Cambodia has 15,216 new cancer cases every year with a mortality rate as high as 74 percent, figures from the International Agency for Research on Cancer show.
Cervical cancer is the most common cancer in women with 1,512 new cases every year, while liver cancer is the number one killer among cancers in men with a mortality rate of more than 95 percent.
Cancer is formed when abnormal and uncontrollable cells grow and invade one of the body’s organs and can spread to neighbouring and distant organs.
Scientists have not fully understood the biology and all causes of cancers yet. Defects in different genes lead to different types of cancer.
According to Dr Hav Monirath, head of pathology at Calmette Hospital, groups of genes whose defects usually lead to cancer development are oncogenes, tumour suppressor genes and DNA repair genes.
“Oncogenes are responsible for cellular proliferation. When they are defective, the cells will grow out of control,” Dr Monirath said.
“Tumour suppressor genes function like the cells’ bodyguards. When an abnormal growth signal is detected, these bodyguards will stop the cells from growing and will call in the DNA repair genes to fix the mistakes before letting the cells further proliferate.”
Dr Monirath added if the DNA repair genes cannot repair the mistakes, the suppressor genes, known here as the bodyguards, will force the abnormal cells to commit suicide (apoptosis). In some cancers, the suppressor genes are defective, leading to the lack of control mechanism for abnormal cell growth.
In other cancers, the DNA repair genes are not working well, leading to the accumulation of genetic errors, also leading to cancer development
Dr Monirath said another mechanism that makes cancer very aggressive is its invasion of other important neighbouring or distant organs by means of blood and lymphatic vessels. This invasion process is known as metastasis.
“Some cancers are more aggressive than others because they have different target for metastasis. Aggressive cancer cells like to travel to the brain, lungs, and liver which are all noble organs without which human cannot survive. No effective treatment exists to replace all of these organs and still maintaining the quality of life for the patients,” said Dr Monirath,
According to the world Health Organisation, although cancers can be deadly, between 30 and 50 percent of them are preventable.
Scientists have identified lifestyle related risk factors that contribute to cancer development. These include tobacco use (lung and oral cancers), alcohol use (oral, colorectal cancer, breast, and liver cancers), obesity and physical inactivity (almost all types of cancers), infection (mainly cervical, liver and stomach cancers) and environmental pollution (mainly lung, liver, and colorectal cancers).
Worldwide, tobacco use is the single greatest avoidable risk factor for cancer mortality and kills approximately 6 million people each year from cancer and other diseases.
Tobacco smoke has more than 7000 chemicals. At least 250 are known to be harmful and more than 50 are known to cause cancer.
Dr Monirath recommends that the public be more aware of these lifestyle-related cancer risks and modify them accordingly to minimize their own cancer risk.