People whose treatment for cancer is delayed by even one month have a 6-13 per cent higher risk of dying, suggests research published online in the BMJ.
In light of the treatment delays resulting from the pandemic, Canadian and UK researchers carried out a review and analysis of relevant studies published between January 2000 and April 2020.
Included studies examined data on surgical interventions, systemic therapy or radiotherapy for seven forms of cancer - bladder, breast, colon, rectum, lung, cervix and head and neck. Delays were measured from diagnosis to the first treatment or from the completion of one treatment to the start of the next.
The search identified 34 suitable studies for 17 indications, with data from more than 1.2 million patients. The analysis identified a significant association between delay and increased mortality for 13 of the 17 indications (P<.05>
For surgery, there was a 6-8 per cent increase in the risk of death for every four-week treatment delay. Estimates for systemic treatment varied (HR range, 1.01-1.28). Four-week delays in radiotherapy were for radical radiotherapy for head and neck cancer (HR, 1.09; 95% CI, 1.05-1.14), adjuvant radiotherapy after breast-conserving surgery (HR, 0.98; 95% CI, 0.88-1.09) and cervical cancer adjuvant radiotherapy (HR, 1.23; 95% CI, 1.00-1.50).
Delays of up to eight and 12 weeks further increased mortality. An eight-week delay in breast cancer surgery was linked to a 17 per cent increased mortality, and a 12-week delay would increase mortality by 26 per cent.
A surgical delay of 12 weeks for patients with breast cancer continuing for one year - which is likely to be the case as the pandemic continues - would lead to 1400 excess deaths in the UK.
The authors said the results of this study could be used to guide policymaking on the organisation of cancer services, particularly as the pandemic continues and further delays are expected.