Breast Cancer Screening
Early Diagnosis Through Screening
Breast cancer screening is the best way to detect breast cancer in its early stages and
prevent it from becoming more dangerous. The most common screening test available
for breast cancer is mammography, which is essentially an x-ray of the breast.
Mammograms can detect small tumors and ductal carcinoma in situ (DCIS), which may
not be felt on physical examination. DCIS is a pre-invasive stage of breast cancer in
which abnormal cells are confined to the milk ducts only.
Screening recommendations for breast cancer:
- The United States Preventive Services Task Force recommends mammography every two years for women between the ages of 50 to 74. In some women, the benefits of mammography before the age of 50 outweigh the harms. These women may choose to begin screening at 40. The benefits of mammography are not evident in the case of
women who are 75 years of age or older.
- There is insufficient evidence to suggest any benefits of breast ultrasonography, 3D mammography, magnetic resonance imaging (MRI), or other adjunctive methods to screen for breast cancer.
Despite the proven benefits, mammography for breast cancer screening has not yet
been integrated into the public sector of the Caribbean region, except in the Bahamas
and Dominica. Clinical Breast Exam (CBE) remains the most widely used screening
method in public hospitals of Antigua & Barbuda, Belize, Grenada, Guyana, Jamaica, St Lucia, St Vincent and the Grenadines.
Mammography is available in many private hospitals throughout the Caribbean region,
but due to lack of awareness and financial access, most breast cancers are only
detected at an advanced stage.
Risk factors and causes of breast cancer:
- Age: The risk of breast cancer and other cancers increases with age. Breast cancer is more commonly found in women over 50 years, particularly those who have gone through menopause. The risk for women who are 65 or older is also 5.8 times greater than who are younger than 65 years of age.
- History of cancerous or non-cancerous breast disease: Women with a personal history of breast cancer or non-cancerous breast disease have a higher risk of developing breast cancer again. The risk of breast cancer increases by 6.8 for women with a history of invasive breast cancer. Invasive breast cancers are those in which cancer cells break free from their site of origin and spread to other parts of the body.
- Gene mutation: BRCA genes – BRCA1 and BRCA2 – are tumor suppressor genes. The presence of a BRCA gene mutation is a major risk factor for breast cancer. In fact, an alteration in BRCA1 increases the risk of breast cancer by up to 200 times, whereas a BRCA2 mutation increases the risk by up to 15 times. However, research suggests that these estimations are subjected to bias and may represent overestimated results as compared to the true risk associated with BRCA mutations.New research also suggests that other genes, such as CHEK2 and TP53, can also play a role in increasing the risk of breast cancer.
- Family history: The risk of breast cancer is greater in women with a mother, sister, daughter, or other first-degree relative with breast cancer.
- Dense breast tissue: Breasts are an intricate body part composed of thousands of milk-producing lobules (tiny glands). These glands contain more cells that other parts of the breast. Women with dense breasts have a high risk of developing cancer as more cells in the dense breast could transform into cancerous cells. Increased density also makes it challenging to spot abnormal tissue in the screening tests.Younger women have comparatively more dense breasts than those of older women. The glandular tissue is replaced by fat tissue as a person ages and the breast density decreases.High breast density is mostly inherited. However, it can also occur in women who:
- drink alcohol
- take postmenopausal hormones
- don’t have children
- had their first pregnancy at a late age
- Estrogen: Estrogen is a hormone that plays an important role in the development and functioning of the female reproductive system. This hormone can stimulate the growth of breast cells. The longer a female is exposed to estrogen, the greater the potential risk of developing breast cancer.Estrogen levels are high during a woman’s reproductive years. Although estrogen exposure is natural, some women have greater exposure due to the following factors:
- Menstruation before the age of 11
- Late menopause
- No history of pregnancy
- Pregnancy after 35 years
- Hormonal therapy: Hormone replacement therapy (HRT) is often advised to cope with the symptoms of menopause. This management strategy increases the risk of breast cancer.Females who receive combined HRT (estrogen + progesterone) have a comparatively higher risk of developing breast cancer as compared to those who receive estrogen-only therapy, but the risk remains high in both forms of HRT.
- Contraceptive pills: Birth control pills can also slightly increase the risk of developing breast cancer. The risk decreases immediately upon stopping contraceptive pills and returns to normal levels 10 years later.
- Obesity: Being overweight or obese are risk factors for breast cancer. This is especially true in women who have been through menopause. Women with obesity have more than 2 times the risk of developing breast cancer than those who are not obese. A research study conducted on breast cancer found that most Caribbean women who had breast cancer were also overweight. This may have some link to the increased incidence of breast cancer in the Caribbean population.
- Alcohol: The risk of breast cancer is greater with the increased alcohol consumption.
- Radiation therapy: Certain treatments require exposure to radiation. Exposure to radiation in the chest region increases the risk of breast cancer. The risk is even greater if radiation therapy was administered during puberty. Moreover, radiation therapy may further increase the risk in women with alterations in BRCA genes, particularly if radiation exposure happened before 20 years of age.If radiation therapy is administered to a single breast, it does not increase the risk of breast cancer in the other breast.
Protective factors are those that reduce the risk of developing breast cancer.
- Lifestyle changes: Regular exercise reduces the risk of cancer. This is
especially true in the case of premenopausal women with a healthy weight.
Women who have been through menopause should pay special attention to their
weight. Excess weight or obesity results in more estrogen produced by the body,
thereby increasing the risk of cancer.
- Reduced exposure to estrogen: Exposure to estrogen is natural, but data
shows that having a pregnancy earlier in life, as well as breastfeeding, affect
hormone levels in a way that can reduce estrogen exposure.
- Mastectomy for risk reduction:Some women with a high risk of breast cancer
choose preventative mastectomies even before signs of cancer are detected.
This is a personal choice and requires intensive risk assessment and counseling
on other protective methods.
- Ovarian ablation: Similar to mastectomy, some premenopausal women opt for
ovarian ablation – treatments which decrease the amount of estrogen in the
body. This is possible through surgical ovary removal, radiation therapy, or drug
- Lifestyle changes: Regular exercise reduces the risk of cancer. This is