Glossary
Aboriginal or Torres Strait Islander: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander. See also Indigenous.
age‑specific rate: A rate for a specific age group. The numerator and denominator relate to the same age group.
age‑standardised rate: A method of removing the influence of age when comparing populations with different age structures. This is usually necessary because the rates of many diseases vary strongly (usually increasing) with age. The age structures of the different populations are converted to the same ‘standard’ structure, which allows comparison of disease rates.
assessment: Further investigation of a mammographic abnormality or symptom reported at screening.
Australian Statistical Geography Standard (ASGS): Common framework defined by the Australian Bureau of Statistics for collection and dissemination of geographically classified statistics. The ASGS replaced the Australian Standard Geographical Classification (ASGC) in July 2011.
benign: Not malignant.
biopsy: Small sample of tissue that is taken to obtain a definitive diagnosis of an abnormality.
BRCA1 or BRCA2 gene mutation: BRCA1 and BRCA2 are human genes that produce tumour suppressor proteins. These proteins help repair damaged DNA and, therefore, play a role in ensuring the stability of the cell’s genetic material. When either of these genes is mutated, or altered, such that its protein product either is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer.
cancer death: A death where the underlying cause of death is indicated as cancer.
People with cancer who die of other causes are not counted in the mortality statistics in this publication.
cancer (malignant neoplasm): A large range of diseases in which some of the body’s cells become defective, and begin to multiply out of control. These cells can invade and damage the area around them, and can also spread to other parts of the body to cause further damage.
confidence interval: A range determined by variability in data, within which there is a specified (usually 95%) chance that the true value of a calculated parameter lies.
DALY (disability‑adjusted life years): Measure (in years) of healthy life lost, either through premature death defined as dying before the expected life span at the age of death (YLL) or, equivalently, through living with ill health due to illness or injury (YLD).
ductal carcinoma in situ (DCIS): A non‑invasive tumour of the mammary gland (breast) arising from cells lining the ducts.
false negative: A test that has incorrectly observed that the disease is not present.
false positive: A test that has incorrectly observed that the disease is present.
first screening round: See screening round.
in situ: A Latin term meaning in place or position; undisturbed.
incidence: The number of new cases (for example, of an illness or event) occurring during a given period, usually 1 year.
index screening year: The year for which an interval cancer rate and program sensitivity rate are determined.
index screens: All screening examinations performed within the index screening year.
Indigenous: A person of Aboriginal and/or Torres Strait Islander descent who identifies as an Aboriginal and/or Torres Strait Islander. See also Aboriginal or Torres Strait Islander.
interval cancer (invasive): (as defined for national reporting purposes by Kavanagh and others (1999), with minor changes endorsed by the then‑named National Advisory Committee):
- an invasive breast cancer diagnosed after completion of a negative screening episode and before the next screening examination (within 24 months from the date of the previous screen)
- a case of invasive breast cancer that is diagnosed at early review or in the interval between assessment and early review, where the recommendation for early review is 6 months or more from the screening date
- breast cancer diagnosed in a participant by BreastScreen Australia within 24 months of a negative screen (early rescreen) if the participant presents with a breast lump and/or clear or bloodstained nipple discharge in the breast in which the breast cancer is diagnosed
- an invasive breast cancer diagnosed between 6 and 24 months after a recommendation for assessment is made and a participant fails to attend assessment.
invasive cancer: A tumour whose cells have spread locally and have the potential to spread to nearby healthy or normal tissue or to more distant parts of the body.
malignant: Abnormalities in cells or tissues consistent with cancer.
mammogram: A radiographic depiction of the breast.
menarche: The first menstrual period.
menopause: Permanent cessation of menstruation.
morbidity: Illness.
mortality: The number of deaths occurring during a given period.
new case (of cancer): A person who has a new cancer diagnosed for the first time.
One person may have more than one cancer and therefore may be counted twice in incidence statistics if it is decided that the two cancers are not of the same origin.
This decision is based on a series of principles set out in more detail in a publication by Jensen and others (1991).
person-years: The denominator for the interval cancer rate, it is the ‘number of years at risk’ of being diagnosed with an interval cancer and takes into account participants who screen annually rather than every 2 years (who would be at risk for the first year after their screen but not the second).
rescreening: The next screening examination after the screening episode in the index screening year.
risk factor: An attribute or exposure that is associated with an increased probability of a specified outcome, such as the occurrence of a disease. Risk factors are not necessarily
the causes of disease.
screening: The performance of tests on apparently well people in order to detect a medical condition at an earlier stage than would otherwise be the case.
screening episode: All attendances for screening and assessment within 6 months relating to a particular round of screening. It starts at the date of attendance for screening. It is completed when:
- a recommendation is made to return the participant to routine rescreening
- a recommendation is made for early review at 6 months or more from the screening date
- a diagnosis of cancer is made
- the participant fails to attend for technical recall or assessment within 6 months
- the participant dies.
screening round: The first screening round is a participant’s first visit to a mammography screening service; a subsequent screening round means that they have been screened before. For example, if they attend for a fourth screening round, they have been screened 3 times before.
significant difference: Where rates are referred to as significantly different, or one rate is deemed significantly higher or lower than another, these differences are statistically significant. Rates are deemed statistically significantly different when their confidence intervals do not overlap, since their difference is greater than what could be explained by chance. See ‘confidence intervals’ in Appendix E for more information.
symptom: Any evidence of disease apparent to the patient. For the purposes of this report, symptoms refer to a self‑reported breast lump and/or bloodstained or watery nipple discharge.
target population: Women in the population who are actively targeted by BreastScreen Australia; this is done on the basis of age and was women aged 50–69 until July 2013, after which time this changed to women aged 50–74.
tumour: An abnormal growth of tissue. Can be benign (not a cancer) or malignant (cancer).
ultrasound: Diagnostic method based on the reflection of ultrasonic sound waves generated through scanning of, in this case, the breast. The reflections are viewed on a computer screen or photograph and checked for variations in images.
underlying cause of death: The condition, disease or injury initiating the sequence of events leading directly to death; that is, the primary, chief or principal cause.
YLD (years lived with disability): A measure of the years of what could have been a healthy life but were instead spent in states of less than full health. YLD represent non‑fatal burden.
YLL (years of life lost): Years of life lost due to premature death, defined as dying before the global ideal life span at the age of death. YLL represent fatal burden.