Effects of chemotherapy on contralateral breast cancer risk in BRCA1 and BRCA2 mutation carriers: A nationwide cohort study.
Breast
; 61: 98-107, 2022 Feb.
Article
in En
| MEDLINE
| ID: mdl-34929424
ABSTRACT
AIM:
BRCA1/2 mutation carriers with primary breast cancer (PBC) are at high risk of contralateral breast cancer (CBC). In a nationwide cohort, we investigated the effects of chemotherapeutic agents given for PBC on CBC risk separately in BRCA1 and BRCA2 mutation carriers. PATIENTS ANDMETHODS:
BRCA1 or BRCA2 mutation carriers with an invasive PBC diagnosis from 1990 to 2017 were selected from a Dutch cohort. We estimated cumulative CBC incidence using competing risks analysis. Hazard ratios (HR) for the effect of neo-adjuvant or adjuvant chemotherapy and different chemotherapeutic agents on CBC risk were estimated using Cox regression.RESULTS:
We included 1090 BRCA1 and 568 BRCA2 mutation carriers; median follow-up was 8.9 and 8.4 years, respectively. Ten-year cumulative CBC incidence for treatment with and without chemotherapy was 6.7% [95%CI 5.1-8.6] and 16.7% [95%CI 10.8-23.7] in BRCA1 and 4.8% [95%CI 2.7-7.8] and 16.0% [95%CI 9.3-24.4] in BRCA2 mutation carriers, respectively. Chemotherapy was associated with reduced CBC risk in BRCA1 (multivariable HR 0.46, 95%CI 0.29-0.74); a similar trend was observed in BRCA2 mutation carriers (HR 0.63, 95%CI 0.29-1.39). In BRCA1, risk reduction was most pronounced in the first 5 years (HR 0.32, 95%CI 0.17-0.61). Anthracyclines and the combination of anthracyclines with taxanes were associated with substantial CBC risk reduction in BRCA1 carriers (HR 0.34, 95%CI 0.17-0.68 and HR 0.22, 95%CI 0.08-0.62, respectively).CONCLUSION:
Risk-reducing effects of chemotherapy are substantial for at least 5 years and may be used in personalised CBC risk prediction in any case for BRCA1 mutation carriers.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Breast Neoplasms
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Female
/
Humans
Language:
En
Journal:
Breast
Journal subject:
ENDOCRINOLOGIA
/
NEOPLASIAS
Year:
2022
Document type:
Article
Affiliation country:
Países Bajos