Family history of cancer and risk of breast cancer

Abstract

The relationship between breast cancer risk and family history of cancer in first-degree relatives was investigated using data from a multicentric case-control study conducted in Italy between June 1991 and April 1994 on 2,569 women aged less than 75 years, with histologically confirmed incident breast cancer, and 2,588 control women admitted to hospital for acute, non-neoplastic, non-gynaecological conditions. Relative to women with no history, those with a family history of breast cancer had an odds ratio (OR) of 2.4 [95% confidence interval (CI) 1.9-3.0], and those with family history of intestinal cancer had an OR of 1.3 (95% CI 1.0-1.7). No significant relations emerged between breast cancer risk and family history of prostate (OR 1.1), ovarian (OR 1.3), cervical or endometrial (OR 1.2) or other cancers, except gallbladder (OR 8.6). The OR for family history of any type of cancer except breast cancer was 1.1. For family history of breast cancer the ORs were similar across strata of age of the proband, being 2.4 below age 45, 2.2 at age 45-59 and 2.7 above age 60, and whether the relative affected was the mother, sister(s) or both, while the risk appeared higher if the age at onset of breast cancer in the relative was lower than 40 years (OR 3.5), rather than higher (OR 2.2). Thus, our results, based on the investigation of all neoplasms in first-degree relatives, confirm that breast cancer risk is increased in women with a family history of breast cancer, while there was no material association with family history of cancer in general, excluding breast cancer. Int. J. Cancer 72:735-738, 1997. Wiley-Liss, Inc.A large amount of epidemiological evidence shows that the risk of breast cancer is increased in subjects with family history of the disease and that the association is evident in both cohort and case-control studies (Houlston and Peto, 1996). This may be due partly to the fact that relatives tend to be exposed to the same environmental risk factors, but also to an inheritable (genetic) susceptibility. Some studies found that a family history of breast cancer was a stronger risk factor at younger proband age (Brinton et al., 1982;Claus et al., 1990;Calle et al., 1993), although the evidence is not totally consistent (Colditz et al., 1993;Parazzini et al., 1993;Peto et al., 1996). Age at onset of breast cancer in relatives and whether the relative affected is the mother and/or the sister(s) may also give rise to different breast cancer risks (Peto, 1980). Furthermore, family history of colon, prostate, ovarian and other gynecological cancers, and a number of other cancers, has been associated with an increased risk of breast cancer in some but not all studies (Thompson and Schildkraut, 1990;Anderson et al., 1992;Tulinius et al., 1992;Anderson and Badzioch, 1993;Parazzini et al., 1993;Goldgar et al., 1994;Teare et al., 1994;Peto et al., 1996).Most research has been conducted in North America and North European countries. The familial predisposition to breast cancer, however, may have different genetic and ...

Population-based estimates of the relation between breast cancer risk, tumor subtype, and family history

“…Research indicates that women with an affected first-degree relative (mother/father/sister/brother/daughter/son) or with any affected family member diagnosed \50 years have particularly high risks [1][2][3][4][5][6][7]. These associations may reflect a combination of factors, including high-penetrance inherited genetic mutations in genes such as BRCA1 and BRCA2, low-penetrance inherited mutations in genes such as GSTP1, and a shared family environment [8].…”

Population attributable risks for breast cancer in Swedish women by morphological type

“…These studies suggest that the subtypes do not tend to share a common risk profile although some of the results are inconsistent [1][2][3][4]. Some well-known risk factors for breast cancer include family history [5][6][7][8], nulliparity [9], late age at first child birth [9], early menarche [10], late menopause [10], use of hormone replacement therapy [11] and high socioeconomic status [12]. Among women whose first child birth occurred after age 35 years, the risk is higher than those of nullipara [10].…”