A "practice-changing" pill can cut the risk of dying from lung cancer by half, research has shown.
Taking the drug osimertinib after surgery dramatically reduced the risk of dying by 51%, according to the findings of an international study.
Lung cancer is one of the most common forms of cancer, with more than than 43,000 people diagnosed in the UK every year.
Osimertinib, which is taken once a day, targets non-small cell lung cancer (NSCLC) where the tumour has been completely removed by surgery.
The latest findings were presented at an American Society of Clinical Oncology (ASCO) meeting in Chicago on Sunday.
Dr Roy Herbst, lead author of the study and deputy director of Yale Cancer Center, hailed the survival benefit as "thrilling".
He told the conference: "Thirty years ago there was nothing we could do for these patients, even 20 years ago.
"Now we have this potent drug, we're using it early on. This exceeded our high expectations.
"Fifty per cent is a big deal in any disease, but certainly in a disease like lung cancer which has typically been very resistant to therapies."
The Adaura trial was conducted in 26 different countries across Europe, the Asia-Pacific, North America, and South America.
It involved patients aged between 30 and 86 years, with an average age of 64 years in the osimertinib group and 62 years in the placebo group.
All patients had a mutation of the EGFR gene, which is found in around a quarter of lung cancer cases worldwide.
Dr Herbst described the results as "practice-changing", saying they instill confidence that osimertinib will become the "standard of care" for lung cancer patients with the EGFR mutation.
Nathan Pennell, an ASCO expert, added: "We have been using one-size-fits-all adjuvant chemotherapy for every patient with lung cancer despite a decade of advances in targeted treatments for select groups of patients that result in dramatically better outcomes.
"In a first for the lung cancer field, adjuvant osimertinib unequivocally improves survival in people with resected EGFR-mutated non-small cell lung cancer.
"This should be the new standard of care for these patients."
Osimertinib, which is made by AstraZeneca, is also currently being evaluated in other stages of NSCLC, including before surgery.
It was approved in the US by the Food and Drug Administration (FDA) for early stages in December 2020.
Dave Fredrickson, Executive Vice President at the Oncology Business Unit, said at the time: “We know the earlier a patient’s cancer is detected and treated, the greater chance they may have of being cured, which is why this approval is significant.
"For the first time, patients in the EU with EGFR-mutated lung cancer have a targeted, biomarker-driven treatment option available in the early stages of their disease that can help them live cancer-free longer."
The drug could become routinely used on the NHS if it receives NICE approval.
