What is Radiation Therapy for Early-Stage Breast Cancer?
Breast cancer is the most commonly found cancer in women all around the world and, apart from skin cancer, it is the most usual type of cancer among women in the United States. Every year, around 250,000 cases of invasive, or spreading, breast cancer are diagnosed, resulting in about 40,000 incidents of death from breast cancer. Happily, the number of those dying from breast cancer has been decreasing. This improvement is believed to be due to a mix of factors; more people now know about breast cancer, we have better ways to detect it early through screening, and advances in cancer treatments over the last 20 or so years.
What Causes Radiation Therapy for Early-Stage Breast Cancer?
In the US, about one out of every eight women will develop breast cancer during her lifetime. That equates to a 12% lifetime risk. Unfortunately, the cause of most breast cancer cases is still unknown. However, several risk factors have been identified. The most significant risk factors are being female and advancing age. Other notable risk factors include the age a woman first starts menstruating, the age at which menopause starts, the age at first pregnancy, family history, use of estrogen supplements, alcohol consumption, exposure to chest radiation, certain benign breast diseases, the density of breast tissue seen on a mammogram, and genetic mutations.
About 10% of breast cancer cases are linked to inherited gene changes, such as mutations in the BRCA1 and BRCA2 genes. These are the most common gene mutations linked to breast cancer. There are also other gene mutations that have a mild to moderate risk. Women who have the BRCA1 mutation typically have a 55% to 65% lifetime risk of developing breast cancer, while BRCA2 mutation carriers have around a 45% risk. For men, BRCA2 mutations carry a lifetime breast cancer risk of about 7%. These BRCA mutations also increase the risk for ovarian cancer. The BRCA2 mutation carries a 10-15% lifetime risk of ovarian cancer.
Having preventative surgery to remove the breasts (prophylactic mastectomy) can greatly reduce the risk of breast cancer. Another surgery to remove the ovaries and fallopian tubes (prophylactic bilateral salpingo-oophorectomy) can decrease the risk of ovarian and fallopian tube cancers by 80% and breast cancer by 50%. Yet, it’s important to note that most breast cancers occur in women who do not have a family history of the disease. Most breast cancers result from random gene changes (somatic mutations) due to aging and environmental factors, rather than inherited gene changes (germline mutations).
Risk Factors and Frequency for Radiation Therapy for Early-Stage Breast Cancer
In 2017, predictions suggested that roughly 252,000 new cases of invasive breast cancer would be diagnosed in the United States, along with 63,000 cases of noninvasive cancer. Despite the grim fact that breast cancer is expected to claim the lives of about 40,000 women that year, the good news is that overall death rates from the disease have been falling.
Even so, breast cancer remains the second leading cause of cancer-related deaths after lung cancer. It’s also worth noting that the risk and mortality rates differ among various racial and ethnic groups. African Americans, for example, have higher death rates than whites, while Asians, Hispanics, and Native Americans have a lower risk of both developing the disease and dying from it.
- About 252,000 invasive and 63,000 noninvasive breast cancer cases were estimated in 2017.
- Approximately 40,000 women were expected to die from the disease, though death rates are declining.
- Breast cancer is the second most common cause of cancer-related deaths, following lung cancer.
- Death rates are higher in African Americans compared to whites.
- Risk of developing and dying from breast cancer is lower in Asians, Hispanics, and Native Americans.
Signs and Symptoms of Radiation Therapy for Early-Stage Breast Cancer
It’s essential to know your medical history, including any risk factors and your gynecological history when examining breast health. A physical examination focusing on the breasts and nearby nodes is vital. Specific things to be checked during the exam include the presence of any tumors, changes to the skin or chest wall, changes to the nipple such as inversion, and the condition of the axillary (armpit) and supraclavicular (above the collarbone) areas. Signs of possible breast health issues can vary but may include finding a lump in the breast, having an inverted nipple, noticing discharge or bleeding from the nipple, or finding a lump under the arm.
- Medical and gynecological history
- Physical examination of breasts and nearby nodes
- Presence of any tumors
- Changes to the skin or chest wall
- Nipple changes or inversion
- Condition of the axillary and supraclavicular areas
- Presence of a lump on the breast
- Nipple discharge or bleeding
- Lump under the arm
Testing for Radiation Therapy for Early-Stage Breast Cancer
Breast imaging typically starts with a mammogram and ultrasound. These imaging techniques help to visually inspect the breasts for any unusual growths or formations. Sometimes, if the breasts are very dense, or if the doctor suspects there may be more than one tumor or they are hidden, a Breast MRI may also be used.
Additional imaging techniques may include a CT scan of the chest and abdomen, a bone scan, an MRI of the brain, and a PET-CT, which is a type of imaging that combines data from a CT scan and a PET scan in a single image. These additional tests are only used when necessary; for example, if the doctor suspects that the cancer may have spread beyond the breast.
To establish a diagnosis, a biopsy may be conducted. This is a process where a small piece of breast tissue or a suspicious lymph node from the armpit is taken out and studied under a microscope. This biopsy helps to determine the nature of the tumor, including whether it is cancerous and what kind of cancer it is.
Several factors are studied in the lab to guide treatment recommendations. These include the status of estrogen receptor (ER), progesterone receptor (PR), HER2/neu (HER2), and Ki-67, all proteins that can influence the growth of the cancer. In addition, a test known as Oncotype DX may be performed on hormone positive, HER2 negative, node-negative breast tumors. This test analyses 21 genes in a tumor to help decide if chemotherapy is needed.
The lab will also run a complete blood count (CBC), blood chemistry tests, and liver function tests as part of routine evaluation.
If a patient is suspected to be at high risk for hereditary breast cancer, they may also be offered genetic counseling. Additionally, premenopausal women may receive fertility counseling.
It’s also important to note that managing the emotional and social facets of a breast cancer diagnosis is crucial for holistic care. Therefore, screening and management of any distress, addressing psychological, social, and physical needs of the patient are integral components of caring for breast cancer patients.
Treatment Options for Radiation Therapy for Early-Stage Breast Cancer
In the early stages of breast cancer (stage I and II), treatment usually involves Breast Conservation Therapy (BCT), which aims to protect as much of the healthy breast tissue as possible. This often involves minor surgery known as lumpectomy, which removes only the cancerous lump, and testing the sentinel lymph nodes (the first set of lymph nodes that the cancer is likely to spread to) for invasive breast cancer. However, this staging is not necessary for a type of non-invasive cancer called ductal carcinoma in situ.
There are certain situations where BCT may not be suitable, such as if the disease is in multiple parts of the breast, there’s a large tumor compared to the breast size, there are widespread tiny calcium deposits (microcalcifications), there’s still signs of cancer even after multiple re-excision surgeries, the patient has previously had radiation therapy to the breast, has a skin condition called scleroderma, or is pregnant. In these cases, a more extensive surgery like mastectomy, which involves removing the whole breast, is generally recommended.
Treatment for ductal carcinoma in situ (Stage 0) is usually tailored to the patient based on their unique circumstances and personal preferences. A lumpectomy is typically the favored approach. Post operation, radiation therapy is suggested to lower the chances of the cancer returning in the local breast area. However, in some patients who have a low-risk profile, this additional therapy can sometimes be skipped.
To help make these decisions, an Oncotype DX score is often used. This score is derived from a test that examines the activity of certain genes in the tumor tissue, which can give doctors an idea of how likely the cancer is to recur, and therefore, guide the treatment plan.
In patients with more aggressive tumors, chemotherapy is usually recommended to reduce the risk of the cancer returning, especially in those with a larger tumor, lymph-node-positive disease (cancer has spread to the lymph nodes), or triple-negative or HER2-positive subtype (which describe the presence or absence of certain receptors that fuel cancer growth).
The Oncotype DX score also plays a role in identifying the patients who might benefit from chemotherapy, in cases of hormone receptive, HER2-negative, node-negative breast tumors. Please note ‘ node-negative ‘ means that the cancer hasn’t spread to the nearby lymph nodes.
Traditionally, chemotherapy is administered after surgery, but increasingly it’s being given before surgery (neoadjuvant therapy) to shrink the tumor, increasing the chances of saving as much of the breast as possible. Neoadjuvant therapy has become the standard care for high-risk groups like younger patients or those with advanced or aggressive types of cancer.
Following lumpectomy, radiation therapy is often advised to lower the risk of cancer returning in the breast. This treatment typically targets the entire breast tissue, with a conventional dose given over 6 weeks. If there’s a higher risk of the cancer returning, radiation therapy can also be directed at the regional lymph nodes, the small glands that filter harmful substances from the body.
For low-risk patients who are 50 years or older with a smaller, well-defined tumor, negative margins indicating no cancer cells at the edge of the tissue that was removed, and no involvement of lymph nodes, there’s a shorter radiation therapy schedule. This approach, known as hypofractionation, is delivered in fewer treatment sessions (fractions).
For similar low-risk patients, a technique called Partial Breast Irradiation, that targets only the area from which the tumor was removed, can also be considered. This treatment is typically completed over a course of one week.
In addition to these therapies, hormone therapy can also be given to patients with hormone-receptive tumors, which are tumors that grow in response to certain hormones present in the body.
What else can Radiation Therapy for Early-Stage Breast Cancer be?
There are several conditions similar to acute appendicitis that doctors may need to rule out. These include:
- Duct ectasia
- Ductal carcinoma
- Extramedullary acute myeloid leukemia
- Hyalinized fibroadenoma
- Inflammatory carcinoma
- Mastitis
- Radial scar
Doctors need to consider these alternatives and conduct the necessary tests to make sure the diagnosis is accurate.
