Breast Cancer Screening in Quebec: Guide to the PQDCS Program and Risk Factors
Breast cancer remains the most frequently diagnosed cancer among women, affecting approximately one in eight individuals over their lifetime. To catch tumors early, Quebec operates the Programme québécois de dépistage du cancer du sein (PQDCS), inviting women aged 50 to 74 to undergo a free mammogram every two years. Participants receive a letter by mail inviting them to schedule an appointment at a designated screening center in their region, such as the L’Hôpital de Mont-Laurier, the CMSSS d’Argenteuil, and the CMSSS de Sainte-Agathe in the Laurentians.
- The PQDCS invites women aged 50 to 74 by mail for a free screening mammogram every two years, targeting a high-frequency disease where early detection significantly alters patient outcomes.
- Quebec’s screening program excludes women aged 45 to 49, drawing criticism from the Canadian Cancer Society and the Association des radiologistes du Québec despite a provincial recommendation to expand coverage.
- Mammography remains the only screening exam proven to reduce breast cancer mortality, lowering the risk of death by about 40 percent in women aged 50 to 69.
Screening Access Gaps for Women Aged 45 to 49
While the standard program focuses on older populations, women aged 45 to 49 remain excluded from the PQDCS, a discrepancy highlighted by the Canadian Cancer Society. La Presse reported that the Institut national d’excellence en santé et en services sociaux (INESSS) recommended integrating this younger cohort a year ago, yet the government has not implemented systematic screening for them. Dr. Denis Soulières, hematologist-oncologist and scientific and medical spokesperson for the Canadian Cancer Society, explains that a higher breast cancer mortality rate is observed in Quebec compared to the rest of Canada, alongside an incidence rate that is also higher than elsewhere in the country. Data shows an increase in cases among younger women, rising from 7-8% to 12-13% over 30 years, while Statistique Canada reported there were 131 cases of breast cancer per 100,000 women aged 40 to 49 across the country in 2019. The Ministère de la Santé et des Services sociaux (MSSS) took a position last December in favor of a gradual approach to improve the PQDCS before committing to expanding it to women aged 45 to 49, while the Fondation du cancer du sein du Québec believes it is necessary to target Quebec women of all ages with a moderate or high risk of breast cancer rather than specifically targeting those aged 40 to 49 or 45 to 49.
Quebec Records High Mammogram Anomaly Recall Rates
Discussions surrounding program expansion involve balancing early access with clinical follow-up capacity. In Quebec, the recall rate for anomalies following an initial mammogram among women aged 50 to 69 reached 22,4% in 2023, representing one of the highest rates in the country according to an INESSS report, which also notes that wait times for access to a mammogram exceed ministerial targets in certain regions. Dr. Grégoire Bernèche, president of the Association des radiologistes du Québec, acknowledged the high recall rate but argued it should not halt expansion, suggesting that high-volume readers can effectively absorb the additional volume from women in their late forties.
Risk Factors and Diagnostic Pathways in Regional Centers
Beyond age, breast cancer risk involves personal characteristics such as being a woman, age, a history of breast cancer, high breast density, exposure to chest radiotherapy before the age of 30, early onset of menstruation, late pregnancy or absence of pregnancy, and menopause occurring after age 55. Heredity also plays an important role through family history on either the maternal or paternal side, genetic mutations in the BRCA1 and BRCA2 genes—where the risk for ovarian cancer is estimated between 16% and 68% for BRCA1 mutation carriers and between 11% and 27% for BRCA2 carriers—as well as Ashkenazi Jewish ancestry. Modifiable risk factors include alcohol consumption, smoking, postmenopausal obesity, and postmenopausal hormone replacement therapy.
Mammography reduces mortality by approximately 40 percent in the 50-to-69 demographic and often spares patients from intensive treatments like mastectomies or chemotherapy.
Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.