Treatment of Stage 1 Breast Cancer
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While stage 1 breast cancer is considered an early stage breast cancer, it still requires prompt treatment to ensure the best possible outcomes. The treatment approach for this stage of breast cancer involves both local and systemic therapies. Patients diagnosed with stage 1 breast cancer should discuss their treatment options with their healthcare team to determine and understand the best approach for their needs.
What is stage 1 breast cancer?
Stage 1 invasive breast cancer is an early stage of breast cancer. Anatomically, stage 1 invasive breast cancer is a cancer that is localized to the breast and has not spread beyond the breast tissue. Invasive breast cancer means that the breast cancer cells have spread into the surrounding breast tissue. The most common type of invasive breast cancer starts either in the milk duct (called invasive ductal cancer) or in the milk sac (called invasive lobular cancer). Based on the American Joint Committee on Cancer (AJCC) TNM staging system, stage 1 breast cancer typically has these features:
● Small tumor size
The tumor is relatively small, measuring 3/4 of an inch (2 cm) in diameter or less. It is confined to the breast tissue and has not invaded nearby structures.
● No lymph node involvement
There is typically no evidence of cancer cells in the nearby lymph nodes (lymph node-negative).
● No distant metastasis
Stage 1 breast cancer has not spread to distant organs such as the lungs, liver, bones, or brain. It is localized within the breast.
It is important to note that many medical institutions, especially in the United States, now use an updated staging system which includes other factors to determine a patient’s treatment and outcome. This is known as prognostic staging. Prognostic staging takes into account the tumor grading, estrogen receptor (ER) status, progesterone receptor (PR) status, ‘human epidermal growth factor 2’ (HER2) status and sometimes multigene prognostic tests, in addition to the cancer’s anatomical characteristics. In this current staging system, the stage of cancer is determined from a combination of all of these factors. While it is a more accurate classification, it is also much more complex. Therefore, it is best to consult with your doctor on your specific cancer classification and what it means for you.
What treatment is necessary for stage 1 breast cancer?
Treatment for stage 1 breast cancer involves local therapy, such as surgery and radiation therapy, as the cancer is still contained within the breast. Adjuvant (post-operative) systemic therapy may also be used depending on the specific characteristics of the tumor and the patient’s overall health and risk factors.
Local therapy
Local therapy refers to treatments that target the cancerous tumor and the surrounding area without affecting the entire body. It is often used with the goal of removing or destroying the cancer cells in a specific area while preserving as much healthy tissue as possible. The types of local therapy used for stage 1 breast cancer include surgery and radiation therapy.
Surgery
The primary treatment for stage 1 breast cancer is often surgery. There are two main surgical options:
- Lumpectomy (Breast-conserving surgery)
In this procedure, the surgeon removes the tumor and a small margin of healthy tissue around it. This allows the patient to keep most of their breast. After a lumpectomy, radiation therapy is often recommended to reduce the risk of cancer recurrence in the breast. However, some studies are now looking at who can be spared postoperative radiation therapy.
When a patient undergoes a mastectomy, the entire breast is removed. Some patients may choose this option for various reasons, including a strong family history of breast cancer, or personal preference. In some cases, a nipple-sparing mastectomy or skin-sparing mastectomy may be possible to preserve the appearance of the breast. In many cases of stage 1 breast cancer, a sentinel lymph node biopsy is performed during surgery. This involves removing a small number of lymph nodes from the underarm (axilla) to check if cancer cells have spread to the lymph nodes.
Radiation Therapy
Radiation therapy is a cancer treatment method that uses high doses of radiation to kill cancer cells and shrink tumors. If a lumpectomy is performed, radiation therapy is often recommended to target any remaining cancer cells in the breast. This helps reduce the risk of local recurrence. Patients who undergo a mastectomy may also receive radiation therapy in certain situations, although this rarely applies to those with stage 1 breast cancer.
Systemic therapy
Systemic therapy is a type of cancer treatment designed to target cancer cells throughout the entire body. Unlike local therapies, which focus on treating the tumor in the breast and surrounding area, systemic therapies are delivered through the bloodstream and can reach microscopic cancer cells that may have moved to various parts of the body. As stage 1 breast cancer is contained within the breast, systemic therapy is more often used after surgery as an adjuvant treatment in combination with local therapies. However, there may be some situations in which chemotherapy is given as a neoadjuvant (pre-operative) treatment.
The types of systemic therapy used for stage 1 breast cancer include:
If the breast cancer is hormone receptor-positive (estrogen or progesterone receptor-positive), hormone therapy (such as tamoxifen or an aromatase inhibitor) may be recommended to block the effects of hormones on cancer cells.
Chemotherapy may be recommended if the tumor has features that suggest a fast-growing nature or where the tumor is 0.5 cm or larger. Specifically, patients with invasive breast cancers that are hormone receptor-negative, HER2-positive, or considered high risk based on multigene tests may also require chemotherapy.
In cases where the cancer overexpresses HER2/neu receptors (called HER2-positive), targeted therapies like Herceptin (trastuzumab) may be considered in combination with chemotherapy.
Treatment choice depends on factors such as the type of cancer, the patient's overall health, and their personal preferences. Patients need to thoroughly discuss with their oncologist and surgical team to determine the most appropriate treatment plan for their situation. Breast cancer treatment is often tailored to the unique characteristics of the disease and the patient.
