Cancer patients in "the most deprived areas are the most likely to delay" seeing a doctor about their symptoms, the co-director of the King's College London's Early Presentation Group said.
Dr Lindsay Forbes, lead author on the report, said: "This research highlights that we must do more to make sure the public recognises key symptoms of cancer like unexplained pain, unusual bleeding or weight loss, as well as a lump and make sure they get these checked out as soon as possible
"Although a worrying number of patients across society are waiting too long to go to their doctor, it is those in the most deprived areas that are most likely to delay."
The research found that almost half of prostate cancer patients and 37% of rectal cancer patients reported a delay of three months or more between first noticing the symptoms to going to see a doctor while only 8% of breast cancer patients waited this long.
Embarrassment, worrying about wasting a doctor's time and not realising their symptoms were serious were among the most common reasons for delay.
One in five cancer patients wait over three months before visiting a doctor about their symptoms, a new study suggests.
Twenty one percent of patients in the study waited for at least 90 days before raising the issue with a medical professional.
Patients with prostate cancer and rectal cancer were most likely to delay while breast cancer patients were the least likely, according to the research published in the British Journal of Cancer.
Researchers surveyed 2,371 patients with 15 different cancers about the symptoms that had led to diagnosis.
A man with the kind of skin cancer that often kills has made what doctors are calling a miraculous recovery.
The credit for his recovery has gone to a new "immunotherapy" drug treatment which strengthens the body's own immune system against cancer.
The treatment works by improving the body's own ability to fight cancer and as our Health Editor Catherine Jones, reports it could be extended to combating other forms of the disease.
Ninety-four-year-old dare-devil pensioner Tom Lackey from Solihull is gearing up for his 30th wing walk from Land's End to the Scilly Isles, in the name of teenage cancer sufferer Stephen Sutton.
The 19-year-old from Burntwood in Staffordshire lost his battle with the illness this week.
Mr Lackey is dedicating his latest stunt, scheduled for this Thursday, to Stephen. He told ITV News Central:
"He's done so much good and raised all this money and he would have done a wing walk. He always put his thumbs up in the air so when I do this one from Lands End to the Isles of Scilly I think I will put my thumbs up for him and imagine that he's with me."
A 94-year-old man from Solihull is taking part in a wing-walk in memory of Stephen Sutton.
Over the years Tom Lackey has done a number of high-flying plane stunts, but he says he's been inspired to do one more by Stephen's story.
The 19-year-old from Burntwood in Staffordshire lost his battle with bowel cancer this week.
His Just Giving page has now raised nearly £3,900,000 for the Teenage Cancer Trust.
On Thursday the dare-devil pensioner will carry out his 30th wing walk, travelling from Lands End to the Isles of Scilly strapped to the top of a plane.
Speaking at his home, the 94-year-old paid an emotional tribute to Stephen, saying he would have his thumbs up in the air for the teenager while carrying out the stunt, imagining the 19-year-old's up there with him.
The Church of England has offered Lichfield Cathedral as a funeral venue to the family of inspirational teenager Stephen Sutton.Read the full story ›
Celebrities have been wearing an array of colourful wigs to support this year's Wig Wednesday and raise money for children with cancer.Read the full story ›
A friend of "inspirational" teenager Stephen Sutton has told Good Morning Britain "what a great guy" the cancer sufferer was.
Film maker Greg Richters filmed Stephen as part of a documentary on the teenagers' life after he received his terminal cancer diagnosis.
Ritchers explained: "We gave him a couple of cameras and he just filmed it to really show us that this is not a story of someone with cancer. This is a story about a 19-year-old kid who did so much in so little time."
Stephen Sutton's fundraising page for the Teenage Cancer Trust has now reached more than £3.5 million in donations following his death yesterday.
One person who donated to the fund wrote on the page: "An extraordinary legacy to leave at just 19 years old but you were an extraordinary young man. I'm proud of you and I've never even met you."
Fresh footage of Stephen Sutton has emerged, showing the "courageous" 19-year-old enjoying life to its fullest with his friends.
Good Morning Britain has obtained the footage which Stephen, who passed away yesterday from incurable bowel cancer, insisted show him "enjoying life" so he would not "become a sob story".