Phenocopy breast cancer rates in Israeli BRCA1 BRCA2 mutation carrier families: is the risk increased in non-carriers?

Phenocopy in a patient with triple negative breast cancer: a case report

A total of 1.67 million breast cancer cases per year are reported worldwide. Of these, 5%-10% are caused by inherited mutations. Phenocopy is a rare phenomenon, with only a few cases reported in the literature. In phenocopies, phenotypes identical to those with genetic origin occur because of environmental factors rather than familial mutations. We describe a case of phenocopy in a 44-year-old female patient with triple-negative breast cancer. The mother and sister wee heterozygous for c.1813delA, p.Ile605TyrfsTer9 in BRCA2 . The patient underwent genetic testing for BRCA1 and BRCA2 and exome sequencing. Familial or other cancer variants were not detected. The most accepted phenocopy theory is that patients without genetic variants but who are carriers of these mutations undergo cellular changes due to environmental factors, increasing the risk of breast cancer. Therefore, the detection of phenocopy in patients with breast cancer is important in clinical practice.

Information and support needs of young women regarding breast cancer risk and genetic testing: adapting effective interventions for a novel population

Young women from hereditary breast and ovarian cancer (HBOC) families face a unique set of challenges in managing their HBOC risk, where obtaining essential information to inform decision making is key. Previous work suggests that this need for specific health information also comes at a time of heightened distress and greater individuation from family. In this report, we describe our adaptation of a previously-studied behavioral intervention for this population, utilizing a systematic approach outlined by the Centers for Disease Control and Prevention. First, we assessed the information needs and levels of distress in this population and correlates of this distress. These data then were used to inform the adaptation and piloting of a three-session telephone-based peer coaching intervention. One hundred young women (M age = 25 years) who were first or second degree relatives of BRCA1/2 mutation carriers participated. Sixty-three percent of the sample endorsed unmet HBOC information needs and they, on average, reported moderate levels of cancer-related distress (M = 21.9, SD = 14.6). Greater familial disruption was associated with greater cancer-related distress in multivariable models (p < .05). Ten women who participated in the survey completed the intervention pilot. They reported lower distress from pre- to post- (15.8 vs. 12.0), as well as significantly lower decisional conflict (p < .05) and greater endorsement of an array of healthy coping strategies (i.e., active coping, instrumental coping, positive reframing, planning, p's < .05). Our survey results suggest that young adult women from HBOC families have unmet cancer genetic information and support needs. Our pilot intervention was able to reduce levels of decisional conflict and promote the use of effective coping strategies. This approach needs to be further tested in a larger randomized trial.

Risks of breast or ovarian cancer in BRCA1 or BRCA2 predictive test negatives: findings from the EMBRACE study

PURPOSE

BRCA1/BRCA2 predictive test negatives are proven noncarriers of a BRCA1/BRCA2 mutation that is carried by their relatives. The risk of developing breast cancer (BC) or epithelial ovarian cancer (EOC) in these women is uncertain. The study aimed to estimate risks of invasive BC and EOC in a large cohort of BRCA1/BRCA2 predictive test negatives.

METHODS

We used cohort analysis to estimate incidences, cumulative risks, and standardized incidence ratios (SIRs).

RESULTS

A total of 1,895 unaffected women were eligible for inclusion in the BC risk analysis and 1,736 in the EOC risk analysis. There were 23 incident invasive BCs and 2 EOCs. The cumulative risk of invasive BC was 9.4% (95% confidence interval (CI) 5.9-15%) by age 85 years and the corresponding risk of EOC was 0.6% (95% CI 0.2-2.6%). The SIR for invasive BC was 0.93 (95% CI 0.62-1.40) in the overall cohort, 0.85 (95% CI 0.48-1.50) in noncarriers from BRCA1 families, and 1.03 (95% CI 0.57-1.87) in noncarriers from BRCA2 families. The SIR for EOC was 0.79 (95% CI 0.20-3.17) in the overall cohort.

CONCLUSION

Our results did not provide evidence for elevated risks of invasive BC or EOC in BRCA1/BRCA2 predictive test negatives.

No evidence of increased breast cancer risk for proven noncarriers from BRCA1 and BRCA2 families

In families screened for mutations in the BRCA1 or BRCA2 genes and found to have a segregating mutation the breast cancer risk for women shown not to carry the family-specific mutation might be at above "average" risk. We assessed the risk of breast cancer in a clinic based cohort of 725 female proven noncarriers in 239 BRCA1 and BRCA2 families compared with birth-matched controls from the Danish Civil Registration System. Prospective analysis showed no significantly increased risk for breast cancer in noncarriers with a hazard ratio of 0.67 [95 % confidence interval (CI) 0.32-1.42, p = 0.29] for all family members who tested negative and 0.87 (95 % CI 0.38-1.97, p = 0.73) for non-carries who were first-degree relatives of mutation carriers. Proven noncarriers from BRCA1 and BRCA2 families have no markedly increased risk for breast cancer compared to the general population, and our data do not suggest targeted breast cancer surveillance for noncarriers from BRCA1 and BRCA2 families.

Analysis of chromosomal radiosensitivity of healthy BRCA2 mutation carriers and non-carriers in BRCA families with the G2 micronucleus assay

Breast cancer risk drastically increases in individuals with a heterozygous germline BRCA1 or BRCA2 mutation, while it is estimated to equal the population risk for relatives without the familial mutation (non-carriers). The aim of the present study was to use a G2 phase-specific micronucleus assay to investigate whether lymphocytes of healthy BRCA2 mutation carriers are characterized by increased radiosensitivity compared to controls without a family history of breast/ovarian cancer and how this relates to healthy non-carrier relatives. BRCA2 is active in homologous recombination, a DNA damage repair pathway, specifically active in the late S/G2 phase of the cell cycle. We found a significantly increased radiosensitivity in a cohort of healthy BRCA2 mutation carriers compared to individuals without a familial history of breast cancer (P=0.046; Mann-Whitney U test). At the individual level, 50% of healthy BRCA2 mutation carriers showed a radiosensitive phenotype (radiosensitivity score of 1 or 2), whereas 83% of the controls showed no radiosensitivity (P=0.038; one-tailed Fishers exact test). An odds ratio of 5 (95% CI, 1.07–23.47) indicated an association between the BRCA2 mutation and radiosensitivity in healthy mutation carriers. These results indicate the need for the gentle use of ionizing radiation for either diagnostic or therapeutic use in BRCA2 mutation carriers. We detected no increased radiosensitivity in the non-carrier relatives.

Clinical follow-up and breast and ovarian cancer screening of true BRCA1/2 noncarriers: a qualitative investigation

PURPOSE

Most women from BRCA1/2 mutation-positive families who did not inherit the familial mutation have breast and ovarian cancer risks similar to those of women of the same age in the general population. However, recent studies suggest that some of these noncarriers may exhibit screening practices that may be considered as excessive compared to general population screening guidelines. Reasons for such tendencies remain largely unknown. This study aims to better understand how the implications of a noncarrier status are explained to these women and how their own realization of this status affects their screening behaviors.

METHODS

A qualitative study was conducted with five focus groups (n = 28) in Quebec City and Montreal, Canada.

RESULTS

Thematic analysis of the discussions highlighted four major themes: (i) acquiring a noncarrier identity takes place progressively; (ii) noncarriers show a range of opinions about screening; (iii) noncarriers have mixed feelings about the follow-up by their physicians and gynecologists; and (iv) noncarriers need more information in a context where genetics progresses ever more rapidly.

CONCLUSION

Our results provide novel insights regarding the physician-patient interaction and the organizational aspects of the health-care system that may significantly impact the cancer screening practices of BRCA1/2 noncarriers.Genet Med 18 6, 627-634.