5
Recommendation 4.2
➤ For women with breast cancer who have a mutation in a moderate-
penetrance breast cancer predisposition gene and who have been
treated or are being treated with unilateral mastectomy, the decision
regarding CRRM should not be based predominantly on the mutation
status. (Moderate recommendation; FC-L)
Note: Additional factors that predict CBC such as age at diagnosis and family history
should be considered, as they are in all cases. The impact of CRRM on decreasing risk of
CBC is dependent on the risk of CBC for each individual gene. Data regarding the risk
of CBC due to moderate-penetrance genes are limited.
Recommendation 5.1
➤ For breast cancer patients with a deleterious germline BRCA1/2
mutation interested in a contralateral risk-reducing mastectomy,
physicians should discuss the option of nipple-sparing mastectomy as
a reasonable oncologic option. (Strong recommendation; FC-I)
Recommendation 5.2
➤ For breast cancer patients with a mutation in a moderate-penetrance
gene who are interested in a contralateral risk-reducing mastectomy,
physicians should discuss the option of nipple sparing mastectomy as
a reasonable oncologic option. (Moderate recommendation; FC-L)
Recommendation 6.1
➤ For women with breast cancer who are treated with BCT or with
mastectomy for whom post-mastectomy radiotherapy is considered,
radiation therapy should not be withheld due to mutation status,
except for mutations in TP53 (see Recommendation 6.3). (Strong
recommendation; FC-I)
Note: There is no evidence of a significant increase in toxicity or contralateral breast
cancers (CBC) related to radiation exposure among patients with a mutation in a
BRCA1/2 or a moderate-penetrance gene.
Recommendation 6.2
➤ For women with breast cancer who are carriers of an ATM mutation,
radiation therapy should be offered when clinically indicated. Data
regarding rates of toxicity between ATM mutation carriers and
non-carriers are limited and inconsistent. Potential absolute risks
appear to be small. However, more research is needed. (Moderate
recommendation; FC-L)
Note: Discussion with ATM carriers interested in BCT is encouraged.
