Doctors fear thousands of Australians are living with undiagnosed breast cancer after COVID halts services

Tarah Haste was in her mid-20s when she was diagnosed with breast cancer.

"I couldn't believe it at the age of 27 - I was fit and healthy," she said.

In just two weeks her tumor had doubled in size.

"When they removed the tumor it was at six centimetres," she said.

"I was very lucky, so time is definitely of the essence."Ms Haste is urging anyone with concerns to get screened for breast cancer.

"Just get the all clear even if you think you are going to be wasting their time," she said.

But with screening temporarily put on hold during the height of the coronavirus pandemic, and preventative surgeries suspended, doctors fear thousands of Australians could be missing the window for early diagnosis.

Dr Lisa Erzetich, director of Brisbane's Wesley Hospital Breast Cancer Clinic, said there was a "significant drop" in patient numbers in April and May.

Likewise, specialist oncoplastic breast cancer surgeon Dr Jane O'Brien said there had been approximately a 40 per cent decline.

The most affected age group is those between 50 and 74, with a 30 per cent drop in referrals to cancer specialists.

More than 8000 Australians living with breast cancer don't even know they have it - which is why screening is important.

A mammogram can find cancers as small as a grain of rice before you or your doctor can pick up any symptoms.

"The earlier you detect, the easier the cure and the less invasive treatment," Dr O'Brien said.