Wise guidance and its challenges: the new Canadian recommendations on breast cancer screening

Psychological consequences of MRI-based screening among women with strong family histories of breast cancer

PURPOSE

MRI-based screening in women with a ≥ 25% lifetime risk of breast cancer , but no identifiable genetic mutations may be associated with false positives. This study examined the psychological impact of abnormal screens and biopsies in non-mutation carriers participating in high-risk screening with no personal history of breast cancer.

METHODS

Non-mutation carriers participating in the High-Risk Ontario Breast Screening Program at two sites were mailed demographic surveys, psychological scales, and chart review consent. Scales included the Consequences of Screening in Breast Cancer questionnaire, Lerman Breast Cancer Worry Scale, and Worry Interference Scale. Missing data were managed with multiple imputation. Multivariable regression was used to assess whether abnormal screens or biopsies were associated with adverse psychological effects.

RESULTS

After contacting 465 participants, 169 non-mutation carriers were included. Median age was 46 years (range 30-65). Over a median 3 years of screening, 63.9% of women experienced at least one abnormal screen, and 24.9% underwent biopsies. Statements relating to cancer worry/anxiety scored highest, with 19.5% indicating they worried "a lot". Higher scores among anxiety-related statements were strongly associated with higher dejection scores. Overall, coping and daily functioning were preserved. Women indicated some positive reactions to screening, including improved existential values and reassurance they do not have breast cancer. Abnormal screens and biopsies were not significantly associated with any psychological scale, even after adjustment for patient characteristics.

CONCLUSION

Non-mutation carriers undergoing MRI-based screening had considerable baseline anxiety and cancer worry, although daily functioning was not impaired. Abnormal screens and biopsies did not appear to have adverse psychological effects.

Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation (PERSPECTIVE I&I)

Early detection of breast cancer through screening reduces breast cancer mortality. The benefits of screening must also be considered within the context of potential harms (e.g., false positives, overdiagnosis). Furthermore, while breast cancer risk is highly variable within the population, most screening programs use age to determine eligibility. A risk-based approach is expected to improve the benefit-harm ratio of breast cancer screening programs. The PERSPECTIVE I&I (Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation) project seeks to improve personalized risk assessment to allow for a cost-effective, population-based approach to risk-based screening and determine best practices for implementation in Canada. This commentary describes the four inter-related activities that comprise the PERSPECTIVE I&I project. 1: Identification and validation of novel moderate to high-risk susceptibility genes. 2: Improvement, validation, and adaptation of a risk prediction web-tool for the Canadian context. 3: Development and piloting of a socio-ethical framework to support implementation of risk-based breast cancer screening. 4: Economic analysis to optimize the implementation of risk-based screening. Risk-based screening and prevention is expected to benefit all women, empowering them to work with their healthcare provider to make informed decisions about screening and prevention.

Abnormal screens among nonmutation carriers in the High Risk Ontario Breast Screening Program

BACKGROUND

The Ontario Breast Screening Program was expanded in 2011 to offer annual MRI and mammography to women with high-risk genetic mutations (e.g., BRCA1/2) and women with strong family histories and ≥25% estimated lifetime risk of breast cancer. Data to support high-risk screening is less clear in the nonmutation carrier group, as MRI has lower specificity among this population. The potential unintended consequences may be considerable and need to be explored. We aimed to describe the frequency of abnormal screens and biopsies.

METHODS

Demographic surveys and chart review consent were sent to a sample of 441 individuals enrolled in a high-risk screening program at two tertiary care hospitals in Toronto, Ontario. Retrospective cross-sectional chart review was undertaken for clinicopathologic data. The frequencies of abnormal screens and biopsies were calculated.

RESULTS

One hundred sixty-nine nonmutation carriers were included. The majority were white, employed, and highly educated. The median International Breast Cancer Intervention Study lifetime risk of breast cancer was 28.0% (range 24.5%-89.0%). 108 individuals (64%) experienced at least 1 abnormal screen and 13 (8%) had 3 or more over a median 3 years of screening (range 1-6 years). Of 55 biopsies, 3 (5.5%) were malignant. The cancer detection rate was 8.4/1000 screens (95% CI 3.2-22.4).

CONCLUSIONS

An MRI-based screening program for nonmutation carriers was effective at diagnosing breast cancer. However, this population experienced a high rate of abnormal screens and intervention. Further research is needed to improve the performance of MRI-based screening in these women.