Data published by the Cancer Council Victoria in the Medical Journal of Australia on Monday shows 10 per cent fewer cancer screening pathology tests were ordered between April and October last year.

They estimate that equates to 2530 missed cancer diagnoses.

Director of the Victorian Cancer Registry Professor Sue Evans says any delays would have the greatest impact on patients later diagnosed with more aggressive cancers.

"Our modelling indicates that it's possible that approximately 2500 Victorians will not only be faced with the prospect of being diagnosed with cancer but with a later stage cancer than they possibly may have been, and this would be devastating for patients, families and loved ones," she said in a statement.

"This potential spike in later-stage cancers could increase demand on our health system, as well as on supportive care services."

Professor Evans said the most significant decrease in pathology notifications, and therefore likely missed diagnoses, occurred for head and neck, prostate and breast cancer and melanoma.

Older Victorians, men and people living in higher socio-economic areas are at highest risk.

CEO of Cancer Council Victoria Todd Harper says there's been a 30 per cent decline in certain cancer diagnostic procedures and an 18 per cent decline in treatments during the first six months of the pandemic.

"As we emerge into a state of 'COVID-normal' it is imperative for us all to encourage and support each other to prioritise our health. If you have been invited to participate in a cancer screening program, please do not delay," Mr Harper said.

"Cancer screening saves lives - it is one of the most effective ways to detect the early signs of cancer, when successful treatment is more likely."

Australian Associated Press