Clinical significance of fatty liver disease induced by tamoxifen and toremifene in breast cancer patients.

BACKGROUND AND AIM: The aim of this study was to identify the effect of selective estrogen receptor modulator (SERM) on non-alcoholic fatty liver disease (NAFLD) in Asian women. METHODS: We retrospectively evaluated fatty liver development and/or serum alanine aminotransferase (ALT) elevation during SERM treatment in 1061 women who were diagnosed and treated with breast cancer in 2005 at Asan Medical Center. RESULTS: 45 of 618 SERM-treated patients with normal ALT at baseline experienced ALT elevation during SERM treatment. Among the 112 SERM-treated patients who underwent liver imaging test, fatty liver was observed in 47 and both fatty liver and ALT elevation developed in 16 of 102 SERM-treated patients with normal baseline ALT. The cumulative rates of ALT elevation (10.7 vs. 4.3%; P = 0.002), fatty liver (48.5 vs. 20.9%; P < 0.001), and both fatty liver and ALT elevation (17.7 vs. 7.1%; P = 0.02) at 60 months were significantly higher in the SERM group than non-SERM group. By multivariate analysis, SERM treatment increased the risk of ALT elevation (hazard ratio [HR], 2.20; P = 0.01), fatty liver development (HR, 3.59; P < 0.001), and both fatty liver and ALT elevation (HR, 4.98; P = 0.01). After discontinuation of SERM, elevated serum ALT normalized in 39 (92.9%) and there were no instances of liver-related death or progression to liver cirrhosis in patients who experienced fatty liver or ALT elevation. CONCLUSIONS: Although SERM treatment is significantly associated with NAFLD in Asian women, considering the tolerability and reversibility of NAFLD induced by SERM, it can be continued with liver function monitoring in relevant patients.

Assessment of current criteria for primary nonresponse in chronic hepatitis B patients receiving entecavir therapy.

UNLABELLED: A primary nonresponse to oral drugs against hepatitis B virus (HBV) is a generally accepted criterion for interrupting treatment. We investigated whether the concept of primary nonresponse suggested by current American (AASLD) and European (EASL) guidelines is appropriate for treatment with entecavir (ETV). The study included 1,254 treatment-naïve patients who had pretreatment HBV DNA levels of >2,000 IU/mL and received ETV 0.5 mg/day for over 6 months. "Primary nonresponse" was defined as a <2 log drop in HBV DNA after 6 months of therapy by AASLD and as a <1 log drop after 3 months by EASL. The cumulative probability of virological response (VR; HBV DNA of <15 IU/mL) was compared in patients with and without primary nonresponse. Median time to achieve VR was significantly shorter in primary responders by AASLD than nonresponders (12 versus 24 months; P = 0.004), but the cumulative probability of achieving a VR at 54 months was similar in the two groups (95.8% versus 100%). Time to achieve a VR and cumulative probability of VR over time did not differ between primary responders and nonresponders by EASL. On-treatment virological breakthrough occurred in 18 patients with a cumulative rate of 5.6% at 72 months. ETV resistance was detected in 13 of these 18 patients (72.2%), who were all classified as primary responder according to both guidelines. CONCLUSION: Long-term ETV therapy generally leads to a VR in treatment-naïve patients, although the time to achieve it is delayed in primary nonresponders. The current recommendation to change therapy in primary nonresponders needs to be modified to reflect drug differences in antiviral potency and resistance risk.

Characterization of long-circulating cationic nanoparticle formulations consisting of a two-stage PEGylation step for the delivery of siRNA in a breast cancer tumor model.

Polyethylene glycol (PEG) has been used widely in liposomal formulations as a strategy to inhibit opsonization by plasma proteins and to prolong liposome plasma circulation time. PEG can be incorporated onto the surface of liposomes either during the spontaneous self-assembling process or inserted after vesicle formation. The advantages of employing the PEG postinsertion method include improved drug encapsulation efficiency and the ability to incorporate PEG conjugates for enhanced cell binding and uptake. In this study, we propose to evaluate a cationic lipid nanoparticle formulation containing two PEGylation steps: pre- and post-siRNA insertion. Our results indicate that formulations consisting of the extra PEG post-insertion step significantly increased siRNA circulation in the plasma by two-folds in comparison with the formulations consisting of only the single PEGylation step. Moreover, this formulation was able to efficiently carry siRNA to the tumor site, increase siRNA stability and significantly downregulate luciferase mRNA expression by >50% when compared with the controls in an intraperitoneal and subcutaneous breast cancer tumor model. Overall, our cationic lipid nanoparticle formulation displayed enhanced plasma circulation, reduced liver accumulation, enhanced tumor targeting, and effective gene knockdown--demonstrating excellent utility for the delivery of siRNA.

Validating the use of a luciferase labeled breast cancer cell line, MDA435LCC6, as a means to monitor tumor progression and to assess the therapeutic activity of an established anticancer drug, docetaxel (Dt) alone or in combination with the ILK inhibitor, QLT0267.

A significant issue in drug efficacy studies is animal study design. Here we hypothesize that when evaluating new or existing therapeutics for the treatment of cancer, the location of disease burden will influence drug efficacy. To study this, Female NCr nude mice were inoculated with luciferase-positive human breast cancer cells (LCC6WT-luc) orthotopically (o.t.), intraperitoneally (i.p.) or intracardiacly (i.c.) to create localized, ascites or disseminated disease, respectively. Tumor development was monitored using bioluminescence imaging. Docetaxel (Dt) pharmacokinetics and distribution to sites of tumor growth were determined. Disease progression was followed in animals treated with Dt alone and in combination with QLT0267, an Integrin Linked Kinase inhibitor. Tumor related morbidity was most rapid when cells were inoculated i.c., where disease progression was observed in brain, ovaries, adrenal glands, and lungs. Dt pharmacokinetics were comparable regardless of the model used (mean plasma AUC0-24 hrs 482.6 ng/ml*hr), however, Dt levels were lowest in those tissues developing disease following i.c. cell injection. Treatment with low dose Dt (5 mg/kg) increased overall survival and reduced tumor cell growth in all three models but the activity was greatest in mice with orthotopic tumors. Higher doses of Dt (15 mg/kg) was able to prolong survival in animals bearing i.p. tumors but not i.c. tumors. Addition of QLT0267 provided no added benefit above Dt alone in the disseminated model. These studies highlight a need for more comprehensive in vivo efficacy studies designed to assess multiple disease models and multiple endpoints, focusing analysis of drug parameters on the most chemoresistant disease.