Cancer screening in the elderly

Cancer screening in the elderly presents several unique challenges. There are no prospective trials of any cancer screening exam that have conclusively demonstrated efficacy in this age group. Any assessment of cancer screening in the elderly must include measuring an improvement in quality of life and functional status as well as decreased mortality from early cancer detection. Older patients usually prefer improved quality over quantity of life; they may be less interested in a trade-off of months or years of life in exchange for the side effects of cancer treatment. The elderly may need more home assistance during the treatment of the detected cancers; physicians should arrange for this. All of these variables must be included in studies of cancer screening in the elderly; the need for these studies is great. The following recommendations are probably the most reasonable in view of the currently inadequate knowledge base. Screening for breast cancer has demonstrated efficacy, with growing evidence for a cumulative effect from monthly breast self-examination, yearly breast examination by a physician, and yearly or biennial mammography. There may be no need to screen for cervical cancer in women after age 65 who have had regular Pap smear screening; however, older women who have never had Pap smears should have regular Pap smears for several years. Finally, because of the high frequency of colorectal and prostate cancers in the elderly, physicians should probably perform yearly rectal examinations with stool guaiac and regular sigmoidoscopy in this age group until definitive data support continuing or discontinuing these screening examinations. Physicians should educate their elderly patients to the importance of regular cancer screening and cancer risk-factor modification and should offer cancer screening examinations and counseling to elderly patients on a regularly scheduled basis.     

Bacterial adherence to tantalum versus commonly used orthopedic metallic implant materials

OBJECTIVES: Evaluation of bacterial adhesion to pure tantalum and tantalum-coated stainless steel versus commercially pure titanium, titanium alloy (Ti-6Al-4V), and grit-blasted and polished stainless steel. DESIGN: Experimental in vitro cell culture study using Staphylococcus aureus and Staphylococcus epidermidis to evaluate qualitatively and quantitatively bacterial adherence to metallic implants. METHODS: A bacterial adhesion assay was performed by culturing S. aureus (ATCC 6538) and S. epidermidis (clinical isolate) for one hour with tantalum, tantalum-coated stainless steel, titanium, titanium alloy, grit-blasted and polished stainless steel metallic implant discs. Adhered living and dead bacteria were stained using a 2-color fluorescence assay. Adherence was then quantitatively evaluated by fluorescence microscopy and digital image processing. Qualitative adherence of the bacteria was analyzed with a scanning electron microscope. The quantitative data were related to the implant surface roughness (Pa-value) as measured by confocal laser scanning microscopy. RESULTS: Bacterial adherence of S. aureus varied significantly (p = 0.0035) with the type of metallic implant. Pure tantalum presented with significantly (p < 0.05) lower S. aureus adhesion compared to titanium alloy, polished stainless steel, and tantalum-coated stainless steel. Furthermore, pure tantalum had a lower, though not significantly, adhesion than commercially pure titanium and grit-blasted stainless steel. Additionally, there was a significantly higher S. aureus adherence to titanium alloy than to commercially pure titanium (p = 0.014). S. epidermidis adherence was not significantly different among the tested materials. There was no statistically significant correlation between bacterial adherence and surface roughness of the tested implants. CONCLUSIONS: Pure tantalum presents with a lower or similar S. aureus and S. epidermidis adhesion when compared with commonly used materials in orthopedic implants. CLINICAL IMPLICATION: Because bacterial adhesion is an important predisposing factor in the development of clinical implant infection, tantalum may offer benefits as an adjunct or alternative material compared with current materials commonly used for orthopedic implants.     

Tumor size and extent of disease at diagnosis predict the response to initial therapy for papillary thyroid carcinoma in children and adolescents

Treatment of papillary thyroid carcinoma (PTC) in children and adolescents is controversial. We previously showed that large tumor size, multifocal disease, and extensive disease at diagnosis predict recurrence. We examined 47 patients with PTC to determine whether these features predict response to treatment. Overall, 70% of the patients (33/47) remitted with initial treatment. 79% (15/19), of Class I, 86% (12/14) of Class II, and 100% (6/6) of Class III, but none of Class IV patients (n = 8) (p < 0.001) achieved remission. Tumor size for patients who entered remission (2.0 +/- 0.2 cm) was less than for patients with persistent disease (4.2 +/- 0.4) (p < 0.0005). Extent of disease at diagnosis correlated with the number of radioactive iodine (RAI) treatments (p = 0.022) and dose (p = 0.002) required to achieve first remission. We conclude that extensive disease at diagnosis and larger tumor size predict failure to remit after initial treatment of PTC in children and adolescents.     

The administration of vitamin B1 by intraspinal injection: Observations and deductions

The widespread publicity given by the daily press to the inaccurate, optimistic accounts of medical research frequently arouses false hopes in those afflicted with the disorders which happen to be the subjects of the scientific investigation unfortunately exploited for sensational news value. Our attention was directed to the intraspinal injection of vitamin b₁ in the treatment of chronic neurologic disorders by patients who had such disorders and who had learned of the injections through the accounts in their newspapers. A survey of the medical and scientific literature indicated that there was a relationship between vitamin Bi and metabolism in the neural tissues, that a “biochemical lesion” in the central nervous system was caused by Bi hypovitaminosis, that the clinical manifestations of beriberi (absolute Bi hypovitaminosis) included nervous symptoms now acknowledged to be remarkably similar to those seen in degenerative neurologic disorders, and that the use of vitamin Bi in some disorders of the peripheral nerves, for example the neuritides, brings about improvement. The intraspinal injection of vitamin b₁, in the light of the survey, seemed to merit consideration, particularly since reports of improvement following such therapy appeared in the medical literature. The administration of vitamin Bi by intraspinal injections (and other avenues as well) was evaluated in a group of patients suffering from chronic neurologic disorders. Our experience with this type of therapy has led to several conclusions.     

Distribution and Uptake of Key Polychlorinated Biphenyl and Polybrominated Diphenyl Ether Congeners in Benthic Infauna Relative to Sediment Organic Enrichment

As part of a broader study of budgets, transport, and bioaccumulation of persistent organic contaminants in the Strait of Georgia, Canada, matching samples of sediment and bulk benthos were collected near two marine sewage outfalls, two large urban harbours, and background areas. Samples were analyzed for polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) congeners. We present data for those congeners that fell within the top six rankings by concentration (23 PCBs and 10 PBDEs) within at least one of the environmental media measured in other studies (air, water, sediments, benthos, pelagic biota). Multifactor regression analyses incorporating sediment characteristics (total organic carbon, fines) predicted uptake (r ² = 0.74 to 0.98, p < 0.04) over the range of congeners and habitats examined. PBDEs were taken up by biota more readily than PCBs, suggesting a large, potentially available biological reservoir of PBDEs in sediments. Dominant congeners in benthos comprised PBDEs 47, 99, 209, and 100 and PCBs 138/163, 153, 101, 118, and 110. PBDE uptake was anomalously high near one wastewater outfall, likely due to selective feeding on PBDE-enriched particulates from that source. Conversely, outfalls supply food and sediments with PCB concentrations similar to ambient sediments. However, organic enrichment of sediments near outfalls clearly enhanced PCB uptake by benthos, probably due to greatly increased biomass turnover near these sources. Data suggest there to be an initial reservoir of PCBs in newly settled juvenile benthos, which is much less evident for PBDEs. This is likely a consequence of the ecosystem-wide distribution of legacy PCBs but not the more current-use PBDEs. Congener-uptake patterns were dependent on source and input dynamics, feeding methods, and contaminant metabolism or debromination, particularly of deca-BDE.     

The expression of vascular endothelial growth factor and the type 1 vascular endothelial growth factor receptor correlate with the size of papillary thyroid carcinoma in children and young adults.

Vascular endothelial growth factor (VEGF) is essential for the growth of many solid tumors, but there are little data regarding VEGH in childhood thyroid cancers. We examined the relationships between VEGF, the type 1 VEGF receptor (FLT-1) and clinical outcome for a group of thyroid cancers in children and young adults. The expression of VEGF and FLT-1 were determined by immunohistochemistry using archival, paraffin-embedded thyroid tissue blocks and compared with the retrospective clinical outcome for each patient. The study included 67 children and young adults with papillary thyroid carcinoma (PTC, n = 42), follicular thyroid carcinoma (FTC, n = 8), benign lesions (n = 15), or controls (n = 2). VEGF expression was greater in PTC (mean intensity 2.23 +/- 0.25, p = 0.002) and FTC (2.8 +/- 0.73, p = 0.01) than benign lesions (1.0 +/- 0.27), and correlated with PTC size (r = 0.42, p = 0.008). FLT-1 expression was greater in PTC (mean intensity 2.8 +/- 0.17) than FTC (1.9 +/- 0.25, p = 0.015) and benign lesions (1.7 +/- 0.32, p = 0.002); and correlated with PTC size (r = 0.41, p = 0.01) as well as VEGF expression (r = 0.52, p = 0.002). Recurrent disease developed exclusively in patients with PTC which expressed VEGF (7/28, 95% CI 10.6%-44.2%). PTC that did not express VEGF (0/8, 95% CI = 0%-31.2%) did not recur; however, the difference was not statistically significant (p = 0.15). We conclude that the expression of VEGF and FLT-1 are directly correlated with the size of PTC in children and young adults.