Primary node negative breast cancer in BRCA1 mutation carriers has a poor outcome

Background:The association between BRCA1 germ-linemutations and breast cancer prognosis is controversial. A historical cohortstudy was designed to determine the prognosis for women with axillary lymphnode negative hereditary breast cancer. Patients and methods:We tested pathology blocks from 118Ashkenazi Jewish women with axillary lymph node negative breast cancer for thepresence of the two common BRCA1 founder mutations, 185delAG and5382insC. Patients were followed up for a median of 76 months. SomaticTP53mutations were screened for by immunohistochemistry, and directsequencing was performed in the BRCA1-positive tumours. Results:Sixteen breast cancer blocks (13.6%) carried aBRCA1 mutation. Young age of onset, high nuclear grade, negativeestrogen receptor status and over-expression of p53 were highly associatedwith BRCA1-positive status (P-values all <0.01).BRCA1 mutation carriers had a higher mortality than non-carriers(five-year overall survival, 50% and 89.6%, respectively,P = 0.0001). Young age of onset, estrogen receptor negative status,nuclear grade 3, and over-expression of p53 also predicted a poor outcome. Coxmultivariate analyses showed that only germ-line BRCA1 mutationstatus was an independent prognostic factor for overall survival (P= 0.01). Among nuclear grade 3 tumours, the BRCA1 mutation carrierstatus was a significant prognostic factor of death (risk ratio 5.8,95% confidence interval: 1.5–22, P = 0.009). Sequencingof BRCA1-related breast cancers revealed one TP53missensemutation not previously reported in breast cancer. Conclusions:Using a historical cohort approach, we haveidentified BRCA1 mutation status as an independent prognostic factorfor node negative breast cancer among the Ashkenazi Jewish women. Thosemanaging women carrying a BRCA1 mutation may need take these findingsinto consideration. Additionally, our preliminary results, taken together withthe work of others suggest a different carcinogenic pathway inBRCA1-related breast cancer, compared to non-hereditary cases.