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Take a look at a selection of our recent media coverage:
20th December 2022
Widespread state medical marijuana legalisation in the US is associated with a lower rate of opioid dispensing and pain-related hospital events among some adults receiving treatment for newly diagnosed cancer according to an analysis by US researchers.
Pain is an extremely common cancer symptom with a 2022 meta-analysis of 12 studies (10 with breast cancer and 2 lung cancer) patients, finding a pooled pain prevalence rate of 40%. Although paracetamol and non-steroidal anti-inflammatory drugs are universally accepted as part of the treatment of cancer pain at any stage of the WHO analgesic ladder, strong opioids are the mainstay of analgesic therapy in treating moderate to severe cancer-related pain. Nevertheless, with tightened regulations leading to a decrease in opioid prescribing across the United States, evidence points to a decline in opioid use among end-of-life care in those with cancer although there has been a rise in pain-related emergency department visits, suggesting that end of life cancer pain management may be worsening. Although medical marijuana has been studied and found to be efficacious for relief of pain in patients with advanced cancer pain not fully relieved by strong opioids, a 2016 review suggested that while marijuana may have the potential for refractory cancer pain, much of the data are based on animal data, small trials, or are outdated.
With the potential to help patients with cancer pain, in the current study, US researchers set out to assess the associations between medical marijuana legalisation and opioid-related and pain-related outcomes for adult patients receiving cancer treatment. The team used data from national commercial claims between 2012 to 2017. The researchers assessed several measures including the proportion of patients having 1 or more days of opioids and 1 or more pain-related emergency department visits or hospital events, during the 6 months after a new cancer diagnosis.
Medical marijuana and opiate use
A total of 38,189 patients with newly diagnosed breast cancer, 12,816 with colorectal cancer (55.4% male) and 7,190 (51.1% female) with lung cancer were included in the analysis.
Medical marijuana legalisation was associated with a reduction in the rate of 1 or more opioid days from 90.1% to 84.4% (difference = 5.6, 95% CI 2.2 – 9.0, p = 0.01) among breast cancer patients. For colorectal cancer patients, there was also a reduction, this time from 89.4% to 84.4% (difference = 4.9, 95% CI 0.5 – 9.4, p = 0.03). Finally, opioid use reduced from 31.5% to 22.1% (difference = 9.4, 95% CI 0.8 – 17.9, p = 0.03) among patients with lung cancer with recent opioids.
Medical marijuana legalisation was also associated with a reduction in the rate of 1 or more pain-related hospital events from 19.3% to 13.0% (difference = 6.3, 95% CI 0.70 – 12.0, p = 0.03) among patients with lung cancer with recent opioids. However, the difference for the other two forms of cancer was not significant.
The authors concluded that medical marijuana legalisation was associated with a lower rate of opioid dispensing and pain-related hospital events among some adults receiving treatment for newly diagnosed cancer.
Bao Y et al. Medical Marijuana Legalization and Opioid- and Pain-Related Outcomes Among Patients Newly Diagnosed With Cancer Receiving Anticancer Treatment. JAMA Oncol 2022
23rd September 2022
The exposure to particulate matter derived from air pollution represents a mechanism through which lung cancer can develop among individuals who have never smoked according to the findings of research presented at the European Society for Medical Oncology (ESMO) Congress 2022 by scientists of the Francis Crick Institute and University College London.
Globally in 2020 there were an estimated 2.21 million cases of lung cancer and 1.80 million deaths. There are two primary forms of lung cancer, small cell lung cancer and non-small cell lung cancer (NSCLC) with this latter form accounting for approximately 84% of all cases. It has been recognised for several years that particulate matter in outdoor air pollution with a size of at least 2.5 micrometers, leads to an 18% higher risk of lung cancer among those who had never smoked. However, the mechanisms driving this increased risk among those who do not smoke has remained unclear.
In the study presented at the ESMO congress, researchers focused on lung cancers due to a mutation in the epidermal growth factor receptor (EGFR), which is a transmembrane receptor tyrosine kinase protein, expressed in some normal epithelial, mesenchymal, and neurogenic tissue. Moreover, research suggests that EGFR protein expression is a risk factor in patients with NSCLC. Using normal lung tissue samples from humans and mice, the team investigated the consequences of increasing 2.5um particulate matter (PM2.5) concentrations with cancer risk.
Particulate matter exposure and cancer risk
Samples were analysed from 463,679 individuals and the team found that increasing PM2.5 levels were associated with a greater risk for EGFR mutated NSCLC samples from England, South Korea and Taiwan. This was also associated with an increased risk of mesothelioma (hazard ratio, HR = 1.19), lung (HR = 1.16), anal (HR = 1.23), small intestine (HR=1.30), glioblastoma (HR=1.19), lip, oral cavity and pharynx (HR = 1.15) and laryngeal carcinomas (HR = 1.26) in UK Biobank samples, for each 1 ug/m3 PM2.5 increment.
A further interesting finding was the presence of EGFR driver mutations in 18% of normal lung samples and a further mutation (KRAS) in 33% of samples. The team also showed that PM promoted a macrophage response and a progenitor-like state in lung epithelium harbouring mutant EGFR. Consistent with particulate matter promoting NSCLC in at-risk epithelium harbouring driver mutations, PM increased tumour burden in three EGFR or KRAS driven lung cancer models in a dose-dependent manner.
In a press release discussing their findings, Charles Swanton who presented the findings at ESMO, said ‘We found that driver mutations in EGFR and KRAS genes, commonly found in lung cancers, are actually present in normal lung tissue and are a likely consequence of ageing. In our research, these mutations alone only weakly potentiated cancer in laboratory models. However, when lung cells with these mutations were exposed to air pollutants, we saw more cancers and these occurred more quickly than when lung cells with these mutations were not exposed to pollutants, suggesting that air pollution promotes the initiation of lung cancer in cells harbouring driver gene mutations. The next step is to discover why some lung cells with mutations become cancerous when exposed to pollutants while others don’t.‘
6th May 2022
The detection of emphysema via visual or quantitative assessment on a CT-scan has been found to be linked with a higher odds of developing lung cancer. This was the conclusion of a systematic review by researchers from the Departments of Epidemiology, Radiology and Pulmonary Diseases, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
The World Health Organization reported that in 2020 there were 2.21 million cases of lung cancer which resulted in 1.8 million deaths. A chest computer tomography (CT) scan enables quantification of the amount of emphysema present in the lungs and while some evidence suggests that emphysema on a CT scan is related to lung cancer in a high-risk population, other data indicates that no CT measures of emphysema have an independent association with lung cancer.
With some uncertainty over the association between the presence of emphysema seen on a CT scan and lung cancer, for the present study, the researchers decided to undertake a systematic review and meta-analysis to further probe this association. They searched all the major databases and included studies that specifically assessed the association between emphysema and the diagnosis of lung cancer based on histopathologic examination. The team defined visual emphysema as disrupted lung vasculature and parenchyma with low attenuation occupying any lung zone on the chest CT scan and quantitative emphysema as the percentage of total lung volume below a given Hounsfield unit threshold (-950 HU at full inspiration). They also sought to examine whether the severity of emphysema was associated with lung cancer and graded this as trace, mild, moderate/severe. The studies were stratified based on whether visual or quantitative assessments were used and the presence of confirmed lung cancer was the main outcome of interest expressed and expressed as an odds ratio, adjusted for age, gender and smoking status.
Emphysema and lung cancer risk
A total of 21 studies met the inclusion criteria with 3907 patients who had lung cancer and 103,175 controls.
The pooled odds ratio (OR) for lung cancer in the presence of emphysema was 2.3 (95% CI 2 – 2.6) in studies which employed visual assessment and 2.2 (95% CI 1.8 – 2.8) where the authors used quantitative assessment.
When stratified by disease severity, the overall pooled OR for lung cancer increased with disease severity although there were differences based on whether the data was acquired by visual or quantitative assessment. For example, in studies that employed visual assessment, the ORs for lung cancer were 2.5 (trace disease), 3.7 (mild disease) and 4.5 (moderate to severe disease). While these odds ratios were still elevated based on quantitative assessments, the magnitudes were slightly lower e.g., 1.9 for trace disease and 2.5 (moderate to severe disease).
Based on their findings, the author concluded that the presence of emphysema diagnosed on a chest CT scan was independently associated with a higher odds of developing lung cancer.
Yang X et al. Association between Chest CT–defined Emphysema and Lung Cancer: A Systematic Review and Meta-Analysis Radiology 2022
20th January 2022
Smoking cessation at the time of a lung cancer diagnosis is linked to an improved survival from both non-small and small cell lung cancer, according to the findings of a systematic review by a team from the Institute for Cancer Research, Prevention and Clinical Network, Florence, Italy
Data from the World Health Organization shows that in 2020, globally, there were 2.21 million cases of lung cancer and which led to 1.8 million deaths. In addition, lung cancer has a poor prognosis and Cancer Research UK suggests that only around 15% of those with lung cancer will survive for 5 years or more after diagnosis. Cigarette smoking is a major factor in the development of lung cancer, with one analysis of the burden of respiratory tract cancers indicating that smoking contributed to an estimated 64·2% of all deaths from tracheal, bronchus, and lung cancer and 63·4% of all deaths from larynx cancer in 2019.
Although one study with 517 smokers, found that smoking cessation at the time of a lung cancer diagnosis can reduce the risk of future lung cancer, for the present study, the Italian team sought to provide a more robust estimate of the overall prognostic value of smoking cessation at or around the time of a lung cancer diagnosis. They searched for articles which included those who continued to smoke and those who quit in relation to their cancer diagnosis and the associated changes in survival. The team calculated relative risks for the association between smoking cessation and the survival from lung cancer.
A total of 21 studies were included in the systematic review with patients diagnosed with non-small cell lung cancer (10 studies, 5315 patients) and small cell lung cancer (5 studies, 1133 patients), together with a further six studies of both cancer subtypes or where the subtype was not specified. The mean age of lung cancer diagnosis across the studies ranged from 60 to 70 years and the proportion of men ranged from 40.2% to 91.8%. The duration of follow-up also ranged from 12 months to 27.7 years.
Smoking cessation at or around the time of diagnosis was associated with a better overall survival regardless of lung cancer type. For smoking cessation at any time, compared to those who continued smoking (used as the reference group), the relative risk for non-small cell lung cancer was 0.77 (relative risk, RR = 0.77, 95% CI 0.66 – 0.90) and this reduction was broadly similar compared to those stopping strictly at or after their diagnosis or up to 12 months before the diagnosis. For small cell lung cancer, overall survival was also broadly similar (RR = 0.75, 95% CI 0.57 – 0.99). Even in studies where the cancer subtype was not specified, there were survival benefits among quitters (RR = 0.81, 95% CI 0.68 – 0.96).
The authors calculated an overall benefit for those who undertook smoking cessation at or around the time of their lung cancer diagnosis, finding that such individuals had a 29% improvement in their overall survival compared to those who continued to smoke (RR = 0.71, 95% CI 0.64 – 80).
The authors concluded that advice to quit smoking at or around the time of a lung cancer diagnosis, should arguably become a non-optional part of the management of these patients.
Caini S et al. Quitting smoking at or around diagnosis improves the overall survival of lung cancer patients: a systematic review and meta-analysis J Thorac Oncol 2022
20th September 2021
According to Cancer Research UK, there are around 47,800 new lung cancer cases each year and approximately 35,100 deaths, which equates to 96 deaths every day. Furthermore, Cancer Research UK estimates that 79% of lung cancer cases in the UK are preventable with 72% caused by smoking. With such a high incidence of not only cases, but more importantly, preventable cases, there is an urgent need for effective screening methods, especially among individuals who are deemed at high risk such as smokers. In a 1999 study, a low computed-tomography (CT scan) was shown to greatly improve the likelihood of detecting small, non-calcified nodules and hence lung cancer, at an earlier and hence more curable stage. Moreover, subsequent studies have also demonstrated a reduction in lung cancer mortality among those undergoing a low dose CT scan.
With the value of CT screening already firmly established, a UK-based team have published their own findings of a trial comparing the effect of a low dose CT scan compared to usual care, in high-risk patients. The UK lung cancer screening (UKLS) trial, randomised patients to low dose CT screening or usual care, i.e., with no CT scan and was undertaken at two thoracic hospitals in the UK. Eligible patients, aged 50 to 75 years, were those deemed to be at a high risk of developing lung cancer over the next 5 years defined by a risk score of at least 4.5% based on the Liverpool Lung Project risk model (LLPv2). This model includes several possible risk factors such as gender, age, smoking status, smoking duration, family history of lung cancer. Included patients were then randomised to the intervention group (CT scan) or usual care although given the nature of the intervention, blinding was not possible. The primary outcome was mortality due to lung cancer, defined as a death during the follow-up period where lung cancer was listed as an underlying cause. In an effort to provide further evidence, the researchers also undertook a meta-analysis of other recent trials and included their own data, to get a more robust estimate of the benefits of CT scanning.
A total of 1987 and 1981 individuals were randomised to the CT scan and control arm respectively and followed for a median of 7.3 years. The median age at consent was 68 years (25% female) and among the CT scan group, 38% were current smokers, of whom, 93% had smoked for more than 20 years. During the follow-up period, 76 lung cancers were detected, 30 in the CT scan arm and 46 in the control arm although this difference was not significant (relative risk, RR = 0.65, 96% CI 0.41 – 1.02, p = 0.062). Furthermore, there were no significant differences between the sexes. In addition, there were 512 deaths from any cause and again there was no significant difference between the groups (p = 0.315).
When these results were added to a meta-analysis of 9 randomised, controlled trials, low dose CT scan screening was associated with a 16% relative reduction in lung cancer mortality compared with no screening (RR = 0.84, 95% CI 0.76 – 0.92).
The authors concluded that while their trial had not demonstrated a statistically significant reduction in lung cancer mortality, when their data was combined with other studies, the pooled estimate was significant and provided further support for lung cancer screening via a low dose CT scan.
Field JK et al. Lung cancer mortality reduction by LDCT screening: UKLS randomised trial results and international meta-analysis. Lancet Regional health Europe 2021