Britons have been delaying going GP visits despite noticing something unusual, AXA PPP healthcare has reported.
AXA PPP's research showed people would have to feel physically unwell before making an appointment and the insurer warned early detection of cancer could be missed.
A poll of 2,000 adults found 61% of Brits have delayed making an appointment with their GP after noticing something unusual for their bodies.
A "sizeable" minority of those questioned had experienced potential signs or symptoms of cancer, from changes in bowel habits to blood in their urine, yet fewer than half of people had seen their GP.
But the exception was two thirds of those with lumps in their breasts had visited their doctor.
Dr Gary Bolger, healthcare chief medical officer at AXA PPP, said: "A key to the early detection of cancer is knowing what normal feels like for your body so you are able to identify a significant change. We need to stop the idea that you have to be physically unwell to see your doctor for advice.
"It's regrettable that too many people present themselves to their GP or even to A&E with cancer in its late stage.
"This makes the cancer harder to treat and treatment less successful. Overcoming people's reluctance to seek medical advice when appropriate is a big public health issue.
"People who find signs or symptoms of cancer should not be afraid to see their doctor for advice straight away. It really is a case of the sooner the better."
Reasons behind lack of GP appointments were; difficulty in making an appointment for 30%; being too busy for 27%; and 25% feared what they might find out. Less than a third of respondents (28%) said they would make an appointment to see their GP immediately if they noticed something unusual.
Cancer featured highly in respondent consciousness while 32% said they knew cancer was common but did not think about it day to day. One in ten people were "terrified" of the disease and think about it a lot, with 29% saying they thought about it every day.
The majority were able to identify potential signs and symptoms of cancer and were aware of the NHS screening programme for breast cancer (78%), cervical cancer (60%) and bowel cancer (37%).
Londoners were least likely to say they would make an appointment to see their GP immediately compared with people in Scotland and the North East who were keenest to do so.
The Cancer Consciousness findings have been published as part of AXA PPP healthcare's Little Big Things campaign to raise people's awareness of the cancer journey.
