Continuity of care between dyslipidemia patients and multiple providers: A cohort study

OBJECTIVE

This study aimed to investigate the impacts of continuity of care (COC) between patients and multiple providers, i.e., doctors and community pharmacists, on clinical and economic outcomes.

METHODS

This is a retrospective cohort study and analyzed Korean national claims data for ambulatory care setting between 2007 and 2018. Patients with dyslipidemia newly diagnosed in 2008 were identified. COC between providers and patients was computed using the continuity of care index (COCI). Based on COCIs, the study patients were allocated to four groups: HM/HP, HM/LP, LM/HP, and LM/LP. Each symbol represents H for high, L for low, M for doctor, and P for pharmacist. The primary study outcome was the incidence of atherosclerotic cardiovascular disease (ASCVD).

RESULTS

126,710 patients were included. Percentages of patients in the four study groups were as follows: HM/HP 35%, HM/LP 19%, LM/HP 12%, and LM/LP 34%. During the seven-year outcome period, 8,337 patients (6.6%) developed an ASCVD, and percentages in the study groups were as follows; HM/HP 6.2%, HM/LP 6.3%, LM/HP 6.8%, and LM/LP 7.1%. After adjusting for confounding covariates, only the LM/LP group had a significantly higher risk of ASCVD than the reference group, HM/HP (aHR = 1.16 [95% confidence interval = 1.10~1.22]). The risk of inappropriate medication adherence gradually increased 1.03-fold in the HM/LP group, 1.67-fold in the LM/HP, and 2.26-fold in the LM/LP group versus the HM/HP group after adjusting for covariates. Disease-related costs were lower in the HM/HP and LM/HP groups.

CONCLUSIONS

The study shows that patients with high relational care continuity with doctors and pharmacists achieved better clinical results and utilized health care less, resulting in reduced expenses. Further exploration for the group that exhibits an ongoing relationship solely with pharmacists is warranted.

Clinical and economic burden of immune tolerance induction in entire patients with hemophilia A: Insights from a real-world Korean setting

INTRODUCTION

The most notable challenge facing hemophilia A treatment is the development of inhibitors against factor VIII, resulting in increased clinical and socioeconomic burdens due to the need for expensive bypassing agents (BPAs). Although immune tolerance induction (ITI) is currently the primary approach for inhibiting and reducing the inhibitors, the lengthy duration of ITI necessitates the continued use of BPA to manage bleeding episodes. In this study, we aimed to obtain real-world evidence on the clinical and economic aspects and associated burdens experienced by patients with hemophilia A with inhibitors undergoing ITI in Korea.

METHODS

Claims data from January 1, 2007, to December 31, 2020, were used in this study. The study cohort comprised patients with hemophilia A undergoing ITI, who were categorized into three groups: successful, failed, or continuation of ITI. We evaluated clinical and economic burdens, including monthly healthcare visits, medication costs, and total medical expenses.

RESULTS

The study involved 33 cases of ITI across 32 patients. Excluding seven continuation cases where success could not be determined at the observation point, the estimated success rate of ITI was 80.8 %. The median duration of ITI for all patients was 25.7 months. While no significant disparities were noted in the ITI duration between successful and unsuccessful cases (24.51 vs. 25.66 months), substantial discrepancies were observed in the duration of BPA usage (11.10 vs. 25.66 months) and the number of prescribed BPAs (1.79 vs. 2.97).

CONCLUSION

Successful ITI reduced both clinical and economic burdens, resulting in decreased monthly medication expenses and overall medical costs.

Clinical pharmacokinetic study of tacrolimus in continuous intravenous administration for lung transplantation

Tacrolimus is a cornerstone of immunosuppression after lung transplantation. However, there are no clear guidelines on how to administer the drug and the duration to achieve the required therapeutic range in the early phase of lung transplantation. This is a single-center cohort study of adult patients who had lung transplantation. Tacrolimus was administered beginning with a low dose of 0.01 mg/kg/day immediately after transplantation. In addition, the designated clinical pharmacist conducted a daily intervention with trough concentrations to achieve the target of 10-15 ng/mL. Time in the therapeutic range (TTR_in, %), time to the therapeutic range (TTR_to, days), and coefficient of variation (CoV) of tacrolimus were evaluated for the 2-week post-transplant period. A total of 67 adult patients who had received first-time lung transplantation were included in the analysis. The median percentage of tacrolimus TTR_in was 35.7% (21.4-42.9%) for the 2-week postoperative period. The median day of TTR_to was 7 days (5-9 days), and the median tacrolimus trough concentration was 10.02 ng/mL (7.87-12.26 ng/mL) for the 2-week postoperative period. The median CoV of tacrolimus was 49.7% (40.8-61.6%). Acute kidney injury following tacrolimus infusion occurred in 23 (34.3%) patients, but there was no neurotoxicity or acute cellular rejection within 1 month of the postoperative period. In conclusion, continuous intravenous administration with the daily measure and dose titration of tacrolimus trough concentrations allowed the therapeutic range of tacrolimus to be reached within 1 week without significant adverse events, although the pharmacokinetic parameters were highly variable over time.

A comparison of methods for the measurement of adherence to antihypertensive multidrug therapy and the clinical consequences: a retrospective cohort study using the Korean nationwide claims database

OBJECTIVES

In observational studies, the methods used to measure medication adherence may affect assessments of the clinical outcomes of drug therapy. This study estimated medication adherence to multidrug therapy in patients with hypertension using different measurement methods and compared their impacts on clinical outcomes.

METHODS

This was a retrospective cohort study using the Korean National Health Insurance Service-National Sample Cohort database (2006-2015). Adults diagnosed with hypertension who initiated multidrug antihypertensive therapy in the index year 2007 were included. Adherence was defined as over 80% compliance. Adherence to multidrug antihypertensive therapy was measured in 3 ways using the proportion of days covered (PDC) with 2 approaches to the end-date of the study observations: PDC with at least one drug (PDCwith≥1), PDC with a duration weighted mean (PDCwm), and the daily polypharmacy possession ratio (DPPR). The primary clinical outcome was a composite of cardiovascular and cerebrovascular disease-specific hospitalizations or all-cause mortality.

RESULTS

In total, 4,226 patients who initiated multidrug therapy for hypertension were identified. The mean adherence according to the predefined measurements varied from 72.7% to 79.8%. Non-adherence was associated with an increased risk of a primary outcome. The hazard ratios (95% confidence intervals, CIs) primary outcomes varied from 1.38 (95% CI, 1.19 to 1.59) to 1.44 (95% CI, 1.25 to 1.67).

CONCLUSIONS

Non-adherence to multidrug antihypertensive therapy was significantly associated with an increased risk of a primary clinical outcome. Across the varying estimates based on different methods, medication adherence levels were similar. These findings may provide evidence to support decision-making when assessing medication adherence.

Association between cost-sharing and drug prescribing in Korean elderly veterans with chronic diseases: A real-world claims data study

This study aimed to investigate the relationship between cost-sharing and drug prescribing and its appropriateness in Korean elderly veterans with chronic conditions. This is a cross-sectional study using real-world claims data. Veterans with primary hypertension or dyslipidemia were compared with two controls with higher levels of cost-sharing. Study subjects (age ≥65 years) were selected through stratified random sampling and matching the individual attributes. The primary outcome was the annual amount of drugs prescribed per patient, and the secondary outcomes included several other measures investigating multifaceted aspects of drug prescribing, medical institution utilization behavior, and prescribing appropriateness. Gamma regression models or logistic regression models were employed. Veterans were prescribed 59%~74% more drugs (exp (β) = 1.59 [95% confidence interval [CI] = 1.55-1.64] ~ 1.74 [1.70-1.79]) compared to the National Health Insurance (NHI) patients. This was attributed mainly to longer prescribing days (44%) and slightly more prescriptions (6%~7%) than NHI patients. Veterans spent 14%~15% higher medication costs. Veterans were less likely to visit multiple medical institutions by estimates of 0.77 (0.76-0.79) ~ 0.80 (0.79-0.82). Similar but smaller differences were observed between veterans and medical aid (MedAid) patients. The veteran patients showed a more than 50% increased risk of therapeutic duplication than the other two controls (adjusted odds ratio [ORs] = 1.47 [1.37-1.57] ~ 1.61 [1.50-1.72]). Inappropriate drug prescribing was also more common in veterans than the two controls (adjusted ORs = 1.20 [1.11-1.31] ~ 1.32 [1.22-1.43]). In Korean elderly veterans with chronic illnesses, a level of cost-sharing was associated with having more prescribed medicines, and increased inappropriate prescribing.

Assessment of the effects of methodological choice in continuity of care research: a real-world example with dyslipidaemia cohort

OBJECTIVE

To determine if the choice of methodological elements affects the results in continuity of care studies.

DESIGN

This is a retrospective cohort study. The association between continuity of care and clinical outcome was investigated using the Continuity of Care Index. The association was explored in 12 scenarios based on four definitions of the relative timing of continuity and outcome measurements in three populations (three Ps × four Ts).

SETTING

National Health Insurance claims from all primary and secondary care facilities in South Korea between 2007 and 2015.

PARTICIPANTS

Participants were patients diagnosed with dyslipidaemia, made ≥2 ambulatory visits and were newly prescribed with ≥1 antihyperlipidaemic agent at an ambulatory setting in 2008. Three study populations were defined based on the number of ambulatory visits: 10 084 patients in population 1 (P1), 8454 in population 2 (P2) and 4754 in population 3 (P3).

MAIN OUTCOME MEASURE

Hospitalisation related to one of the four atherosclerotic cardiovascular diseases, including myocardial infarction, stable or unstable angina, ischaemic stroke and transient ischaemic attack.

RESULTS

Concurrent measure of continuity and outcome (T1) showed a significantly higher risk of hospitalisation (adjusted HRs: 2.73-3.07, p<0.0001) in the low continuity of care group, whereas T2, which measured continuity until the outcome occurred, showed no risk difference between the continuity of care groups. T3, which measured continuity as a time-varying variable, had adjusted HRs of 1.31-1.55 (p<0.05), and T4, measuring continuity for a predefined period and measuring outcomes in the remaining period, had adjusted HRs of 1.34-1.46 (p<0.05) in the low continuity of care. Within each temporal relationship, the effect estimates became more substantial as the inclusion criteria became stricter.

CONCLUSIONS

The study design in continuity of care studies should be planned carefully because the results are sensitive to the temporal relationship between continuity and outcome and the population selection criteria.

36 A YEAR WITHOUT THE FLU: MODELLING THE EFFECTS ON CARDIOVASCULAR MORTALITY FROM INFLUENZA IN IRELAND

Background

Cardiovascular diseases (CVDs) are consistently ranked among the leading causes of death among older adults in Ireland. COVID-19 and influenza infection are associated with cardiovascular complications. However, percentage of deaths caused by CVD among adults aged 75 and over in Ireland decreased from 32.9% to 31.0% from 2019 to 2020. Government-imposed social distancing measures resulted in abolition of influenza activity (IA). We analysed population data from the 2010/11–2019/20 influenza seasons to estimate the impact of reduced IA on CVD mortality rates during the COVID-19 pandemic season.

Methods

Quarterly mortality data for acute myocardial infarction (AMI) and cerebrovascular disease from first quarter (Q1) 2010 to fourth quarter (Q4) 2020 was obtained from the Central Statistics Office. Weekly data on influenza-like illness (ILI) rates and positive percentages (PP) (i.e. proportion of influenza-positive sentinel respiratory specimens) from week 40 2010 to week 20 2020 was obtained from the Health Protection Surveillance Centre. Excess mortality rate during influenza season was calculated as the percentage difference between Q4/Q1 and preceding third quarter (Q3) mortality rates. We adopted the Goldstein index (ILI rate × PP) as an indicator of IA. Time series analyses, Pearson correlation coefficients (r) and linear regression models were used to evaluate the relationships between IA and excess AMI and cerebrovascular disease mortality rates.

Results

Statistically significant positive associations were observed between IA and excess AMI (r = 0.557, p = 0.011) and cerebrovascular disease (r = 0.858, p < 0.001) mortality rates. Linear regression models predicted 0.072% (95% confidence interval 0.019%, 0.125%) and 0.095% (0.067%, 0.123%) increases in excess AMI and cerebrovascular disease mortality rates respectively per unit increase in IA levels.

Conclusion

Elimination of IA may have contributed towards limiting the effects of COVID-19 on CVD mortality rates, and consequently total excess mortality, among older adults in Ireland.

Comparing the Sensitivities of Measures of Adherence to Antihypertensive Drugs Using Korean National Health Insurance Claims Data

PURPOSE

Numerous studies have utilized various forms of adherence measures. However, methods for measuring adherence are inconsistent. Moreover, few studies are available that have compared sensitivities of the effects of several criteria on medication adherence. This study aims to compare measures of adherence using varied analytical decisions.

MATERIALS AND METHODS

We included three measures for adherence: proportion of days covered with one or more medications (PDC_with≥1), duration weighted mean PDC (PDC_wm), and daily polypharmacy possession ratio (DPPR). We compared the sensitivities of the measures by changing parameters in the Korean nationwide claims database. First, we used PDC_with≥1 as our base model. Then, we divided an adherence measure algorithm into three categories: (1) definition of data cleaning, (2) inclusion criteria and observation period, and (3) calculation methods of medication adherence. The categories included eight decision nodes that incorporated 25 alternative options. Finally, we assessed the medication adherence for the base-case with commonly used values and then varied to measure with each alternative option.

RESULTS

The base-case included 14,288 beneficiaries with antihypertensives. Among eight decisions, both handling an end-date-of-study and overlaps had the strongest impacts on measuring PDC_with≥1, PDC_wm, and DPPR, with small differences in sample size. Instead of the estimates of adherence from PDC_wm, those of PDC_with≥1 and DPPR were similar. Furthermore, a tendency toward a higher medication adherence was observed with a smaller study population.

CONCLUSION

The decisions regarding identifying an end-date-of-study and overlaps showed meaningful impacts of all three measures including PDC_with≥1, PDCwm, and DPPR on measuring medication adherence.

Digital health screening tool for identification of elder mistreatment

PURPOSE

It is estimated that 15.7% of people aged 60 years and older were subjected to some form of Elder Mistreatment (EM) globally (Yon et al., 2017). In the USA, as many as 1 in 24 EM cases are left unidentified by professionals, with a 300% increased mortality risk for older adults who do not receive help (National Center on Elder Abuse, n.d.; Dong, 2009). Current methods of screening tend to miss less obvious signs of EM and may discourage older adults from disclosing EM, due to either a lack of understanding of what constitutes mistreatment or fear of retaliation from the perpetrator.

METHOD

Our approach shifts the focus of EM identification to the older adults themselves through an automated tablet-based tool. The Virtual cOaching in making Informed Choices on Elder Mistreatment Self-Disclosure (VOICES) tool includes various multimedia components such as videos, audio, and animations designed to educate and enhance screening. Patients screened as positive are guided through a Brief Negotiated Interview (BNI) utilizing motivational interviewing to assist in self-identification (recognize that they are experiencing elder mistreatment) or self-disclosure (inform others about their elder mistreatment experiences). During tool development, we conducted a qualitative study to evaluate the perceived value and likelihood of adopting a tablet-based approach to facilitate screening and self-disclosure of EM in the ED. We held 3 focus groups with stakeholders, including 24 adults 60 years or over, 2 social workers, 2 caregivers, and 2 ED clinicians. We used the findings from the focus groups and User-Centered Design approach (UCD) to develop the tablet-based screening tool. Once the tool was ready, we tested its usability and acceptability with 14 older adults.

RESULTS AND DISCUSSION

Focus group participants supported use of a tablet-based tool to screen for EM, indicating that digital screening benefits from feelings of privacy and anonymity. On a 7-point Likert scale ranging from "1=Very Comfortable" to "7=Very Uncomfortable", older adults scored 2.8 on average for whether they would feel comfortable using a tablet device to screen for EM. Prominent suggestions made by older adults included using a female voice for the tool narrator, larger font size, more multimedia, headphones for privacy; and having someone available during screening for assistance if needed. Participants indicated that it is difficult for older adults experiencing EM to ask for help and that any type of mistreatment screening would be helpful. They also highlighted the need to explain community resources available to older adults once EM is disclosed, especially resources offering help to the caregiver. Participants of the usability evaluation rated the tool a mean score of 86.6 (median= 88.8, iQR =18.1) on the System Usability Scale (SUS), far above the benchmark SUS score of 68, which indicates that the system is "good" or "acceptable" (Bangor et al., 2008). Shifting the focus from the provider to the older adult may encourage self-disclosure of EM by addressing major barriers to traditional screening processes. In summary, this study supported the use of self-administered automated tablet-based screening for EM. Participants generally believed that the use of digital health tools to facilitate the screening process would be beneficial in the ED setting.

Comprehensive Trends and Patterns of Antihypertensive Prescriptions Using a Nationwide Claims Database in Korea

Purpose

The number of people receiving antihypertensive prescriptions in Korea has increased more than threefold from 2002 to 2016. However, previous studies regarding the current use of these medications have been fairly limited. We aimed to examine the current trends and changes in the patterns of antihypertensive prescriptions based on a nationwide claims database.

Patients and Methods

Patients receiving antihypertensive medications over 30 days, without any limited therapeutic indication, were identified using the Health Insurance Review and Assessment Service (HIRA) database between 2015 and 2017. For each patient, the use of antihypertensive medication was specified as the class of drug used for the longest duration in each year.

Results

A total of 8,625,821 patients in 2015, 8,997,829 patients in 2016, and 9,357,751 patients in 2017 taking antihypertensives were included in this study. Angiotensin II receptor blockers (ARB) (35.9% in 2015 and 38.9% in 2017) and calcium channel blockers (CCB) (37.1% in 2015 and 35.2% in 2017) for monotherapy, ARB+CCB combinations (49.3% in 2015 and 56.3% in 2017) for dual therapy, and ARB+CCB+diuretics combinations (48.8% in 2015 and 48.9% in 2017) for more than triple therapy were the most frequently prescribed. Subjects aged ≥70 showed the highest prescription rate of antihypertensives compared with those <70; however, a decreasing trend presented from 62.3% in 2015 to 54.2% in 2017. Additionally, in subjects aged >70 years, the rate in women was higher than that in men, but this was reversed in younger patients. While changes arose in the patterns of the use of antihypertensives, these were similar each year.

Conclusion

The trends and changes in the patterns of the use of antihypertensive medications were affected by age, sex, and type of therapy. Our findings may contribute to a better understanding of the actual status regarding the use of antihypertensive medications in Korea.

Study of hospitalization and mortality in Korean diabetic patients using the diabetes complications severity index

BACKGROUND

The prevalence of type 2 diabetes mellitus (T2DM) is expected to increase from 7.7% in 2017 to 8.4% in 2045 worldwide. Diabetes complications contribute to morbidity and mortality. To evaluate whether the diabetes complications severity index (DCSI) was associated with increased risks of mortality and hospitalization.

METHODS

A retrospective cohort study was conducted using the National Health Insurance Database (NHID) sample cohort of 1,102,047 patients (2002-2015) in Korea. Diabetes complications were evaluated at 2 years after the initial diagnosis and during the subsequent follow-up period (mean duration 6.56 ± 2.81 years). The type and severity of complications were evaluated on the basis of the International Classification of Disease Ninth (ICD-9) codes used in DCSI with 7 categories and 55 subcategories of complications. The Cox proportional hazard and Poisson regression models were used to evaluate the mortality and hospitalization rates. The incidence and relative risk of diabetes complications as well as the risk of mortality and hospitalization were the main outcome measures.

RESULTS

A total of 27,871 patients were finally included and grouped by the number of complications present at 2 years. Four hundred ninety patients (5.37%) died without complications, 659 (7.31%) died with one complication and 1153 (11.85%) died with two or more complications. As DCSI at index date increased, the risk of additional new diabetes complications increased by 26% [relative risk (RR) 1.26, 95% CI 1.25-1.27]. The risks of mortality and hospitalization were linearly related to DCSI [hazard ratio 1.13 (95% CI 1.11-1.16), relative risk 1.04 (95% CI 1.03-1.06)].

CONCLUSIONS

Patients with higher incidence and severity of diabetes complications have increased risks of mortality and hospitalization.

Abstract PD04-03: Is breast conservation therapy an option for young women with operable breast cancer? Local recurrence rates in young women following surgery: a single centre experience

Background: Breast cancer (BC) is less common in young women (defined here as ≤ 40 years age), but is associated with more aggressive biological features, higher risk of local recurrence (LR) and poorer overall survival. This study examines and compares the incidence of LR following breast conservation therapy (BCT) versus mastectomy in women with operable BC treated at our centre.

Methods: The POWCC breast cancer database was retrospectively reviewed for the period January 1995 to December 2008. 2250 eligible women with BC undergoing primary breast surgery were identified. LR rate was compared between young women and older women (age &gt; 40 years), and according to type of surgery. Data were analysed using a competing risk Cox model to account for distant recurrence and death as competing events for local recurrence.

Results: Median follow-up was 70 months. Of 2250 women, 246 (11%) were young women, and the mastectomy rate was 49.2%. In older women (89%), mastectomy rate was 41.7%. LR occurred in 17 (6.9%) and 57 (2.8%) in young and older women respectively (p = 0.001). Amongst the young women, 12 (9.6%) and 5 (4.1%) patients recurred locally in BCT and mastectomy respectively (p = 0.09). Amongst the older women, 43 (3.7%) and 14 (1.7%) patients recurred locally in BCT and mastectomy respectively (p = 0.008). In univariate Cox analysis, significant risk factors for LR were BCT (p = 0.003), positive surgical margins (p = 0.03), age ≤ 40 years (p = 0.001), premenopausal status (p = 0.003) and no adjuvant systemic therapy (0.02). Age remains a significant predictor of LR in multivariate Cox analysis (Table). There was no significant interaction between age and type of surgery on LR (p = 0.72).

Discussion: Our results demonstrate that young women who undergo BCT have the highest risk of early LR. Adjuvant systemic therapy is protective of early LR. This study is hypothesis-generating and a definitive prospective clinical trial is required to better determine the optimal type of breast surgery in young women.

Pathological characteristics, distant recurrence rates, and survival outcomes of breast cancer with triple-negative phenotype

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Background: Breast cancer is a heterogeneous disease encompassing entities with distinct biological characteristics and clinical course. Triple-negative disease (TND) is clinically aggressive disease with limited effective therapy. We compare the clinico- pathologic characteristics, recurrence and survival rates of patients with TND and non-TND. Methods: The POWH Cancer Centre breast cancer database was retrospectively reviewed from January 1995 to December 2005. 1254 eligible women with breast cancer undergoing definitive primary breast surgery were identified. TND was defined as ER-, PR- and HER2 0 or 1+ by IHC and / or florescent in- situ hybridization (FISH) negative. Non-TND was defined as either ER+ and / or PR+ and/or HER2+. Further comparisons of survival outcomes were analyzed in a subgroup of 785 patients subdivided into three groups: ER+ and/or PR+ and HER2-, HER2+ and TND. Results: There were 135 patients (10.8%) with TND. TND tumours were characterized by larger size (p=0.02), histological grade 3 (p<0.001), presence of lymphovascular invasion (p=0.03), and less likely to be diagnosed by screening mammography (p<0.001) when compared with non-TND. Amongst those developing distant metastases, the median time to recurrence was 16 months for TND compared to 35 months in non-TND. There was a trend in visceral metastases for TND as compared to non-TND (OR=1.86, p=0.06). The adjusted rates for distant recurrence (HR=3.55, p=0.006), and death (HR=3.48, p=0.01) were significantly higher for TND when compared with non-TND only for first two years after diagnosis. Beyond the two years, there was no difference in distant recurrence and overall survival. Majority of the patients did not receive adjuvant anti-HER2 therapy during the study period. When compared to ER+ and/or PR+ and HER2- cohort, the survival rate was significantly poorer for TND (HR=2.66, p<0.001) but non-significant for HER2+ (1.61, p=0.1). Conclusions: Poorer histopathological phenotypes are observed in TND. Patients with TND have higher rates of developing distant metastases. Survival rates are also poorer in TND patients. The risks of distant recurrence and death are not proportional across time and these risks are strongly time-dependent.

No significant financial relationships to disclose.

Disposition of CP-671, 305, a selective phosphodiesterase 4 inhibitor in preclinical species

1. The disposition of (+)-2-[4-({[2-(benzo[1,3] dioxol-5-yloxy)-pyridine-3-carbonyl]-amino)-methyl)-3-fluoro-phenoxyl-propionic acid (CP-671,305), a potent and selective inhibitor of phosphodiesterase 4 (subtype D), was characterized in several animal species in support of its selection for preclinical safety studies and potential clinical development. 2. CP-671,305 demonstrates generally favourable pharmacokinetic properties in all species examined. Systemic plasma clearance after intravenous administration was low in Sprague-Dawley rats (9.60+/-1.16 ml min(-1) kg(-1)), beagle dogs (2.90+/-0.81 ml min(-1) kg(-1)) and cynomolgus monkeys (2.94+/-0.87ml min(-1) kg(-1)) resulting in plasma half-lives > 5 h. Moderate to high bioavailability in rats (43-80%), dogs (45%) and monkeys (26%) was observed after oral dosing. In rats, oral pharmacokinetics were dose dependent over the dose range studied (10 and 25 mgkg(-1)). 3. CP-671,305 was > 97% bound to plasma proteins in rat, dog, monkey and human. 4. The principal route of clearance of CP-671,305 in rats and dogs was by renal and biliary excretion of unchanged drug. This finding was consistent with CP-671,305 resistance towards metabolism in hepatocytes and NADPH-supplemented liver microsomes from preclinical species and human. 5. CP-671,305 did not exhibit competitive inhibition of the five major cytochrome P450 enzymes, namely CYP1A2, 2C9, 2C19, 2D6 and 3A4 (IC50's > 50 microM). Likewise, no time-dependent inactivation of the five major cytochrome P450 enzymes was discernible with CP-671,305. 6. Overall, the results indicate that the absorption, distribution, metabolism and excretion (ADME) profile of CP-671,305 is relatively consistent across preclinical species and predict potentially favourable pharmacokinetic properties in humans, supporting its selection for toxicity/safety assessment studies and possible investigations in humans.

Regional radiotherapy may improve outcomes in patients with early stage breast cancer undergoing breast conservation therapy

BACKGROUND

Breast conservation therapy (BCT) is recommended as standard management of early breast cancer. The aim of this study was to retrospectively evaluate the results of BCT to identify prognostic factors predictive of treatment outcomes.

PATIENTS AND METHODS

Four hundred and ninety-eight eligible women with unilateral stage I-II breast cancer who had undergone BCT were analyzed.

RESULTS

The cumulative incidence of local recurrence (LR) was 1.9% and 3.7% at 3- and 5-years respectively. The 5-year disease-free, cancer-specific, and overall survival (DFS, CSS, OS) were 80.0%, 87.3% and 85.4% respectively. Significant independent predictors for LR included young age and absence of chemotherapy. Regional nodal radiotherapy was significantly associated with improved DFS and OS.

CONCLUSION

Our results confirmed the efficacy of BCT in the treatment of early breast cancer and indicated that inclusion of regional nodal areas within the radiotherapy field might be beneficial in the BCT setting, particularly for patients with adverse risk features.