Out of a poll of 81 NHS hospital trusts, 43 postponed at least one cancer surgery between December and February, according to a survey by the Health Service Journal (HSJ).
Hospitals in England were told to delay pre-planned operations and routine outpatient appointments throughout January to help overcome severe winter pressures.
Yet NHS England stressed cancer operations and time-critical procedures should go ahead as planned.
Delays in cancer-patient procedures could affect people's survival prospects, Macmillan Cancer Support warns.
Last Tuesday, Cambridge University Hospitals announced non-emergency operations have been temporarily cancelled due to a large influx of emergency cases.
NHS trusts in England were forced to cancel hundreds of cancer operations last winter (stock)
HOW HOSPITALS TACKLED THE CRISIS
- Non-urgent operations and hospital appointments scheduled for January were postponed.
- Cancer operations and time-critical procedures went ahead as planned.
- Hospitals contacted patients to tell them if their appointments were cancelled.
MIXED SEX WARDS
- NHS rules banning mixed sex wards were temporarily lifted to help hospitals use all available beds.
- Usually hospitals are fined £250 every night that a patient has to stay in a mixed ward, however, this was waived.
- Patients could request a move if they had strong objections.
DOCTORS ON THE DOORS
- Consultants whose appointments were cancelled were expected to pitch in by manning the doors of A&E.
- Patients could be questioned by doctors as soon as they arrived at hospital.
- The patients were then told to wait for a full examination, be seen immediately or be given advice and sent home.
At least 500 cancer operations cancelled last winter
Result suggest NHS trusts cancelled at least 500 cancer operations during the winter period.
This figure does not include certain diagnostic procedures, such as biopsies.
Fran Woodard, executive director of policy and impact at Macmillan Cancer Support, told HSJ: 'Depending on the type of operation, a delay could mean that the cancer not only progresses in that time but that the chances of survival are also affected.'
Yet, an NHS England spokeswoman argued: 'Actually, despite all the pressures from flu and norovirus, NHS hospitals treated 2,615 more cancer patients this January than last January - that's 5.7 per cent up.
'What's more, the proportion of cancer patients fast-tracked for treatment within 62 days was the highest this January that it has been for the past three years.'
What was the impact of cancelling routine operations?
Last year, winter pressures were described as a humanitarian crisis, however, in 2018, a 'perfect storm' of bad weather, a flu outbreak and norovirus made matters even worse.
The past winter has seen the worst flu season since 2011, with thousands also being affected by norovirus, leading to hundreds of hospital beds being closed every day.
The Royal College of Surgeons (RCS) said at least 62,000 fewer NHS treatments, including surgical operations, were performed by consultants this past winter compared to the season before.
In trauma and orthopaedics, there was an 8.4 per cent fall in treatments.
RCS added the 'necessary evil' of postponing all planned surgery in January to relieve pressure on A&E departments resulted in many patients not receiving treatment when they required it, 'extending their time in pain or discomfort'.
Delays in cancer procedures could affect patients' survival prospects, experts warn (stock)
WHAT REGIONS OF THE UK WERE MOST AFFECTED BY THE NHS WINTER CRISIS?
During the NHS winter crisis, certain hospitals declared themselves at the most severe pressure level while doctors warned scores are operating at almost full capacity.
The Royal College of Emergency Medicine warned overcrowding in A&E departments leads to avoidable deaths.
It also cautioned pressure on the health system results in lengthy waits and patients being treated in corridors.
Meanwhile, a number of ambulance services were also under severe pressure, with one even resorting to using taxis to ferry patients to hospital.
The East of England Ambulance Service said that during December 30, 31 and January 1, 13 patients deemed to be 'low acuity', meaning they did not require intensive nurse care, were transported to hospital by taxi.
During the first few days of 2018, paramedics working for the trust wasted more than 500 hours waiting outside hospitals admiting patients due to ‘handover delays’.
A number of hospital trusts also declared they were Operational Pressures Escalation Level 4, which means patient care is compromised.
Darent Valley Hospital A&E in Kent, Royal Cornwall Hospital and University Hospitals Of Leicester NHS Trust all said they declared OPEL4 at the end of 2017-beginning of 2018.
Meanwhile, Somerset Clinical Commissioning Group said the health system in the whole county declared OPEL4.
University Hospitals of North Midlands NHS Trust’s medical director Dr John Oxtoby admitted the pressure was severe over Christmas. Summary of the NHS winter crisis
At the beginning of the year, NHS chiefs demanded radical action to free up beds and medical staff due to casualty units being under 'extreme and sustained' pressure with flu cases, with at least 306 related deaths, according to Public Health England.
Up to 55,000 non-urgent operations were postponed until February, along with thousands of outpatient appointments and scans.
Strict rules regarding single-sex wards were waived, while doctors were also expected to man the doors in A&E.
For part of the winter crisis, which lasted from around November to February, Nottingham's Queen's Medical Centre was put on 'black alert', meaning it was operating at full capacity with no beds left.
During one week a patient arrived at the centre's A&E every two minutes, prompting 346 operations to be cancelled in January alone.
PRIME MINISTER THERESA MAY FINALLY APOLOGISES FOR THE 55,000 OPERATIONS CANCELLED... A DAY AFTER REFUSING TO ACCEPT THE NHS WAS IN THE MIDST OF A CRISIS
Mrs May finally apologised to patients who faced a delay on January 4
Prime Minister Theresa May finally apologised to patients who faced a delay on January 4, after it was announced 55,000 operations will be postponed.
The unprecedented move to cancel non-urgent procedures to free up beds and frontline staff was made by NHS bosses.
The decision prompted an apology from Health Secretary Jeremy Hunt yesterday, following pressure from his critics that he was 'running scared'.
Mrs May apologised during a visit today to Frimley Park Hospital in Surrey, one of many trusts affected by the NHS move to cancel procedures.
After refusing to accept the NHS was in a crisis the day before, she said: 'I know it's difficult, I know it's frustrating, I know it's disappointing for people, and I apologise.'
Her comments followed official data which showed record numbers of patients are being forced to wait in ambulances for treatment.
Some 16,900 people were forced to wait for more than 30 minutes in ambulances to be seen by staff at A&E over the Christmas week - the highest total this winter.