Many stomach cancer patients are diagnosed too late for treatment, with as many as 15% diagnosed in Accident and Emergency.
According to experts stomach and oesophageal cancers are "particularly aggressive" and prognosis is extremely poor if caught at a late stage.
One of the main reasons for this delay is lack of awareness around symptoms - many of which are often ignored.
Consultant gastroenterologist Stuart Riley, member of the British Society of Gastroenterology, said: "Stomach and oesophageal cancer typically afflicts the elderly, and men are twice as likely to be affected compared to women."
He adds: "The public should be made aware of the alarm symptoms which include problems with swallowing, persistent vomiting and weight loss. National guidelines recommend that GPs make an urgent referral for an endoscopy."
Here are some of the key stomach cancer symptoms to look out for, courtesy of Cancer Research UK.
The earliest symptoms of stomach cancer are often acidity and burping. Many people diagnosed with stomach cancer have had symptoms like these for years. But they are symptoms of other stomach problems too. Most people who have long term indigestion and wind never develop cancer. Less than 1 in every 50 people going to the doctor with indigestion and burping have cancer.
Another early symptom can be feeling full up sooner than usual when eating your meals. If this leads to eating less over a period of time, you will start to lose weight.
Even early stomach cancers can bleed into the stomach. Losing blood over a period of time can make you anaemic. This means your red blood cell count is too low. Anaemia makes you look pale and feel tired. If you are very anaemic you may also feel breathless. Vomiting blood is not a common early symptom, but it can happen. If it does, the blood may not be clearly seen. The blood you bring up may be bright red, which means it is fresh bleeding. Or it may look dark brown, like used coffee grounds, if the blood has been in the stomach for a while.
People with stomach cancer are more likely to get blood clots. If you have pain or swelling in a leg or sudden chest pain and breathlessness, you could have a blood clot in your leg or lung. You should contact your doctor straight away because you will need immediate anti-clotting medicines.
Losing your appetite and losing weight are often later symptoms and can be a sign that the cancer is more advanced. Although some people with early stomach cancer lose their appetite too.
With an advanced cancer, it may be possible for your doctor to feel a lump in your tummy (abdomen). Some people with advanced stomach cancer develop fluid in the abdomen. This is called ascites.
Some stomach cancers bleed but don't make you vomit. The blood goes through your digestive system. This can make your bowel movements look black, like tar.