With October being Breast Cancer Awareness Month, let’s look at the established risk factors for this enigmatic disease.
Breast Cancer is an enigmatic disease that puzzles and taxes the patient, the clinician and researcher. The fact that we still do not understand the risk factors for breast cancer illustrates this point. The risk factors are multiple with complex and, perhaps, unpredictable interactions with each other and the individual. This is why many women with strong risk factors for breast cancer live a disease-free life, while others who have no identifiable risk factors seem to succumb to the disease. To list some of the established factors:
Gender: Being a woman is the main risk factor for developing breast cancer. Constant exposure to the growth-promoting effects of the female hormones oestrogen and progesterone are responsible for this. Men can develop breast cancer, but this is relatively uncommon.
Increasing age: Risk increases as one ages. A lump in a teenager’s breast is invariably benign; in a 60-year-old it is likely to be a cancer.
Race: It is generally held that white women are slightly more likely to develop breast cancer than are African-American women, Asian, Hispanic and Native-American women. But, this may well be related to lifestyles in a significant manner. A South Asian migrant family in a developed country may start off with a low risk for breast cancer, but their descendents acquire the risk of the local population.
Family history: Having one first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles a woman’s risk. Women with a family history of breast cancer in a father or brother also have an increased risk of breast cancer. However, the majority of women with breast cancer do not have a family history of the disease.
Genetic and hereditary factors: A very small group of breast cancers are due to a faulty gene. The most important of these are referred to as BRCA1 and BRCA 2 genes. However, even these do not always cause breast cancer.
Menstrual and Obstetric factors: Women who started menstruating early (before age 12) or who have menopause late (after age 55) have a slightly higher risk. This may be related to a higher lifetime exposure to the hormones oestrogen and progesterone. Women who have had no children or who had their first child after age 35 have a slightly higher risk too.
Breast feeding: Prolonged breast feeding, perhaps, has a protective role.
Contraceptive: Recent oral contraceptive use enhances the risk. But this risk declines once their use is stopped.
Post-menopausal hormone therapy: Long term use (five years and more) of combined hormone therapy (oestrogen and progesterone) increases the risk of breast cancer.
Previous breast disease: A few specific benign breast problems raise a woman’s risk of future malignancy. And women who have had a previous breast cancer have 3-4-fold increased risk of developing a new cancer in the other breast or in another part of the same breast.
Alcohol is linked to an increased risk. The risk increases with the amount of alcohol consumed. With social and binge drinking becoming common, it is important for women to introspect about this habit.
Obesity after menopause seems to increase the risk of breast cancer, by raising oestrogen levels. Lack of physical activity may also play a role. The role of a high fat diet in this context is unclear. Many other risk factors have been suggested: brassieres, antiperspirants, environmental chemicals, stress, silicone breast implants, working night shifts ... There is no scientific evidence about any of these.
But one must appreciate that all risk factors are relative and not absolute. Such a clear perspective is imperative; else, we become destined for mass breast cancer phobia and hysteria. This, in turn, makes us susceptible to the marketing hype, which push random mammography at us through the media incessantly.
What is a mammogram?
It is an x-ray photograph of the breast.
Are there different types?
Screening mammograms are done every year or two to check for early signs of breast cancer. Diagnostic mammograms focus on getting more information about a specific area of concern usually due to a suspicious screening mammogram or a suspicious lump.
How is a mammogram done?
A technician, almost always a woman, places one breast at a time between two plates. Compression is used to flatten and spread the breast tissue, making it less dense and easier to read. Pictures are now taken.
Is it uncomfortable?
There may be some discomfort, when compression is applied, but this is momentary. Schedule the test at least a week after the menstrual period when the breasts are unlikely to be tender. If there is pain, rather than discomfort, alert the technician and radiologist in charge.
Is a mammogram accurate?
Mammograms are accurate but have limitations. Both false positives and false negatives can occur; between 55 and 75 per cent of abnormal mammograms turn out to be benign. Ultrasound is the most common complement to mammography. But false negative diagnoses can occur with both techniques.
Is there a radiation risk?
There is a small dose of radiation involved but it is a negligible risk.
What are digital mammograms?
Digital mammography takes an electronic image of the breast and stores it directly in a computer, allowing improvement in image storage and transmission. It uses less radiation than film mammography. Radiologists use software to help interpret digital mammograms. The equipment is costlier than the film-based machine and this cost is offloaded on the paying patient.
How should one prepare for a mammogram?
Eat and drink normally before a mammogram and take routine medication. But discuss the medications earlier. Take previous films and reports and hand them over. Avoid use of deodorant, powder or skin lotion of any kind on the day of the mammogram. Certain metallic constituents in these products can appear on as spots and cause confusion.
Will the results be available immediately?
No. It usually takes about a day for the reports to be ready. The technician and radiologists are not competent to discuss the results with the patient. Only the clinician who has examined the patient can collate the information: medical history, clinical examination results and mammogram results and come to a conclusion.
What if the results are abnormal?
Further evaluation will be recommended. This may be merely following the progression of the abnormality or additional views or tests such as image-guided needle biopsies. This information will be collated by the clinician and a diagnosis will be offered with a treatment plan.
Are there any other tests available for breast imaging?
While mammography and ultrasound are the mainstay imaging modalities, other imaging tools may also be useful. MRI, PET scan and Scintimammography are complementary tests and are utilised only in select situations. The role of some commercially available and emerging technologies continues to be defined.