Family history:
Genetic factors contribute to about 5% to10% of all breast cancers and up to 25% of women who are diagnosed before the age of 30. The increase in the risk structure depends on how close the relative is and how many have had breast cancer in the past, in the paternal and/or the maternal side. Being born into a family with breast-cancer carries the greatest risk and it is significantly important for one self to identify if one is a ‘high-risk woman’. Studies have indicated that among women with a family history of breast cancer, there is little protection from later age of menarche, no protection from multiple births, or from early age at first birth. In fact there is a particularly adverse effect of first pregnancy. Therefore, surveillance of high-risk family members is the most important in the protocol of management. This includes monthly BSE, biannual clinical examination and mammography, with a biopsy being performed on any suspicious breast lesion.
[Chart of a family with history of breast cancer]
Racial predisposition:
While breast cancer seems to be affiliated with the white women in the industrialized countries, it is the western urban lifestyle that is largely associated with the disease. However, breast cancer behaves differently in different countries. In Malaysia, the National Cancer Registry [2003] recorded a higher incidence of breast cancers amongst the Chinese women between the ages of 40-49 and a slightly lower incidence in the Malays and Indians. There may be some diet or genetic factors that are independent of the environmental risks contributing to the higher incidence in the younger Chinese women.
Benign breast diseases:
Women who are detected to have ‘benign proliferative disease’ have a 2 fold increased risk of subsequent breast cancer; whilst those with ‘atypical hyperplasia’ have a 5-6 times increased risk of developing breast cancer. It is therefore important that an individual woman having undergone any breast biopsies attain a better understanding of the biopsy findings and determining its possible relationship to breast cancer risk.
Personal history:
A woman who has had cancer in one breast is at increased risk of developing cancer in the opposite breast [10%]. Similarly women with cancer of the uterus have a significantly higher risk of developing breast cancer and vice versa.
Exposure to radiation at an early age:
It has been documented that children exposed to radiation rays either in the line of investigations and/or treatment with radiation to the chest wall i.e. in the management of scoliosis, or therapy for Hodgkin’s disease, have an increased risk of developing breast cancer in early adulthood.
Lifestyle factors:
Alcohol intake is another determinant of breast cancer risk. Women who drink regularly and exceed more than 9 units of alcohol [Fig x] are at increased risk for breast cancer. So it would be wise to restrict your intake to one unit a day or not at all.
Women who are overweight after the age of menopause are at a higher risk of developing breast cancer [Fig x]. Much data have not directly implicated high-fat diet to breast cancer, however, a diet containing excess caloric intake [significantly this is derived from fats] increases the amount of adipose tissue, which in turn influences the hormonal levels. It is now known that fat cells manufacture estrogen, and these altered levels have a significant influence on the risk of breast cancer, particularly in postmenopausal women. Women having an ‘apple shape’ obesity i.e. waist bigger than the hip, have an increased risk of developing breast cancer, whilst women with a ‘pear shaped’ obesity are associated with increased risk of heart disease.
[Fig x - picture of an obese woman]
Sedentary lifestyle and physical inactivity is responsible for an increased number of women with obesity, hypertension, diabetes mellitus and breast cancer. There is abundance of data to indicate that women who exercise have a lower amount of estrogen, therefore a decreased hormonal influence on the breast tissue. One major Swedish study indicate that women under the age of 40 who exercise for more that 4 hours per week had a 58% reduced risk of developing breast cancer. It is evident that exercise leads to higher level of frontline defense against the emergence of tumors that might produce cancer. Exercising women tend to lose weight and thereby avoid cancers related with obesity i.e. breast, ovarian, colon etc. at the same time reduces the risk of developing or dying from heart disease, stroke and diabetes.
It is evident that breast cancer may be prevented in certain groups of women by changing their endogenous hormonal profile through a change to a low-fat diet or increased level of exercise.
Is it feasible to reduce one’s risk in developing breast cancer? ……..YES
The possible primary interventions according to ages are:
In summary, the cause of breast cancer remains generally unknown. There are apparent links between breast cancer and lifestyle factors and it is notable that women who smoke or consume two or more alcoholic drinks per day are at a greater risk for the disease, as are women who are obese and get insufficient exercise. Women who have several affected family members should consider the possibilities of genetic counseling to understand further an individual risk. The recommendation for adult, healthy women over the age of 40 is to get annual screening mammogram. This single thing, along with breast self-exam, can help a woman reduce her risk of death from breast cancer.
Berita Menopos - December 2005 