Abstract 645P
Background
Germline mutations of the BRCA2 gene were reported in men with prostate cancer (PrCa), but clinical criteria for BRCA2 screening need to be clarified.
Methods
Prostate cancer patients included in this study were selected among the ones who were recruited in the PROGENE study. This study has been approved by the CCP Ile de France IV (IRB: 00003835). All patients have provided written informed consent in order to participate in the study. Germline DNA from 325 PrCa patients (median age at diagnosis: 57 years old) was screened for BRCA2 mutation. The mutation frequency was compared between three groups: patients with an age at diagnosis at 55 years old and under (Group I); a personal or family history of breast (BrCa), uterine (UtCa) or ovarian cancer (OvCa) (Group II); or a metastatic disease (Group III).
Results
The proportion of BRCA2 mutation was 5.9% in Group I, 10.9% in Group II and 6.9% in Group III (Table). The frequency of BRCA2 mutation was significantly higher among patients of Group II (P=0.006), and reached 15.6% among patients of this group who presented a metastatic disease. Mutual information analysis showed that contribution towards the predicted mean of the positive mutational status, according the direct effect of phenotype observed in each group, was 16%, 63% and 22% for group I, II and III, respectively. The frequency of BRCA2 mutation didn’t differ according to ethnicity or prostate cancer familial status. The median age at diagnosis of the 21 BRCA2 mutation carriers was 57 years old (range: 43-74). Fifteen (71.4%) of the 21 BRCA2 mutation carriers had an aggressive form of the disease. Four (19%) of them died from PrCa after a median follow-up duration of 64.5 months. Table: 645P
Frequency of BRCA2 mutations
| Criteria of selection | Number of patients | Number of patients with BRCA2 mutation | BRCA2 mutation frequency (%) |
| None | 325 | 21 | 6.5 |
| Age at diagnosis ≤ 55 years (Group I) | 152 | 9 | 5.9 |
| Personal or familial history of Br/Ut/OvCa (Group II) | 137 | 15 | 10.9 |
| Metastatic PrCa (Group III) | 130 | 9 | 6.9 |
| Age at diagnosis ≤ 55 years & Personal or familial history of Br/Ut/OvCa (Groups I & II) | 38 | 5 | 13.2 |
| Personal or familial history of Br/Ut/OvCa & Metastatic PrCa (Groups II & III) | 32 | 5 | 15.6 |
| Age at diagnosis ≤ 55 years & Metastatic PrCa (Groups I & III) | 32 | 3 | 9.4 |
| Age at diagnosis ≤ 55 years & Personal or familial history of Br/Ut/OvCa & Metastatic PrCa (Groups II & II & III) | 8 | 1 | 12.5 |
Conclusions
Our results showed that a higher frequency of BRCA2 mutation carriers is observed, not only among PrCa patients with young onset or a metastatic disease, but also with a personal or a familial history of breast cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Cussenot.
Funding
Has not received any funding.
Disclosure
S. Oudard: Honoraria (self): Sanofi; Honoraria (self): Bayer; Honoraria (self): Astellas Pharma; Honoraria (self): Janssen. L. Jouffe: Full/Part-time employment: Bayesia SAS. All other authors have declared no conflicts of interest.