What is Breast Cancer?
Breast cancer is the most common type of cancer among women and the second leading cause of death from cancer globally. The breast, positioned on top of the large chest muscle, consists of milk-producing cells organized into smaller clusters called lobules. These lobules form larger sections known as lobes, which are interspersed with fatty tissue. Milk and other secretions are made in tiny sacs, then released through channels that open at the nipple. Bodies known as Cooper ligaments, which support the breast, firmly attach the breast to the underlying muscle layer.
Most commonly, breast cancer begins in the lining of the channels (ductal carcinoma), but it can also start in the lobules (lobular carcinoma). Many risk factors for breast cancer have been identified. In Western countries, most breast cancers are discovered through screenings before symptoms appear. However, in many developing areas, the first signs usually are a lump in the breast or unusual nipple discharge. It’s diagnosed through a physical exam, breast imaging, and a tissue sample. Different treatment options such as surgery, chemotherapy, radiation, hormonal therapy, and more recent, immunotherapy are available. The type, stage, tumor markers, and genetic abnormalities of the cancer are factors that determine the best treatment plan for each patient.
What Causes Breast Cancer?
Knowing what increases the likelihood of developing breast cancer is crucial in performing health checks for women. Various elements may raise the risk of breast cancer, such as:
Age: The chance of being diagnosed with breast cancer grows as women get older.
Gender: Breast cancer comes up mostly in females.
Previous medical issues: If a woman has had breast cancer in one breast, she has a higher chance of developing cancer in the other breast.
Breast biopsy results: Certain abnormalities found in the tissue during a breast biopsy, like lobular carcinoma in situ (LCIS) and atypical cell growth, are significant risk factors for breast cancer.
Family history and genetics: Women with a close relative who has had breast cancer are two to three times more likely to develop the disease themselves. While only 5-10% of all breast cancer cases are linked to genetics, this cause becomes more prevalent in younger women, accounting for about 25% of cases in women under 30. The two key genes related to breast cancer risk are BRCA1 and BRCA2.
Reproductive history: The more exposure a woman has to estrogen over her lifetime, the greater her risk of breast cancer. This risk can increase for women who started menstruating before age 12, had their first child after age 30, didn’t have children, or went through menopause after turning 55.
Hormonal medication usage: Taking medications that contain hormones like estrogen and progesterone can put women at risk. This is commonly given to younger women for birth control and to older women to help with symptoms of menopause.
Other: A variety of other factors, including exposure to radiation or certain chemicals, being overweight, and drinking a lot of alcohol, may also increase the risk of developing breast cancer.
Risk Factors and Frequency for Breast Cancer
Breast cancer is the most common cancer in women around the globe, making up about 11.7% of new cancer cases in 2020. In the United States (US), 1 in 8 women and 1 in 1000 men will experience breast cancer in their lifetimes. The rate of breast cancer increases with age, peaking in women between 75 to 79 years old. About 95% of new cases are diagnosed in women 40 years or older and the average age at diagnosis is 61.
Until the year 2000, there was a rapid increase in reported cases of breast cancer. After 2000, a decrease was observed, becoming more significant among women under the age of 50. With early detection and strides in treatment, death rates due to breast cancer have decreased in the past 25 years in North America and parts of Europe. In fact, there has been a 43% decrease in breast cancer-related deaths in the US, from 1980 to 2020. However, in many parts of Africa and Asia (like Uganda, South Korea, and India), the incidences and death rates from breast cancer continue to increase.
Even within the US, there are differences in detection and survival rates based on socioeconomic status and race. Non-Hispanic white women have the highest incidence of breast cancer, but African American women experience significantly higher death rates. The American Cancer Society (ACS) provides the following rates of breast cancer amongst various racial and ethnic groups:
- Non-Hispanic white: 128.1 in 100,000
- African American: 124.3 in 100,000
- Hispanic/Latina: 91.0 in 100,000
- American Indian/Alaska Native: 91.9 in 100,000
- Asian American/Pacific Islander: 88.3 in 100,000
Signs and Symptoms of Breast Cancer
The American College of Obstetricians and Gynecologists (ACOG) advises regular checks of a patient’s history to assess their risk for breast cancer. This can be done using online calculators. Many people with breast cancer don’t show symptoms and the disease is often found during routine checks or a mammography scan. However, as the disease progresses, they may feel a lump. Breast pain is a rare symptom, occurring in just 5% of cases. More severe disease can show symptoms including skin changes on the breast, ulcers, swollen lymph nodes under the arms (axillary lymphadenopathy), or signs that the disease has spread elsewhere in the body. Inflammatory breast cancer: an advanced form of the disease may show the same symptoms as a breast abscess, such as swelling and redness.
A thorough physical check is important when assessing for breast cancer. This involves checking both breasts while the patient sits, stands, and lies down, with the arm lifted and rotated. During this check, the health professional should pay attention to any changes in the skin over the breast, discharge from the nipple, swelling, skin changes, ulcers and carefully feel the area around the lymph nodes for swelling. Some organisations no longer advise routine breast checks for women at low risk who don’t show symptoms, as it doesn’t seem to reduce death rates. However, ACOG says that routine checks could be offered (but not required) for these women. They suggest a routine check every 1-3 years for women aged 25-39 and annually for women over 40.
Regardless, a clinical breast exam is always performed for high-risk and symptomatic women. Please see further resources for more information on how clinical breast exams are performed.
Testing for Breast Cancer
Mammography is the most common method used for checking and diagnosing breast cancer. Abnormalities found on a mammogram could include mass lesions, calcifications or architectural distortion. If these are found on an initial mammogram, a better quality mammogram with several views is typically required for further examination.
However, mammograms are not as useful in patients with dense breasts, younger patients, and those who can’t withstand the pressure applied to the breasts during the scan. In these situations, other methods like breast ultrasound or magnetic resonance imaging (MRI) with contrast might be used. Although MRI tends to be the most sensitive, it can be time-consuming, not always readily available, and costs more.
When using MRI in breast examination, indications may include axillary lymph node disease (lymph nodes in the armpit), an undetectable primary cancer, Paget disease, multiple or bilateral cancers, assessing response to preliminary chemotherapy treatment and screening of high-risk patients.
The results from breast imaging are categorized on a scale, known as the Breast Imaging Reporting and Data System (BI-RADS), which corresponds to findings and their probability of being cancerous. It also gives a general treatment recommendation. The BI-RADS categories range from 0 to 6. Each category represents a different level of risk, ranging from ‘inadequate’ (category 0) to ‘biopsy proven’ (category 6) with varying recommendations and cancer probabilities.
If a suspicious lesion is identified, a biopsy is usually done using a core needle with the help of imaging. The core needle biopsy is better than fine needle aspiration and is the preferred method. For patients with regional lymph nodes that seem to be involved, an ultrasound-guided core needle biopsy is done. It’s important to insert markers during the biopsy to help locate the lesion later. The breast tissue, once removed, is sent for testing, including hormonal and Herceptin receptor tests.
If you have operable breast cancer, routine laboratory tests or imaging to check for systemic disease isn’t usually necessary unless there are additional symptoms present. If there are symptoms, various scans might be performed depending on the symptom. If preliminary chemotherapy is planned, a full blood count and metabolic panel including liver function tests are required. For advanced breast cancer, a CT scan of the chest, abdomen, and pelvis along with a bone scan or an FDG-PET scan is usually employed.
Treatment Options for Breast Cancer
Breast cancer treatment is a complex process based on several factors, such as the stage of the disease, the specific type of cancer, the patient’s preferences, and the resources available. The management strategies can be grouped into three primary categories: early-stage breast cancer, locally advanced breast cancer, and metastatic (wide-spread) breast cancer.
In early-stage breast cancer, tumors are typically less than 5 cm in size without visible gland involvement. Treatments may include surgery, chemotherapy, radiation, and hormonal therapy, depending on the specific case and the type of cancer. Some of the methods used include:
* Surgery: The main tumor may be removed via breast-saving surgery like partial mastectomy or lumpectomy, or, in some cases, a total mastectomy might be performed.
* Gland management: During surgery, the sentinel lymph nodes (the first few nodes likely to be affected by the cancer) are also checked. Further procedures on the gland could depend on the results of this test.
Chemotherapy is usually used based on the stage and type of the tumor. In hormone-sensitive cancers, chemotherapy is initiated based on risk evaluation using advanced analysis kits. Patients with high risk may also be given chemotherapy along with hormone therapy.
Patients who had breast-saving surgery must receive radiation to the breast to reduce the chance of recurrence. Hormonal therapy may also be applied in all patients with hormone-sensitive cancers.
Early-stage triple-negative and HER2-positive tumors may also receive chemotherapy before surgery (neoadjuvant therapy). This technique offers several benefits, like allowing doctors to monitor the response to the treatment, increasing chances of completing chemotherapy, and may improve the chance of saving the breast.
Locally advanced breast cancer involves larger tumors or those with affected glands. Patients with locally advanced tunes usually receive neoadjuvant therapy, followed by surgery and radiation. The tumor and affected nodes must be marked before starting chemotherapy, given that tumors can shrink and vanish after the treatment.
After chemotherapy, imaging is repeated and further treatment, including surgery, is then determined. Similar to early-stage cancer, surgery to remove the tumor and gland management are common practices. But patients with persistent disease after chemotherapy may benefit from additional chemotherapy.
Lastly, metastatic breast cancer, which has spread to other parts of the body, is mainly managed using systematic treatment approaches. Surgery is generally not recommended unless for symptom relief and palliation. Options could involve chemotherapy, targeted therapy, immunotherapy, and hormonal therapy, depending on the type of cancer and patient’s condition. Radiation may also be used to control the growth of the primary disease and metastases (spreading tumors) to the brain, bone, and lung.
What else can Breast Cancer be?
When doctors diagnose breast cancer, they also have to consider the chance of other possible conditions that can show similar symptoms. These might include:
- Breast infection or abscess: Sometimes, inflammation can be mistaken for a type of breast cancer. If inflammation doesn’t improve with antibiotics, it would need to be examined further.
- Fat necrosis: Injury to the breast can cause fat in the breast tissue to harden and feel like a lump, mimicking breast cancer.
- Fibroadenoma: These are noncancerous lumps in the breast that are often removed if they are larger than 2 cm just to be certain that they are not associated with breast cancer.
In these cases, the doctor will need to carry out additional tests or procedures to confirm or rule out breast cancer. It is necessary because these conditions can sometimes show symptoms that are very similar to those of breast cancer.
Surgical Treatment of Breast Cancer
Surgery plays a key role in treating breast cancer. Due to advancements in chemotherapy and targeted therapy treatments, surgeries have become less intense and causeless discomfort, improving patient survival rates. Surgery is usually used to control and manage the primary tumor and provides crucial information regarding the stage of the cancer. Breast-conserving surgery (BCS) can be done for most patients with tumors smaller than 5 cm, provided that the breast size allows for a satisfactory cosmetic result. Mastectomy, which is the removal of an entire breast, is needed for larger tumors, cancers invading the skin or chest wall, multi-location cancers, inflammatory breast cancer, and for patients who cannot undergo radiation treatment. Sentinel lymph node biopsy is a crucial procedure for staging cancer in patients with no clinical signs of axillary spread. Axillary lymph node dissection, or removal of some axillary lymph nodes, is typically necessary for patients with evidence of axillary spread.
There are several types of surgeries for breast cancer:
The Lumpectomy, also known as Partial Mastectomy, is when a portion of the breast tissue is removed, along with a small portion of healthy tissue surrounding the cancerous cells. The size of the incision can depend on the location of the tumor and the cosmetic appearance desired. This method of surgery is a mainstay of breast-conserving surgery, as it allows for conservation of a majority of the breast. The cosmetic result depends on the quantity of the removed breast tissue compared to the remaining breast tissue and preserved nipple. For failures to feel the cancerous growths, careful tumor tracking beforehand is necessary to ensure effective removal of the entire tumor.
With a Simple Mastectomy, the entire breast and nipple area is removed. Also included is the removal of the underlying tissue that covers a large chest muscle (pectoralis major fascia). The skin preservation can vary depending on whether the patient plans for reconstruction surgery and the type of reconstruction that is planned. A Nipple-sparing Mastectomy is a variation of the simple mastectomy, where the nipple is spared and the breast tissue is removed through a smaller incision around the nipple. This technique yields better cosmetic results compared to a traditional mastectomy, with a minimally increased risk.
The Modified Radical Mastectomy combines simple mastectomy with axillary lymph node dissection. Both breast and axillary (near the armpit) contents are removed through an extended incision. The Radical Mastectomy which includes removal of chest muscles and certain nerves, is rarely performed these days.
The Axillary Sentinel Lymph Node Biopsy and Axillary Lymph Node Dissection relate to the axillary lymph nodes, which are a key part of the breast’s drainage system. A special dye or radioactive substance is injected near the primary site, and any lymph nodes in the vicinity that highly absorb this substance are removed. Depending on whether the patient has undergone lumpectomy, this surgery could employ the same incision or require a separate one. Axillary Lymph Node Dissection involves removing all tissue and lymphoid material in certain levels, while preserving specific nerves.
What to expect with Breast Cancer
The outlook for breast cancer heavily depends on how far it’s advanced. Both Stage 0 and Stage I breast cancers have a 100% survival rate over five years. For Stage II and Stage III, the survival rate over the same period is approximately 93% and 72% correspondingly. However, when the disease spreads throughout the body, the outlook drastically worsens. Only 22% of patients with Stage IV breast cancer will likely survive the next five years.
Possible Complications When Diagnosed with Breast Cancer
When it comes to treatments such as chemotherapy, radiation therapy, hormonal therapy, or surgery, there can be various complications.
Surgical treatment can lead to:
- Infection
- Pain
- Bleeding
- Cosmetic issues
- Permanent scarring
- Changes to or loss of feeling in the chest area and reconstructed breasts
Chemotherapy can result in:
- Nausea, vomiting, and diarrhea
- Hair loss
- Memory loss, often referred to as “chemo brain”
- Vaginal dryness
- Menopausal symptoms or fertility problems
- Neuropathy, or nerve damage
With Hormonal Therapy, possible complications include:
- Hot flashes
- Dryness or discharge in the vagina
- Tiredness
- Nausea
- Impotence in men diagnosed with breast cancer
Radiation treatment can cause:
- Pain and changes to the skin
- Fatigue
- Nausea
- Hair loss
- Long-term heart and lung problems
- Neuropathy
Preventing Breast Cancer
Breast cancer is the most common type of cancer found in women. It’s crucial to pay attention to both environmental and personal factors that can increase the risk of breast cancer, as addressing these can help reduce the number of cases. Early detection plays a key role in fighting this disease – it can help uncover cancer before any symptoms appear, which often means better chances of survival.
We need to pay special attention to those at high risk for developing breast cancer and monitor them closely. Various tools like mammograms, ultrasounds, and MRIs can be used for early detection and diagnosis. Additionally, all patients should have a biopsy, a type of test that checks for cancer at the cellular level and identifies specific markers that can guide treatment.
For early-stage breast cancer, doctors usually recommend preserving as much of the breast as possible during surgery, followed by radiation, chemotherapy, or hormonal therapy. For more advanced forms of the disease, an integrated approach using a combination of different treatments can provide the best results. Continuous monitoring and sticking to the suggested therapy regimen can significantly enhance chances of survival.
