People who have annual chest radiography screening do not have a significantly lower rate of death from lung cancer compared with people who aren't screened, a US study has suggested.

Dr Martin Oken, of the University of Minnesota, and colleagues examined data from the large Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Published in the journal JAMA, the study looked at people who were either given annual chest x-rays - known as chest radiography - or standard medical care without screening.

In the randomised controlled trial of 154,901 participants aged 55-74, around half (77,445) were offered an annual chest radiograph over a four-year period, while the remaining 77,456 received standard care.

There were 1,696 lung cancers detected in the annual chest radiograph group and 1,620 lung cancers in the control group during the entire 13-year study period.

1,213 lung cancer deaths were observed in the former group over the 13-year follow-up period, compared with 1,230 in the latter.

In conclusion, the authors wrote: "These findings provide good evidence that there is not a substantial lung cancer mortality benefit from lung cancer screening with four annual chest radiographs."

In an accompanying editorial, Professor Harold C Sox of Dartmouth Medical School wrote that the study "provides convincing evidence that lung cancer screening with chest radiography is not effective".

Professor Sox described the PLCO trial as "another important step, confirming expectations rather than setting new ones".

Hazel Nunn, head of evidence and health information at Cancer Research UK, agreed: "This study is important because it strongly suggests chest x-rays are not effective at screening healthy people for the early signs of lung cancer.

"Earlier this year, a different study called the National Lung Screening Trial showed that early detection of lung cancer with a screening method called spiral CT can reduce the risk of dying from the disease. But it compared spiral CT against chest x-rays, not against people who hadn't been screened.

"The next step is to see if spiral CT lowers deaths from lung cancer when compared to no screening. There are considerable risks associated with the investigations that follow a positive screening result, so it will also be vital to continue research to help better understand these harms."

Source: CRUK