Occurrence of both breast and ovarian cancer in a woman is a marker for the BRCA gene mutations: a population-based study from western Sweden.
OBJECTIVE
This study aimed to analyze whether the occurrence of both breast and ovarian cancer in a woman serves as a marker for BRCA gene mutations.


METHODS
This population-based study included 256 women in western Sweden who developed both invasive breast and ovarian tumors between 1958 and 1999. Archival paraffin tissue blocks of their tumors were retrieved for DNA-extraction to analyze the founder mutation, BRCA1 c.3171_3175dup (c.3171ins5), which is most common in this geographic area and four other common Scandinavian BRCA1 gene mutations and one BRCA2 mutation. Together, account these mutations for approximately 75% of the BRCA1/2 gene mutations in the clinical unit.


RESULTS
Ninteen percent (95% confidence interval (CI) 14-24%) of the women carried one of the analyzed BRCA1 gene mutations but none of the women were positive for the analyzed BRCA2 mutation. One-third of the women with both tumors before age 60 were mutation carriers. BRCA1 c.3171_3175dup (c.3171ins5) constituted 84% of all identified mutations. Although the majority of breast cancers were invasive ductal and atypical medullary types, a variety of other breast malignancies were seen among mutation carriers. Serous ovarian carcinomas predominated among ovarian tumors. A variety of other ovarian tumors, including three granulosa-theca cell tumors, were also observed among mutation carriers.


CONCLUSIONS
The occurrence of both breast and ovarian cancer in a woman is associated with a high likelihood of a constitutional BRCA1 mutation. These women and their families might therefore be considered for mutation screening after appropriate genetic counselling.
Einbeigi
Zakaria
Z
Department of Oncology, Sahlgrenska University Hospital, S413 45 Göteborg, Sweden. zakaria.einbeigi@oncology.gu.se
Bergman
Annika
A
Meis-Kindblom
Jeanne M
JM
Flodin
Anna
A
Bjursell
Cecilia
C
Martinsson
Tommy
T
Kindblom
Lars-Gunnar
LG
Wahlström
Jan
J
Wallgren
Arne
A
Nordling
Margareta
M
Karlsson
Per
P
D017668:Age of Onset; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D005820:Genetic Testing; D005828:Genetics, Population; D006801:Humans; D009154:Mutation; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000235:genetics*; D009386:Neoplastic Syndromes, Hereditary; D010051:Ovarian Neoplasms / Q000453:epidemiology / Q000235:genetics*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000706:statistics & numerical data; D013548:Sweden / Q000453:epidemiology
D014408:Biomarkers, Tumor