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Background and Aims Patients with left-sided breast cancer receive a higher mean heart dose (MHD) after radiotherapy, with subsequent risk of ischaemic heart disease. However, the optimum dosimetric predictor among cardiac substructures has not yet been determined. Methods and results This study retrospectively reviewed 2158 women with breast cancer receiving adjuvant radiotherapy. The primary endpoint was a major ischaemic event. The dose–volume parameters of each delineated cardiac substructure were calculated. The risk factors for major ischaemic events and the association between MHD and major ischaemic events were analysed by Cox regression. The optimum dose–volume predictors among cardiac substructures were explored in multivariable models by comparing performance metrics of each model. At a median follow-up of 7.9 years (interquartile range 5.6–10.8 years), 89 patients developed major ischaemic events. The cumulative incidence rate of major ischaemic events was significantly higher in left-sided disease (P = 0.044). Overall, MHD increased the risk of major ischaemic events by 6.2% per Gy (hazard ratio 1.062, 95% confidence interval 1.01–1.12; P = 0.012). The model containing the volume of the left ventricle receiving 25 Gy (LV V25) with the cut-point of 4% presented with the best goodness of fit and discrimination performance in left-sided breast cancer. Age, chronic kidney disease, and hyperlipidaemia were also significant risk factors. Conclusion Risk of major ischaemic events exist in the era of modern radiotherapy. LV V25 ≥ 4% appeared to be the optimum parameter and was superior to MHD in predicting major ischaemic events. This dose constraint could aid in achieving better heart protection in breast cancer radiotherapy, though a further validation study is warranted. [ABSTRACT FROM AUTHOR]

Background: Radioactive iodine (RAI) is widely used for the treatment of thyroid cancers. However, information on associations between RAI dose and second primary malignancy (SPM) is lacking.Methods: Patients without antecedent cancer age 20 years or older and newly diagnosed with thyroid cancer were recruited from the Taiwan National Health Insurance database between 1997 and 2010. Standardized incidence ratios (SIRs) for the cancers were calculated to compare the incidence of thyroid cancer with the general population. The association between RAI dosage and cancer development was estimated using time-dependent Cox regression analysis. All statistical tests were two-sided.Results: A total of 692 cases of SPM were identified among 20 235 patients with thyroid cancer. Regarding the latter, 79.7% of the patients were women, the median age was 46 years, and the follow-up period included 134 178 person-years. The SIR for any SPM was 1.41 (95% confidence interval [CI] = 1.31 to 1.52). A statistically significantly higher SIR was observed in leukemia (2.74), non-Hodgkin's lymphoma (2.38), prostate (2.30), lung and mediastinum (1.93), pancreas (1.83), kidney (1.81), breast (1.48), and colon-rectum (1.31) cancers. Cumulative RAI dose (per 30 mCi increase) conferred a strong risk for SPM (adjusted hazard ratio [aHR] = 1.01, 95% CI = 1.01 to 1.02, P < .001) and leukemia (aHR = 1.03, 95% CI = 1.02 to 1.04, P < .001) occurrences. A cumulative RAI dose greater than 150 mCi possessed a statistically significant risk for all cancer combined (aHR = 1.30) and leukemia (aHR = 6.03).Conclusions: An increased risk of SPM was observed for thyroid cancer patients, especially with cumulative RAI doses over 150 mCi. [ABSTRACT FROM AUTHOR]

An association between use of oral fluoroquinolones and retinal detachment has been described but remains controversial. The current study found that recent use of an oral fluoroquinolone is significantly associated with rhegmatogenous retinal detachment. Hazard ratios differ for specific fluoroquinolones.Background. An association between use of oral fluoroquinolones (FQs) and retinal detachment remains controversial. This study was to determine the association of recent use of oral FQs and rhegmatogenous retinal detachment (RRD) after adjustment for confounding factors known to be associated with RRD.Methods. This retrospective population-based cohort study with parallel groups included adults treated with an oral FQ (FQ cohort = 178 179 prescriptions) and propensity score–matched adults treated with oral amoxicillin (amoxicillin cohort = 178 179 prescriptions). The data were extracted from the Taiwan National Health Insurance Research Database from 1998 to 2010. Interaction terms were used to identify populations at risk. RRD was defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification.Results. During the 90-day follow-up period, 96 patients (0.054%) in the FQ cohort developed RRD compared to 46 (0.026%) among the matched amoxicillin cohort. The overall adjusted hazard ratio (HR) for FQ use and RRD was 2.07 (95% confidence interval [CI], 1.45–2.96). The interval between use of oral FQs and onset of RRD was 35.5 days (interquartile range, 14–57 days). Interaction terms were not significant for age, sex, diabetes, indications for antimicrobials, or underlying ophthalmic conditions. The adjusted HRs differed for specific FQs. These were 10.68 (95% CI, 3.28–34.82) for ciprofloxacin, 2.41 (95% CI, .76–7.68) for levofloxacin, 2.00 (95% CI, 1.06–3.79) for norfloxacin, and 1.17 (95% CI, .59–2.31) for ofloxacin.Conclusions. The use of oral FQs was associated with the subsequent occurrence of RRD. The FQ risk was independent of age, sex, diabetes, indications for antimicrobials, and underlying ophthalmic conditions. Certain FQs carried higher risk of RRD. [ABSTRACT FROM AUTHOR]

Background. Klebsiella pneumoniae liver abscess (KPLA) is prevalent in East Asia. Use of amoxicillin/ampicillin may lead to overgrowth of K. pneumoniae in the intestine and predispose to KPLA. We used an animal study and nationwide population-based database to investigate the association between ampicillin/amoxicillin use and KPLA in Taiwan.Methods. In an animal study, ampicillin or sterile water was administered orogastrically in serotype K1 K. pneumoniae–colonized mice and the outcome was compared. We identified 855 cases with liver abscess and selected 3420 age- and sex-matched control subjects from the National Health Insurance Research Database. Conditional logistic regression was used to estimate the adjusted odds ratios (ORs) for the association between recent use of ampicillin/amoxicillin and KPLA.Results. Ampicillin administration predisposed K. pneumoniae–colonized mice to increased bacterial burden, liver abscess and necrosis, and lethality. The population-based study showed that the adjusted OR associating the use of ampicillin/amoxicillin within the past 30 days with KPLA was 3.5 (95% confidence interval, 2.5–5.1). No association was found with use in the past 31–90 days.Conclusions. Ampicillin/amoxicillin therapy started within the past 30 days was associated with increased risk for KPLA. We should avoid the overuse of these antibiotics to prevent undesired disease in the endemic area. [ABSTRACT FROM AUTHOR]

Osteoporotic fractures are associated with increased mortality risk. However, little data are available on the risk of acute myocardial infarction (AMI) after hip fracture. Therefore, we investigated whether hip fracture increased the risk of AMI in a large, nationwide cohort study. We obtained data from 8758 patients diagnosed with hip fracture from 2000 to 2009 and from 4 matched controls for each patient from the Longitudinal Health Insurance Database (LHID 2000), Taiwan. Controls were matched for age, sex, comorbid disorders, and enrollment date. All subjects were followed up from the date of enrollment until AMI, death, or the end of data collection (2009). Cox's regression model adjusted for age, sex, comorbid disorders, and medication was used to assess independent factors determining the risk of development of AMI. As expected, despite the matching, the hip fracture patients had more risk factors for AMI at baseline. A total of 8758 subjects with hip fractures and 35,032 controls were identified. Among these patients, 1183 (257 hip fracture patients and 926 controls) developed AMI during the median 3.2-year (interquartile range 1.4 to 5.8 years) follow-up period. Patients with hip fractures had a higher incidence of AMI occurrence when compared with controls (8.7/1000 person-years versus 6.82/1000 person-years). Multivariate analysis adjusted for baseline covariates indicated that hip fracture was associated with a greater risk for AMI development (hazard ratio [HR] = 1.29; 95% confidence interval [CI] 1.12-1.48; p < 0.001). We conclude that hip fracture is independently associated with a higher risk of subsequent AMI. © 2013 American Society for Bone and Mineral Research [ABSTRACT FROM AUTHOR]