Of 53% of participants who experienced a cancer warning sign, only 2% considered the symptom to be cancer-related.
Lead study author Dr. Katriina Whitaker, senior research fellow at University College London in the UK, analyzed the responses of 1,724 people aged 50 and over to a health questionnaire that was sent to them in April 2012.
The questionnaire asked participants whether they had experienced any of 17 symptoms, 10 of which are defined as cancer "alarm" symptoms by Cancer Research UK. These symptoms include unexplained cough, changes in mole appearance, unexplained bleeding, persistent change in bowel habits, unexplained weight loss, difficulty swallowing and unexplained lumps.
Participants were not told which symptoms are cancer warning signs.
The respondents were also asked what they thought was the cause of any symptoms they experienced, whether they deemed the symptoms to be serious and whether they visited their doctor as a result of their symptoms.
Only 2% of respondents considered warning symptoms to be cancer-related
Results of study - published in the journal PLOS ONE - revealed that 53% of participants reported that they had experienced at least one cancer warning sign over the past 3 months.
- Over the next 20 years, the number of new cancer cases is expected to rise by around 70% globally
- The most common cause of cancer death is lung cancer, which caused 1.59 million deaths worldwide in 2012
- More than 60% of the world's total new annual cancer cases occur in Africa, Asia and Central and South America.
The most common cancer warning symptoms reported were persistent cough and persistent change in bowel habits, while unexplained weight loss and problems swallowing were the least common.
However, the researchers were surprised to find that of the respondents who reported cancer warning symptoms, only 2% considered cancer to be a potential cause.
What is more, Dr. Whitaker says that of participants who reported the most obvious signs of cancer - such as unexplained lumps or changes in mole appearance - most did not consider them to be cancer-related.
"Even when people thought warning symptoms might be serious, cancer didn't tend to spring to mind," adds Dr. Whitaker. "This might be because people were frightened and reluctant to mention cancer, thought cancer wouldn't happen to them or believed other causes were more likely."
On a positive note, respondents did deem the cancer warning signs to be more serious than symptoms not linked to cancer - such as shortness of breath, fatigue and sore throat - and 59% of those who experienced cancer warning signs visited their doctor.
But the researchers say their findings show that the majority of people are dismissing potential warning signs of cancer, which could be putting their health at serious risk. Dr. Whitaker says:
"Most people with potential warning symptoms don't have cancer, but some will and others may have other diseases that would benefit from early attention. That's why it's important that these symptoms are checked out, especially if they don't go away. But people could delay seeing a doctor if they don't acknowledge cancer as a possible cause."
"Most cancers are picked up through people going to their general practitioner (GP) about symptoms, and this study indicates that opportunities for early diagnosis are being missed," adds Sara Hiom, director of early diagnosis at Cancer Research UK. "Its results could help us find new ways of encouraging people with worrying symptoms to consider cancer as a possible cause and to get them checked out straight away with a GP."
Medical News Today recently reported on a study published in The Lancet Oncology claiming that each year, half a million cancer cases can be attributed to high body mass index (BMI).