Barriers to Clinical Trial Participation: Comparative Study Between Rural and Urban Participants.

BACKGROUND: The National Clinical Trials Network program conducts phase 2 or phase 3 treatment trials across all National Cancer Institute's designated cancer centers. Participant accrual across these clinical trials is a critical factor in deciding their success. Cancer centers that cater to rural populations, such as The University of Kansas Cancer Center, have an additional responsibility to ensure rural residents have access and are well represented across these studies. OBJECTIVE: There are scant data available regarding the factors that act as barriers to the accrual of rural residents in these clinical trials. This study aims to use electronic screening logs that were used to gather patient data at several participating sites in The Kansas University of Cancer Center's Catchment area. METHODS: Screening log data were used to assess what clinical trial participation barriers are faced by these patients. Additionally, the differences in clinical trial participation barriers were compared between rural and urban participating sites. RESULTS: Analysis revealed that the hospital location rural urban category, defined as whether the hospital was in an urban or rural setting, had a medium effect on enrolment of patients in breast cancer and lung cancer trials (Cohen d=0.7). Additionally, the hospital location category had a medium effect on the proportion of recurrent lung cancer cases at the time of screening (d=0.6). CONCLUSIONS: In consideration of the financially hostile nature of cancer treatment as well as geographical and transportation barriers, clinical trials extended to rural communities are uniquely positioned to alleviate the burden of nonmedical costs in trial participation. However, these options can be far less feasible for patients in rural settings. Since the number of patients with cancer who are eligible for a clinical trial is already limited by the stringent eligibility criteria required of such a complex disease, improving accessibility for rural patients should be a greater focus in health policy.

Long-term high copper intake: effects on indexes of copper status, antioxidant status, and immune function in young men.

BACKGROUND: Short-term high copper intake does not appear to affect indexes of copper status or functions related to copper status, but the effects of long-term high copper intake are unknown. OBJECTIVE: A study was conducted in men to determine the effect of long-term high copper intake on indexes of copper status, oxidant damage, and immune function. DESIGN: Nine men were confined to a metabolic research unit (MRU) for 18 d and were fed a 3-d rotating menu providing an average of 1.6 mg Cu/d. The men continued the study under free-living conditions for 129 d and supplemented their usual diets with 7 mg Cu/d. The men then returned to the MRU for 18 d of the same diet as during the first period, except that copper intake was 7.8 mg/d. Plasma copper, ceruloplasmin activity, ceruloplasmin protein, plasma malondialdehyde, benzylamine oxidase activity, erythrocyte superoxide dismutase, hair copper, urinary copper, and urinary thiobarbituric acid-reactive substances were measured during each MRU period. RESULTS: Ceruloplasmin activity, benzylamine oxidase, and superoxide dismutase were significantly higher at the end of the second MRU period than at the end of the first. Urinary copper excretion, hair copper concentrations, and urinary thiobarbituric acid-reactive substances were significantly higher during the second MRU period than during the first. Polymorphonuclear cell count, the percentage of white blood cells, lymphocyte count, and interleukin 2R were affected by copper supplementation. Antibody titer for the Beijing strain of influenza virus was significantly lower in supplemented subjects after immunization than in unsupplemented control subjects. CONCLUSIONS: Under highly controlled conditions, long-term high copper intake results in increases in some indexes of copper status, alters an index of oxidant stress, and affects several indexes of immune function. The physiologic implications of these changes are unknown.

Zinc supplementation has no effect on circulating levels of peripheral blood leucocytes and lymphocyte subsets in healthy adult men.

As a result of evidence documenting harmful effects of Zn supplementation on immune function and Cu status, thirty-eight men were recruited onto a Zn supplementation trial. The aim was to examine the effects of chronic Zn supplementation on circulating levels of peripheral blood leucocytes and lymphocyte subsets. Subjects (n 19) took 30 mg Zn/d for 14 weeks followed by 3 mg Cu/d for 8 weeks to counteract adverse effects, if any, of Zn supplementation on immune status resulting from lowered Cu status. A control group (n 19) took placebo supplements for the duration of the trial. Dietary intakes of Zn approximated 10 mg/d. Blood samples, taken throughout the trial, were assessed for full blood profiles and flow cytometric analyses of lymphocyte subsets. Putative indices of Cu status were also examined. Results indicate that there was no effect of Zn supplementation on circulating levels of peripheral blood leucocytes or on lymphocyte subsets. Cu status was also unaltered. Independent of supplement, there appeared to be seasonal variations in selected lymphocyte subsets in both placebo and supplemented groups. Alterations in circulating levels of B cells (cluster of differentiation (CD) 19), memory T cells (CD45RO) and expression of the intracellular adhesion molecule-1 (CD54) on T cells were observed. Findings indicated no adverse effects of Zn supplementation on immune status or Cu status and support the US upper level of Zn tolerance of 40 mg/d. The seasonal variations observed in lymphocyte subsets in the group as a whole could have implications for seasonal variability in the incidence of infectious diseases.

Nonagenarians from the Swedish NONA Immune Study have increased plasma antioxidant capacity and similar levels of DNA damage in peripheral blood mononuclear cells compared to younger control subjects.

The results of previous work from our laboratories have suggested that free radical damage to T cells as they age may contribute to the age-related decline in the T cell-mediated immune response. The aims of this investigation were to assess the efficiency of in vivo antioxidant capacity through determining the antioxidant capacity of plasma using the ferric reducing ability of plasma assay, and to assess the levels and types of DNA damage (as a measure of in vivo antioxidant efficiency) using the alkaline comet assay and two enzymatic modifications of the comet assay, in peripheral blood mononuclear cells (PBMCs) from nonagenarian subjects drawn from the Swedish NONA Immune Study. The results obtained were compared with those from middle-aged (40-60 years) controls to identify potential anti-immunosenescent effects of in vivo antioxidants. The results revealed a significantly higher plasma antioxidant capacity in NONA subjects compared to controls, and these results support a relationship between longevity and intact immune function, which may be underpinned by antioxidant defences which reduce free radical damage to PBMC, thus helping to maintain cell function. The NONA subjects were found to have similar levels of DNA damage in their PBMCs to those found in middle aged controls.