Risk Assessment: Controversies and Management of Moderate- to High-Risk Individuals

[Breast cancer screening in high risk populations]

We aim to define which patients make up the populations with high and intermediate risk of developing breast cancer, to review the studies of screening with magnetic resonance imaging in addition to mammography in high risk patients (describing the imaging characteristics of the cancers in this group), to review the studies of screening with magnetic resonance imaging in patients with intermediate risk, and to update the guidelines for screening in patients with high or intermediate risk (based on the recent recommendations of the main scientific societies/American and European guidelines).

Objective and subjective breast cancer risk: relationships with natural killer cell activity and psychological distress in healthy women

BACKGROUND

Breast cancer (BC) risk, based on either known risk factors (objective) or self-assessment (subjective), may influence natural killer cell activity (NKCA) directly or through psychological distress.

OBJECTIVE

The main objective of this study was to examine the relationships of objective and subjective BC risks with NKCA and a mediating role of psychological distress in a community sample of healthy women.

METHODS

In a cross-sectional descriptive study, a convenience sample of 117 healthy women (mean age, 36.5 years) completed questionnaires for BC risk and psychological distress and provided blood for NKCA measurement.

RESULTS

Objective and subjective BC risks were positively correlated (P < .001). Regression analyses revealed that objective BC risk had a significant negative relationship with NKCA at the 12.5:1 effector-to-target cell ratio (P = .011), whereas subjective risk was not associated with NKCA at any effector-to-target cell ratio tested. Only subjective risk had a positive association with both BC-specific (P = .002) and general (P < .001) psychological distress. Psychological distress failed to mediate the relationship between subjective risk and NKCA.

CONCLUSIONS

Objective BC risk had a limited but significant relationship with NKCA. Subjective risk was highly associated with psychological distress but was not associated with NKCA.

IMPLICATIONS FOR PRACTICE

Despite the limited relationships between BC risk and NKCA, the impact of BC risk on other tumor defense mechanisms needs to be further explored. Collective findings in this area will suggest early preventive strategies for monitoring BC risk and maintaining better tumor defense in healthy women.

Genetic susceptibility to breast cancer

Deleterious mutations in two breast and ovarian cancer susceptibility genes, BRCA1 and BRCA2 have been identified in breast and ovarian cancer families. Women with a BRCA1 or BRCA2 mutation are candidates for additional risk reduction measures such as intensive screening, prophylactic surgery or chemoprevention. Additional susceptibility genes have been identified, including PTEN, ATM, TP53, CHEK2, CASP8, PBRL and BRIP1. Yet, many women with a personal or family history suggestive of a hereditary susceptibility to breast cancer undergo genetic testing and no significant genetic alteration is found. Thus, there are other susceptibility genes that have not been identified, and it is likely that the remaining familial contribution to breast cancer will be explained by the presence of multiple low penetrance alleles that coexist to confer high penetrance risks (a polygenic model). The American Cancer Society has identified cancer prevention as a key component of cancer management and there is interest in developing individualized cancer prevention focused on identifying high risk individuals who are most likely to benefit from more aggressive risk reduction measures. Breast cancer risk assessment and genetic counseling are currently provided by genetic counselors, oncology nurse specialist, geneticists, medical and surgical oncologists, gynecologists and other health care professionals, often working within a multidisciplinary clinical setting. Current methods for risk assessment and predictive genetic testing have limitations and improvements in molecular testing and risk assessment tools is necessary to maximize individual breast cancer risk assessment and to fulfill the promise of cancer prevention.

Breast Cancer Risk and Immune Responses in Healthy Women

PURPOSE/OBJECTIVES

To summarize the findings of objective and subjective breast cancer risk assessments and their association with psychological distress and immune responses in healthy women with a family history of breast cancer.

DATA SOURCES

Published articles and book chapters.

DATA SYNTHESIS

Healthy women with a family history of breast cancer have shown decreased immune responses (i.e., low natural killer cell activity and low Th1 cytokine production), exaggerated biophysiologic reactivity to stimuli, and increased psychological distress.

CONCLUSIONS

Objective and subjective breast cancer risk is associated with impaired immune responses and exaggerated biophysiologic responses in healthy women with a family history of breast cancer. Increased psychological distress can contribute further to negative immune responses. Additional studies are warranted to substantiate and extend the findings based on more comprehensive assessments of objective and subjective breast cancer risk.

IMPLICATIONS FOR NURSING

Biophysiologic assessment is a useful approach for nurses in early identification of women at risk for breast cancer and developing appropriate strategies to reduce the risk.

Prospective breast cancer risk prediction model for women undergoing screening mammography

BACKGROUND

Risk prediction models for breast cancer can be improved by the addition of recently identified risk factors, including breast density and use of hormone therapy. We used prospective risk information to predict a diagnosis of breast cancer in a cohort of 1 million women undergoing screening mammography.

METHODS

There were 2,392,998 eligible screening mammograms from women without previously diagnosed breast cancer who had had a prior mammogram in the preceding 5 years. Within 1 year of the screening mammogram, 11,638 women were diagnosed with breast cancer. Separate logistic regression risk models were constructed for premenopausal and postmenopausal examinations by use of a stringent (P<.0001) criterion for the inclusion of risk factors. Risk models were constructed with 75% of the data and validated with the remaining 25%. Concordance of the predicted with the observed outcomes was assessed by a concordance (c) statistic after logistic regression model fit. All statistical tests were two-sided.

RESULTS

Statistically significant risk factors for breast cancer diagnosis among premenopausal women included age, breast density, family history of breast cancer, and a prior breast procedure. For postmenopausal women, the statistically significant factors included age, breast density, race, ethnicity, family history of breast cancer, a prior breast procedure, body mass index, natural menopause, hormone therapy, and a prior false-positive mammogram. The model may identify high-risk women better than the Gail model, although predictive accuracy was only moderate. The c statistics were 0.631 (95% confidence interval [CI] = 0.618 to 0.644) for premenopausal women and 0.624 (95% CI = 0.619 to 0.630) for postmenopausal women.

CONCLUSION

Breast density is a strong additional risk factor for breast cancer, although it is unknown whether reduction in breast density would reduce risk. Our risk model may be able to identify women at high risk for breast cancer for preventive interventions or more intensive surveillance.

Preventive health behaviors and familial breast cancer

AIM

To examine medical and lifestyle preventive behaviors among women with varying levels of familial breast cancer risk.

METHODS

Using cross-sectional data from the Minnesota Breast Cancer Family Study, a historical cohort of 426 families, we compared medical (mammography adherence, antiestrogen use, and prophylactic surgery) and lifestyle (physical activity, smoking, alcohol, and diet) behaviors across three groups of cancer-free women ages 18 to 95 defined by their family history of breast cancer. Family history was classified as high-risk, moderate-risk, or average to low-risk depending on the number and degree of relationship of family members with breast cancer.

RESULTS

After adjusting for age and education, high-risk women were twice as likely to have ever used an antiestrogenic agent (9.0% versus 4.6% among moderate-risk and 4.1% among average to low-risk; P = 0.002). Among women ages <40, the high-risk group were more likely to have ever had a mammogram (82% versus 47% among moderate-risk and 35% among average to low-risk; P < 0.001). Average to low-risk women were the least likely to be current smokers and high-risk women may consume slightly fewer fruits and vegetables compared with the other groups, but there were no other differences in lifestyle behaviors, including physical activity and alcohol use.

CONCLUSIONS

Women with strong family histories of breast cancer are more likely to undertake medical but not lifestyle preventive behaviors.