Elucidation of the basic mechanisms involved in the pathogenesis of breast cancer and numerous potential applications await further study of BRCA1, BRCA2, and other breast cancer susceptibility genes.

Patients carrying…

Li-Fraumeni syndrome was first identified in 1969 in a description of four kindreds identified through children with sarcomas whose cousins or siblings also had childhood soft-tissue sarcomas and whose other relatives had excessive cancer occurrence.…

The study of clinical syndromes that include an increased incidence of breast cancer has provided insight into the mechanisms by which genetic mutations result in the development of breast cancer. The most frequently…

Two groups have analyzed data from the Cancer and Steroid Hormone (CASH) Study, a large case-control study initiated in 1981. In this study group, 11% of breast cancer patients reported a…

Even though researchers are beginning to understand the influence of genetic factors on the incidence of breast cancer in largely white, Western populations of women, very little is known about breast…

The first attempts to determine the influence of family history on breast cancer risk were published in the first half of the twentieth century. Although many of these studies have methodological…

Introduction
Although noninherited factors certainly play a major role in familial clustering of breast cancer, breast cancer susceptibility genes appear directly responsible for 5% to 10% of all breast cancer. Much…

Approaches for the primary prevention of breast cancer according to period of life are discussed here briefly and are considered in more detail elsewhere. Although the major reasons for the high rates of…

As noted in the first section of this chapter, the search for specific breast cancer risk factors has been stimulated by the large differences in rates of breast…

Much is known about the behavioral factors that influence breast cancer risk, and the links between these factors and the pathophysiology of the disease are becoming clearer. Known and suspected risk factors are described in…

A review of 115 studies conducted between 1971 and 1994 found little support for an association between specific occupations and breast cancer risk. Limited evidencesuggested that cosmetologists, beauticians,…

Evidence of geographic variation in incidence and mortality rates of breast cancer within the United States, the steady increase in incidence over time, and the identification of suspected breast cancer clusters have stimulated interest in…

Ionizing radiation to the chest in moderate to high doses (e.g., 1 to 3 Gy) at a young age substantially increases breast cancer risk. Among survivors of the atomic bombing of Hiroshima and Nagasaki, breast…

Regular physical activity has been hypothesized to prevent breast cancer, largely by reducing circulating levels of sex hormones. The mechanisms by which physical activity reduces exposure to hormones vary by period of life. Young girls…

Regardless of whether diet is related to the occurrence of breast cancer, if postdiagnosis diet were related to risk of recurrence or survival, then dietary modifications might assist in breast cancer treatment.…

Diets high in fiber have been hypothesized to protect against breast cancer, perhaps due to inhibition of the intestinal reabsorption of estrogens excreted via the biliary system. A high-fiber diet has been…

Nutritional factors have been prominent among the environmental determinants of breast cancer hypothesized to account for the large variation in breast cancer incidence around the world and the large increases in rates among the offspring…

Family history of breast cancer in a first-degree relative is a consistent risk factor; risk increases with earlier age at diagnosis in first-degree relatives and with the number of relatives affected. In…

By the mid-1970s, almost 30 million prescriptions for postmenopausal hormones were being filled annually in the United States. A challenge in studying the relationship between postmenopausal hormone use and breast cancer is the substantial…

Since oral contraceptives were first introduced in the 1960s, they have been used by many millions of women. In 1988, more than 10.7 million U.S. women were current oral contraceptive users.133 Most combined oral contraceptives…

Several lines of evidence have long suggested that sex hormones play a central role in the etiology of breast cancer. As noted in the section Age-Incidence Curve of Breast Cancer Risk, rates of…

This section addresses reproductive factors during the course of a woman’s life in relation to risk of breast cancer. An underlying concept is that ovarian hormones initiate breast development and that subsequent monthly menstrualcycles induce…