High risk – Canadian Partnership Against Cancer

Screening individuals at high risk

Individuals at high-risk have a greater lifetime risk of developing breast cancer or developing more aggressive breast cancers at an earlier age. Currently, there are no national guidelines for screening individuals at high-risk and screening protocols vary across jurisdictions. The definition of high-risk of developing breast cancer also varies across Canada.

Three provinces and two territories breast cancer programs manage participants identified as high-risk of developing breast cancer. Their management strategies include recommending mammography, MRI and/or ultrasound screening. Some programs do not manage high-risk participants directly, but refer those individuals to a high-risk program or clinic. Depending on the province or territory, guidelines recommend that individuals at high-risk start screening at age 30, 40 or 50 and stop at age 69 or 74.

Definitions of high-risk for breast cancer

P/T	Known carrier of a deleterious gene mutation (e.g. BRCA1, BRCA2)	First-degree relative of a mutation carrier (e.g. BRCA1, BRCA2) and have declined genetic testing	At ≥ 25% lifetime risk of breast cancer (assessed using IBIS or BOADICEA/ CanRisk risk assessment tool)	Received chest radiation before age 30 and at least 8 years previously	Other
YT					Does not classify participants as high risk
NT	✓	✓		✓	· Confirmed mutations of BRCA1 or BRCA2 genes · Radiation treatment to chest area · First degree family history of breast cancer · Personal or first degree family history of ovarian cancer · Highly dense breast tissue (Greater or equal to 75% as shown on mammogram) · Personal history of breast biopsies showing Atypical Ductal Hyperplasia
NU					· Patient who has had breast cancer · 1^st line relative · Patient is symptomatic
BC	✓	✓	✓	✓	· Very strong family history of breast cancer: 2 cases of breast cancer in close female relatives on the same side of the family, both diagnosed before age 30, or 3 or more cases of breast cancer in close female relatives on the same side of the family, with at least one diagnosed before age 50
AB	✓	✓	✓	✓	· Ashkenazi decent · ADH, ALH, LCIS
SK	✓	✓	✓	✓	· Radiologist recommendation · Breast density · ADH, ALH, LCIS · physician/radiologist request
MB	✓				· The ‘Claus model’ of risk assessment · Ashkenazi decent · ADH, ALH, LCIS
ON	✓	✓	✓	✓	· Ages 30-74 * · No breast cancer symptoms · Deleterious gene mutations that confer higher risk of breast cancer (e.g., TP53, PTEN, CDH1)
QC					Does not classify participants as high risk
NB					Under evaluation as part of current Increased /High Risk Guideline development
NS	✓	✓	✓	✓
PE	✓	✓	✓	✓
NL	✓	✓		✓

_{ON: *The High Risk Ontario Breast Screening Program (OBSP) does not accept new participants over age 70. However, when participants already in the High Risk OBSP turn 70, the program will continue to screen them with only mammography every year until they are age 74.

Abbreviations: Atypical Ductal Hyperplasia (ADH)^, Atypical Lobular Hyperplasia (ALH)^, and Lobular Carcinoma in Situ (LCIS)~

^ cancer.org/cancer/breast-cancer/non-cancerous-breast-conditions/hyperplasia-of-the-breast-ductal-or-lobular.html

~ cancer.org/cancer/breast-cancer/non-cancerous-breast-conditions/lobular-carcinoma-in-situ.html}

Management of participants at high-risk by screening programs

P/T	Does the program manage participants who are high risk?	How are high risk participants managed?	Recommended screening modality	Recommended start age	Recommended interval	Recommended stop age
YT
NT	✓	Mammography only other modalities managed by PCP	YKBSP: mammography and ultrasound; MRI in some cases HRBSP: mammography	40	Based on radiologist recommendation	74
NU	✓	Referred to diagnostic centre	Mammography	Varies
BC		Eligible for annual routine screening, but no supplemental screening, referred to high risk clinic	Mammography	40	Annual	74
AB		Managed by PCP or high risk clinics	Mammography and screening breast MRI	No earlier than 25 and no later than 40	Annual	74
SK		Managed by PCP referral to High Risk Screening program	N/A	N/A	N/A	N/A
MB		Eligible for annual routine screening	Mammography	50	Annual (can vary) Or as per radiologist recommendations	74 (75+ have option to continue screening)
ON*	✓	Referred to the High Risk OBSP by physician Once enrolled in the High Risk OBSP, the participant’s High Risk OBSP site manages their initial and subsequent screenings and communication of results.	30-69: Mammography and MRI (or ultrasound if MRI is not medically appropriate) 70-74: Mammography only	30	Annual	74
QC
NB		Currently managed by radiologist	Under evaluation as part of current Increased/High Risk Guideline development	Under evaluation as part of current Increased/High Risk Guideline development	Under evaluation as part of current Increased/High Risk Guideline development	Under evaluation as part of current Increased/High Risk Guideline development
NS^	✓	Eligible for annual screening mammography and screening breast MRI. Annual requisitions for MRI no longer required. High risk patients will be managed similar to average risk clients.	Screening Mammography and MRI spaced 30 days apart	30	Annual	74
PE	✓	Annual screening (referral from PCP is required)	Mammography and MRI	40 (or as recommended by a radiologist)	Annual	74
NL		Eligible for annual routine screening, but no supplemental screening, PCP may order supplemental testing – MRI

_{ON: *Participants must have no breast cancer symptoms and require a valid Ontario Health Insurance Plan number and confirmed high risk status based on program criteria to participate in the High Risk Ontario Breast Screening Program (OBSP). The High Risk OBSP does not accept new participants over age 70. However, when participants already in the High Risk OBSP turn 70, the program will continue to screen them with only mammography every year until they are age 74.

NS: ^Nova Scotia Breast Screening Program’s high-risk screening clinical practice guideline has been approved.}

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Screening individuals at high risk

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