In the year to March 2018, the proportion of cancer patients who first presented at hospital as an emergency fell to 18.8% - down from 21% in the year to December 2012.
Over roughly the same period, cancers detected at an early stage increased significantly - rising from 46% in 2013 to 52% by mid-2017, according to figures from the National Cancer Intelligence Network (NCIN).
Hampshire GP Dr Richard Roope - clinical champion for cancer for the RCGP and charity Cancer Research UK - told GPonline: 'General practice is delivering remarkable outcomes considering the stressed and strained place it is in.'
Dr Roope, who highlighted the NCIN figures at this month's RCGP conference, said the outlook for patients diagnosed with cancer was now 'the best it has ever been'. He added: 'That is a reflection of hard work across the whole cancer treatment and diagnosis pathway. GPs can take a lot of credit.'
The cancer specialist GP said it was important for general practice to hear the positive news about the impact of its work 'after another tough year'.
He backed the government's recent pledges to improve cancer care - pointing to commitments from prime minister Theresa May in her recent party conference speech.
But he said there was room for improvement - warning that GPs need better access to key diagnostic tools for cancer, and calling for the rollout of 'smart referral pathways' to limit administrative workload and speed up management of patients.
GPs are 'the doorway through which patients make their way into the cancer diagnosis and treatment pathway', he said. Good patient outcomes depend on patients identifying that symptoms are worth talking to their doctor about and doctors picking up on symptoms that could point to underlying cancer.
'Patients need to be on the ball, and GPs need to be on the ball - if you get those, you hugely increase chances of a good outcome,' said Dr Roope.
The 'Be Clear on Cancer' campaign had helped boost patients' awareness of symptoms, and NICE's decision to lower the referral threshold for possible cancer symptoms in 2015 had helped GPs to identify more cases, he said.
Dr Roope said more work was needed to emphasise to GPs how cancer affects their patient population. He highlighed the low number of QOF points for cancer targets as a factor that could draw GPs' attention elsewhere - but warned: 'Cancer is by far and away the biggest cause of premature death in the UK.'
A live poll at the RCGP conference showed that less than half of the audience realised cancer was the top cause of premature death, he added.
Dr Roope hit out at cuts to public health services, warning that reductions in smoking cessation services were among 'the biggest travesties in the wider health system'.
He urged GPs to consider 'brief advice' to help patients engage with lifestyle modification that could have a major impact on factors that cause cancer, such as smoking, alcohol use and obesity.
GPonline reported earlier this year on research showing that GPs were as good as consultants at making appropriate use of cancer diagnostic tests - and yet pledges to give GPs direct access to four key diagnostic tests - blood tests, chest X-ray, ultrasound and endoscopy - have not been delivered in many areas.
Dr Roope said 'a minority' of GPs currently had access to all four tests. He called for wider use of smart referral pathways and wider rollout of multispecialty referral centres - clinics that could offer a place for GPs to send patients with so-called 'vague' symptoms, such as weight loss or abdominal pain - to avoid multiple referrals to individual hospital departments for patients with suspected cancer.