What is cancer?
Cancer is a disease of the cells of the body. It happens when cells grow and multiply in an uncontrolled way. These cancer cells can form tumours and invade and destroy surrounding healthy tissue.
Sometimes cells that are growing abnormally do not spread. These cells are called ‘benign’, or not dangerous.
Some cells spread, or are capable of spreading, to surrounding areas or to other parts of the body. These cells are called ‘malignant’, or cancer. When cancer spreads to other parts of your body, this is called ‘metastasis’.
The most common cancers in Australia are:
- prostate cancer
- breast cancer
- bowel cancer
- endometrial cancer
- lung cancer
- skin cancers
- head and neck cancers
- uterine cancer
- cervical cancer
- ovarian cancer
- thyroid cancer
What are the symptoms of cancer?
Early signs of cancer include changes to your body's normal processes, such as a change to your bowel habits. Other symptoms can include unexplained bleeding or the development of a lump.
Usually, these changes don’t mean you have cancer. But it’s important you see your doctor so they can investigate.
Potential signs and symptoms of cancer include:
- lumpiness or a thickened area in your breasts
- any changes in the shape of your breasts
- unusual nipple discharge
- a nipple that turns inwards (if it hasn't always been that way)
- unusual breast pain
- a lump in the neck, armpit or anywhere else in the body
- sores or ulcers that don't heal
- coughs or hoarseness that won't go away or coughing up blood
- changes in toilet habits that last more than 2 weeks
- blood in a bowel motion (poo) or in urine (wee)
- new moles or skin spots
- moles or skin spots that have changed shape, size or colour
- moles or skin spots that bleed
- unusual vaginal discharge or bleeding
- unexplained weight loss
- diarrhoea or constipation for no obvious reason
- a feeling of not having fully emptied your bowels after going to the toilet
- pain in your abdomen (tummy) or your rectum (back passage)
- persistent bloating
CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.
What causes cancer?
Often we don’t know why cancer happens. But there are some things that significantly increase your cancer risk.
Smoking is responsible for 1 in every 9 cases of cancer and 1 in every 5 deaths from cancer. Other risk factors include:
- drinking alcohol
- eating a poor diet
- being overweight
- not getting enough exercise
- being exposed to radiation (such as from sunlight)
Sometimes cancer runs in families. You can inherit genes that make you more likely to get cancer.
In other cases, cancer is associated with an infection. For example, cervical cancer is associated with some types of human papillomavirus (HPV) infection.
Being exposed to some chemicals and dust can also increase your risk of developing cancer.
When should I see my doctor?
There is a much greater chance of successfully treating cancer if it is found early. If you notice any changes, see your doctor immediately.
How is cancer diagnosed?
Many cancers grow slowly and it can be years before they cause symptoms.
Sometimes cancer is found during routine tests or when screening for cancer. Accurately diagnosing cancer can take time.
Sometimes a doctor may look inside your body. This is done with an endoscope, a long tube that has a light and camera attached to the end.
If cancer is suspected, your doctor will often take a biopsy. This involves taking a small sample of tissue that is examined in the laboratory. This will provide your doctors with information about the type of cancer and how aggressive it is.
How is cancer treated?
There are many ways to treat cancer. Treatments are improving all the time. The best type of treatment for you depends on the type of cancer and how advanced it is.
Some treatment options include:
- chemotherapy: powerful cancer-killing medicines
- radiotherapy: the controlled use of high energy X-rays
- surgery: to remove the cancer
- immunotherapy: treatment that uses parts your immune system to fight the cancer
- targeted therapy: medicine that only targets the cancer and not the other cells in your body
- hormone therapy: a treatment that uses hormones to stop or slow the cancer’s spread
- stem cell transplant: also called a bone marrow transplant, to treat some blood cancers
- palliative care: treatment to enhance your quality of life
- complementary therapies: therapies like massage and relaxation, to help you cope with treatment
You will see a range of health professionals during treatment. These may include an oncologist (cancer doctor), radiologist, surgeon, pathologist, nurses and your own doctor.
You might be invited to take part in a clinical trial. This is a way of testing new treatments. Clinical trials may give you access to treatments that aren’t usually available in Australia.
You can find out more about clinical trials and whether there is one available to test treatment for your cancer at the Australian Clinical Trials website.
What are the costs of cancer treatment?
Living with long-term illness can be expensive. The cost of cancer treatment depends on different factors, such as:
- whether you are treated in a public or private hospital
- if you continue to work, or take time off from work
- if you need to travel to receive treatment
- if you have private health insurance
Can cancer be prevented?
Almost 1 in 3 cancers can be prevented. The best ways to prevent cancer are to:
- quit smoking
- reduce your alcohol intake
- make sure your weight is healthy
- eat a balanced diet
- get enough exercise
- protect yourself from the sun
You can check your risk of cancer by using Cancer Australia’s online risk assessment tools.
What are the complications of cancer treatments?
Cancer treatments can cause side effects such as:
- hair loss
- fertility problems
Your doctor will tell you what side effects you may experience with your treatment. They will also help you manage the side effects.
Chemotherapy, bone marrow transplantation, and radiotherapy increase your risk of having a second cancer. But this will be considered carefully by your doctors when your treatment is planned.
Following a healthy lifestyle will also help to protect you from developing another cancer.
Who can I talk to for advice and support?
If you’ve been diagnosed with cancer, it’s normal to feel shocked, sad, angry or worried. It’s a good idea to look after yourself by:
- keeping active
- eating a nutritious diet
- talking to your doctor for help to manage any pain or sleep problems
- managing your finances and other affairs
There is plenty of support for you. The Cancer Council can give you advice on how to tell other people, including children.
Patient organisations have local groups where you can meet other people who have been diagnosed with cancer and are having treatment.
Your doctor or specialist will be able to answer your questions. You may also find it helpful to talk to a trained counsellor, psychologist or call a specialist helpline. If you have feelings of depression, talk to your doctor who will be able to provide advice and support.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: June 2022