Journals Watch - Colorectal cancer and COPD

Pre-diagnostic NSAID use and survival after diagnosis of colorectal cancer
Gut 2010; doi:10.1136/gut.2010.221143

While evidence has shown that NSAIDs reduce the incidence of colorectal cancer and adenoma recurrence in patients with prior colorectal neoplasia, the influence of NSAIDs on survival is not well documented.

This US follow-up study looked at colorectal cancer patients aged between 20 and 74 years. The main outcome measure was death due to colorectal cancer after diagnosis.

NSAID use prior to diagnosis of cancer was found to reduce mortality by approximately 20 per cent compared with those who had never used NSAIDs.

The lowest rates were seen in patients with the longest duration of NSAID use, particularly in proximal bowel cancer. NSAID use conferred no mortality benefit in distal or rectal disease.

Bitter taste receptors associated with bronchodilation in asthma
Nat Med 2010; 16(11): 1299-304

Asthma poses a significant health burden in the UK. There are more than 1,000 deaths per year in England and Wales attributable, in part, to smoking and poor adherence to medication. There are, however, a number of patients with severe disease in whom standard treatments are modest in their efficacy.

This study described the presence of bitter taste receptors on airway smooth muscle (ASM). While these receptors, described as TAS2Rs, prevent the ingestion of toxic substances, it has been postulated that they cause contraction of ASM to prevent the inhalation of toxic inhaled substances.

Interestingly, however, the researchers found a relaxation of ASM that was up to three times more potent than that elicited by beta-agonists when exposed to bitter substances.

This research may pave the way for a class of bronchodilator, perhaps revolutionising the management of asthma.

Clopidogrel with or without omeprazole in coronary artery disease
N Engl J Med 2010; 363: 1,909-17

Recent studies have indicated that PPIs reduce the efficacy of clopidogrel and increase the risk of MI in patients relying on this as an antiplatelet agent.

This study looked at the interaction between omeprazole and clopidogrel by randomising patients on aspirin and clopidogrel to take either omeprazole or placebo.

Clinical endpoints looked at adverse outcomes in both the gastrointestinal and cardiovascular systems.

A total of 3,761 patients were included in the analysis.

Omeprazole reduced adverse gastrointestinal outcomes from 2.9 per cent to 1.1 per cent at 180 days. Adverse cardiovascular outcomes were not significantly higher in the omeprazole group.

Population and primary healthcare factors and hospital admission rates for COPD
Thorax 2010; doi:10.1136/thx.2010.147058

Given the economic climate, there has been a huge drive to reduce unplanned hospital admissions in patients with chronic diseases.

COPD admissions have been reduced by around 20 per cent in Buckinghamshire due to an effort by the local collaborative. This national cross sectional study looked at population-related factors in England that may influence COPD admission.

COPD admission rates varied widely across PCTs, between 124.7 and 646.5 per 100,000.

There was a strong association between admission and deprivation and smoking whereas access to primary care, influenza vaccinations and adequate staffing in primary care were considered protective.

Long-term effect of aspirin on colorectal cancer incidence and mortality
Lancet 2010; doi:10.1016/S01406736(10)61543-7

With more than 100 people diagnosed with colorectal cancer each day, efforts to diagnose early and reduce mortality are high.

While aspirin at high doses has been shown to reduce mortality in these patients, the risk of adverse gastrointestinal events limits its use.

This study analysed data from a number of trials and specifically looked at the effect of low-dose aspirin on colorectal cancer.

Aspirin taken for five years or longer reduced the 20-year risk of proximal disease by around 70 per cent. Rectal disease was also reduced if aspirin was taken for a sufficient period.

The effect of aspirin and a PPI on colorectal cancer mortality may be required to make this data meaningful on a population basis.

Monoclonal antibody targeting of N-cadherin and prostate cancer
Nat Med 2010; doi:10.1038/nm.2236

Prostate cancer can become resistant to hormonal therapy heralding a progression in disease. The goal would be to prevent transition to castration-resistant disease and hence reduce cancer growth and metastasis.

The researchers in this study looked at gene expression of N-cadherin, which was found to be higher in castration-resistant and metastatic disease.

Monoclonal antibodies against N-cadherin were then studied, and were shown to reduce local invasion of disease, progression to castration-resistant disease, metastatic disease and, when used at higher doses, complete disease regression was demonstrated.

• Dr Thakkar is a GP in Wooburn Green, Buckinghamshire, and a member of our team who regularly review journals