Cancer is a disease where the body’s cells grow uncontrollably and can spread to other parts of the body, damaging organs and affecting normal cell function. It is estimated that around 30-50% of cancers are potentially preventable, and with early detection, diagnosis, and treatment, outcomes can be improved greatly.

Cancers may be caused by a large variety of factors, which can be broadly categorised into modifiable and non-modifiable risk factors.

Modifiable risk factors:

1. Alcohol

Moderate to excessive levels of alcohol consumption have been shown to increase the risk of several types of cancer, including bowel, breast, mouth, throat, oesophageal, liver, and stomach.

2. Being overweight or obese

Obesity has been linked strongly to many types of cancer, including bowel, oesophageal, breast, ovarian, liver, stomach, and more.

3. Diet and nutrition

Diets high in red meats, processed meats, salted foods, and low in fruits and vegetables have been shown to increase the risk of cancers such as bowel, nose, mouth, and stomach.

4. Lack of physical activity

Being physically active helps to reduce the risk of developing colon, breast, and endometrial cancer.

5. Use of tobacco

Up to 80 cancer-causing agents can be found in tobacco smoke. Upwards of 22% of all cancer deaths worldwide can be attributed to smoking.

6. Radiation

Prolonged and unprotected exposure to ultraviolet radiation from the sun, sunlamps, and tanning beds can also lead to melanoma and skin malignancies.

7. Infection

Certain infections such as Human Papillomavirus (HPV) can increase the risk of contracting cervical and rectal cancers, while Hepatitis B and Hepatitis C makes one vulnerable to liver cancers. The Epstein-Barr virus can increase the risk of nose and blood cancers.

Non-modifiable risk factors:

1. Age

2. Genetics

Some individuals are born with certain genetic changes that increase their risk of developing cancers. For example, women who carry the BRCA 1 or BRCA 2 gene have a much higher risk of developing breast cancer, however, it is also worth noting that these only account for 5% of all breast cancer cases.

3. Weakened Immune System

In certain cases, an individual whose immune system needs to be suppressed (eg. lupus, or having undergone organ transplant) can also have an increased risk of developing cancers.

How can one get cancer from an infection?

Certain infections increase the risk of developing cancers. In Southeast Asia, Hepatitis B is one of the main risk factors of contracting cancer. This infection can be transmitted via blood or sexual encounters. In most cases, a person who is infected may not exhibit any symptoms whatsoever and will only start to manifest once the virus has matured. Hepatitis B is easily preventable with vaccines.

Certain types of Human Papillomavirus (HPV) infection are also associated with higher cancer risk. HPV infections are generally categorized under high risk or low risk strains. The high risk group is associated with higher cancer risks – especially for cervical, penile, oral and anal cancer. The virus is usually transmitted sexually and does not present any symptoms when initially infected. Symptoms would only begin to develop once the person has reached later stages of cancer. Low risk HPV can cause genital warts, but generally do not cause cancer.

Both men and women who engage in receptive anal sex are at risk of developing anal cancer due to high risk HPV infections.

Over 90% of all cervical cancers are due to high risk HPV infections. Fortunately, HPV infection is preventable with an effective vaccine. The latest vaccine against HPV is the Gardasil 9 vaccine, which protects against both cancer and wart-related HPV strains.

Women can also reduce the risk of cervical cancer by undergoing regular pap smear tests if one is sexually active and below the age of 30. For those above the age of 30, pap smear and high risk HPV infection testing is recommended every 5 years, and has been found to be more sensitive in detecting early cervical cancers than pap smears alone.

What about Hepatitis C?

Much like Hepatitis B, Hepatitis C can also be transmitted through blood and sexual encounters.

While there are screenings available for the virus, no vaccine is currently available for more effective protection.

However, best practices can be applied in order to avoid contracting the virus:

• Use single-use needles
• Use properly sterilised equipment
• Practice safe sex

How do I know if I have cancer?

Many health screening blood tests may include cancer markers, which can be abnormally elevated if someone has cancer. A few examples of cancer markers would be PSA for prostate cancer, CEA for bowel and breast cancer, and CA 19-9 for pancreatic cancer. An abnormal reading does not necessarily mean that cancer is present, but may necessitate further tests to confirm or exclude a diagnosis.

While cancer is a much dreaded word even in current times, treatment for many cancers are now highly effective and no longer carry as many side effects compared to in the past.

Despite that, the best thing one can do is to modify their lifestyle to reduce risk factors, obtain recommended vaccinations, and opt for regular screenings so that they are always aware of their health status.