Australia is likely to see a significant rise in delayed colorectal cancer diagnoses as a direct result of the COVID-19 pandemic, surgeons warn.

Colorectal cancers were diagnosed at later stages, and preventive measures — including screening, GP visits and endoscopies — fell markedly as the country coped with lockdowns, their registry study found.

As a proportion of all cancers diagnosed, stage I cancer went from 23% of the total to 19% by the end of last year.

This was associated with a spike in stage III cancers, from 29% of cases to 34%, although there was no difference in stage IV disease, according to the data from the Binational Colorectal Cancer Audit, covering both Australia and New Zealand.