Digestive cancers common globally — Oncologist

Dr Zee speaks to the media on digestive cancers.

Dr Zee speaks to the media on digestive cancers.

MIRI: Digestive cancers such as those affecting the colorectal system (large intestine and rectum) and liver are common among people worldwide.

Medical oncology consultant Dr Zee Ying Kiat explained that colorectal cancer is one of the top three most common digestive cancers for men and women.

“Though many cancers developed for reasons that are still not known to medical science, but we are able to identify some risk factors that possibly contribute to the chances of developing certain cancers,” he said during a special media interview recently.

“Colorectal cancer, for example, the risk factors could be due to diet such as diets that are low in fibre, high in saturated fat and high in red meat; these factors have been identified to increase the chances of developing colorectal cancer.”

He said various other factors include obesity and lack of exercise, as well as smoking and alcohol consumption.

Dr Zee pointed out that common symptoms of colorectal cancer are a change in bowel habits such as diarrhoea or constipation, blood (either bright red or very dark) in the stool, stools that are narrower than usual, frequently having gas pains or cramps, feeling full or bloated, unexplained weight loss, nauseousness and feeling tired all the time.

He explained that colorectal cancer is curable depending on its stage.

“Usually we would refer to how far the cancer cells have spread around the body. During Stage 1, the cancer is usually found in the superficial wall (within the colon and rectum). Of course, early diagnosis would give the patient a chance of survival.

“To put numbers to this, out of 100 patients of Stage 2 colorectal cancers who undergo surgery alone, we expect 85 to 95 per cent to be free of cancer after five years,” he said.

During Stage 2, the cancer would spread deeper into the superficial wall while at Stage 3 it usually spreads near the lymph nodes.

Stage 4 is advanced and would have spread from the colon to other parts of the body.

“If the cancer has spread too far away to the body, the chances of survival are often less than 5 per cent.

“Even so, with advances of technology in the treatment of cancer, a combination of surgery and the use of medicine like chemotherapy, a proportion of patients in an advanced stage of cancer can still be cured but of course not everyone is able to survive.”

He said using an aggressive approach of a combination of medicine and surgery has cured 30 per cent of patients with metastatic stage four colorectal cancer, but added that careful selection of patients is very important.

“Not all cancer is incurable. Even for certain patients deemed to have advance stage four cancer. Therefore, it is vital for patients to seek professional advice and to work closely with other specialists for other options like chemotherapy and radiotherapy.”

He said liver cancer, which often occurs in Southeast Asia (SEA), should not be ignored.

“The main reason for liver cancer is because of infection of viral hepatitis B and viral hepatitis C. Though alcohol, to some extent, contributes to the cancer, but still the most common factor that contributes to liver cancer in SEA is still down to viral infection,” he said.

Dr Zee pointed out that early stage liver cancer shows no symptoms and only when it is much worse will there be signs of abdominal distensions with fluids (ascites), encephalopathy (altered mental state), jaundice, or gastrointestinal tract bleeding.

Besides that, some patients may have mild to moderate upper abdominal pain, weight loss, early satiety, lethargy, anorexia or a palpable mass in the upper abdomen.

“In the earliest stage, where the cancer has developed at just one spot of the liver, the main treatment would involve surgery to remove that infected spot. But if there are several spots, it would make the surgery difficult. Even so, we still have other approaches that includes radio frequency abrasion (RFA) where we insert a needle, heat it up to high temperature to effectively destroy the tumour cells.”

RFA, he said, is effective for smaller tumours which are less than three centimetres in size as the technique is able to kill off over 80 to 90 per cent of tumour cells with just one treatment.

In cases where the tumour has gotten to the extent of infecting other parts of the body, some patients may be given the option of a liver transplant, he said.

Dr Zee, who is from the Parkway Cancer Centre in Singapore, is a member of the American Society of Clinical Oncology and founding member of the Hepatopancreatobiliary Association of Singapore.

In addition to general medical oncology, Dr Zee has a special interest in gastro-oesophageal, hepatobiliary, pancreatic and colorectal cancers.