Position Paper of the American Council on Science and Health on Risk Factors for Breast Cancer: Established, Speculated, and Unsupported

Abstract

This article provides the position of the American Council on Science and Health regarding how breast cancer is defined and classified; the magnitude of the public health problem of breast cancer among women; the implications of variation in incidence of breast cancer internationally and with migration; access to health care as a factor in slight differences in incidence and mortality rates among African‐American and white women; and the evidence concerning various proposed human‐breast‐cancer risk factors. The article classifies risk factors as either established, speculated, or unsupported on the basis of available evidence. Specific genes have been identified that may explain as much as 5–10% of new breast cancer cases. Inherited predispositions may be characterized by family history of breast or ovarian cancer, young age at diagnosis, breast cancer diagnosed in both breasts, and male breast cancer. Benign breast disease (BBD), particularly the subtypes of BBD involving atypical hyperplasia, and exposure early in life to ionizing radiation is an established risk factor for breast cancer. Several reproductive characteristics are established as risk factors for breast cancer: early age at menarche, first full‐term pregnancy after age 35 years of late age, and late age of menopause. Obesity and low physical activity are established as risk factors for breast cancer and are modifiable. Speculated risk factors for breast cancer that are gaining scientific support include nulliparity, oral contraceptive use, and postmenopausal estrogen replacement therapy. Speculated risk factors for which there is conflicting or preliminary support include not breast feeding, postmenopausal estrogen/progestogen replacement therapy, prescribed diethylstilbestrol, low consumption of phytoestrogens, specific dietary practices, alcohol consumption, not using nonsteroidal antinflammatory drugs, abortion, and breast augmentation. Unsupported risk factors include higher than average consumption of phytoestrogens, premenopausal obesity, electromagnetic fields, and low‐dose ionizing radiation after 40 years of age. There is only limited support for xenoestrogens and large breast size as risk factors for breast cancer.

Câncer de mama e fatores associados

“…Detevese aos fatores relacionados à menarca, menopausa, história familiar, paridade, amamentação, tabagismo, atividade física, raça, uso de anticoncepcional e de terapia hormonal. Estes critérios foram baseados na classificação de fatores de risco para o câncer de mama, elaborada pelo Conselho Norte Americano sobre Ciências da Saúde, que são: idade, antecedentes pessoais para o câncer de mama, antecedentes familiares, história de lesões proliferativas mamárias, estrogênios endógenos e as radiações ionizantes (1,4) . Os critérios utilizados para se determinar a relação com os riscos de câncer de mama foram: idade, menarca, menopausa, história familiar, idade da primeira gestação, paridade, amamentação, hábitos (fumo e atividade física), raça, uso de anticoncepcional e terapia hormonal.…”

Histopathological Analysis of Breast Lump in a Tertiary Care Hospital.

“…Demographic factors might play a role, considering the large number of young females within the population of these groups.Maximum number of cases of fibroadenoma was seenin third and fourth decade of life, similar to other studies 9,10,11 The fibrocystic disease was seen in 9.14% cases in our study which is at par with studies by Jamal A et al 12,13 (13.1% and 12%). Hormonal imbalance with prolonged exposure to estrogen is hypothesized to be the main cause of these disorders 14 .Majorityof the patients belonged to the 3rd and 4th decades.Most of the cases of fibrocystic disease diagnosed in our study (around 76.58%)were Simple and this is less dangerous than proliferative fibrocystic disease (23.41%), which is associated with an increased risk of breast cancer 14,15 Inflammation of the breast was found in 9.14% of biopsies. The pattern of inflammatory breast disease in ourstudy is relatively close to that observed in Saudi Arabia and Jordan 16,17 .Social factors and personal behaviors could be the possible cause of this condition where repeated pregnancies and lactations with accompanying change of breast physiology predispose women to breast infections.…”

Untitled

“…Breast cancer is the most common cause of cancer death among women in 140 of 184 countries worldwide and the most frequently diagnosed cancer among women which now represents one in four of all cancers in women [8]. Breast cancer Epidemiology and BurdenBreast cancer is the most common female cancer, the second most common cause of cancer death in women, and the main cause of death in women ages 40 to 59 [15]. Breast cancer is a common form of cancer among women globally.…”