Cancer not only severely impacted Samran Somjai's physical health, the disease also withered his spirit.

"No one wants to spend agonising moments with cancer, but the disease got me," recalled Samran, a retired teacher. "And suddenly my life's direction became unclear."

A native of Lop Buri, in 2006 Samran was diagnosed as suffering a gastrointestinal stromal tumour _ a rare yet life-threatening cancer of the digestive system _ when a 13cm x 12cm growth was detected in his small intestines. At that time, Samran was going through severe weight loss and had turned extremely pale. Medication was immediately prescribed and surgery scheduled.

Despite the cancer weakening Samran's physical health, he still had to take care of his 92-year-old mother, a challenge he rose to.

"My mum was very old and she had fallen victim to paralysis. Looking at her, suddenly I realised I had to be strong because I was then the one responsible for taking care of her. I could not be sick and I had to get back to normal as fast as I could," he said.

Samran underwent five operations to remove the tumour and the affected intestine, and has been taking regular doses of medication since. And now, although the cancer is not completely gone, the carcinoma has been under control and Samran can live his life normally.

"Now my life has started to head in a good direction again," said the 69-year-old.

A gastrointestinal stromal tumour (GIST) usually develops from cells in the wall of the digestive tract. According to the president of the Thai Society of Clinical Oncology, Asst Prof Sudsawat Laohavinij, even though gastrointestinal stromal tumours are less common than other types of gastrointestinal cancer, the disease should not be overlooked given that it can be fatal if left untreated.

"In the US, there are approximately 4,000 to 5,000 people diagnosed as having a gastrointestinal stromal tumour each year. In Thailand alone, an estimate of 250 new patients has been reported on an annual basis. Despite such a low incidence rate, the number of new cases is constantly on the rise," explained Dr Sudsawat, also chief of the oncology unit at the Department of Medicine, Rajavithi Hospital.

Similar to many other types of cancer, the cause and risk factors for gastrointestinal stromal tumours are unknown, added the oncologist. The malignant tumours are most often detected in the stomach, followed by the small intestine, the large intestine and the oesophagus. The cancer is usually found in patients aged above 55.

Diagnosis can be challenging in the early stages, as most patients have no signs or symptoms of cancer.

Studies found that one third of GIST patients developed no significant symptoms prior to the diagnosis. Patients might only suffer stomach ache and discomfort which, if left untreated, turns into loss of appetite, weight loss, fatigue, bleeding in the digestive tract and paleness. In the terminal stage, the malignancy may spread to other organs such as the liver and abdominal lining.

''Unfortunately, most patients are diagnosed four to six months after symptoms develop, which might be too late,'' explained Dr Sudsawat, adding that the earlier the tumour is detected, the higher the chance of survival.

While diagnosis is difficult, treatment is equally challenging.

According to advisor and former president of the Thai Society of Clinical Oncology Asst Prof Vichien Srimuninnimit, the tumours are, in most cases, resistant to conventional cancer treatments _ especially chemotherapy.

In the past, patients _ especially those in the final stages _ usually ended up waiting hopelessly for their last moments of life.

But the development of a targeted drug called Imatinib during the past 10 years, said Dr Vichien, has helped save the lives of a large number of patients worldwide. This medication, which comes in tablet form, halts the growth of cancerous cells and, subsequently, prolongs patients' lives.

''Prior to the advent of targeted therapy, patients in the final stage, when cancer had already spread to other organs, were only able to live for about 18 months. But after the drug became available, on average terminally ill patients can now live up to five years,'' explained Dr Vichien, also head of the Division of Medical Oncology, the Department of Medicine, Siriraj Hospital.

And Imatinib can also help shrink the size of the malignant tumour. According to Dr Vichien, 68% of tumours were found to reduce in size after the medicine was prescribed, while for another 16%, the tumour size remained unchanged.

''Simply put, the medication is proven to control the tumour in up to 84% of patients,'' he said.

There is no need for Thai patients to worry that the medication will strain their wallet given Imatinib is currently included in the universal healthcare scheme and is under social security cover, which means it is accessible to all free of charge. Without the universal healthcare coverage, patients would need to pay up to 100,000 baht a month for the targeted therapy.

To prevent gastrointestinal stromal cancer, Dr Sudsawat said regular physical check-ups are paramount.

''If you feel you are easily full after a meal or often experience stomach discomfort or bloating, do not hesitate to visit a specialist,'' Dr Sudsawat advised. ''Do not wait until the condition becomes serious. It may sound like a cliche, but when it comes to cancer, early detection is the most significant and fundamental key to a longer and healthier life.''

QUICK FACTS

The World Health Organization (WHO) has revealed some interesting cancer-related facts and figures:

Lung, stomach, liver, colon and breast cancer cause the most cancer deaths each year.

About 30% of cancer deaths are due to the five leading behavioural and dietary risks: high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco use, alcohol use.

Tobacco use is the most important risk factor for cancer, causing 22% of global cancer deaths and 71% of global lung cancer deaths.

Approximately 70% of cancer deaths occur in low- and middle-income countries.

Deaths from cancer worldwide are projected to continue rising, with an estimated 13.1 million deaths in 2030.

30% of cancers could be prevented by modifying or avoiding key risk factors, including tobacco use, being overweight or obese, unhealthy diet with low fruit and vegetable intake, lack of physical activity, alcohol use, sexually transmitted HPV infection, urban air pollution and indoor smoke from household use of solid fuels.