Background: Adjuvant trastuzumab (T)-based chemotherapy reduces relapse and improves overall survival in early breast cancer. However, T-associated cardiotoxicity potentially limits its use. Our study aims to report the incidence, severity and reversibility of cardiotoxicity amongst Asian breast cancer patients. Methods: This is a retrospective review of patients who have received adjuvant T from June 2005 to March 2011 at our centre. CT was defined as a drop in left ventricular ejection fraction (LVEF) to less than 50% and / or reduction of ≥ 10% of baseline. Cardiovascular (CVS) risk factors were defined as having at least one of the following factors: family or previous history of CAD, hypertension, diabetes mellitus, hyperlipidemia and smoking. One-way repeated measures ANOVA was used to evaluate the mean LVEF change and Chi-square test to evaluate the association of demographics and CT. Results: A total of 314 female patients were reviewed. CT was reported in 124 (39.5%), of whom 96 had asymptomatic decline in LVEF and 28 were symptomatic. T was withheld (n=53) due to asymptomatic decline in LVEF (n=40), symptomatic heart failure (n=3) and both (n=10). Forty-three patients with resolution of CHF (n=11) or LVEF recovery (n=32) were rechallenged. Cardiotoxicity recurred in 14 - asymptomatic decline in LVEF (n=10), recurrent CHF (n=1) and both (n=3). Overall, there were no cardiac-related deaths. Factors that predicted for CT included low normal pre-trastuzumab LVEF (<60%) (p=0.01), prior anthracyclines (p=0.011), decline in LVEF pre-anthracycline and before T (p=0.022) and BMI ≥ 23kg/m2 (p=0.018). Three-monthly LVEF showed statistically significant decline against baseline over the time points (p=0.005). As expected, the decline in LVEF demonstrated significant interaction with CT groups and non CT group (p<0.001). Conclusions: A higher incidence of CT (39.5%) was observed among Asian breast cancer patients compared to previously reported in Caucasians (24%). Although 77.4% of patients presented with asymptomatic decline in LVEF, approximately one-third of patients experienced recurrent CT upon rechallenge. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-18-05.

ABSTRACT:Prepolymers of polyquinazolone have been prepared from 4,4' -diaminodiphenyl-3,3' -dicarboxylic acid and aromatic diacetoamido compounds by melt condensation. Optimum preparative conditions were established for each individual system on the basis of reduced viscosity and thermogravimetry (TG) results. The soluble prepolymers were converted to the quinazolone structure by thermal cyclization under two heating programmes. A significant amount of uncyclized carboxylic groups have been identified by X-ray photoelectron spectroscopy (XPS). Quantitative measurements of the C = O/COOH ratio at the surface of the resultant polymers have been carried out by XPS, which provide a reliable measure of the degree of cyclization. Comparison of XPS results with TG data indicates a direct correlation between degree of cyclization on the polymer surface and thermooxidative stability of the bulk polymer.KEY WORDS Heat Resistant Polymer / Polyquinazolone / X-Ray Photoelectron Spectroscopy / Thermogravimetry / Degree of Thermal Cyclization / Thermooxidative Stability / thermal stability. One of the major limitations of synthetic polymers is their poor thermooxidative stability compared with other materials, especially metals, alloys and ceramics. To overcome this problem as well as to meet the rapid development of atomic reactors and space aviation, a new generation of heat resistant polymers has been prepared during the past decades.The attempt to synthesize polymers capable of withstanding prolonged exposure to elevated temperature, has been three pronged.1. To improve the existing polymers by structural modification. 2. To devise new organic systems tailored to resist the effect of heat and oxidation. 3. To synthesize new classes of inorganic and semi-inorganic polymers of highIn the second mode of attack, the most fruitful of these three lines of research, a whole new generation of carbon-based polymers with inherently rigid chains have been developed. The polymers were prepared by incorporating highly stable rigid, carboxylic and/or heterocyclic ring systems directly into the polymer chain. An infinite variety of such structures is possible, and many have been synthesized. One of the most serious draw backs of heat resistant polymers is their insolubility and intractability conferred by the very structural features desirable for high thermal stability. In the case of the most promising heat resistant polymers such as polyimides, 1 -3 the most commercially successful of all the heat resistant polymers, polybenzimidazole, 4 polyquinazolones, 5 polyt To whom correspondence should be addressed. 883