Dietary and other risk factors in women having fibrocystic breast conditions with and without concurrent breast cancer: A nested case‐control study in Shanghai, China

Abstract

Risk of breast cancer is increased in women with proliferative benign breast conditions. Most of these conditions, however, do not progress to breast cancer. The purpose of our study was to identify factors possibly associated with this progression. Women with proliferative fibrocystic breast conditions alone (214), and women with proliferative fibrocystic breast conditions and concurrent breast cancer (130), were compared to each other, and each of these groups of women were also compared to 1,070 controls; and 176 women with non-proliferative benign breast conditions alone, and 155 also with breast cancer, were similarly compared. All study subjects were selected from a cohort of women enrolled in a trial of breast self-examination in Shanghai. Women were interviewed to ascertain information on suspected risk factors for breast cancer and dietary habits. Conditional logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Increased risks of both proliferative fibrocystic breast conditions alone, and with breast cancer, were associated with low parity, a prior benign breast lump and breast cancer in a first-degree relative. Decreasing trends in the risk of both conditions with increasing intake of fruits and vegetables were observed. No factors were significantly associated with risk of breast cancer relative to risk of proliferative changes. Similar, but in some instances weaker, associations were observed for non-proliferative fibrocystic conditions with and without breast cancer. The possible risk or protective factors that were observed in our study most likely alter the risk of breast cancer at an early stage in the carcinogenic process, and probably do not alter risk of progression from proliferative fibrocystic breast conditions to breast cancer. ' 2005 Wiley-Liss, Inc.Key words: breast cancer; fibrocystic breast conditions; risk factors; diet; fruits; vegetables Women who have undergone a breast biopsy for benign breast disease are at increased risk of breast cancer. 1 Although nonproliferative breast conditions do not seem to be associated with increased risk of breast cancer, proliferative fibrocystic breast conditions without and with atypia have been associated with 2-fold and 4-fold increased risks of breast cancer, respectively. 2-8 Most women who are diagnosed with proliferative fibrocystic breast conditions do not develop breast cancer, however, suggesting the presence of risk factors necessary for progression.Breast cancer presumably results when a cell first undergoes an initiating genetic alteration, and then either this cell or one of its daughter cells, which inherits that initiating genetic damage is transformed into a cell with malignant characteristics by undergoing one or more subsequent events. In this scenario, proliferative activity may play an important role by increasing the expansion of initiated cells and the likelihood that one will undergo subsequent events ultimately leading to transformation to a malignant phenotype. 9,10 The morp...

Soyfood Intake in the Prevention of Breast Cancer Risk in Women: A Meta-Analysis of Observational Epidemiological Studies

“…In addition, three publications shared the data from the Shanghai Breast Cancer Study, with almost the same cases (19,21,32). Two publications from a randomized trial of breast self-examination in Shanghai had to be considered as one study (28,30). However, two studies reported by Horn-Ross et al originated from different projects: the Bay Area Breast Cancer Study (case-control study) (20) and the California Teachers Study (cohort study) (36).…”

Glutathione S-transferase M1 and P1 polymorphisms and risk of breast cancer and fibrocystic breast conditions in Chinese women

“…Eligible cases, defined as women who had a breast biopsy and were diagnosed with either a fibrocystic breast condition or breast cancer, were selected from studies of mammary epithelial cell proliferation and breast cancer conducted between September 1995 and July 2000 (Wu et al [53];Li et al [54];Shannon et al [55]). In these studies, 551 (89%) of the 622 eligible women with fibrocystic conditions and 376 (88%) of the 426 eligible women with breast cancer were interviewed.…”

Plasma Isoflavones and Fibrocystic Breast Conditions and Breast Cancer Among Women in Shanghai, China

“…Exposures and reproductive lifestyle factors that modulate steroid hormones are associated with both breast cancer and fibrocystic breast conditions (4).…”

“…Epidemiologic studies of the relationship between intake of soy foods and breast cancer have yielded inconsistent results (7). One study found a significant inverse association between soy food intake and risk of proliferative fibrocystic breast conditions, but not of nonproliferative fibrocystic conditions, or of breast cancer with or without concomitant proliferative fibrocystic conditions in extratumoral tissue (4). For the most part, these studies have relied on estimating soy and isoflavone intake using food frequency questionnaires or other dietary report instruments.…”