Breast cancer adjuvant chemotherapy dosing in obese patients

BACKGROUND Substantial variation in adjuvant breast cancer chemotherapy dosing in obese women suggests that there is uncertainty about optimal practices. The purpose of this study was to investigate variations in dose determinations in clinical trial protocols and publications over the last 3 decades as potential sources of this uncertainty. METHODS The National Cancer Institute database was used to identify protocols of breast cancer adjuvant chemotherapy conducted by cooperative groups between 1970–2000, and these protocols were then obtained directly from the cooperative groups. Dose determinations were categorized in each protocol and in published reports from each clinical trial. Fisher exact tests were used to compare the proportions of protocols that used full weight-based doses over time. RESULTS Protocol-specified chemotherapy dosing was obtained for all of 44 eligible trials. A significant increase was identified in the use of full weight-based doses in the later time period compared with the earlier ( P = .004; 2-sided Fisher exact test). A notable exception was 1 cooperative group that continues to require dose limitations for doxorubicin and cyclophosphamide in patients with a body surface area of more than 2.0 m 2 . Regardless of publication date, published reports of clinical trials rarely provide information on use of full or limited weight-based doses. CONCLUSIONS Variations in dose determinations among clinical trial protocols and lack of information on use of full weight-based doses in most publications are 2 likely sources of variation in chemotherapy dosing in obese women. Developing consensus and disseminating information on optimal chemotherapy dosing will likely reduce such variation and may improve survival among obese patients with breast cancer. Cancer 2008. © 2008 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58590/1/23416_ftp.pd

Polar bears are inefficient predators of seabird eggs

Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears\u27 foraging performance on common eider (Somateria mollissima) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density

Adjuvant chemotherapy dosing in low-income women: the impact of Hispanic ethnicity and patient self-efficacy

Unwarranted breast cancer adjuvant chemotherapy dose reductions have been documented in black women, women of lower socioeconomic status, and those who are obese. No information on the quality of chemotherapy is available in Hispanic women. The purpose of this study was to characterize factors associated with first cycle chemotherapy dose selection in a multi-ethnic sample of low-income women receiving chemotherapy through the Breast and Cervical Cancer Prevention Treatment Program (BCCPT) and to investigate the impact of Hispanic ethnicity and patient self-efficacy on adjuvant chemotherapy dose selection. Survey and chemotherapy information were obtained from consenting participants enrolled in the California BCCPT. Analyses identified clinical and non-clinical factors associated with first cycle chemotherapy doses less than 90 % of expected doses. Of 552 patients who received chemotherapy, 397 (72 %) were eligible for inclusion. First cycle dose reductions were given to 14 % of the sample. In multivariate analyses, increasing body mass index and non-academic treatment site were associated with doses below 90 % of the expected doses. No other clinical or non-clinical factors, including ethnicity, were associated with first cycle doses selection. In this universally low-income sample, we identified no association between Hispanic ethnicity and other non-clinical patient factors, including patient self-efficacy, in chemotherapy dose selection. As seen in other studies, obesity was associated with systematic dose limits. The guidelines on chemotherapy dose selection in the obese may help address such dose reductions. A greater understanding of the association between type of treatment site and dose selection is warranted. Overall, access to adequate health care allows the vast majority of low-income women with breast cancer to receive high-quality breast cancer chemotherapy

Polar bear foraging on common eider eggs: estimating the energetic consequences of a climate-mediated behavioural shift

Climate-mediated phenological shifts can cause species to lose access to their primary prey while increasing opportunities for alternative-prey encounters. Species that are able to capitalize on alternative resources could potentially profit from prey-switching should the benefits of procuring these alternative resources outweigh their acquisition costs. Polar bears, Ursus maritimus, use sea ice as a platform to hunt seals, and individuals inhabiting the southern-most extent of their range rely on accumulated fat reserves to sustain themselves during the increasingly lengthy ice-free season. In response to declining access to their primary prey through documented sea ice loss, some polar bears are foraging on the eggs of birds in lieu of hunting opportunities on ice, as their onshore arrival is increasingly overlapping with birds’ breeding schedules. To gain a better understanding of the energetic consequences of this behaviour, we used aerial drones to record polar bears foraging on sea duck eggs (common eider, Somateria mollissima) on Mitivik Island, Nunavut, Canada. Using these data, we examined variation in individual polar bear foraging behaviours and estimated the energetic benefits and costs associated with foraging on common eider eggs. Because of low costs associated with nest searching and consumption, the energetic cost of foraging remained relatively constant throughout the 2-week observation period. However, we found that as the common eider breeding season progressed, polar bears consumed eggs at a lower rate as they depleted the nesting colony and spent proportionally more time searching for nests. Collectively, this foraging pattern led to an overall declining trend in the net energy gained from egg consumption. Foraging on common eider eggs during increasingly lengthy ice-free seasons is apparently beneficial for polar bears, but only during a limited window of opportunity. By coupling energetic estimates with detailed behavioural data collected through aerial videography, this study provides a quantification of both the benefits and costs of egg consumption for polar bears

Adjuvant chemotherapy dosing in low-income women: the impact of Hispanic ethnicity and patient self-efficacy

Unwarranted breast cancer adjuvant chemotherapy dose reductions have been documented in black women, women of lower socioeconomic status, and those who are obese. No information on the quality of chemotherapy is available in Hispanic women. The purpose of this study was to characterize factors associated with first cycle chemotherapy dose selection in a multi-ethnic sample of low-income women receiving chemotherapy through the Breast and Cervical Cancer Prevention Treatment Program (BCCPT) and to investigate the impact of Hispanic ethnicity and patient self-efficacy on adjuvant chemotherapy dose selection. Survey and chemotherapy information were obtained from consenting participants enrolled in the California BCCPT. Analyses identified clinical and non-clinical factors associated with first cycle chemotherapy doses less than 90 % of expected doses. Of 552 patients who received chemotherapy, 397 (72 %) were eligible for inclusion. First cycle dose reductions were given to 14 % of the sample. In multivariate analyses, increasing body mass index and non-academic treatment site were associated with doses below 90 % of the expected doses. No other clinical or non-clinical factors, including ethnicity, were associated with first cycle doses selection. In this universally low-income sample, we identified no association between Hispanic ethnicity and other non-clinical patient factors, including patient self-efficacy, in chemotherapy dose selection. As seen in other studies, obesity was associated with systematic dose limits. The guidelines on chemotherapy dose selection in the obese may help address such dose reductions. A greater understanding of the association between type of treatment site and dose selection is warranted. Overall, access to adequate health care allows the vast majority of low-income women with breast cancer to receive high-quality breast cancer chemotherapy

Feasibility and Acceptability of Real-Time Antiretroviral Adherence Monitoring among Depressed Women Living with HIV in the Deep South of the US

This study presents feasibility and acceptability data on the use of a real-time wireless electronic adherence monitor (EAM), among African American women living with HIV with co-occurring depression, residing in remote areas of the Southeastern United States. EAM and self-report ART adherence was monitored over an average of 14.8 weeks among 25 participants who were recruited at four HIV clinics in Alabama. Intra-class correlation showed a low degree of concordance between EAM and self-report (ICC = 0.33, 95% bootstrap CI 0.13, 0.59). 83% of data collected via EAM was transmitted in real-time. Due to technological failures, 11.4% were not transmitted in real-time, but were later recovered, and 5.7% were lost entirely. Acceptability was examined through surveys and qualitative interviews. Results suggest that EAM monitoring is acceptable and feasible in a rural US setting; however, technological difficulties, such as loss of connectivity may impede the device's usefulness for just-in-time adherence interventions

Polar bears are inefficient predators of seabird eggs

Climate-mediated sea-ice loss is disrupting the foraging ecology of polar bears (Ursus maritimus) across much of their range. As a result, there have been increased reports of polar bears foraging on seabird eggs across parts of their range. Given that polar bears have evolved to hunt seals on ice, they may not be efficient predators of seabird eggs. We investigated polar bears\u27 foraging performance on common eider (Somateria mollissima) eggs on Mitivik Island, Nunavut, Canada to test whether bear decision-making heuristics are consistent with expectations of optimal foraging theory. Using aerial-drones, we recorded multiple foraging bouts over 11 days, and found that as clutches were depleted to completion, bears did not exhibit foraging behaviours matched to resource density. As the season progressed, bears visited fewer nests overall, but marginally increased their visitation to nests that were already empty. Bears did not display different movement modes related to nest density, but became less selective in their choice of clutches to consume. Lastly, bears that capitalized on visual cues of flushing eider hens significantly increased the number of clutches they consumed; however, they did not use this strategy consistently or universally. The foraging behaviours exhibited by polar bears in this study suggest they are inefficient predators of seabird eggs, particularly in the context of matching behaviours to resource density