such as proteins. For DOSI measurements, breast tumors are line-scanned and spectral information on each point is spatially mapped to generate an image.&#x2028; Subjects & Methods: DOSI was employed to measure 15 infiltrating ductal carcinoma (IDC) patients before treatment. Five IDC and one infiltrating lobular carcinoma (ILC) tumors were also measured along the course of neoadjuvant chemotherapy. Patient responses were determined from standard pathology: complete (N=2), partial (N=2) and non-responders (N=2). The spectral features of tissue water absorption from 935 nm to 998nm were compared to those of a pure water spectrum measured at body temperature in order to acquire the Bound Water Index (BWI: the residual between tissue and pure water spectra). In spectroscopic images, the Cancer BWI Ratio (CBR) was calculated by counting the fraction of the BWI less than 20% of the BWI range of pre-chemo (baseline) measurement in a primary cancer. Lower BWI means the cancer has more free water. The CBR communicates the changes of tissue water state along the course of therapies in the similar way to Signal Enhanced Ratio (SER) used in contrast enhanced MRI.&#x2028; Results: In our in vivo clinical studies with 15 IDC tumors, a high inverse correlation between BWI and Nottingham Bloom-Richardson histopathological score (R=-0.87) was found. In the neoadjuvant chemotherapy studies, BWI increased during the entire course of the therapy in complete responders while it fluctuated then stayed close to baseline values in partial responders. In non-responders, the change amount of BWI was very small and the BWI values decreased below baseline values. Quantitatively, for complete responders, BWI increased (more bound water) 59% from baseline and CBR decreased (less pixels for cancer) 26.9% and the pixels presenting cancer property disappeared. In partial responders, BWI increased 4.7% and CBR decreased 8.2% whereas, in non-responders, BWI decreased 16.4% and CBR increased 28.7%.&#x2028; Discussion: The high correlation between BWI and histopathological score communicates that water state measurements using DOSI report on disease grades of breast cancer non-invasively. In the neoadjuvant chemotherapy studies, bigger tissue water state changes have been measured in complete than partial responders and the changes to the opposite direction in non-responders. There results demonstrate a potential of tissue water state with DOSI as a non-invasive pathological grade monitor during chemotherapy, which can be used as a substitute for a biopsy at any point during the treatment cycle.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 803.

Diffuse optical spectroscopic imaging measures tumor functional response to bevacizumab: initial studies

Abstract #6056

Background: Diffuse Optical Spectroscopic Imaging (DOSI) is a non-invasive, bedside functional imaging technique that quantifies the concentrations and molecular states of tissue hemoglobin, water, and lipids. Pilot studies have shown that DOSI may be a useful tool for quantifying neoadjuvant chemotherapy response, typically by comparing the degree of change in tumor water and deoxy-hemoglobin concentrations before and after therapy. DOSI may offer a point-of-care measurement of tumor responses to therapeutic intervention. The majority of these DOSI studies have measured responses to Anthracyclines. However, the optical response to Bevacizumab has not been demonstrated in vivo in human subjects.&#x2028; Materials and Methods: Twenty-one patients diagnosed with stage II/III cancers were followed with DOSI prior to and during their two-stage neoadjuvant chemotherapy regimen that featured (a) Anthracyclines (2-4 cycles) and (b) Trastuzumab/Bevacizumab (for HER2+/HER2- status, respectively). Changes between pre-treatment and pre-surgical DOSI-measured parameters were compared against final surgical pathology (complete, partial, or non-responder). A functional tissue optical index (TOI) was calculated that has been shown to discriminate between normal and malignant tissues.&#x2028; Results: Both short-term and long-term changes in tumor physiology were observed. For both therapy strategies (N=21), statistically significant changes were measured in TOI from baseline to pre-surgery between complete (95+/-15%), partial (79+/-11%) and non-responders (38+/-42%). TOI changes after the initial therapy stage were strongest in patients with more favorable pathological responses (78%, 56%, and 12% for complete, partial, and non-responders respectively). For patients receiving Bevacizumab (N=9), more detailed serial image analysis of tumor deoxy-hemoglobin revealed short-term changes (7-14 days) where initial decreases in hemoglobin were soon followed by slow increases back to pre-treatment levels. Two of the patients who received Bevacizumab demonstrated detectible residual disease by DOSI after completion of all neoadjuvant therapy, despite that contrast-enhanced MRI signals had disappeared.&#x2028; Discussion: We have provided evidence that DOSI may be well-suited to monitor the response of different cancer drugs, including anti-angiogenic compounds such as Bevacizumab, in breast cancer patients. While the usage of Bevacizumab in human subjects is still under investigation in breast cancer, we foresee that DOSI may be a useful tool in general for the development of drugs and dosing strategies.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6056.

Assessing the spatial extent of breast tumor intrinsic optical contrast using ultrasound and diffuse optical spectroscopic imaging

Abstract #806

Background: Near infrared (NIR) light is sensitive to several important tissue components and has been used to detect, characterize, and monitor breast tumor functions. However, little is known about the relationship between anatomic and functional contrast derived from intrinsic optical signals. Diffuse Optical Spectroscopic Imaging (DOSI) is a non-invasive, bedside functional imaging technique that quantifies the concentrations and molecular states of tissue hemoglobin, water, and lipids. Pilot studies have shown that DOSI may be a useful tool for breast lesion detection/characterization and therapeutic monitoring.&#x2028; Materials and Methods: DOSI data were compared with theoretical computer simulations to estimate the nature and extent of optical contrast with respect to standard ultrasound imaging. DOSI reflectance measurements were obtained from 10 breast tumor patients, with both malignant (N=5) and benign (N=5) lesions. Patient average ages: 35+/-7.8 years vs. 44.3+/-14.7 years, lesion depth 10.9+/-5.5 mm vs. 15.8+/-5.3 mm, and maximum size 13.0+/-6.0 mm vs. 14.8+/-4.9 mm for benign and malignant, respectively. Two trial tumor models were simulated to model actual tumor optical properties (hemoglobin): (a) a discrete target constrained to ultrasound dimensions, and (b) a distributed target that spatially extended beyond ultrasound dimensions.&#x2028; Results: High optical contrast (i.e., the ratio target to background) was observed for both benign (1.53+/-0.17) and malignant (2.06+/-0.4) lesions, even for this younger population. While the discrete target model could not match experiment and simulation, a distributed model provided excellent agreement. The spatial extent of optical properties in breast tumor was significantly greater than anatomical dimensions reported by ultrasound imaging. The extent of the distribution was greater in the malignant lesions than in the benign ones. Further simulations also suggested that invasive breast tumors in this population with anatomical size 10 mm may still be detectable at depth 30 mm using DOSI in reflectance.&#x2028; Discussion: The spatial extension of tumor optical contrast complicates co-registration of optical functional images with anatomic images. The true optical contrast is significantly higher in breast cancer tumors, likely 4-5x than the hemoglobin levels in normal tissues. Breast tumor optical contrast is more realistically modeled as a spatially distributed target, which facilities a fast 3D imaging scheme in reflectance geometry. Results from these topographic reconstructions will be discussed.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 806.

In vivo water state measurements in breast cancer using broadband diffuse optical spectroscopy

Structural changes in water molecules are related to physiological, anatomical and pathological properties of tissues. Near infrared (NIR) optical absorption methods are sensitive to water; however, detailed characterization of water in thick tissues is difficult to achieve because subtle spectral shifts can be obscured by multiple light scattering. In the NIR, a water absorption peak is observed around 975 nm. The precise NIR peak's shape and position are highly sensitive to water molecular disposition. We introduce a bound water index (BWI) that quantifies shifts observed in tissue water absorption spectra measured by broadband diffuse optical spectroscopy (DOS). DOS quantitatively measures light absorption and scattering spectra and therefore reveals bound water spectral shifts. BWI as a water state index was validated by comparing broadband DOS to magnetic resonance spectroscopy, diffusion-weighted MRI and conductivity in bound water tissue phantoms. Non-invasive DOS measurements of malignant and normal breast tissues performed in 18 subjects showed a significantly higher fraction of free water in malignant tissues (p < 0.0001) compared to normal tissues. BWI of breast cancer tissues inversely correlated with Nottingham-Bloom-Richardson histopathology scores. These results highlight broadband DOS sensitivity to molecular disposition of water and demonstrate the potential of BWI as a non-invasive in vivo index that correlates with tissue pathology.

Pathologic complete response (pCR) following weekly (wkly) paclitaxel (cremophor or albumin-bound) and carboplatin (TC) ± trastuzumab (H), ± bevacizumab (B) in patients (pts) with doxorubicin/cyclophosphamide-resistant (AC-Res) and AC-sensitive (AC-S) large and inflammatory breast cancer

591

Introduction: Historically, pCR is rare in AC-Res in contrast to AC-S BC except following TCH in HER2+ BC in preliminary analysis (SABCS-2004, #1110). Moreover, robust predictors of pCR are needed. Methods: 106 consecutive BC pts on neoadjuvant studies were treated with GM/G-CSF supported dose-dense AC (except 7**- Table ), 2 cycles if AC-Res and 4 if AC-S. Pts then received 9–12 wkly TC (3 wks on, 1 off) ± 6–8 bi-wkly B if HER2- or +12–16 wkly H if HER2+, followed by surgery. Fisher’s exact test was performed to compare pCR percentages by various characteristics. Results: pCR in breast and lymph nodes in 38 of 84 assessable tumors in the first 82 pts were documented. 67% (56/84) tumors were reduced to ≤5 mm. Overall, no difference in pCR rates were found between AC-S and AC-Res BC, but pCR rates were 2- to 4-fold higher in HER2+, AC-S (79%) and AC-Res (65%) subsets compared to HER2-, AC-S (32%) and AC-Res (16%) subsets. Higher pCR rates were associated with HER2+/hormone receptor- (HR-) > HER2+/HR+, HER2-/HR- (triple-) > HER2-/HR+, and within the HER2+ subset-IHC 3+/FISH+ or unknown > IHC 3+/FISH- or IHC 1–2+/FISH+, and ductal > other histology. No patient had clinical cardiac dysfunction or EF <50, except 1 on AC/TC. 13/106 (12%) progression or death at a median follow-up of 22 months (range 2–46) is mostly due to stage IV and CNS progression. Conclusion: Short course of TCH achieves a high rate of pCR in AC-Res and AC-S, HER2+ BC in contrast to TC ± B in AC-Res and AC-S, HER2- BC. This is the first demonstration of high rate of complete AC resistance reversal across stage II-IV, inflammatory and recurrent HER2+ BC. In vivo response adjusted 2–4 cycles of dose-dense AC limited clinical cardiac toxicity. HER2+ (IHC 3+/FISH+ or unknown), HR- and ductal histology are significant predictors of high pCR. HER2 and HR confer 4 predictive subtypes of BC.

[Table: see text]

No significant financial relationships to disclose.

Spectroscopy enhances the information content of optical mammography

Near-infrared (NIR) diffuse optical spectroscopy and imaging may enhance existing technologies for breast cancer screening, diagnosis, and treatment. NIR techniques are based on quantitative measurements of functional contrast between healthy and diseased tissue. In this study we measured the spectral dependence of tissue absorption (mu(a)) and reduced scattering (mu'(s)) in the breasts of 30 healthy women and one woman with a fibroadenoma using a seven-wavelength frequency-domain photon migration probe. Subjects included pre- and postmenopausal women between the ages of 18 and 64. Multi-spectral measurements were used along with a four-component fit to determine the concentrations of de-oxy and oxy-hemoglobin, water and lipids in breast. The scattering spectral shape was also quantified. Our measurements demonstrate that the measured concentrations of NIR analytes correlate well with known breast physiology. Although the tissue scattering at a single wavelength was found to have little value as a functional parameter, the dependence of the scattering on wavelength provided key insights into breast composition and physiology. Lipids and scattering spectra in the breast were found to increase and decrease, respectively, with increasing body mass index. Simple calculations are also provided to demonstrate potential penalties from ignoring the contributions of water and lipids in breast measurements. Finally, water is shown to be a possible indicator for detecting a fibroadenoma, whereas the hemoglobin saturation was found to be a poor indicator. Multi-spectral measurements, compared to measurements restricted to one or two wavelengths, provide additional information that may be useful in managing breast disease.

Automated DNA mutation analysis by single-strand conformation polymorphism using capillary electrophoresis with laser-induced fluorescence detection

Automation is essential for rapid genetic-based mutation analysis in clinical laboratory to screen a large number of DNA samples. We propose in this report an automatic process using Beckman Coulter P/ACE capillary electrophoresis (CE) with laser-induced fluorescence (LIF) system to detect a single-point mutation in the codon 12 of human K-ras gene. Polymerase chain reaction (PCR) using a fluorescently labeled reverse primer and a plain forward primer to specifically amplify a selected 50 bp DNA fragment in human K-ras gene. The amplified DNA is placed on the sample tray of the CE system with a pre-programmed step for single-strand conformation polymorphism (SSCP) analysis. Sample injection and denaturation processes are performed online along with separation and real-time data analysis. The concept of automation for rapid DNA mutation analysis using CE-LIF system for SSCP is presented.

Absence of K-ras mutations in the pancreatic parenchyma of patients with chronic pancreatitis

BACKGROUND

Human pancreatic cancers exhibit a high frequency of K-ras mutations.

METHODS

In this study we used oligonucleotide specific hybridization to compare the frequency of K-ras mutations in genomic DNA samples prepared from 21 normal pancreatic tissues, 26 chronic pancreatitis tissues, and 24 pancreatic cancers.

RESULTS

None of the DNA samples from normal or chronic pancreatitis tissues exhibited a K-ras mutation at codons 12 or 13 of K-ras. In contrast, 17 of 24 DNA pancreatic cancers harbored a K-ras mutation. Validity of the methodology was confirmed by genotyping 7 human pancreatic cancer cell lines. Analysis of focal areas of proliferation from 5 chronic pancreatitis and 5 pancreatic cancer samples processed by selective ultraviolet radiation fractionation (SURF), a procedure used to enrich DNA isolation from foci of proliferating cells, revealed complete concordance with total genomic DNA analysis.

CONCLUSIONS

These findings indicate that the pancreatic parenchyma in patients with chronic pancreatitis most frequently does not possess a K-ras mutation.