1. 1

2. National Cancer Institute, Cancer Screening Overview, 2012.
What is screening?
Screening is the name given to a range of tests that can detect cancer at an early stage before symptoms appear
Finding cancer early usually means it is easier to treat/cure
By the time symptoms appear, the cancer may have grown and spread and therefore be more difficult to treat/cure
Breast Cancer Screening
Evidence: NCI Screening Overview 2012 (p 1)
National Cancer Institute, Cancer Screening Overview, 2012.

3. Screening: the rationale
For screening to be effective, two requirements must be met:
A test or procedure must be available to detect
cancers earlier than if the cancer were detected
as a result of the development of symptoms !
Evidence must be available that treatment initiated
earlier as a consequence of screening results in an
improved outcome
Evidence: NCI Cancer Screening HCP 2012 (p2) !
National Cancer Institute, Cancer Screening HCP, 2012.

4. Patient‘s blood sample
Screening tests
A variety of tests are used in cancer screening:
Physical exam and history: check general health and review medical history
Laboratory tests: investigate samples of tissue, blood, urine, etc.
Imaging: visualise the insides of the body using e.g. x-ray, ultrasound, CT, MRI, etc
Molecular tests: look for specific mutations that are linked to some types of cancer
Cervical Cancer Screening
Normal
Pap smear
Abnormal
Biopsy
Evidence: NCI Cancer Screening Overview 2012 (p1)
Pathology
Patient‘s blood sample or
tissue sample
Proteomic profile
Genomic profile
National Cancer Institute, Cancer Screening Overview, Artwork originally created for the National Cancer Institute.
Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.

5. Screening: pros and cons
Reduction in cancer deaths
3–35% of premature deaths due to cancer could be avoided with screening
Improved outcomes (does not apply in all cases)
Cons
Some screening procedures carry their own risks
False negative results – patient wrongly assured there is no problem
False positive results – patient may receive treatment they do not need
Evidence: NCI Cancer Screening HCP 2012 (p1, 3)
National Cancer Institute, Cancer Screening HCP, 2012.

6. Screening and high risk populations
By focusing on high-risk populations, screening resources can be better applied
Patients with a personal history/strong family history of cancer are deemed to be high-risk
The ability to test for specific genetic mutations has further refined the identification of high-risk patients
Heredity and cancer
All Breast Cancer Patients
Inherited factor(s)
Other factor(s)
Genes and Cancer
Chromosomes
are DNA molecules
Evidence: NCI Cancer Screening HCP 2012 (p2)
Chemicals
Radiation
Heredity
Viruses
National Cancer Institute, Cancer Screening HCP, Artwork originally created for the National Cancer Institute.
Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.