Breast screening in Canada, 2023-24
Management of participants with high breast density
On this page:
- Definition and data collection for high breast density by screening programs
- Notification of participants’ breast density
Evidence has shown that having dense breasts is associated with an increased risk of developing breast cancer, and that having dense breasts can make it more difficult to detect breast cancer by mammogram alone.
In Canada, some jurisdictions classify individuals with high breast density (defined as ≥75% glandular tissue or BI-RADS category D) as being at elevated risk; usually these individuals are eligible for more frequent screening.
Twelve provincial and territorial breast screening programs collect information on breast density. Nine jurisdictions notify participants of their breast density assessment alongside their mammography results and a breast density fact sheet. Others do not directly notify the participant of their breast density assessment; however, they inform the participants’ primary care provider.
Definition and data collection for high breast density by screening programs
| P/T | Definition of high breast density | Does the program collect information on breast density? | Does the program recommend more frequent screening for those with high breast density? |
|---|---|---|---|
| YT | BI-RADS* category D | ✓ | ✓ |
| NT | ≥75% glandular tissue | ✓ | ✓ |
| NU | ✓ | ||
| BC | BI-RADS*^ | ✓ | |
| AB | BI-RADS* category D | ✓ | ✓ |
| SK | BI-RADS category D* | ✓ | ✓ |
| MB | BI-RADS* category D | ✓ | |
| ON | BI-RADS Category D~ | ✓ | ✓ Recalled in one year instead of two years |
| QC | ≥75% glandular tissue | ✓ | |
| NB | BI-RADS* category C (heterogeneously dense) or D (extremely dense)** | ✓ The program’s legacy database is currently unable to collect this new BI-RADS classification data set. Historical data of categories as < or > 50% data is available |
Recommendation is mammography every two to three years with individualized supplemental screening, such as tomosynthesis, CESM, U/S or MRI, to be based upon radiologist recommendations |
| NS | BI-RADS category D (extremely dense) | ✓ | Participants with category D breast density will receive annual screening |
| PE | ≥75% glandular tissue
BI-RADS category D |
✓ | ✓ |
| NL | ≥75% glandular tissue | ✓ | ✓ Recalled in one year instead of two years |
*YK, BC, MB, NB, SK: Breast Imaging and Reporting Data System (BI-RADS) categories for breast density:
A — almost entirely fatty (<25% glandular)
B — scattered fibroglandular densities (25-50% glandular)
C — heterogeneously dense (51-75% glandular)
D — extremely dense (>75% glandular).
^BC: BC radiologists categorize breast composition using BI-RADS to assess the volume of breast density. The C and D categories are commonly referred to as “dense.” BC Breast Screening currently provides BI-RADS assessment for participants and providers; however, it has no definition for “high breast density.”
~ON: As of July 24, 2023, participants who have a breast (chest) density classification of BI-RADS D are recalled in 1 year. Prior to this date, the 1 year recall due to breast (chest) density was based on percent mammographic density (PMD) ≥75%.
**NB: Using Densitas AI technology province-wide for breast density reporting.
Notification of participants’ breast density
| P/T | Are participants notified of their breast density? | If participants are not notified of their breast density, are there any plans to send out notifications? |
|---|---|---|
| YT | No Participants can request information from their PCP; all screening reports include density information. |
Not at this time; working on a plan to implement this. |
| NT | No Documented on mammogram report sent to PCP, but not included on results letter received by participants. |
Intend to explore. |
| NU | – | – |
| BC | Yes Participants receive their BI-RADS breast density assessment with their results, along with an informational brochure. |
|
| AB | Yes Participants receive their BI-RADS breast density assessment with their results; additional information may be provided in pamphlet or accessed online. |
|
| SK | Yes^ Radiologist report detailing density is available on participant’s electronic health record, through their PCP, or by contacting the program. Additionally, clients in BI-RAD category D receive a letter informing them that they have breast density, along with a recommendation to screen annually with an information leaflet about breast density. |
New software being developed. |
| MB | Yes Participants receive their BI-RADS breast density assessment with their results, along with an informational brochure. |
Density is provided in the patient results letter. |
| ON | Yes As of summer 2023~, all participants with a normal screening result ≥ 75% fibroglandular tissue receive a screening result letter that includes their BI-RADS breast (chest) density category as well as accompanied by a breast (chest) density fact sheet. The letter also informs the participants with BI-RADS D breast (chest) density that their next mammogram should be in one year due to dense breast tissue as seen on their mammogram. |
Participants who have abnormal results do not receive result letters from the OBSP. If a mammogram result is abnormal and more testing is needed, the OBSP site, family doctor or nurse practitioner will contact the participant directly. Participants without a family doctor or nurse practitioner can find out their density result by contacting their OBSP site for a copy of their OBSP screening mammogram report. |
| QC | No PCP receives report with breast density. PCP can inform the patient. |
|
| NB | Yes Participants are notified of their breast density (BI-RADS category) in their screening results letter, accompanied by a breast density info sheet. |
|
| NS | Yes Participants are notified of their breast density (BI-RADS category) in their screening results letter, accompanied by a breast density fact sheet. |
|
| PE | Yes As of January 2020, participants receive a screening results letter with their breast density and a density fact sheet. Prior to this, the PCP was notified of breast density information. |
|
| NL | Yes Patient are told in results letter that MBD is >75% or ≤75%. |
*NT: Under review; CPGs will be updated to include both breast density and notifying patients of their results.
^SK: Participants are informed that they have dense breasts.
~ON: As of July 24, 2023, participants who have a breast (chest) density classification of BI-RADS D are recalled in 1 year. Prior to this date, the 1 year recall due to breast (chest) density was based on percent mammographic density (PMD) ≥75%.
-NU: No information was provided at the time data were collected.