Cancer is a disease that we’re all aware of, but until you or someone close to you receives a diagnosis, you may not be familiar with exactly what cancer is, why it happens and the risk factors that may predispose you to it.
Cells division is a normal function of a healthy, working body and happens countless times a day. Cells divide for many reasons, for example, if you cut yourself, cell division occurs to replace the damaged cells.
Usually when cells in the body divide, the new cells are exact replicas of the old cells. When this process goes wrong, the new cells are slightly different from the old ones. This is called a mutation.
More on Mutations
Most mutations are spontaneous, with no real reason for the change. The majority of these mutations serve no purpose and simply die. However, a small number will become abnormal and multiply out of control, causing cancers.
Most cancers are not caused by a single event. There are usually several different things that happen over time which cause cells to become abnormal.
Most cancers start in a particular organ, which is known as the primary site or primary tumour. As the cells increase, they gain strength and can invade tissue and organs around them, spreading or ‘metastasising’ to other parts of the body.
The difference between benign and malignant tumours:
Cancerous tumours are described as ‘malignant’, whilst non-cancerous are ‘benign’.
Benign tumours do not spread to other parts of the body, although some benign tumours are precancerous and may progress to cancer if left untreated.
Malignant tumours are made up of cancer cells. Initially, this malignant tumour may be confined to its original site. If untreated, the cancer cells could metastasise.
What is metastasis?
Metastasis is a way of describing how cancer spreads from one organ to another. It occurs when cancer cells break away from the primary tumour and travel via blood or lymph vessels to a new organ to form secondary tumours.
The new metastatic tumour is classed as the same cancer as the primary tumour. So if breast cancer cells spread to the brain, these cancer cells are breast cancer cells, not brain cancer cells.
What are the different types of cancer?
Cancers are usually named for the organ or cell type of the primary cancer. For example, cancer that started in the lung would be referred to as lung cancer.
There are a number of different cancer type groupings:
- carcinoma: cancer that begins in the skin or in tissues that line or cover internal organ
- sarcoma: cancer that begins in bone, fat, muscle, blood vessel, or other supportive or connective tissue.
- leukaemia: cancer that begins in the tissues that make blood cells, such as the bone marrow.
- lymphoma and myeloma: cancers that start in cells of the immune system .
- central nervous system cancer: cancer that begins in the brain or spinal cord - for example, glioma.
What are the risk factors?
Cancer doesn’t discriminate. It can affect anyone, regardless of age, gender or socioeconomic status. For most cancers the causes are not fully understood. However, certain lifestyle choices can reduce your risk of developing cancer, These are known as ‘lifestyle risk factors’ .
The most prevalent lifestyle risk factors include:
- Smoking: Associated with lung, esophagus, larynx, mouth, throat, kidney, bladder, liver, pancreas, stomach, cervix, colon, and rectum cancers, as well as acute myeloid leukemia .
- Alcohol consumption: There is evidence that drinking alcohol increases the risk of female breast, liver, mouth, throat, oesophagus and bowel cancer. It may also increase the risk of stomach cancer .
- High intake of processed meat and high-fat foods: High fat, low fibre foods may increase the risk of bowel, lung, prostate and uterine cancers .
- Obesity: Being overweight increases your risk of breast, bowel, kidney, liver, endometrial, ovarian, stomach, oesophagus, gallbladder, pancreas and prostate cancers. Obesity is the cause for nearly 4,000 cancer cases in Australia each year.
- Physical Inactivity: Physical inactivity increases your risk of bowel cancer and breast cancer, and possibly prostate, uterine and lung cancer. Being inactive also contributes to obesity.
- UV radiation: Exposure to UV radiation from the sun can cause melanomas, and other skin cancers.
Other risk factors are less easy to control. The risk of cancer increases as we age, because the older we get, the more times our cells divide, thus leading to a higher occurrence of mutations.
Contracting certain infections can also increase risk. For example, the HPV infection can help abnormal cells continue to live and divide and is the cause of most cases of cervical cancer, and chronic hepatitis B or C infection can be associated with liver cancer.
Family history can, in some cases, greatly increase the risk factor. Some genes that can predispose a person to cancer can be passed on from parent to child.
If you have a family history of cancer or have some worrying symptoms, the best thing you can do is schedule an appointment to see your GP .
Cancer today
Thanks to research, the 5-year relative survival for all cancers combined has increased to 69% (2012-2016) from 51% (1987-1991) . This means that people diagnosed with cancer have a 69% chance of surviving for at least 5 years.
It is estimated that 145,483 (76,729 males and 68,754 females) will be diagnosed with cancer this year alone, and that 48,099 (26,938 males and 21,161 females), demonstrating that cancer still poses a major threat.
The ten most common cancer types in Australia are:
- Breast cancer
- Prostate cancer
- Melanoma of the skin
- Colorectal cancer
- Lung cancer
- Non-Hodgkin Lymphoma
- Kidney cancer
- Pancreatic cancer
- Thyroid cancer
- Uterine cancer
The estimated ten most common causes of cancer death in Australia this year are:
- Lung cancer
- Colorectal cancer
- Pancreatic cancer
- Prostate cancer
- Breast cancer
- Cancer of unknown primary site
- Liver cancer
- Non-Hodgkin Lymphoma
- Brain cancer
- Melanoma of the skin
Despite these frightening statistics, a cancer diagnosis is no longer an automatic death sentence. Overall, people diagnosed with cancer are now living longer . Early detection and treatment methods have improved significantly over the years but can only continue to improve if crucial research is funded.
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If you have a family history of cancer, have some worrying symptoms or just want to make sure you’re fit and healthy, the best thing you can do is schedule an appointment to see your GP . They can test you, talk you through symptoms, or, if needed, refer you to a specialist. The fastest and easiest way to search for and book healthcare appointments online is with MyHealth1st.
Resources:
Cancer Australia AIHW