Risk factors and prognostic factors in patients with double primary cancer: epithelial ovarian cancer and breast cancer.
OBJECTIVE
The most important known risk factor for ovarian cancer is the BRCA1-2 mutation, which is clinically often manifested through a positive family history of cancer of the breast and/or ovary. Whether other risk factors and prognostic factors in women with a positive family history of cancer of the breast and/or ovary and/or with BRCA1-2 mutation are important remains to be elucidated. Recent studies have shown that in the double primary breast and ovarian cancer (DPBOC), BRCA1-2 mutation is present in at least 86% of cases. Therefore, the group of patients with DPBOC, especially with epithelial ovarian cancer and breast cancer, is the most suitable for such an analysis. The aim of this study was to verify the hypothesis that, in this group, some other risk factors, in addition to a specific family history of cancer, as well as unfavourable pathomorphological prognostic factors, are more expressed than in a control group of patients with sporadic epithelial ovarian cancer only.


METHODS
We compared the study group of 31 patients with DPBOC (epithelial ovarian cancer) to a control group of 62 patients with a single, sporadic epithelial ovarian cancer and negative specific family history. The data were obtained from the Cancer Registry of Slovenia and from clinical records. For every patient, we filled-in a protocol and analysed the data, comparing other risk factors in addition to specific family history and prognostic, clinical, and pathomorphological factors. Statistical analysis was performed using descriptive statistics, chi-square test and t-test. Multivariate analysis was also planned, but the necessary conditions were not met.


RESULTS
In the study group, we found a higher percentage of positive non-specific family histories than in the control group, but the difference was not statistically significant. No difference in procreative risk factors was observed between the groups. There was a higher percentage of borderline significance of women from the study group that developed ovarian cancer between 45 and 59 years of age. In the study group, ovarian cancer was significantly more often found at Stage I, although the groups did not differ in detection procedures. Also, we did not find any differences in the distribution of tumour grades or histologic tumour types.


CONCLUSIONS
The results did not confirm our hypothesis, yet they indicated some differences between the groups regarding the risk factors for ovarian cancer. Regarding the prognostic factors, we even found a significantly higher percentage of Stage I epithelial ovarian cancer in the study group, with no difference in the mode of detection. Considering the results that are not typical of BRCA-related cancer (what double primary cancer of the ovary and breast is supposed to be) and previous reports, we find it more likely that the patients with BRCA1-2 mutations represent only a subgroup within the group of patients with double primary breast and ovarian cancer.
Cvelbar
M
M
Institute of Oncology, University Medical Center, Ljubljana, Slovenia.
Ursic-Vrscaj
M
M
Rakar
S
S
D000328:Adult; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D012307:Risk Factors; D017524:Slovenia / Q000453:epidemiology