A new taskforce will meet next week to kick-start the recovery of cancer services across the NHS in England.
Charities believe the pandemic has led to a significant reduction in people being referred for urgent cancer treatment.
Cancer Research UK says three million people have missed cancer screenings since March.
The taskforce aims to investigate how to ensure more people are referred, tested and checked.
At Liverpool's new Clatterbridge cancer centre, which opened in June, treatment is up and running. The coronavirus meant face-to-face contacts with patients like Ian Crompton were greatly reduced.
Ian has previously been treated for prostate cancer, which meant he had to self-isolate throughout lockdown. Now he needs a scan to make sure all is well.
So his first appointment actually meeting staff has come as something of a relief.
"With being in isolation, in lockdown, you felt alone," Ian says.
"I find consultations face to face a lot better because you can ask questions.
"On the phone, there's no eye contact, which I find unusual."
Services are now starting to come back up to speed, but there is a significant backlog of patients who need treatment.
It's also estimated that around 350,000 fewer patients than normal have been referred for an urgent cancer investigation.
Media playback is unsupported on your deviceMedia caption Hatti Gayner, 28, described a lump she'd found in her breast to a GP over the phone
Hatti Gayner is a dancer and performer, who appeared with her group on BBC TV's The Greatest Dancer earlier this year.
A lively and chatty Geordie, the 28-year-old is now undergoing treatment for breast cancer.
She's being supported by the Trekstock charity, which helps younger people who have been diagnosed with cancer.
Towards the end of lockdown she found a lump in her breast, but she had to make do with a telephone consultation with her GP.
Initially she was told it might be an abscess or a cyst and was prescribed antibiotics.
But her mum told her to push for a face-to-face consultation - and when that happened, it became clear it was much more serious.
"I'm a young girl, 28. I'm not a hypochondriac, I don't just phone up about nothing," she says.
"I know they don't know that, necessarily, but I think I should have been seen and I think I should have been examined."
Infection control and social distancing mean it now takes longer to treat people safely, and there are concerns about how much capacity there is to reduce the backlog of patients.
NHS England says that between March and July of this year, more than 207,000 people started cancer treatment.
That's around 85% of the number the NHS in England treated in the same period in 2019.
Meanwhile a taskforce, involving all the main cancer charities and organisations such as the Royal College of GPs, will start work next week.
The body, led by Prof Peter Johnson, national clinical director for cancer in England, aims to ensure more people are checked and tested.
"People have been staying away because they didn't want to put pressure on the NHS when it was busy coping with a huge number of people with the coronavirus," he said.
"We're very keen that they should come back, and if anybody's worried about symptoms, they should come forward now.
"We are working to try and match the capacity that we have got, whether it's across the NHS or in the independent sector, to the demand that we can see coming through," Prof Johnson said.
"And we're expecting during September and October that we're probably going to see more than the usual number of people as we catch up."