Delaying treatment by even one month can increase the risk of dying from cancer by 6-13%, warns study
A surgical delay of 12 weeks for all patients with breast cancer for a year, for example, would lead to 6,100 excess deaths in the US
Cancer treatment delay is a problem in health systems worldwide and it can have adverse consequences on a patient’s outcome, say experts. People whose treatment for cancer is delayed by even one month have in many cases a 6 to 13% higher risk of dying –– a risk that keeps rising the longer their treatment does not begin, suggest researchers in a new study.
The authors calculated delays of up to eight weeks and 12 weeks to show how it further increased the risk. Using the example of an eight-week delay in breast cancer surgery, they say it would up the risk of death by 17%, and a 12-week delay would increase the risk by 26%. A surgical delay of 12 weeks for all patients with breast cancer for a year, for instance, would lead to 6,100 excess deaths in the US, 1,400 in the UK, 700 in Canada, and 500 in Australia, assuming surgery was the first treatment in 83% of cases, and mortality without delay was 12%.
The experts emphasize that the results, published in The BMJ are both “sobering and staggering” and calls for policies focused on minimizing system-level delays in cancer treatment initiation.
“A four-week delay in treatment is associated with an increase in mortality across all common forms of cancer treatment, with longer delays being increasingly detrimental. In light of these results, policies focused on minimizing system-level delays in cancer treatment initiation could improve population-level survival outcomes,” suggests Timothy Hanna from Queen’s University in Kingston, Canada.
The findings are important 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 combat the Covid-19 pandemic.
The precise impact of delays in treating cancer –– from diagnosis to receipt of treatment –– on mortality has not been thoroughly analyzed. Accordingly, a research team led by Hanna conducted a review and analysis of relevant studies into the subject published between January 2000 and April 2020. These reports 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 –– that together, represent 44% of all incident cancers globally.
The main outcome measure was the risk to overall survival every four-week delay for each indication and delays were measured from diagnosis to first treatment, or from the completion of one treatment to the start of the next. The investigators found 34 suitable studies for 17 types of conditions that needed to be treated (indications) involving more than 1.2 million patients, collectively. The association between delay and increased mortality was significant for 13 of these 17 indications.
The results reveal 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. 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.
The authors note that their study has limitations such as the fact that it was based on data from observational research, which cannot perfectly establish cause, and that patients with longer treatment delays may have been destined to have inferior outcomes for reasons of having multiple illnesses or treatment morbidity. However, they emphasize that the analysis was based on a large amount of data and good-quality studies that had high validity, meaning they accurately measured what they were investigating.
“Our results reflect the impact of delay on large and expectedly heterogeneous populations with varying risks of recurrence. Therefore, these estimates are best used at a policy and planning level for modeling, rather than for individual risk prediction,” writes the team.
According to a linked editorial, the findings should be used as an aid to model future projections for patient outcomes following changes in expected waiting times, rather than to create or justify specific waiting time targets. “The Covid-19 pandemic increases the urgency of developing new initiatives and to understand the unintended consequences of the pandemic for patients with cancer. (The) data can be used as a resource for modeling studies exploring how future treatment delays could influence absolute measures such as years of life lost to patients with cancer or, in pandemics, the balance of risk and benefit associated with pandemic measures at the population level. Global initiatives should be designed to generate high quality, granular, patient-focused data on the impact of delays in treatment, which is essential for system-level efforts to provide timely and effective cancer care both during and after this pandemic,” recommend experts.