In this study, participants aged 55-74 years old, who had history of cigarette smoking >30 years or former smokers who had quit within 15 years were screened using low-dose CT (LDCT) or chest X-ray (CXR), yearly for three consecutive years.
Those who had yearly LDCT screening had higher number of lung cancer diagnosed when compared with screening using CXR only.
Conversely, the lung cancer specific mortality was 20% lower in the LDCT screening group.
Why patients who had LDCT screening live longer?
- More lung cancers diagnosed at earlier stage (stage 1: 50% vs 31%) and
- Lesser patients diagnosed at later stage (stage 3&4: 43% vs 61%).
What should I do?
If one is to read the study in more detail, the absolute risk reduction for lung cancer specific mortality was just 3 in 1000 or the number needed to screen to prevent one lung cancer specific death is 330 (1/0.003).
For the government, it’s just not cost-effective to implement LDCT due to the large number of patients needed to be screened just to prevent one lung cancer specific death.
However, if you fall into the above risk group and you can afford to pay for your own LDCT screening, you should get it done…yesterday. Ha3.
Else, in government setting, I always believe in sustainability and optimal utilisation of resources. I actually find X-ray very useful, quick and cheap when compared with other diagnostic modalities.
A simple chest X-ray will still be able to detect around 40% of early lung cancers (stage I & II)
There are active research being conducted using tumour auto-antibodies (TAA) and circulating tumor cells as complementary tools to improve early detection of lung cancer.
Tumour auto-antibodies had been found to be present even before the disease become symptomatic, with aim to detect patients with lung cancer more accurately at earlier stage.
Currently, there are using a panel of seven tumour auto-antibody and the results from their study was very impressive, with positive predictive value of 95%!