Lung cancer screening

Lung cancer is the highest single cause of cancer deaths in men and women worldwide. Recently the government has introduced an awareness campaign – Be Clear on Cancer, encouraging patients to seek medical attention when symptoms suggestive of cancer develop. Unfortunately, by the time symptoms do develop, many patients are already in the advanced stages of the disease.  Treatment options in this setting tend to be more limited and patients have poorer outcomes.

Why should we screen?

An interesting paradigm in lung cancer management is that we are not always able to quantify the benefits for a number of the “standard” treatment options that we offer.  For example, we do not know what the magnitude of benefit of surgery might be in comparison to equally fit patients who do not choose surgery. In 2011, an intervention was identified as having a 20% reduction in 5 year lung cancer related death in a large scale multi-centre US randomised trial with over 53,000 participants – the intervention was low dose CT screening. The data generated a lot of excitement as it was the largest randomised trial to date on this subject with a significant quantifiable benefit.

As a result, many US professional organisations including the American Society of Clinical Oncology, American Thoracic Society, American College of Chest Physicians and the American Association of Thoracic Surgeons all recommend CT screening with an aim to diagnose lung cancer in an earlier stage when interventions is most successful.

Who should we screen?

Currently, most US and European guidelines recommend that we offer lung cancer screening to patients who are at risk of developing lung cancer, and this cohort as defined by the large US randomised trial as patients more than 55 years old with more than a 30 pack years history of smoking. It is this group that is expected to derive the full benefit of CT screening.

How do we screen?

One important take home message is that screening is not simply performing a CT scan, and certainly many authorities (International Association of the Study of Lung Cancer and the European Society of Medical Oncology) recommend that individual doctor do not offer CT screening. Rather, it should be performed in a dedicated programme led by a multi-disciplinary group with specific expertise in lung cancer.

At the BUPA Cromwell Hospital in London, lung cancer screening is offered by the highly qualified multidisciplinary team at the Lung Centre. Screening starts with lung function testing, counselling on the benefits and risks, patient specific risk modelling followed by a low-dose CT scan on a dedicated protocol designed to minimise radiation. It is estimated that 1 in 4 patients will have an abnormal results that would require further assessment, and appropriate referrals would be undertaken. For the remaining patients the negative results is conveyed on the same visit for reassurance. The results are also presented, reviewed and discussed with the entire multidisciplinary team.

Screening is not undertaken as a single visit but as a yearly event. Currently experts have not yet agreed on the optimal length of time required for screening because lung cancer risk increases with age, most recommendation yearly screening up to the age of 75 or as long as the patient remains a candidate for definitive therapy.

What are the risks of screening?

Unfortunately, few interventions in medicine exist without accompanying risks. With regards to lung cancer screening, risks principally relate to cumulative yearly exposure to radiation and the complications associated with biopsy. For the former, the actual risks of a small amount of annual radiation exposure are unknown, and experts estimate through theoretical modelling that 1 in 2500 patients screened may experience a cancer related death as a result of the radiation exposure.  Complications from biopsies are rare but may include bleeding, collapsed lung and even death (less than 1%).

Summary

The vast majority of patients with lung cancer present very late in the disease and outcomes in general are poor. Lung cancer screening has the potential to reduce lung cancer related death by 20% over 5 years, and is best undertaken through a dedicated undertaken programme with an expert multidisciplinary team.

If you would like to make an appointment to discuss lung cancer screening please visit contact me.