Breast cancer

The Québec Breast Cancer Screening Program (PQDCS), was initiated in 1998 by the Ministry of Health and Social Services, offered as most other Canadian provinces and several other countries.

For any questions:

The program is aimed at women aged 50 to 69 who have never been diagnosed with breast cancer. They are advised to have a screening mammogram every two years.

The invitations are sent by personalized mail, using a list of protected data provided by the Régie de l’assurance maladie du Québec.

Many studies have shown that a screening mammogram can reduce mortality from breast cancer in this specific age group.

For more details about this screening program, please consult the PQDCS website.

What is a mammogram?

A mammogram is a radiological examination that uses X-rays to assess breast tissue.


Mammography remains the most effective and most radiologically sensitive method for detecting anomalies, benign or malignant lesions in the breast.


It allows detection of very small nodules, of a diameter of about 5 millimeters, that are non-palpable under physical examination, as well as microcalcification. The sensitivity of mammography is about 90%. This means that a normal mammogram does not rule out the presence of breast cancer.


During examination, breast compression is uncomfortable, but necessary for the following reasons:

  • it give a better picture of the interior of the breast;
  • it increases the accuracy of details;
  • it separates overlapping structures
  • it reduces movement;
  • it decreases the amount of radiation.

A breast can be compared to a bunch of grapes. The only way to detect a raisin in the center is by spreading the bunch.

Should I wear a thyroid shield during a screening mammogram?

It is not recommended to wear a thyroid shield during mammography. Not only is the radiation dose transmitted to the thyroid during a mammogram extremely low, but a shield risks masking important parts of the breast, perhaps making it necessary to repeat the procedure. For more details, visit: Association canadienne des radiologistes (in French only) 

Breast observation

It is important for women of every age to pay careful attention to their breasts.


When on the lookout for any changes in their breasts, women should:

  • know what is normal;
  • be aware of possible signs of cancer;
  • inspect them visually and by touching;
  • seek immediate consultation upon noticing any changes.


Stay attentive to any changes that may occur:

  • change in size, thickness, shape;
  • change in the skin (redness, irritation, folds, vascularization, etc.);
  • change in the nipples (discharge, dimpling, retraction, ulceration, etc.).

What about breast self-examination?

Numerous scientific studies have demonstrated that this method does not reduce breast cancer mortality and may result in unnecessary tests.

Genetic Testing

One in nine women will develop breast cancer in her lifetime. It is estimated that 5-10% of breast cancers are hereditary, 15 to 20% are familial.

In other words, the majority of breast cancers are unrelated to family history, rather they are caused by a genetic mutation referred to as sporadic or acquired, i.e. the cell damage is often the result of chance or of certain risk factors such as smoking or obesity.

What is genetic testing?

First, you should be aware that the result of this test only determines whether or not a woman is a carrier of a BRCA mutation, and is used to assess her risk of developing breast cancer. It does not predict whether she will develop breast cancer in her lifetime.


Genetic testing is performed on the basis of a blood sample. It detects the presence of a mutation in the genes, such as BRCA genes.


It is compulsory for genetic testing to be preceded by genetic counseling from various oncogenetic specialists. The only access to such counseling is through referral by a physician.

What is a BRCA gene?

The BRCA1 and BRCA2 genes, discovered in the 1990s, take their name from the words BReast CAncer. These genes, which are present in every cell of every human being, are specialized in controlling cell division, and are a protection against developing breast cancer. If one is born with a mutation in one of these genes, its ability to function well is impaired, and the risk of developing several cancers, including breast cancer, is increased.

Eligibility for genetic testing

Women are generally admitted for genetic testing if they are over 18 years of age and their risk of having a gene mutation is higher than 10%. This risk is assessed by taking the following criteria into account:

  • a BRCA mutation previously identified in the family;
  • multiple cases of first degree breast cancer in the family, especially before age 50;
  • breast cancer in a male relative;
  • breast cancer before age 45;
  • bilateral breast cancer, especially before age 50;
  • breast cancer and ovarian cancer;
  • certain types of breast cancer and ovarian cancer;
  • Ashkenazi Jewish ancestry;
  • A family history pointing to a rarer hereditary syndrome.

For more information on genetic testing, call the Info-cancer Hotline at 1-800-363-0063. A nurse will answer all your questions and let you know whether this test is indicated for you.

Consulter en génétique : cancer du sein ou de l’ovaire. CHU de Québec, Centre des maladies du sein Deschênes-Fabia, Quebec City 2013, 66 pp. Available in electronic format (in French only).