Understanding cancer statistics
Statistics is a type of maths. It involves collecting and interpreting large amounts of information.
Cancer statistics show what happens in large groups of people with cancer. They cannot predict what will happen to you or any other individual person.
Where do cancer statistics come from?
Information about all cancers that occur in Australia is collected by law. It is collected by hospitals and pathology laboratories, as well as registries of births, deaths and marriages. It is then sent to cancer registries in each state or territory.
The information is kept securely and can only be used for specific reasons. These include:
- calculating how many people are diagnosed with cancer or die from cancer
- measuring how well cancer treatments or programs are working
- planning services for people with cancer
- developing reports about different cancers
- undertaking cancer research.
What is cancer incidence?
Cancer incidence describes the number of new cases of cancer in a population or large group of people. It is not the same as an individual person’s chance of getting cancer.
Cancer incidence describes the number of new cases of cancer in a particular group of people over a certain period of time. It can be described as a number of people out of the whole group, or as a percentage of the group.
Incidence can be used to see how common cancers are. It can also show whether they get more or less common over time.
EXAMPLE
In NSW in 2014:
- 5,064 people were diagnosed with bowel cancer
- 1,069 people were diagnosed with pancreatic cancer.
This shows that bowel cancer was more common than pancreatic cancer in NSW in 2014.
(Information from the Cancer Institute NSW)
What is cancer survival?
Cancer survival rates measure the number of people who are still alive a certain time after cancer diagnosis. Reading or talking about survival rates can be upsetting. Talk to your doctor if you have any questions or concerns about this.
Cancer survival can be described in many ways, but it always includes some key pieces of information. These are:
- a time period – usually 1, 5 or 10 years
- a group or population – the people being looked at
- a cancer type – either all cancers or a particular type of cancer.
EXAMPLE
The 5-year survival of females in NSW diagnosed with cancer between 2005 and 2009 was 65.6%.
- time period = 5 years
- group = females in NSW who got a cancer diagnosis between 2005 and 2009
- type of cancer = all cancers.
This means that out of all females in NSW diagnosed with any cancer between 2005 and 2009, more than 65 in every 100 were still alive 5 years after their diagnosis.
Survival rates are also measured for groups of people whose cancer was at a certain stage when they were diagnosed.