New research shows minimizing delays to cancer treatment could improve survival rates

Nov. 6 2020 Even a four-week delay of cancer treatment can increase mortality by about 10% in many cases, researchers found in a new study published online in The BMJ. The mortality risk rises as delay increases, say researchers.

Most countries have experienced deferral of elective cancer surgery, and impacts on use of radiotherapy and systemic therapy because of COVID 19. Researchers felt because of this, there needed to be a better understanding of the impact of treatment delay on outcomes.  They carried out a review and analysis of relevant studies into the subject published between January 2000 and April 2020. 

These studies provided 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 per cent of all incident cancers globally.

They found 34 suitable studies, involving over 1.2 million patients. The association between treatment delay and mortality was significant in 13 of 17 treatments for these seven cancers.

This team of researchers from Canada and the United Kingdom was led by Dr. Timothy Hanna, an Ontario Institute for Cancer Research (OICR) Clinician Scientist,  Cancer Care and Epidemiology. and researcher in the Cancer Research Institute at Queen’s University. Other researchers on the team include Drs. Chris Booth and Will King from Queen’s University, along with Drs. Ajay Aggarwal and Richard Sullivan from King’s College, London.

The researchers found that patients have in many cases a six to 13 per cent higher risk of dying from the condition when treatment was delay by four weeks. That risk rises the longer treatment does not begin. The authors provide the example of breast cancer surgery, where among 1000 patients, a four-week delay is associated with an excess risk of 10 deaths, and a 12-week delay, 31 deaths.

“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." Dr. Hanna noted. "In light of these results, policies focused on minimizing system level delays in cancer treatment initiation could improve population level survival outcomes.”

“As we move towards the second COVID-19 wave in many countries," says Dr.  Ajay Aggarwal, Oncologist, London School of Hygiene and Tropical Medicine, the results emphasize the need to prioritize cancer services including surgery, drug treatments and radiotherapy as even a 4-week delay can significantly increase the risk of cancer death.”

To view the team's research findings, see "Mortality Due to Cancer Treatment Delay: Systematic Review and Meta-Analysis" in The BMJ.