4. Discussion
This prospective study evaluated breast genetic knowledge in
counselees affected with BC after the initial genetic consultation
and its effect on psychological outcomes after receiving the BRCA1/
2 test result. Breast cancer genetic knowledge may be improved
after counseling but cancer risk perception often remains inaccurate
[5,7,10]. This study was meant to add to current knowledge in
the field of breast cancer clinical genetics by clarifying how counselees'
genetic knowledge affects their psychological distress accounting
for their cancer risk perception.
An indirect effect of knowledge was revealed when taking into
account the adequacy of women's perceived probability of genetic
predisposition to cancer relative to objective estimates. Indeed, in
women who over-estimated their risk of having a BRCA1/2 gene
mutation, a higher level of knowledge after the initial genetic
consultation increased the distress specific to genetic risk after the
notification of test result (regardless of the type of result). Worry in
these women who presented higher appraisals of their genetic
predisposition to cancer may have been accentuated by the information
provided during the initial genetic counseling, which may
have persisted after the test result notification. So, it could be
alleged that women who overestimated their probability of carrying
a BRCA1/2 mutation were not disturbed by a deficit in genetic
knowledge but instead by amplified anxious thoughts when confronted
to increased knowledge. It should be noted that some of
these women may want to decide on their cancer risk management
after receipt of their genetic test result and may therefore potentially
make their decisions in a troubled emotional state.
This finding has potentially important clinical implications.
During the initial genetic counseling consultation, the perception of
genetic predisposition to cancer in counselees affected with BC at
high genetic risk should be checked. Discussing with them about
what they already know prior to BRCA1/2 gene testing, helping
them to interpret this knowledge instead of striving to provide
exhaustive genetic details [40] could contribute to minimize their
worries about cancer genetic risk after the notification of their
genetic test result.
In contrast to over-estimation of the risk of genetic predisposition
to cancer, underestimation seemed to be more beneficial in