Systematic review of the relation between smokeless tobacco and cancer in Europe and North America

<p>Abstract</p> <p>Background</p> <p>Interest is rising in smokeless tobacco as a safer alternative to smoking, but published reviews on smokeless tobacco and cancer are limited. We review North American and European studies and compare effects of smokeless tobacco and smoking.</p> <p>Methods</p> <p>We obtained papers from MEDLINE searches, published reviews and secondary references describing epidemiological cohort and case-control studies relating any form of cancer to smokeless tobacco use. For each study, details were abstracted on design, smokeless tobacco exposure, cancers studied, analysis methods and adjustment for smoking and other factors. For each cancer, relative risks or odds ratios with 95% confidence intervals were tabulated. Overall, and also for USA and Scandinavia separately, meta-analyses were conducted using all available estimates, smoking-adjusted estimates, or estimates for never smokers. For seven cancers, smoking-attributable deaths in US men in 2005 were compared with deaths attributable to introducing smokeless tobacco into a population of never-smoking men.</p> <p>Results</p> <p>Eighty-nine studies were identified; 62 US and 18 Scandinavian. Forty-six (52%) controlled for smoking. Random-effects meta-analysis estimates for most sites showed little association. Smoking-adjusted estimates were only significant for oropharyngeal cancer (1.36, CI 1.04–1.77, <it>n </it>= 19) and prostate cancer (1.29, 1.07–1.55, <it>n </it>= 4). The oropharyngeal association disappeared for estimates published since 1990 (1.00, 0.83–1.20, <it>n </it>= 14), for Scandinavia (0.97, 0.68–1.37, <it>n </it>= 7), and for alcohol-adjusted estimates (1.07, 0.84–1.37, <it>n </it>= 10). Any effect of current US products or Scandinavian snuff seems very limited. The prostate cancer data are inadequate for a clear conclusion.</p> <p>Some meta-analyses suggest a possible effect for oesophagus, pancreas, larynx and kidney cancer, but other cancers show no effect of smokeless tobacco. Any possible effects are not evident in Scandinavia. Of 142,205 smoking-related male US cancer deaths in 2005, 104,737 are smoking-attributable. Smokeless tobacco-attributable deaths would be 1,102 (1.1%) if as many used smokeless tobacco as had smoked, and 2,081 (2.0%) if everyone used smokeless tobacco.</p> <p>Conclusion</p> <p>An increased risk of oropharyngeal cancer is evident most clearly for past smokeless tobacco use in the USA, but not for Scandinavian snuff. Effects of smokeless tobacco use on other cancers are not clearly demonstrated. Risk from modern products is much less than for smoking.</p

Improving the Interprofessional Relationship between Nurses and Speech-Langauge Pathologists - Expansion of a Project

The research presented on this poster explored the impact of extraprofessional education on undergraduate nursing and speech-language pathology students with an overall goal of improving the interprofessional relationship between the two fields. Utilizing quantitative and qualitative methods in the form of a pre-test, educational materials, live guided observation, and post-tests, the researchers found an increase in the nursing students ability to identify the role of the speech-language pathologist in a medical setting. There was also an increase in the speech-language pathology student’s ability to understand how and when to communicate with nurses in a medical setting

The relation between smokeless tobacco and cancer in Northern Europe and North America. A commentary on differences between the conclusions reached by two recent reviews

<p>Abstract</p> <p>Background</p> <p>Smokeless tobacco is an alternative for smokers who want to quit but require nicotine. Reliable evidence on its effects is needed. Boffetta et al. and ourselves recently reviewed the evidence on cancer, based on Scandinavian and US studies. Boffetta et al. claimed a significant 60–80% increase for oropharyngeal, oesophageal and pancreatic cancer, and a non-significant 20% increase for lung cancer, data for other cancers being "too sparse". We found increases less than 15% for oesophageal, pancreatic and lung cancer, and a significant 36% increase for oropharyngeal cancer, which disappeared in recent studies. We found no association with stomach, bladder and all cancers combined, using data as extensive as that for oesophageal, pancreatic and lung cancer. We explain these differences.</p> <p>Methods</p> <p>For those cancers Boffetta et al. considered, we compared the methods, studies and risk estimates used in the two reviews.</p> <p>Results</p> <p>One major reason for the difference is our more consistent approach in choosing between study-specific never smoker and combined smoker/non-smoker estimates. Another is our use of derived as well as published estimates. We included more studies, and avoided estimates for data subsets. Boffetta et al. also included some clearly biased or not smoking-adjusted estimates. For pancreatic cancer, their review included significantly increased never smoker estimates in one study and combined smoker/non-smoker estimates in another, omitting a combined estimate in the first study and a never smoker estimate in the second showing no increase. For oesophageal cancer, never smoker results from one study showing a marked increase for squamous cell carcinoma were included, but corresponding results for adenocarcinoma and combined smoker/non-smoker results for both cell types showing no increase were excluded. For oropharyngeal cancer, Boffetta et al. included a markedly elevated estimate that was not smoking-adjusted, and overlooked the lack of association in recent studies.</p> <p>Conclusion</p> <p>When conducting meta-analyses, all relevant data should be used, with clear rules governing the choice between alternative estimates. A systematic meta-analysis using pre-defined procedures and all relevant data gives a lower estimate of cancer risk from smokeless tobacco (probably 1–2% of that from smoking) than does the previous review by Boffetta et al.</p

Improving the Interprofessional Relationship between Nurses and Speech-Langauge Pathologists - Expansion of a Project

The research presented on this poster explored the impact of extraprofessional education on undergraduate nursing and speech-language pathology students with an overall goal of improving the interprofessional relationship between the two fields. Utilizing quantitative and qualitative methods in the form of a pre-test, educational materials, live guided observation, and post-tests, the researchers found an increase in the nursing students ability to identify the role of the speech-language pathologist in a medical setting. There was also an increase in the speech-language pathology student’s ability to understand how and when to communicate with nurses in a medical setting

Using the negative exponential distribution to quantitatively review the evidence on how rapidly the excess risk of ischaemic heart disease declines following quitting smoking

AbstractNo previous review has formally modelled the decline in IHD risk following quitting smoking. From PubMed searches and other sources we identified 15 prospective and eight case-control studies that compared IHD risk in current smokers, never smokers, and quitters by time period of quit, some studies providing separate blocks of results by sex, age or amount smoked. For each of 41 independent blocks, we estimated, using the negative exponential model, the time, H, when the excess risk reduced to half that caused by smoking. Goodness-of-fit to the model was adequate for 35 blocks, others showing a non-monotonic pattern of decline following quitting, with a variable pattern of misfit. After omitting one block with a current smoker RR 1.0, the combined H estimate was 4.40 (95% CI 3.26–5.95) years. There was considerable heterogeneity, H being <2years for 10 blocks and >10years for 12. H increased (p<0.001) with mean age at study start, but not clearly with other factors. Sensitivity analyses allowing for reverse causation, or varying assumed midpoint times for the final open-ended quitting period little affected goodness-of-fit of the combined estimate. The US Surgeon-General’s view that excess risk approximately halves after a year’s abstinence seems over-optimistic

Systematic review with meta-analysis of the epidemiological evidence relating FEV₁ decline to lung cancer risk

<p>Abstract</p> <p>Background</p> <p>Reduced FEV₁ is known to predict increased lung cancer risk, but previous reviews are limited. To quantify this relationship more precisely, and study heterogeneity, we derived estimates of β for the relationship RR(diff) = exp(βdiff), where diff is the reduction in FEV₁ expressed as a percentage of predicted (FEV₁%P) and RR(diff) the associated relative risk. We used results reported directly as β, and as grouped levels of RR in terms of FEV₁%P and of associated measures (e.g. FEV₁/FVC).</p> <p>Methods</p> <p>Papers describing cohort studies involving at least three years follow-up which recorded FEV₁ at baseline and presented results relating lung cancer to FEV₁ or associated measures were sought from Medline and other sources. Data were recorded on study design and quality and, for each data block identified, on details of the results, including population characteristics, adjustment factors, lung function measure, and analysis type. Regression estimates were converted to β estimates where appropriate. For results reported by grouped levels, we used the NHANES III dataset to estimate mean FEV₁%P values for each level, regardless of the measure used, then derived β using regression analysis which accounted for non-independence of the RR estimates. Goodness-of-fit was tested by comparing observed and predicted lung cancer cases for each level. Inverse-variance weighted meta-analysis allowed derivation of overall β estimates and testing for heterogeneity by factors including sex, age, location, timing, duration, study quality, smoking adjustment, measure of FEV₁ reported, and inverse-variance weight of β.</p> <p>Results</p> <p>Thirty-three publications satisfying the inclusion/exclusion criteria were identified, seven being rejected as not allowing estimation of β. The remaining 26 described 22 distinct studies, from which 32 independent β estimates were derived. Goodness-of-fit was satisfactory, and exp(β), the RR increase per one unit FEV₁%P decrease, was estimated as 1.019 (95%CI 1.016-1.021). The estimates were quite consistent (I² =29.6%). Mean age was the only independent source of heterogeneity, exp(β) being higher for age <50 years (1.024, 1.020-1.028).</p> <p>Conclusions</p> <p>Although the source papers present results in various ways, complicating meta-analysis, they are very consistent. A decrease in FEV₁%P of 10% is associated with a 20% (95%CI 17%-23%) increase in lung cancer risk.</p