A genetic linkage study of familial breast-ovarian cancer

ABO histo-blood groups and Rh systems in relation to malignant tumors of the digestive tract in Bosnia and Herzegovina

The distribution of ABO blood groups and the Rhesus factor was analyzed in 279 patients who suffered from malignant tumors of the digestive system. Patients were registered retrospectively in the Gastroenterohepatology Clinic, Clinical Center, University of Sarajevo over a discontinuous period of 88 months. From the results obtained, it was concluded that: (a) men became ill from gastric cancer significantly more frequently than women; (b) the frequency of liver carcinoma was three times higher than the global frequency and the frequency neighboring ethnic groups; and (c) patients with blood group B and patients with RhD(-) exhibited a significantly higher proportion of disease.

Familial effects of prostate and other cancers on lifetime breast cancer risk

Lifetime probabilities of developing breast cancer were calculated for first-degree female relatives of three groups of breast cancer patients: 114 with bilateral cancer, 186 unselected, and 88 males. The patients were classified according to whether they had a family history of prostate, endometrial, or ovarian cancer, or no family history of these cancers. In families of unselected female and male patients with no family history of prostate, endometrial, or ovarian cancer, the lifetime probability of developing breast cancer was 11.4%. The risk increased slightly to 13.5% when these other cancers may or may not have present (i.e., they were ignored, which is the usual method in computing risks) and increased further to 25.5% when prostate, endometrial, or ovarian cancer was present in the family. In families of patients with bilateral cancer the respective risks were 10.9%, 17.3%, and 34.4%. A family history of prostate cancer increased lifetime risk consistently in each of the groups, to 29.0% in the unselected and male groups and to 38.2% in the bilateral group. Endometrial cancer increased risk only in the bilateral group (to 41.8%) as did ovarian cancer (to 54.6%). Increased risk of breast cancer with a family history of endometrial or ovarian cancer appeared to be influenced by families with hereditary breast-ovarian cancer or the cancer family syndrome. The results indicate that prostate cancer, and endometrial and ovarian cancers in some families, can significantly increase breast cancer risk and should be taken into account when counseling women about their breast cancer risk.

Familial breast cancer risks. Effects of prostate and other cancers

BACKGROUND

Previous studies have provided conflicting results concerning the effects of a family history of prostate and other cancers on breast cancer risks.

METHODS

Three groups of families were studied to determine the effects of a family history of prostate cancer on breast cancer risks. Also considered were the effects of a family history of melanoma, colon, lung, ovarian, and endometrial cancers. Included were 422 first-degree female relatives of 114 patients with bilateral breast cancer, 320 first-degree relatives of 88 male patients with breast cancer, and 633 relatives of 186 unselected female patients. For estimating relative risks, observed numbers of breast cancers in relatives were compared with expected numbers based on population incidence data. Multiple logistic-regression also provided odds ratios of relatives affected with breast cancer.

RESULTS

A family history of prostate cancer increased the breast cancer risks in each of the groups, compared with families without prostate cancer. Ovarian cancer in a family increased the breast cancer risks only in the bilateral breast cancer group, and endometrial cancer increased the risks in the bilateral and unselected groups. These increases in risk appeared to be the consequence of families with multiple cancers, including those with hereditary breast-ovarian cancers and the cancer family syndrome. A family history of melanoma, lung, or colon cancer did not increase breast cancer risks.

CONCLUSIONS

A family history of prostate cancer, as well as endometrial and ovarian cancer, significantly increases the risk of breast cancer.

Linkage mapping in familial breast cancer: improved localisation of a susceptibility locus on chromosome 17q12-21

Fifteen pedigrees with a total of 75 cases of breast cancer, 10 of ovarian cancer and 53 of other cancers have been collected. Polymorphic markers on chromosome 17q have been screened to locate a putative breast-cancer gene using DNA from relevant individuals within these families. Pairwise LOD scores have been calculated for markers CMM86, NM23, 42D6 and MFD188. The maximal summated LOD for the 15 families is 4.45 at theta = 0.025 using 42D6. All cases of bilateral breast cancer and ovarian cancer appear to be linked to this region. Recalculating LOD scores on the assumption of linkage in these cases increases the maximal summated LOD to 5.62 at theta = 0.025 using 42D6. A genetic exclusion map of critical recombinants in linked families suggests that the gene is flanked by markers 42D6 and MFD188, a region 5 to 10 cm in length.

Genetic epidemiology of epithelial ovarian cancer

BACKGROUND

Aside from age, family history is the strongest predictor of ovarian cancer risk. Genetic components of risk for ovarian cancer have been evaluated by a number of designs, including case-control studies of family history and other risk factors, segregation and genetic linkage studies, and studies of biomarkers and tumor-specific cytogenetic abnormalities.

METHODS

Data were extracted from all available case-control studies that included family history. Cytogenetic, biomarker, segregation, analytic, and genetic linkage studies were reviewed.

RESULTS

Family history of ovarian cancer confers a 3.6-fold increased risk for this disease. Segregation studies of breast and ovarian cancer in five large families were consistent with dominant inheritance. Low levels of alpha-L-fucosidase confer mildly increased risk for ovarian cancer. Low galactose-1-phosphate uridyl transferase and type A blood group may increase risk for ovarian cancer. Cytogenetic and oncogene studies have identified regions that may be important in tumorigenesis and metastasis, but discriminating between early and late changes is difficult from these studies. Presence of a genetic susceptibility locus for breast and ovarian cancer has been confirmed on chromosome 17q21.

CONCLUSIONS

Family history is an important predictor of ovarian cancer risk. In rare families, a specific dominantly acting gene can be identified, but in the vast majority of familial ovarian cancers the underlying mechanism remains unclear. Specific studies are needed for women with a family history of ovarian cancer because evidence suggests modification of the effects of oral contraceptive use and reproductive patterns in this population of women.

Chromosome 1 alterations in breast cancer: allelic loss on 1p and 1q is related to lymphogenic metastases and poor prognosis

The development of human breast cancer is characterized by a variety of genetic alterations, and cytogenetic analyses have documented the consistent involvement of both arms of chromosome 1. In the present study, molecular markers detecting restriction fragment length polymorphisms were used in pairwise screening of normal and tumor DNA to determine the frequency of allelic imbalance in breast tumors. Loss of heterozygosity (LOH) in the polymorphic epithelial mucin (PEM or MUCI) gene at 1q21 was found in 16% of 89 informative (constitutionally heterozygous) cases, whereas gain in intensity of one allelic band was more frequent (37%), a total of 47% of cases manifesting either allelic loss or gain. Three additional tumors manifested a structural alteration. Allelic loss or gain in the PEM gene was not associated with other prognostic factors, e.g., tumor size, lymph node status, steroid receptors. DNA ploidy, S phase fraction, protooncogene amplification, histological type, or patient age. However, LOH in the PEM gene was significantly correlated with early disease recurrence (P = 0.006). LOH on 1p was found in 27% of 117 informative cases, using probes for either D1S57 or D1Z2 located at 1p33-p35 and 1p36, respectively. Somatic allelic imbalance on 1p and 1q seemed to be independent events and not the effect of loss of a whole chromosome 1. LOH on 1p was significantly correlated to the presence of lymph node metastasis, to larger tumor size, and to DNA nondiploidy, but not correlation was found to disease outcome at this limited duration of follow-up (median 29 months).

Risk of prostate, ovarian, and endometrial cancer among relatives of women with breast cancer

OBJECTIVE

To investigate the risk of prostate, ovarian, and endometrial cancer among relatives of patients with breast cancer.

DESIGN

Cohort study of 947 pedigrees in which the proband had breast cancer, linked with the Icelandic cancer registry.

SETTING

Iceland.

SUBJECTS

The 947 pedigrees included 29,725 people, of whom 1539 had breast cancer, 467 had prostate cancer, 135 ovarian cancer, and 105 endometrial cancer.

MAIN OUTCOME MEASURES

Risk of prostate, ovarian, and endometrial cancer among blood relatives of women with breast cancer compared with risk in spouses.

RESULTS

The risk of prostate cancer was significantly raised for all relatives (1.5), first degree relatives (1.4), and second degree relatives (1.3) of women with breast cancer. Risk of ovarian cancer was raised for all relatives (1.9) and first degree relatives (1.9) and risk of endometrial cancer was raised for all relatives only (1.9). The risk of prostate cancer was raised if the proband with breast cancer had a first degree relative with prostate cancer.

CONCLUSIONS

Coaggregation exists between breast cancer and cancers of the prostate, ovaries, and endometrium. This risk relation is probably based on genes which act by increasing the risk for cancer at these sites. Environmental factors that are common among relatives may also play a part. Continued research is required into pathophysiological mechanisms that could explain these observations.

Effect of family history, body-fat distribution, and reproductive factors on the risk of postmenopausal breast cancer

BACKGROUND

A family history of breast cancer reflects shared cultural factors, genetic predisposition, or both. There is evidence that the estimated risk associated with a family history of breast cancer increases multiplicatively in combination with other risk factors. We examined the combined effect of family history and anthropometric and reproductive factors on the risk of breast cancer in postmenopausal women.

METHODS

Using data from a prospective cohort study, we studied 37,105 women 55 to 69 years of age to determine whether known risk factors for breast cancer are modified by a reported family history at the time of entry into the study.

RESULTS

During the first 4 years of follow-up, 493 new breast cancers were diagnosed. The association of the waist-to-hip ratio (the circumference of the waist divided by that of the hips) with the risk of breast cancer was limited predominantly to women with a family history of breast cancer; the age-adjusted relative risk of breast cancer for the women above the fourth quintile for waist-to-hip ratio as compared with those below the first quintile was 3.2 in women with a family history of breast cancer and 1.2 for women without such a family history. An interaction was observed between a family history of breast cancer and the number of live-born children; the protective effect of higher parity was observed primarily among women with a family history of breast cancer. Similarly, the age-adjusted relative risk of breast cancer associated with a late age at first pregnancy (i.e., greater than or equal to 30 years) was 5.8 for women with a family history of breast cancer and 2.0 for women without such a family history.

CONCLUSIONS

The increase in the risk of breast cancer associated with a high waist-to-hip ratio, low parity, or greater age at first pregnancy is more pronounced among women with a family history of breast cancer. These findings suggest etiologic differences between familial breast cancer and the sporadic form.

Somatic mutations and human breast cancer. A status report

A systematic study of primary human breast tumor DNA demonstrated that three proto-oncogenes or regions of the genome (c-myc, int-2, and c-erbB2) are frequently amplified and that there is loss of heterozygosity (LOH) on chromosomes 1p(37%), 1q(20%), 3p(30%), 7(41%), 11p(20%), 13q(30%), 17p(49%), 17q(29%), and 18q(34%). Specific subsets of tumors can be defined based on the particular collection of mutations they contain. For instance, LOH on chromosomes 11p, 17p, and 18q frequently occurs in the same tumor. A search for putative tumor suppressor genes within the regions of the genome affected by LOH has been started. In a comprehensive molecular analysis of the p53 gene on chromosome 17p, 46% of the tumors contained a point mutation in the p53 gene.

Hereditary ovarian cancer. Heterogeneity in age at diagnosis

An unknown fraction of the ovarian cancer burden occurs in women with a family history indicative of a putative autosomal dominantly inherited cancer susceptibility syndrome. The results from a five-generation, extended, hereditary breast-ovarian cancer kindred are described 10 years after it was initially ascertained. Significantly more cancers were observed in high-risk family members during this decade than were expected (P less than 0.001). The age of ovarian cancer diagnosis was studied in additional ovarian cancer-prone families of three types: site-specific ovarian cancer syndrome, the breast-ovarian cancer syndrome, and Lynch syndrome II. The age of onset in each of the three sets was significantly (P less than 0.001) earlier than the general population mean of 59, and there were significant differences in the age of onset (P = 0.050) among these three cohorts. Ovarian cancer histology was similar to that of patients with negative family histories. There may be clinically significant heterogeneity in the age at diagnosis of ovarian cancer among these ovarian cancer-prone syndromes. This has important implications for understanding its natural history and targeting surveillance-management strategies.

Heterogeneity and natural history of hereditary breast cancer. Surgical implications

The properly compiled cancer family history can prove to be one of the most cost-effective and powerful instruments for cancer control in breast cancer. Needed, however, is an understanding of the heterogeneity of hereditary breast cancer and knowledge of those facets of its natural history that can expedite a syndrome diagnosis. Priority concerns for cancer control in hereditary breast cancer are the development of registries of cancer-prone families, willingness by third-party carriers to help defray the costs of surveillance, and more research in molecular genetics.

Chromosomal abnormalities in human breast cancer

This review emphasizes cytogenetic changes and DNA analyses by Southern blot in primary breast tumors, rather than metastases, established cell lines, and pleural effusions. The data suggests that the most frequently altered chromosomes and chromosome regions are 1p, 1q, 2q, 3p, 5, 6q, 8p, 8q, 11p, 11q, 12, 13q, 14q, 16, 17p, and 17q. Changes on 8q, 11p, 11q, 13q, and 17q appear to be associated with either progression of the disease or poor prognosis. Alterations on 1p and 3p may represent early events in the development of breast cancer.