Breast cancer is the uncontrolled growth of abnormal cells that develop in the breasts. Signs may include noticing a lump in one or both breasts, a difference in breast shape, dimpling of the skin, fluid coming from the nipple, a newly overturned nipple, or a red scaly patch of skin.
Epidemiology
While breast cancer is more common in women, it can occur in both genders and it is the second most common cause of cancer death in women. Most cases are found in women who are 50 years old or older.
Due to improved screening and therapeutic programs, the survival rate has risen to a 90% 5-year survival rate. Currently, the incidence of breast cancer in Asian women is lower than their western counterparts across all age groups. However, the increased incidence rates of breast cancer in Asian populations make it reasonable to assume that in the future, the prevalence patients worldwide will be of Asian ethnicity.
Risk Factor and Aetiology
Risk factors are due to a variety of factors as mentioned below:
- Increasing age: The risk of breast cancer rises with age: most are diagnosed after age 50.
- Weight and body fat: Body mass index (BMI) differs with menopausal status. There is a higher risk of postmenopausal cancer diagnosis, and a higher BMI is related to a lower risk of premenopausal breast cancer, although the mechanism behind this association is not clear.
- Race/ethnicity: White women have the highest rate of breast cancer, while it is lower in black women (113 per 100,000). It is lowest in Asian Americans/Pacific Islanders (82 per 100,000).
- Height: Increased height is associated with a higher risk of breast cancer in both premenopausal and postmenopausal women.
- Bone mineral density: Women with increased bone density have an increased risk.
- Genetic mutations: Inherited alterations to certain genes, such as BRCA1 and BRCA2, women who possess these genetic changes are at an increased risk of breast and ovarian cancer.
- Reproductive history: Early menstruation before the age 12 and reaching menopause after the age of 55 extends a woman’s exposure to hormones thereby increasing their risk.
- Dense breasts: The density of breast tissue indicates the relative amount of glandular and connective tissue to adipose tissue. Women with dense breasts are more likely to get breast cancer.
- Menopausal hormone therapy: Long-term use of such therapies has been related to an increased risk.
- Family history: There is a positive correlation between an increased risk of breast cancer in families with first-degree female relatives diagnosed with cancer.
- Personal history: A personal history of breast cancer increases the risk of developing cancer in the unaffected breast.
- Previous treatment using radiation therapy: Exposure to ionising radiation of the chest at a young age, is related to a high risk of breast cancer.
- Lifestyle Factors: several adaptable risk factors have been observed that are related to a higher risk. These include the following:
- Physical inactivity: Inactivity is related to a high risk. Physical exercise seems to protect against breast cancer in both premenopausal and postmenopausal women.
- Smoking: Smoking is related to a high risk, especially among premenopausal women.
- Dietary Factors: several dietary factors affect the risk. These include:
- Alcohol: Increased alcohol consumption increases the risk of breast cancer.
- Dietary pattern: A diet composed of mostly fruits and vegetables results may lower the risk.
- Dietary fat intake: Some studies have indicated an association between high consumption of dietary fat and breast cancer, although the overall impact appears small.
- Consumption of red meat: Increased consumption of red meat may be related to a higher risk of hormone-positive premenopausal breast cancer.
- Calcium/vitamin D: Diets low in calcium and vitamin D have been related to a higher risk in premenopausal but not in postmenopausal women.
- Night-shift work: Women who work at night have an increased risk of breast cancer. The primary reason for this persisted understudy but may be linked to the hormone melatonin, which is normally developed at night.
Clinical Features
The following are some clinical features that may indicate warning signs of breast cancer:
- Presence of breast lump(s) or thickening(s) that feels varied from the surrounding tissue.
- The difference in the size, shape, or appearance of a breast.
- Differences to the skin over the breast, such as dimpling.
- A newly overturned nipple.
- Scraping, scaling, crusting, or flaking of the pigmented area of skin surrounding the nipple (areola) or breast skin
- Redness or pitting of the skin over the breast, like the skin of an orange.
When to visit the doctor?
You should make an appointment with your doctor if you notice any mass or nipple discharge or if any modification to skin texture is found during self-examination.
Screening
The objective of breast cancer screening is to discover cancer in its early stages before it grows, spreads, or causes further problems. The following are some methods of breast cancer screening:
- Breast Exam: The doctor will examine the breasts to determine if there are any lumps present.
- Mammogram: A mammogram is an X-ray of the breast and is the primary imaging modality for early detection of breast cancer.
- Breast ultrasound: Ultrasound utilises sound waves to produce images of structures deep within the body and it will help to diagnose lumps that consist of solid cysts.
- Biopsy: A physician will utilise a specialised needle guided by X-ray or another imaging test to extract a core of tissue from the suspicious area. This is a biopsy sample and it will help to differentiate the grade of cancer, and whether the cancer cells have hormone receptors.
- Magnetic Resonance Imaging (MRI): In comparison to mammograms, an MRI of the breasts will often result in “false positives” and occasionally lead to nonessential biopsies. However, MRIs are occasionally used to diagnose breast cancer in women who have an increased risk. MRIs are not a replacement for mammograms, instead they are used together.
Treatment
Treatment options are based on the type of breast cancer, its stage, grade, size, and whether the cancer cells are sensitive to hormones. Surgery, radiation, chemotherapy, and hormone therapy are some of the treatment options available.
Surgery
This may include either removing the tumour (lumpectomy) and a small margin of healthy tissue or removing the entire breast (mastectomy). Other surgical interventions include removing a limited number of lymph nodes (sentinel node biopsy) or removing several lymph nodes (axillary lymph node dissection). Alternatively, some patients who are at higher-risk of breast cancer may choose to do a contralateral preventive mastectomy which constitutes the removal of both breasts.
Radiotherapy
This is commonly done following surgical intervention.
Chemotherapy
In the event of metastasis where cancer spreads from its original site to another part of the body, chemotherapy is recommended.
Hormone therapy
This is used to treat breast cancers that are sensitive to hormones. Oestrogen receptor and progesterone receptor-positive breast cancers are treated with hormone therapy. Hormone therapy treatments include:
- Medications that block hormones from attaching to cancer cells (selective oestrogen receptor modulators)
- Medications that stop the body from making oestrogen after menopause (aromatase inhibitors)
- Surgery or medications to stop hormone production in the ovaries
Complications following surgery include:
- Temporary swelling of the breast.
- Tenderness and hardness of the breast due to scar tissue formation which can occur at the site of the incision.
- Wound infection or bleeding.
- Swelling of the arm due to lymph node removal called lymphedema.
Complications of treatment can also occur after radiation therapy, chemotherapy, or hormone therapy
Breast self-examination
Breast self-examinations are essential to self-screen for breast cancer. A self-examination should be performed monthly after the age of 20 year and should continue throughout life.
