The current understanding of what causes cancer is not complete and there is no single exact cause of cancer. Like many diseases, cancer develops gradually as a result of a combination of environmental, genetic and lifestyle factors.
Smoking tobacco, using smokeless tobacco, or being regularly exposed to second-hand smoke causes up to one-third of all cancer deaths. Smoking accounts for more than 90% of all lung cancer deaths and smokers are more likely to develop larynx, oesophagus, pancreas, bladder, kidney, and cervix cancers than non-smokers. Chewing tobacco can also cause cancers of the mouth and throat. Second-hand smoke is just as damaging to the health.
Ultraviolet (UV/UVA/UVB) Radiation
Singapore has one of the world’s highest UV exposure rates and excessive exposure to sunlight without protection can cause skin cancer. If you are fair-skinned, you are at a higher risk of skin cancer than someone with a darker skin tone. This is because the fair skin has less melanin, a pigment that protects the skin from UV rays.
Alcohol can damage the liver and increase the risk of liver cancer.
Chronic infection with Human Papillomavirus (HPV), Hepatitis B / C viruses, Epstein-Barr virus and Helicobacter Pylori virus increase the risks of cervical, liver, nasopharyngeal and stomach cancers.
It is possible to be born with a genetic mutation that puts one at higher risk for developing a number of cancers such as melanoma (skin cancer), breast, ovary and colon cancers. Not all cancers tend to be hereditary, approximately 5 to 10 percent of all cancers are directly caused by inherited genetic mutations.