It’s a symptom that burdens millions of us every day.
Heartburn can be uncomfortable and, although is usually harmless, could be an early indication of the fourth deadliest cancer in the UK.
The NHS says heartburn could be an early sign of oesophageal cancer – diagnosed around 9,200 times and the cause of 7,900 deaths every year in the UK.
And now, a study has found that regular acid reflux – often the cause of heartburn – could be the root cause of the deadly disease.
People who suffer acid reflux are more than twice as likely to be diagnosed with cancer of the oesophagus or the voice box over their lifetime, according to the findings.
While the study alone cannot prove that acid reflux is the root cause, scientists said it must be investigated further.
Up to 30 per cent of Americans and 25 per cent of Europeans suffer with repeated acid reflux, medically called gastroesophageal reflux disease (GERD).
It can affect anyone but is more likely to be diagnosed in people with obesity, who are pregnant, smoke, or take certain medications.
The burning sensation that comes with it, as well as bloating, pain, and nausea, occurs when stomach acid flows back into the oesophagus.
Could acid reflux cause cancer?
Research has previously indicated that this damage may put patients at risk of developing a type of cancer called esophageal adenocarcinoma.
The latest study, published online in CANCER, a peer-reviewed journal of the American Cancer Society, investigated further.
A team led by Dr Christian C. Abnet, of the National Cancer Institute, looked at 490,605 adults enrolled in the NIH-AARP Diet and Health Study.
Questionnaires were sent to participants in the study in 1995-1996 people aged between 50 and 71 years who were living in various US states.
Using Medicare claims data, the investigators estimated that 24 per cent of participants had a history of GERD.
Those over 60 years old, who used to smoke and were overweight were more likely to have GERD.
Over the following 16 years after participants joined the study, 931 patients developed esophageal adenocarcinoma (EADC) and 301 developed esophageal squamous cell carcinoma (ESCC) – two forms of oesophagus cancer.
A further 876 developed laryngeal squamous cell carcinoma – cancer of the voice box.
People with GERD had about a two-times higher risk of developing each of these types of cancer.
What is oesophageal cancer?
Oesophageal cancer impacts the gullet – which is the long tube that carries food from the throat to the stomach.
Each year in the UK there are around 9,100 cases of this cancer and just 15 per cent of patients survive the cancer for five years or more.
There are many possible symptoms of oesophageal cancer, but they might be hard to spot.
They can affect your digestion, such as:
- having problems swallowing (dysphagia)
- feeling or being sick
- heartburn or acid reflux
- symptoms of indigestion, such as burping a lot
Other symptoms include:
- a cough that is not getting better
- a hoarse voice
- loss of appetite or losing weight without trying to
- feeling tired or having no energy
- pain in your throat or the middle of your chest, especially when swallowing
The elevated risk was seen across people regardless of their gender, whether they smoked or drank booze – other risk factors for certain cancers.
Dr Abnet and colleagues estimated that approximately 17 per cent of cancers of the voice box or oesophagus in adults aged between 50 and 71 years old are linked with acid reflux.
They wrote in their paper that their results add “robust prospective evidence” for the link between GERD and oesophageal cancer.
The paper said it was possible that leftover acid in the oesophagus could be injuring delicate tissue and causing cancer, among other explanations.
Over time, the chronic inflammation in the oesophagus caused by GERD is already known to lead to narrowing, ulcers and damage to the tissue lining.
The latter, called Barrett’s oesophagus, is “associated with an increased risk of esophageal cancer”, according to Mayo Clinic.
GERD can be treated with medicines such as proton pump inhibitors, prescribed by a GP.
But sometimes people with the condition need tests to find out the cause, which can take weeks to arrange on the NHS.
Dr Abnet added that their study alone is “not sufficient to result in specific actions by the public”.
“Additional research is needed to replicate these findings and establish GERD as a risk factor for cancer and other diseases”, he said.
“Future studies are needed to evaluate whether treatments aimed at GERD symptoms will alter the apparent risks.”