Cancer incidence in the first-degree relatives of ovarian cancer patients

Abstract

Summary Cancer incidence was studied among 3072 first-degree relatives of 559 unselected ovarian cancer patients. Among cohort members there were 306 cancer cases. The overall cancer incidence was not increased: the standardised incidence ratio (SIR) in males was 0.9 (95% confidence interval 0.8-1.1) and in females 1.0 (0.8 -1.1). The female relatives had a significantly increased risk for ovarian cancer (SIR 2.8, 1.8-4.2). The excess was attributable to sisters only (SIR 3.7, 2.3 -5.7). The relative risk for ovarian cancer among sisters decreased both by increasing age of the sister and by increasing age at diagnosis of the index patient: the SIRs were 7.3 (1.5-21.4), 4.5 (1.6-9.8) and 3.1 (1.7-5.4) for sisters of index patients diagnosed in age <45, 45 -54 and 55 -75 years respectively. The age dependency of the risk supports the role of genetic factors in familial ovarian cancer. Although the risk of ovarian cancer among sisters from families with breast cancer (SIR 9.2, 3.7-19.0) was significantly higher than among sisters from families with no breast cancer patients (SIR 2.9, 1.6-4.8, rate ratio 3.1, P < 0.05), the excess was not solely attributable to coaggregation of breast and ovarian cancer. Among the 27 families with two or more ovarian cancers, only sisters were affected in 24 families, which might implicate recessive inheritance or shared environmental factors influencing ovarian cancer risk in sisters.

A missense mutation in the BRCA2 gene in three siblings with ovarian cancer

“…The method used for identifying a series of Finnish ovarian cancer families has been described in a previous study (Auranen et al, 1996). Briefly, patients diagnosed with epithelial ovarian cancer in Finland between 1980 and 1982 and their first-degree relatives were studied.…”

Incidence and mortality in epithelial ovarian cancer by family history of any cancer

“…10 In population-based studies with medically verified diagnosis, the familial risk of invasive ovarian cancer has ranged between 2.0 and 3.0. [10][11][12][13][14][15][16][17] Survival in ovarian cancer has been worse for familial compared with sporadic patients. 4 Ovarian cancer is a manifestation in families with BRCA1/2 mutations and in hereditary nonpolyposis colorectal cancer (HNPCC).…”

Segregation analysis of epithelial ovarian cancer in Finland

“…When we estimated breast cancer incidence in this cohort (Auranen et al, 1996), the observed number of breast cancers was exactly the number that was expected, but there was some co-aggregation of breast and ovarian cancer. It is presumed that some of the families with two or more ovarian cancer cases harbour BRCAI or BRCA2 gene mutations, especially some of the ten families that also had a breast cancer case in a close relative.…”

“…The main result of this analysis is complementary to our previous analysis of this material using a different method (Auranen et al, 1996). We estimated the cancer incidence in these first-degree relatives of ovarian cancer patients and found that the incidence of ovarian cancer increased in sisters only.…”

“…The method of data collection has been described in detail elsewhere (Auranen et al, 1996). Briefly, the local registries of the communities where the probands were born were contacted to obtain the names and birth dates of parents and siblings.…”