The search for risk factors in breast cancer.

Abstract

This paper deals with a long-term prospective study of breast cancer to determine the value of periodic screening for this condition, which also incorporates epidemiologic objectives. The methodology of the study, the variables included, and preliminary observations based on detected cases are presented. THE difficulties in conducting prospective studies on comparatively low incidence diseases are so severe that they are rarely undertaken for a specific condition. This holds for breast cancer despite the fact that an estimated 6 per cent of the women develop the disease during their lifetime and about one in five of the deaths from cancer among women is attributable to this condition. However, an opportunity has recently presented itself to incorporate epidemiological objectives related to breast cancer in a long-term prospective study whose main purpose is to investigate the value of periodic breast cancer screening. This paper presents the methodology of the study, the variables included, and preliminary observations based on the breast cancer cases detected in the early stages of the investigation. Before proceeding to this discussion, a brief review of where we are in understanding the epidemiology of breast cancer is in order. THE SEARCH FOR RISK FACTORS IN BREAST CANCERThe outstanding characteristic of the search for risk factors in female breast cancer is the lack of success in identifying specific parameters that are strongly associated with the incidence of the disease. The unifying element in these efforts is a hormonal hypothesis, whether the investigation is concerned with socio-

Reproductive Factors in Breast Cancer Epidemiology

“…A relationship between the total number of years of menstrual activity and risk of breast cancer has been reported (30,31). It has been proposed that breast cancer risk may be directly related to the total number of sterile menstrual cycles (32) and that the effects of various reproductive factors might be explained by their contribution towards a reduction in the number of such cycles (32).…”

Pathways to Care for Cancer Patients

“…What did you get from your therapy in the way of sickness, improvement, pain, shortness of breath, or other reaction? 3. Trace the pathways of care for the illness: Who noticed the first symptom?…”

“…the genesis of cancer (2) and their effect on outcome of treatment (3). Suchman (4) studied the relationship between stage of illness and the seeking of medical care.…”

Molecular and Cellular Basis of the Mammary Gland Susceptibility to Carcinogenesis

“…Pregnancy interruption slightly increases the incidence of carcinomas, and this is related to an incomplete differentiation of the gland (Fig. 6) [13][14][15][16][17][18][19] aData from Russo and Russo (106). 189 in high mitotic and DNA synthetic indices (Table 3) (106).…”