Cannabis smoking and lung cancer risk: Pooled analysis in the International Lung Cancer Consortium
Lunenfeld-Tanenbaum Research Institute1, University of Michigan2, University of California, Los Angeles3, Washington State University Spokane4, University of Sheffield5, Memorial Sloan Kettering Cancer Center6, University of Otago7, Princess Margaret Cancer Centre8, Ontario Institute for Cancer Research9
TL;DR: Results from the pooled analyses provide little evidence for an increased risk of lung cancer among habitual or long‐term cannabis smokers, although the possibility of potential adverse effect for heavy consumption cannot be excluded.
Abstract: To investigate the association between cannabis smoking and lung cancer risk, data on 2,159 lung cancer cases and 2,985 controls were pooled from 6 case-control studies in the US, Canada, UK, and New Zealand within the International Lung Cancer Consortium. Study-specific associations between cannabis smoking and lung cancer were estimated using unconditional logistic regression adjusting for sociodemographic factors, tobacco smoking status and pack-years; odds-ratio estimates were pooled using random effects models. Subgroup analyses were done for sex, histology and tobacco smoking status. The shapes of dose-response associations were examined using restricted cubic spline regression. The overall pooled OR for habitual versus nonhabitual or never users was 0.96 (95% CI: 0.66-1.38). Compared to nonhabitual or never users, the summary OR was 0.88 (95%CI: 0.63-1.24) for individuals who smoked 1 or more joint-equivalents of cannabis per day and 0.94 (95%CI: 0.67-1.32) for those consumed at least 10 joint-years. For adenocarcinoma cases the ORs were 1.73 (95%CI: 0.75-4.00) and 1.74 (95%CI: 0.85-3.55), respectively. However, no association was found for the squamous cell carcinoma based on small numbers. Weak associations between cannabis smoking and lung cancer were observed in never tobacco smokers. Spline modeling indicated a weak positive monotonic association between cumulative cannabis use and lung cancer, but precision was low at high exposure levels. Results from our pooled analyses provide little evidence for an increased risk of lung cancer among habitual or long-term cannabis smokers, although the possibility of potential adverse effect for heavy consumption cannot be excluded.
Citations
More filters
••
01 Dec 2018
TL;DR: Despite increased cannabis use and a changing state-level policy landscape, conclusive evidence regarding the shortand long-term health effects—both harms and benefits—of cannabis use remains elusive.
Abstract: Recent years have seen a rapid rise in the medical and recreational use of cannabis: a broad term that can be used to describe the various products and chemical compounds (e.g., marijuana, cannabinoids) derived from different species of the cannabis plant. Despite increased cannabis use and a changing state-level policy landscape, conclusive evidence regarding the shortand long-term health effects—both harms and benefits—of cannabis use remains elusive.
921 citations
••
TL;DR: In the United States, lung cancer is the second most common diagnosed cancer and the leading cause of cancer-related death and the major risk factor is tobacco smoking.
Abstract: In the United States, lung cancer is the second most common diagnosed cancer and the leading cause of cancer-related death. Although tobacco smoking is the major risk factor accounting for 80% to 90% of all lung cancer diagnoses, there are numerous other risk factors that have been identified as
308 citations
Cites methods from "Cannabis smoking and lung cancer ri..."
...A pooled analysis from the International Lung Cancer Consortium of 2,159 lung cancer cases and 2,985 controls found little evidence for an increased risk of lung cancer among habitual or long-term cannabis smokers (83)....
[...]
••
TL;DR: Evidence indicates that a substantial extent of the risk of adverse health outcomes from cannabis use may be reduced by informed behavioral choices among users, and evidence-based Lower-Risk Cannabis Use Guidelines serve as a population-level education and intervention tool to inform such user choices toward improved public health outcomes.
Abstract: Background. Cannabis use is common in North America, especially among young people, and is associated with a risk of various acute and chronic adverse health outcomes. Cannabis control regimes are evolving, for example toward a national legalization policy in Canada, with the aim to improve public health, and thus require evidence-based interventions. As cannabis-related health outcomes may be influenced by behaviors that are modifiable by the user, evidence-based Lower-Risk Cannabis Use Guidelines (LRCUG)—akin to similar guidelines in other health fields—offer a valuable, targeted prevention tool to improve public health outcomes.Objectives. To systematically review, update, and quality-grade evidence on behavioral factors determining adverse health outcomes from cannabis that may be modifiable by the user, and translate this evidence into revised LRCUG as a public health intervention tool based on an expert consensus process.Search methods. We used pertinent medical search terms and structured search st...
258 citations
••
TL;DR: The objectives of this systematic review were to assess the efficacy of cannabis for treating chronic pain and to provide a broad overview of the short- and long-term physical and mental health effects of cannabis use in Chronic pain and general patient populations.
Abstract: Background Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain. Purpose To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations. Data sources MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017. Study selection Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes. Data extraction Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria. Data synthesis From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient. Limitation Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily. Conclusion Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects. Primary funding source U.S. Department of Veterans Affairs. (PROSPERO: CRD42016033623).
220 citations
••
TL;DR: There is a paucity of rigorous and high-quality data on health outcomes from cannabis ROAs, especially in direct and quantifiable comparison, yet systematic data for comparative assessments are largely lacking.
203 citations
References
More filters
••
TL;DR: A new quantity is developed, I 2, which the authors believe gives a better measure of the consistency between trials in a meta-analysis, which is susceptible to the number of trials included in the meta- analysis.
Abstract: Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice?
Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis.
Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4
Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted?
A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …
45,105 citations
•
01 Feb 1982
TL;DR: This is an account of cancer epidemiology has been expanded and contains new material on cancer biology, molecular epidemiology, preventive strategies and specific types and sites of cancer.
Abstract: This is an account of cancer epidemiology. The second edition has been expanded and contains new material on cancer biology, molecular epidemiology, preventive strategies and specific types and sites of cancer.
2,881 citations
05 Dec 2014
TL;DR: The EMCDDA Programme 2, 'Analysis of responses', set out to identify how social reintegration is understood in each Member State and to map the availability of social reIntegration facilities in Member States according to these national perceptions.
Abstract: INTRODUCTION The issue of social rehabilitation and reintegration (hereafter social reintegration2) is mentioned under the third strategy target of the EU Action Plan 2000–2004. The third EU strategy target is to 'substantially increase the number of successfully treated addicts', and point 3.1.3.4 instructs that 'Member States [are] to ensure that adequate attention is paid to social and professional rehabilitation and reintegration of former addicts'. However, social reintegration is also linked to social exclusion, which is mentioned in chapter 2 of the EU Action Plan, where it is stated that 'the EMCDDA [is] to develop indicators on drug-related crime, the availability of illicit drugs (including at street level) and drug-related social exclusion'. For the EMCDDA, social reintegration comes under strategy target four – that is, as a response to social exclusion – however, target two is clearly also relevant. Social exclusion is often perceived as a cause of problem drug use, although many see it as a consequence of problem drug use. We will not elaborate on this further here, except to note that social exclusion and problem drug use are two phenomena that are very closely interlinked and that social reintegration is a possible response to both. The EMCDDA Programme 2, 'Analysis of responses', set out to identify how social reintegration is understood in each Member State and to map the availability of social reintegration facilities in Member States according to these national perceptions. It became evident at an early stage that this would be a complex task, involving extensive data collection, as national reports generally provided insufficient data on this specific subject. eight countries turned out to be difficult to map and so, in February 2002, the EMCDDA launched a call for tender for a project, 'Mapping social reintegration services in EU countries'. 3 The aim of this project was to describe the state of the art of social reintegration in the following eight countries: The research specifications, to investigate 'the state of the art of social reintegration', suggested that the following should be identified for each of the eight countries: 1 Other contributors will be mentioned in the respective chapters. 2 Our country studies so far have shown that the term 'rehabilitation' is used ambiguously across Europe – from low-threshold refuges, to normal treatment, to actual reintegration into society. For this reason, we shall use the term 'social reintegration' in this report, as this is used much more …
2,183 citations
National Institutes of Health1, Saint Louis University2, University of California, Berkeley3, United States Environmental Protection Agency4, University of Oxford5, Louisiana State University6, Fudan University7, Tata Institute of Fundamental Research8, Queen Mary University of London9, University of Minnesota10, Finnish Institute of Occupational Health11, University of Buenos Aires12, Johns Hopkins University13, Ohio State University14, American Cancer Society15, University of Paris16, University of Turin17, University of Southern California18, Russian Academy19
1,761 citations
••
[...]
1,651 citations