Around 3,500 lives may be lost to four common cancers over the next five years due to delays in diagnosis caused by Covid-19, experts have said.

A drop-off in the number of people seeing their GP with symptoms, and lower referrals for scans, could result in cancer being spotted too late, according to research published in The Lancet Oncology.

Even when people are referred to hospital, there are growing delays in accessing diagnostic services that could save lives, the study warned.

This combined effect means there must be a rapid ramping up of NHS diagnostics to prevent further avoidable deaths.

Our findings estimate a nearly 20% increase in avoidable bowel cancer deaths due to diagnostic delays

NHS figures show that 106,535 urgent cancer referrals were made by GPs in England in May 2020, down from 200,599 in May 2019 – a fall of 47%.

At the same time, 55,500 more people are now waiting to have key cancer tests in England’s hospitals compared with the same point last year.

For the new study, experts created estimates for deaths based on disruption to cancer services and people avoiding seeking help due to Covid-19.

They calculated there could be around 3,500 potentially avoidable deaths from breast, bowel, oesophageal and lung cancer over the next five years in England.

On average, for each avoidable cancer death due to diagnostic delay, 20 years of life will be lost, with a substantial proportion of deaths in younger or middle-aged people, they said.

Overall, breast cancer deaths could rise 8–10% (281 to 344 more deaths by 2025) and bowel cancer deaths by 15–17% (1,445 to 1,563), experts said.

There could also be a 5% (1,235 to 1,372) rise in lung cancer deaths, and a 6% (330 to 342) rise in deaths from oesophageal cancer over the next five years.

Dr Ajay Aggarwal, from the London School of Hygiene and Tropical Medicine in London, who led the research, said: “Our findings estimate a nearly 20% increase in avoidable bowel cancer deaths due to diagnostic delays.

“To prevent this becoming a reality, it is vital that more resources are made urgently available for endoscopy and colonoscopy services which are managing significant backlogs currently, and that patients present promptly to their GP if they have any concerning gastrointestinal symptoms.”

These estimates paint a sobering picture and reflect the many young people who are affected by cancer in the prime of life during their most productive years

Professor Richard Sullivan, from King’s College London, who also worked on the study, said: “On average, for each avoidable cancer death due to diagnostic delay, 20 years of life will be lost.

“These estimates paint a sobering picture and reflect the many young people who are affected by cancer in the prime of life during their most productive years.”

The authors warned the true death toll could be far higher once all types of cancer were factored in together with delays in treatment for those already diagnosed with cancer.

For a separate study in the same journal, the Institute of Cancer Research (ICR) examined data for 20 common cancers.

At present, anyone with suspected cancer is supposed to be seen by a specialist in hospital within two weeks of referral by their GP.

But the new ICR modelling looked at the impact of three different scenarios of lockdown-accumulated backlog – reflecting a 25%, 50% or 75% reduction in people coming forward with symptoms and receiving urgent GP referrals over a three-month lockdown period.

The data suggested that if all patients eventually sought help and were referred for scans or other tests promptly at the end of lockdown in mid-June, there could be between 181 and 542 excess deaths.

However, even more lives would be lost when delays in accessing scans and biopsies in a timely fashion are added to the totals.

While referrals to see a cancer specialist are starting to recover, we are still some way from this returning to normal

The ICR team estimated that a one month per patient delay in diagnosis just via the two-week GP referral pathway would result in 1,412 lives lost, while a six-month delay would result in 9,280 lives lost.

When it came to cancer type, the ICR said delays for suspected bladder, kidney and lung cancers would have the biggest impact on the number of lives lost.

Study leader Professor Clare Turnbull said: “It’s vital that we do everything we can to ensure cancer patients are not left further behind by the disruptions to care caused by the Covid-19 pandemic.

“That means ramping up capacity as quickly as possible to allow cancer diagnostic services to clear the backlog.”

Professor Paul Workman, chief executive of the ICR, said: “It has become clear that the Covid-19 pandemic is taking a heavy toll on people with cancer – by delaying their diagnosis, disrupting access to surgery and other aspects of care, and pausing vital research into new treatments.”

For breast cancer, the scientists modelled that if everyone diagnosed with breast cancer experienced a one-month delay due to the pandemic, this would result in up to 228 more breast cancer deaths.

A six-month delay for everyone could cause 1,629 extra deaths from breast cancer.

Baroness Delyth Morgan, chief executive at Breast Cancer Now, which helped fund the study, said: “Early diagnosis remains absolutely critical.

“While referrals to see a cancer specialist are starting to recover, we are still some way from this returning to normal.”

An NHS spokeswoman said: “Hospitals have successfully and quickly cared for patients urgently referred by their GP, with over 94% of cases being investigated within 14 days in May, and the key point remains that anyone with a possible symptom should come forward for a check-up.

“The NHS is taking urgent action to increase the number of tests carried out so that people are seen quickly and more than 65,000 people have started treatment for cancer during the pandemic.”