A delay in cancer treatment by as few as four weeks may be sufficient to increase the risk of death by about 10%, a meta-analysis shows.

The risk continues to rise with further delays, the researchers say, prompting calls for wait times for surgery, systemic treatment and radiotherapy to be cut from weeks to days.

In a systematic review and meta-analysis of 34 studies, the team used data from 1.27 million patients with seven forms of cancer — bladder, lung, colon, rectum, breast, cervix, and head and neck — to quantify the link between treatment delays and death.

They found that a four-week delay between cancer diagnosis and surgery for most cancer indications was associated with a higher risk of death, ranging from 6% for colectomy to 8% for breast surgery.