[Relative bioavailability of glucosamine after oral, intramuscular and transdermal administration of hondroxid maximum preparation in experiment]

A comparison of the relative bioavailability and intensity of penetration of glucosamine sulfate in oral, injection and topical administration of the dosage form Hondroxid Maximum as a cream containing micellar system for transdermal delivery of glucosamine in the experiment by Sprague-Dawley rats was carried out. On the base on the pharmacokinetic profiles data of glucosamine in rat blood plasma with daily administration in 3 times a day for 1 week by cream Hondroxid Maximum 400 mg/kg and the single injection solution of 4% Glucosamine sulfate 400 mg/kg was found that the relative bioavailability was 61.6%. Calculated penetration rate of glucosamine in the plasma through the rats skin in 4 hours, equal to 26.9 μg/cm2 x h, and the penetration of glucosamine through the skin into the plasma after a single dose of cream in 4 hours was 4.12%. Comparative analysis of literature and experimental data and calculations based on them suggest that medicine Hondroxid Maximum, cream with transdermal glucosamine complex in the treatment in accordance with the instructions can provide an average concentration of glucosamine in the synovial fluid of an inflamed joint in the range (0.7 - 1.5) μg/ml, much higher than the concentration of endogenous glucosamine human synovial joint fluid (0.02 - 0.07 μg/ml). By theoretical calculations taking into account experimental data it is shown that the medicine Hondroxid Maximum can reach the bioavailability level of the modern injection forms and exceed the bioavailability level of modern oral forms of glucosamine up to 2 times.

Abstract P6-12-09: Targeting deregulated cyclin E in inflammatory breast cancer via sequential combination therapy

Inflammatory breast cancer (IBC) is a rare, highly aggressive form of breast cancer, accounting for 2-5% of all breast cancers in the US and 10% of breast cancer deaths. Unfortunately, until recently this disease has not been studied extensively at the molecular/cellular level despite the compelling unmet need to develop more effective therapies. In spite of receiving aggressive multidisciplinary therapy (anthracycline-taxane-based neoadjuvant chemotherapy, modified-radical-mastectomy and adjuvant radiation therapy), only about 40% of IBC patients survive 5 years. The goal of this project is to identify new targets that can be exploited pharmacologically either in combination with current therapies or with other novel agents.

Previous work has identified tumor-specific low molecular weight forms of cyclin E, termed LMW-E, that are preferentially found in triple negative breast cancers (TNBC) and serve as a poor prognostic biomarker. As a result of cleavage, LMW-E preferentially accumulates in the cytoplasm where it exerts its pleiotropic oncogenic functions including deregulating the cell cycle. Furthermore, we have shown that TNBC cells harboring LMW-E are sensitive to CDK inhibitors.

To establish the clinical relevance of targeting the cyclin E/CDK2 axis in IBC, a pilot study was performed to determine the incidence of LMW-E. We performed IHC on 11 post-chemotherapy surgical specimens from MDACC. All tumors expressed cyclin E, 8 of which had predominantly cytoplasmic staining, indicative of LMW-E expression. These results are now being validated in a larger cohort of samples. These promising preliminary results led us to perform in vitro experiments to determine sensitivity to CDK2 inhibitors and characterize cell cycle profiles.

Similar to non-IBC breast cancers, IBC tumors can be ER-positive, TNBC or HER2-overexpressing; however, there are only TN-IBC or HER2+ cell lines. We utilized 2 cell lines for these studies, one of which is TN-IBC, the other of which is ER-negative and HER2-overexpressing. These cell lines were treated with a panel of CDK inhibitors to evaluate their sensitivity in both short-term and long-term assays. The long-term assay we developed called the high-throughput survival assay was used to examine combinations of agents for potential synergies using isobologram analysis. We have demonstrated chemotherapy-specific synergistic cell death when cells are first treated with CDK inhibitor in IBC and non-IBC cell lines.

Using flow cytometry, we have demonstrated that CDK inhibitors induce a G2/M arrest, which is further increased by sequential treatment with chemotherapy. Furthermore, combination treatment leads to cell death, as measured by sub-G1 DNA content.

Taken together, these studies provide solid evidence that targeting CDK2 is a promising strategy in treating IBC tumors that express cyclin E. Beyond these early pre-clinical advances, however, we demonstrated clear sequence-specificity for certain pairs of drugs, implying that future clinical studies should be designed taking into account the mechanism of action of cell cycle targeting drugs.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-12-09.

Abstract P6-08-12: Gains in women’s education has not led to commensurate gains in seeking health-care early in breast cancer patients in urban India

Introduction:

Breast cancer is the leading cancer diagnosed in urban Indian women. Historically the proportion of women presenting with advanced disease has been in excess of 50% at most regional cancer centres. The past 20 years has witnessed rapid economic growth and urbanization with significant gains in women's education and access to health. However, it is not clear if this has translated to earlier seeking of care in the educated.

The aim of this study was to examine if higher education (College) was a determinant in the time of seeking first medical consultation, and whether there were significant differences between women under the age of 40 versus women over 60 years old at the time of diagnosis.

Methods:

The data for analysis were obtained from a prospective longitudinal observational study conducted between 2008-2013 at a medical teaching hospital and a tertiary specialized cancer care centre. A total of 460 patients have been enrolled so far. All patients provided informed consent and the study has been reviewed and approved by the institutional ethics committees at these institutions. We have collected from the patients and their medical records information about their age at diagnosis, educational level, stage of disease, histopathology reports and clinical details.

Results:

Data from 194 patients have been used for the analysis. Patients were divided into one group of < = 40Y of age (Group I, N = 58) and the second of > = 60 years of age (Group II, N = 136). Mean age at presentation for the groups was 35 and 68 years respectively. As expected almost 1.5 times as many women under the age of 40 (36%) were college educated compared to the women over 60 (22%) (p = 0.05). The proportion of LABC in the two groups was not different with group I having 27% and group II 25%. The proportion of older women with LABC and a college degree was 20%. However, rather than the expected decrease in proportion of women with high education and LABC, 31% of young women with LABC had a college degree. LABC in the college educated was not different in the group I when compared to group II. (p = 0.39).

Conclusion:

The determinants of seeking health care are complex and influenced by a variety of factors including socio-economic status, access to health care, education, cultural beliefs, and personal preferences. While urban India's steady economic growth has been highlighted by the scholarly as well as the lay press, the data presented here suggest that there is not an automatic and linear transfer between education, economics and healthcare seeking behaviours. We suggest that while a lot of attention has been paid to awareness and screening, we may need to focus on local cultural factors, and perhaps provide support from female counsellors and care providers as critical components of attempting to bring our women to the hospital at the earliest.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-08-12.

Sustained Release of Diltiazem Hydrochloride from Cross-linked Biodegradable IPN Hydrogel Beads of Pectin and Modified Xanthan Gum

Interpenetrating polymer network hydrogel beads of pectin and sodium carboxymethyl xanthan were prepared by ionotropic gelation with Al(+3) ions and covalent cross-linking with glutaraldehyde for sustained delivery of diltiazem hydrochloride. Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning colorimetry and scanning electron microscopy were used to characterise the hydrogel beads. The swelling of the hydrogel and the release of drug were relatively low in pH 1.2 buffer solutions. However, higher swelling and drug release were observed in pH 6.8 buffer solutions. The carboxyl functional groups of hydrogels undergo ionisation and the osmotic pressure inside the beads increases resulting in higher swelling and drug release in higher pH. The release of drug depends on concentration of polymer, amount and exposure time of cross-linker and drug content in the hydrogel matrices. The present study indicated that the hydrogel beads minimised the drug release in pH 1.2 buffer solutions and to prolong the drug release in pH 6.8 buffer solutions.

In situ liver transection with portal vein ligation for rapid growth of the future liver remnant in two-stage liver resection

Background

Portal vein embolization (PVE) has become a standard procedure to increase the future liver remnant (FLR) and enable curative resection of initially unresectable liver tumours. This study investigated the safety and feasibility of a new two-stage liver resection technique that uses in situ liver transection (ISLT) and portal vein ligation before completion hepatectomy.

Methods

A consecutive series of patients undergoing ISLT and extended right hepatectomy between 2009 and 2011 were compared with consecutive patients undergoing extended right hepatectomy after PVE. All patients had initially unresectable primary or secondary liver tumours, owing to an insufficient FLR (liver segments II/III).

Results

Fifteen patients who had PVE and seven who underwent ISLT before extended right hepatectomy were evaluated. ISLT induced rapid growth of the FLR within 3 days, particularly after insufficient PVE, from a mean(s.d.) of 293(58) ml to 477(85) ml, corresponding to a volume increase of 63(29) per cent. All patients who had ISLT underwent completion extended right hepatectomy within 8 days (range 4–8 days).

Conclusion

ISLT is an effective and reliable technique to induce rapid growth of the FLR, even in patients with insufficient volume increase after PVE.

Poster - Thur Eve - 72: Conversion of helical tomotherapy plans into clinically favourable step-and-shoot IMRT plans deliverable on a c-arm linac

The treatment planning software SharePlan is designed to convert dose distributions generated by the TomoTherapy planning station into step-and-shoot IMRT plans deliverable on a c-arm linear accelerator. Five anal canal patients who were planned for TomoTherapy treatments were exported into a SharePlan system and plans were generated for delivery on an Elekta Synergy unit. A total of 80 plans were generated for those five patients, with either seven, nine, eleven or twenty-one gantry angles and different priorities between focusing on matching either the target doses or healthy tissue sparing of the TomoTherapy plan. The plans generated by SharePlan, while often not matching target coverage at prescription, matched well the TomoTherapy coverage at 95% and 105% of the prescription dose. Organ at risk dose, when heavily emphazied in the SharePlan calculations matched or bettered the TomoTherapy dose due to the placement of the beams and the sharper sup-inf fall off of the dose distribution on a linac. For one of the patients, it was possible to produce a better DVH with SharePlan than the original TomoTherapy plan for those reasons. The TomoTherapy plans boasted significantly shorter delivery times than the plans generated with SharePlan.

An experimental feasibility study on the use of scattering foil free beams for modulated electron radiotherapy

The potential benefit of using scattering foil free beams for delivery of modulated electron radiotherapy is investigated in this work. Removal of the scattering foil from the beamline showed a measured bremsstrahlung tail dose reduction just beyond R(p) by a factor of 12.2, 6.9, 7.4, 7.4 and 8.3 for 6, 9, 12, 16 and 20 MeV beams respectively for 2 × 2 cm(2) fields defined on-axis when compared to the clinical beamline. Monte Carlo simulations were matched to measured data through careful tuning of source parameters and the modification of certain accelerator components beyond the manufacturer's specifications. An accelerator model based on the clinical beamline and one with the scattering foil removed were imported into a Monte Carlo-based treatment planning system (McGill Monte Carlo Treatment Planning). A treatment planning study was conducted on a test phantom consisting of a PTV and two distal organs at risk (OAR) by comparing a plan using the clinical beamline to a plan using a scattering foil free beamline. A DVH comparison revealed that for quasi-identical target coverage, the volume of each OAR receiving a given dose was reduced, thus reducing the dose deposited in healthy tissue.