Cancer screening

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.

adenoma (adenomatous polyp): A benign tumour that arises from epithelial cells. All adenomas have malignant potential. Adenomas in the rectum or colon have a higher chance of developing into cancer (adenocarcinoma) than adenomas in most other organs. Adenoma can be classified from highest risk (advanced) to lowest risk (diminutive).

adverse event: In the context of a colonoscopy, a complication such as bleeding or perforation reported after having the procedure.

assessment: Further investigation of a abnormality or symptom reported at screening.

asymptomatic: Describes being without symptoms.

benign: Term that describes non-cancerous tumours that may grow larger but do not spread to other parts of the body.

biopsy: Small sample of tissue that is taken to obtain a definitive diagnosis of an abnormality.

bowel (colorectal) cancer: Comprises cancer of the colon and cancer of the rectum.

cancer (malignant neoplasm): A large range of diseases in which some of the body’s cells become defective, begin to multiply out of control, can invade and damage the area around them, and can also spread to other parts of the body to cause further damage.

colonoscopy: A procedure to examine the bowel using a special scope (colonoscope) usually carried out in a hospital or day clinic.

cytology: Cytology means ‘study of cells’ and, in the context of cervical screening, refers to cells from the cervix that are collected and examined for abnormalities. Cervical cytology using the Pap test is the primary screening tool of the NCSP.

detection: The process of identifying an abnormality of tissue or cells that may be cancerous.

ductal carcinoma in situ (DCIS): A non-invasive tumour of the mammary gland (breast) arising from cells lining the ducts.

high-grade cervical abnormality: Abnormalities are graded depending on how much of the lining of the cervix abnormal cells occupy; ‘low-grade’ abnormalities are contained in the top layer of the lining of the cervix, while ‘high-grade’ abnormalities occupy more layers.

histology: The examination of tissue through a microscope, the microscopic characteristics of cellular structure and composition of tissue.

HPV (human papillomavirus): Human papillomavirus, a virus that affects both males and females. There are around 100 types of HPV, with around 40 types known as genital HPV that are contracted through sexual contact. Persistent infection with high-risk HPV types can lead to cervical cancer, whereas infection with low-risk types of HPV can cause genital warts.

iFOBT (immunochemical faecal occult blood test): A test used to detect tiny traces of blood in a person’s faeces that may be a sign of bowel cancer. The iFOBT is a central part of Australia’s National Bowel Cancer Screening Program.

incidence: The number of new cases (of an illness or event, and so on) occurring during a given period.

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.

in situ: A Latin term meaning in place or position; undisturbed. A tumour that has not invaded surrounding tissue but in some people or conditions could undergo further change and become invasive. Some authorities call this non-invasive cancer while others say that it is not cancer.

interval cancer: A cancer diagnosed within the screening interval period after a negative (or a negative or inconclusive) screening test result.

invasive: A tumour with the capacity to spread to surrounding tissue or to other sites in the body. Also called malignant.

lymph node: A mass of lymphatic tissue, often bean-shaped, that produces adaptive immune system cells and through which lymphatic fluid filters. These nodes are located throughout the body.

malignant: A tumour with the capacity to spread to surrounding tissue or to other sites in the body. See also invasive.

mammogram: An X-ray of the breast. It may be used to assess a breast lump or as a screening test in women with no evidence of cancer.

morbidity: Ill health in an individual, or the level of ill health in a population or group.

mortality: Number or rate of deaths in a population during a given time period.

mortality rate: Mortality rates are based on numbers of deaths registered in a year divided by the size of the corresponding population. Causes of death are classified according to the Tenth revision of the International Classification of Diseases (ICD) along with codes from other ICD revisions used in the World Health Organization Mortality Database. For making comparisons internationally, age-standardised rates per 100,000 population for selected causes are often calculated using the total OECD population for 2010 as the reference population. The direct method of standardisation is used for age-standardised calculations.

National HPV Vaccination Program: This program was first introduced on 1 April 2007 as a program for females. At its inception, it comprised an ongoing program for females aged 12–13 administered through schools, as well as a catch-up program for females aged 13–26 between 2007 and 2009, with females aged 13–17 vaccinated through schools and females aged 18–26 vaccinated through the community. From February 2013, the current school-based program for females aged 12–13 was extended to males aged 12–13, with a catch-up program in 2013 and 2014 for males aged 14–15.

neoplasm: An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Neoplasm may be benign (not cancer), or malignant (cancer). Also called tumour.

Pap smear (Pap test): Papanicolaou smear, a procedure to detect cancer and pre-cancerous conditions of the female genital tract, which is the screening test of the National Cervical Screening Program. During a Pap test, cells are collected from the transformation zone of the cervix—the area of the cervix where the squamous cells from the outer opening of the cervix and glandular cells from the endocervical canal meet. This is the site where most cervical abnormalities and cancers are detected. For conventional cytology, these cells are transferred onto a slide, and sent to a pathology laboratory for assessment. Collected cells are then examined under a microscope to look for abnormalities.

participation: The proportion of eligible people who participated in a screening program within a specified time frame.

polyp: Polyps are small growths of colon tissue that protrude into the colonic or rectal lumen. They are usually asymptomatic, but sometimes cause visible rectal bleeding and, rarely, other symptoms. Polyps have the potential to become adenomas and, later, cancers.

polypectomy: The removal of a polyp or adenoma.

population-based cancer screening: Involves the systematic use of a test or series of tests to identify individuals at risk of cancer. The screening test is not intended to be diagnostic—it aims to identify individuals who should be referred for further investigation using diagnostic tests. The aim of population-based cancer screening is to reduce the burden of disease, either by detecting cancer at an earlier stage when treatment options are often more effective, or by detecting and treating abnormalities that if left may become cancerous.

positive predictive value: In the context of bowel cancer screening, the percentage of people who returned a positive NBCSP screening test (warranting further assessment) that underwent a diagnostic assessment and were diagnosed with cancer, measured 12 months after the defined period.

prognosis: The likely outcome of an illness.

remoteness classification: Each state and territory is divided territory is divided into 5 classes of remoteness based on their relative accessibility to goods and services (such as to general practitioners, hospitals and specialist care) as measured by road distance. These regions are based on the Accessibility/Remoteness Index of Australia and defined as Remoteness Areas by the Australian Statistical Geographical Standard (ASGS) (from 2011 onwards) in each Census year. The 5 Remoteness Areas are Major cities, Inner regional, Outer regional, Remote and Very remote. 

screening: Testing or examination of asymptomatic individuals for a specific cancer. The screening process may be indiscriminate, opportunistic (during a routine health check) or systematic. See also population-based cancer screening.

screening positivity percentage: The proportion of people who participated in screening and returned a positive screening result (warranting further assessment).

sensitivity: Sensitivity of a screening test is the ability of that test to accurately identify the disease in people who have that disease.

Socio-Economic Indexes for Areas (SEIFA): A set of indexes, created from Census data, that aim to represent the socioeconomic position of Australian communities and identify areas of advantage and disadvantage. The index value reflects the overall or average level of disadvantage of the population of an area; it does not show how individuals living in the same area differ from each other in their socioeconomic group.

socioeconomic position: An indication of how ‘well off’ a person or group is. Socioeconomic position is often reported using the Socio-Economic Indexes for Areas, typically for five groups (quintiles) – from the most disadvantaged (worst off or lowest socioeconomic area) to the least disadvantaged (best off or highest socioeconomic area).

stage: The extent of a cancer in the body. Staging is usually based on the size of the tumour, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

symptom: Any evidence of disease apparent to the patient.

tumour: An abnormal growth of tissue. Can be benign (not a cancer) or malignant (a 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.