Lung Cancer Screen Test

Not directly, but it can detect the body's response to it. When a lung cancer starts to grow, the immune system often produces autoantibodies against proteins on the tumour cells, and these can be measured in blood months or even years before a tumour is large enough to cause symptoms or show clearly on a scan. EarlyCDT Lung measures seven of these autoantibodies. A High result does not mean you have lung cancer; it means your risk is raised enough to justify a CT scan. A Low result lowers your risk but does not rule cancer out. No blood test finds every lung cancer.

You cannot diagnose lung cancer at home, and there is no reliable self-check; the '5 finger test' and similar are not evidence-based. What you can do at home is a risk assessment: know the symptoms, and if you are a current or former smoker, take an autoantibody blood test such as EarlyCDT Lung with a finger-prick kit, which flags people whose immune response suggests they should have a CT scan. Symptoms that need a GP now, not a home test: a cough lasting more than three weeks, coughing blood, breathlessness, chest pain, repeated chest infections, hoarseness or unexplained weight loss.

The kit is posted to you with lancets, a collection tube and a prepaid return envelope. You take a few drops of blood from a fingertip, post the sample back, and the laboratory measures the level of each of seven autoantibodies, reporting each as no significant level, moderate or high, and then an overall result of Low, Moderate or High. That result is combined with your pre-test risk, based on age and smoking history, to give your personal post-test risk of lung cancer and a recommendation on whether a CT scan is warranted.

People aged 50 and over who have smoked the equivalent of a pack a day for 20 years, and people aged 45 to 49 at increased risk: current or former smokers, those exposed to second-hand smoke, radon gas, asbestos or radiation, and those with a family history of lung cancer. It is also used to help assess small lung nodules found on a scan that are too small to biopsy. It is not intended for never-smokers with no risk factors, or for anyone with symptoms, who should see a GP.

The test is designed to be highly specific: in the published studies, a negative result has a negative predictive value of around 99.3 percent in the intended population, meaning very few people with a Low result go on to have lung cancer in the following period. Its sensitivity is lower, around 40 percent, so it catches a meaningful proportion of early cancers but not all; that is why it is offered as a risk assessment alongside, not instead of, CT screening. In the large Scottish ECLS trial, people screened with EarlyCDT Lung were more likely to have their cancer found at an early, treatable stage.

A High result means one or more autoantibodies are significantly raised and your post-test risk of lung cancer is well above the level at which a low-dose CT scan is recommended; your report says so and you should take it to your GP for referral, or arrange a CT scan privately. A Moderate result means your risk is raised and a scan should be discussed. A Low result means no significant autoantibody response was found; your risk is lowered but you should still report any symptoms and, if eligible, take up NHS lung screening.

The NHS Targeted Lung Health Check programme offers people aged 55 to 74 who smoke or used to smoke a low-dose CT scan, by invitation, in areas where it has been rolled out. CT scans find nodules directly, but many are too small to act on and lead to years of repeat scanning. EarlyCDT Lung is a blood test that can be taken by anyone at risk from 45, without waiting to be invited, and is also used to help decide which small nodules need a biopsy. If you are eligible for the NHS programme, take it up; this test adds to it rather than replacing it.

The seven autoantibodies measured by EarlyCDT Lung are against the proteins p53, NY-ESO-1, CAGE, GBU4-5, HuD, MAGE A4 and SOX2, each of which is produced abnormally by lung cancer cells and provokes an immune response. There is no single protein marker for lung cancer in the way PSA is for the prostate, which is why a panel of immune markers is used.

Smoking history is by far the biggest risk factor, responsible for around seven in ten lung cancers in the UK; risk rises with the number of years and cigarettes per day and falls slowly after quitting but never returns to a never-smoker's level. The most common presenting symptom is a persistent cough, followed by breathlessness, chest pain, coughing up blood and unexplained weight loss. Any of these lasting more than three weeks should be seen by a GP.

The EarlyCDT Lung blood test is £340 at Goodbody Clinic, including the home kit, return postage and laboratory analysis. A private low-dose CT scan of the chest typically costs £300 to £600 and can be arranged if your result recommends it. The NHS lung health check is free for those invited.

Results are emailed within 14 working days of your sample reaching the laboratory, as a report showing each autoantibody level, your overall Low, Moderate or High result and your post-test risk, with a recommendation on next steps.

Take the report to your GP, who can refer you for a CT scan on the NHS, or arrange a private low-dose CT scan; our team can advise on options. Most people with a High result do not have lung cancer, but the scan is the way to find out, and when lung cancer is found at its earliest stage the five-year survival rate is very high compared with late diagnosis.