Screening smokers and ex-smokers could dramatically reduce deaths from lung cancer – Britain’s biggest cancer killer – a major new study has found.

Low-dose computerised tomography (CT) scans can detect tumours in people’s lungs early and cut deaths by 16%, according to the UK Lung Cancer Screening Trial (UKLS).

The findings have prompted renewed calls from lung cancer experts for the government to bring in routine screening across the UK of all those who are at risk because of their smoking history. They say that early detection means patients can have potentially curative surgery or radiotherapy.

“Lung cancer early detection and surgical intervention saves lives,” said Professor John Field of Liverpool University, an author of the trial. The results are being presented at a major conference on the disease and published in the journal Lancet Regional Health Europe.

About 47,000 Britons a year are diagnosed with lung cancer, and 35,000 die of the disease. It kills more men than prostate cancer and more women than breast cancer. Only a quarter of lung cancers are found when they are at stages one or two – when treatment may keep someone alive.

The UKLS trial involved 3,968 people in Liverpool and Cambridge aged between 50 and 75. All had been identified as being at risk of developing lung cancer over the next five years. Between October 2011 and February 2013, just over half (1,987) had a CT scan, while the others (1,981) received normal NHS care but were not scanned. All were followed up for seven years.

Eighty-six cancers were detected over that period among those who were screened but fewer – 75 – over those seven years among those who had received normal care.

Significantly, while there were 46 deaths over those seven years among those who had not had a CT scan, many fewer occurred – 30 – in the group that had been screened.

Dr Robert Rintoul, the chair of the UK Lung Cancer Coalition’s clinical advisory group and a co-author of the study, said the findings underlined that “national lung cancer screening programmes are urgently needed.

“In the UK, only one-quarter of new cases of lung cancer are caught at an early stage when treatment with curative intent can be offered. By contrast, around 75% of lung cancers identified through CT screening studies are early stage, and can be treated by surgical removal or radiotherapy.”.

The study is the latest to show that CT screening spots lung tumours early. The results are being sent to the UK National Screening Committee, which advises ministers. Professor Anne Mackie, Public Health England’s director of screening, said the findings would inform the committee’s ongoing discussions into whether to recommend screening of at-risk groups.

NHS England is meanwhile undertaking trials of lung cancer CT screening in various parts of the country.