Breast Cancer Screening

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

1. National Cancer Institute, Cancer Screening Overview, 2012.

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

!

1. National Cancer Institute, Cancer Screening HCP, 2012.

Cervical Cancer Screening

Screening tests

National Cancer Institute, Cancer Screening Overview, 2012. Artwork originally created for the National Cancer Institute. Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.

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

Biopsy

NormalPap smear

AbnormalPap smear

Patient‘s blood sampleor

tissue sample

Pathology

Proteomic profile

Genomic profile

Screening: pros and cons

Pros• 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

1. National Cancer Institute, Cancer Screening HCP, 2012.

Heredity and cancer

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

National Cancer Institute, Cancer Screening HCP, 2012. Artwork originally created for the National Cancer Institute. Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.

All Breast Cancer Patients

Inherited factor(s) Other factor(s)

Genes and Cancer

RadiationViruses

Chemicals

Heredity

Chromosomesare DNA molecules