The impact of an interventional counselling procedure in families with a BRCA1/2 gene mutation: efficacy and safety

Fam Cancer. 2016 Apr;15(2):155-62. doi: 10.1007/s10689-015-9854-4.

Abstract

Background: Predictive genetic testing has high impact on cancer prevention for BRCA carriers and passing this information in BRCA families is important. Mostly, this is proband-mediated but this path is defective and denies relatives lifesaving information.

Objective: To assess the efficacy/safety of an intervention, in which relatives are actively informed.

Design: Sequential prospective study in new BRCA families. The proband informed relatives about predictive testing (phase I). After 6 months, a letter was sent to adult relatives who had not been reached (phase II). Then a phone call was made to obtain a final notion of their wishes. All subjects received psychometric testing (State-Trait Anxiety Inventory, STAI), an interview and routine counselling.

Results: Twenty families were included. Twenty-four of the relatives could not be reached, 59 were 'decliners', 47 participated by the proband and 42 by the letter. Predictive testing was performed in 98% of the participants of which 30 were mutation carriers. The intervention is psychologically safe: the 95% CI for the estimated mean difference in STAI DY1 between phase II/I subjects (mean difference -1.07, 95% CI -4.4 to 2.35, p = 0.53) shows that the mean STAI DY1 score (measured at first consult) for phase II is no more than 2.35 units higher than for phase I, which is not relevant.

Conclusions: A protocol directly informing relatives nearly doubles the number of relatives tested and is psychologically safe. This should lead to a change in counselling guidelines in families with a strong germline predisposition for cancer.

Keywords: BRCA gene mutation; Efficacy; Predictive genetic counselling; Procedure; Safety.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • BRCA1 Protein / genetics*
  • BRCA2 Protein / genetics*
  • Family
  • Female
  • Genetic Counseling* / methods
  • Genetic Counseling* / psychology
  • Genetic Counseling* / statistics & numerical data
  • Genetic Predisposition to Disease
  • Genetic Testing / statistics & numerical data*
  • Heterozygote
  • Humans
  • Male
  • Middle Aged
  • Mutation*
  • Prospective Studies
  • Young Adult

Substances

  • BRCA1 Protein
  • BRCA1 protein, human
  • BRCA2 Protein
  • BRCA2 protein, human