Research published today in the BMJ by an international team of researchers including King’s found there was a significant impact on a person’s mortality if their treatment was delayed, whether that be surgical, systemic therapy (such as chemotherapy), or radiotherapy for seven types of cancer.
The need for better understanding of the impact of treatment delay on cancer outcomes has come into focus during the COVID-19 pandemic because many countries have experienced deferral of elective cancer surgery and radiotherapy as well as reductions in the use of systemic therapies, while health systems have directed resources to preparing for the pandemic.
A review and analysis of relevant studies into the subject published between January 2000 and April 2020 had data on surgical interventions, systemic therapy (such as chemotherapy), or radiotherapy for seven forms of cancer – bladder, breast, colon, rectum, lung, cervix, and head and neck. Together, this represents 44% of all incident cancers globally.
Analysis of the results showed that across all three treatment approaches, a treatment delay of four weeks was associated with an increase in the risk of death.
For surgery, this was a 6-8% increase in the risk of death for every four-week treatment delay whereas the impact was even more marked for some radiotherapy and systemic indications, with a 9% and 13% increased risk of death for definitive head and neck radiotherapy and adjuvant (follow-up) systemic treatment for colorectal cancer, respectively.
In addition, the researchers calculated that delays of up to eight weeks and 12 weeks further increased the risk of death and used the example of an eight week delay in breast cancer surgery which would increase the risk of death by 17%, and a 12 week delay that would increase the risk by 26%.
A surgical delay of 12 weeks for all patients with breast cancer for a year (for example during COVID-19 lockdown and recovery) would lead to 1,400 excess deaths in the UK, 6,100 in the United States, 700 in Canada, and 500 in Australia, assuming surgery was the first treatment in 83% of cases, and mortality without delay was 12%.
The researchers used an example from the UK’s NHS, which at the beginning of the COVID-19 pandemic, created an algorithm to prioritise surgery.
A number of conditions had been considered safe to be delayed by 10 to 12 weeks with no predicted impact on outcome, including all colorectal surgery.