How is breast cancer treated?
The overall treatment plan and standard of care for breast cancer varies, depending on the following factors:
- The type of breast cancer
- The subtype of breast cancer (according to applicable hormone receptor status (ER/PR) and HER2 status)
- The patient’s BRCA1/BRCA2 status
- The stage of the disease
- Genetic markers
- The patient’s age
- The patient’s general state of health
- The patient’s menopausal status
Breast cancer treatment formats
breast cancer treatment can vary (as explained above), depending on the patient’s unique medical conditions. However, at a broad level, the following treatment formats are available to treat a variety of breast cancer types, subtypes and stages:
Surgery: Either in the form of mastectomy (complete breast removal) or lumpectomy (removal of tumor with margins). In mastectomy, the entire breast tissue is removed, followed by reconstruction. In lumpectomy, the tumor is removed along with a part of healthy tissue around it, to obtain a clear margin. It is also called breast conservation therapy (BCT).
Chemotherapy: It is the intravenous administration of medicines that can find and kill cancer cells. Chemotherapy medicines identify cancerous cells by virtue of rapid divisiveness, which means that they sometimes also attack and kill healthy cells that divide normally. Chemotherapy can sometimes be given before surgery in order to decrease the size of tumors, so that surgical intervention is minimal. Chemotherapy can also be administered after surgery to prevent any recurrences.
Radiotherapy, or Radiation Therapy: This uses exposure to high-intensity radiation to kill cancerous cells. The intent of radiation therapy is to remove any residual disease and to minimize the chances of local recurrence. Radiotherapy is used as a component of BCT, where as radiation is advised after mastectomy, depending on the post-surgical pathological findings.
Hormonal therapy: This type of treatment is specific to patients who have been identified as hormone receptor positive, i.e. ER/PR positive. The choice of hormonal agent depends on menopausal status of the patient. For premenopausal women, adjuvant Tamoxifen is used at a dose of 20 mg, to be taken once daily , for a duration of five years after the completion of chemotherapy and radiotherapy. For postmenopausal women, the preferred drug is Anastrozole (a type of aromatase inhibitor), delivered at a single dose of 1mg every day, for a duration of five years.
Targeted therapy: This type of treatment either targets specific genes or proteins found inside cancerous cells making up a tumor, or the tissue environment that enables the growth and survival of cancerous tissue. Targeted therapies are extremely focused, and work differently as compared to chemotherapy. Targeted therapies can control the growth and spread of cancer cells, without damaging healthy cells that is they have minimal side effects.
Treatment of recurrent breast cancer (cases of breast cancer relapse)
For cases of recurrent breast cancer, the treatment depends on the history of initial treatment (treatment that was given when the cancer first appeared), and other characteristics of the cancer – such as the size of the relapsed tumor, location of relapse site (this can be anywhere in the breast tissue, not necessarily the same location as the original site of the tumor), extent of spread into lymph nodes and/or other organs in the body, the status of hormone receptors (ER/PR/HER2), and the originally diagnosed status of BRCA1/BRCA2.
Extraction and analysis of lymph node tissue
In cases of some locally advanced or invasive cancers, cancerous cells are usually present in the axillary lymph nodes. Therefore, it becomes important to extract a lymph node tissue sample, in order to determine the right treatment plan and prognosis.
Sentinel lymph node biopsy
In a sentinel lymph node biopsy, surgical oncologists extract a few lymph nodes from under the armpits. These are usually taken from regions that have been affected first with lymph drainage from the breast(s). By doing a sentinel lymph node biopsy, surgeons are able to avoid removing multiple lymph nodes dissection – most of which will be free from cancer. There are possible long-term side effects to lymph node extraction procedures, such as lymphedema (swelling of the arm), numbness, risk of restricted arm movement and motion-range restriction, which can be avoided by performing smaller lymph node procedures.
Examination of lymph node tissue sample after a sentinel lymph node biopsy
The extracted lymph node tissue sample is examined under a microscope by a pathologist to look for the presence of rapidly dividing (malignant) cells, which are indicative of cancer. To identify the sentinel lymph node, surgeons inject a tracer (either an inert dye or a radioactive marker) behind the nipple or in the area surrounding the nipple. This injection may cause some mild discomfort for 10 to 15 seconds. This dye makes its way to the sentinel lymph node by traveling across the lymph node tissue. Surgeons are able to find the sentinel node when the dye color is seen, or in the case of a radioactive tracer, when the dye shows signs of radiation.
If the sentinel lymph node is found to be free of cancer, it is mostly seen that the remaining lymph nodes are also free of cancer, and indicates that lymph nodes do not need to be surgically removed. If lymph nodes are found to contain cancer cells, then axillary dissection must be recommended.
Axillary lymph node dissection
For this process, surgical oncologists remove multiple lymph nodes from the armpit area, and these are sent for a pathological examination. The number of lymph nodes needed to be removed, is different for each patient. Patients with small tumor sizes and less than 2 cancerous sentinel lymph nodes may also avoid this process. As explained above, having a smaller amount of lymph node tissue removed can reduce the risk of possible side effects, without affecting post-treatment survival rates.
Both sentinel lymph node biopsy and axillary lymph node dissection become optional if the patient is aged more than 65. The requirement to perform either of these procedures, also depends on the general health of the patient and how much they are likely to be affected by the surgical outcomes. For patients of invasive breast cancers who are scheduled to undergo a complete mastectomy, a sentinel lymph node biopsy, or a partial or full axillary lymph node dissection is usually advised before the main surgery. This is done because it is difficult to find sentinel lymph nodes after a mastectomy (because there is nowhere left to inject the dye).
Reconstruction of breasts after breast cancer surgery
Women who undergo a complete mastectomy might want to get a breast reconstruction (re-creation) process done to maintain their natural appearance. Reconstructive surgery uses either synthetic breast implants or tissue which is extracted from a different part of the body. This is usually performed by a plastic surgeon and is traditionally outside the purview of oncology once breast cancer treatment is complete.
Breast reconstruction can be scheduled either immediately after surgery, or it can be delayed, as advised by the treating surgical oncologist – as the feasibility of this depends on the recovery timelines for each individual patient.
Oncoplastic surgery refers to the process of simultaneous lumpectomy and reconstruction. Many breast cancer surgeons are equipped to perform this type of surgery without the assistance of a plastic surgeon. This is done depending on how healthy the other breast or the remaining breast tissue is, and it helps in matching the natural appearance of both breasts.
Glossary of definitions used in this section:
Standard of care: Refers to the best treatments known for early breast cancer and locally advanced breast cancer
Clinical trial: Refers to a study or research process that tests a new medicine/new method of treatment which is not used in mass effect
Treatment plan: This contains a clinical summary of your breast cancer diagnosis, and a layout/schedule for the treatment that your attending oncologists have planned. A treatment plan is meant to provide basic information about your medical history/ongoing treatment history to any doctor who might want to review or get involved in your treatment journey at a later stage.
Multidisciplinary panel: In cancer treatment, doctors from multiple oncology disciplines such as surgical, radiation and medical oncology work together to develop the right treatment plan. Such a team is called a multidisciplinary panel. Sometimes, at treatment delivery centres, these teams can extend to include a variety of healthcare professionals, such as assistant physicians, nurses, pharmacists, counsellors, nutritionists, and even social workers. For patients who are senior citizens (aged 65 and above), a geriatric oncologist may also be involved.
- Standard of care – Refers to the best treatments known for early breast cancer and locally advanced breast cancer
- Clinical trial – Refers to a study or research process that tests a new medicine/new method of treatment which is not used in mass effect
- Treatment plan – This contains a clinical summary of your breast cancer diagnosis, and a layout/schedule for the treatment that your attending oncologists have planned. A treatment plan is meant to provide basic information about your medical history/ongoing treatment history to any doctor who might want to review, or get involved in your treatment journey at a later stage.
- Multidisciplinary panel – In cancer treatment, doctors from multiple oncology disciplines such as surgical, radiation and medical oncology work together to develop the right treatment plan. Such a team, is called a multidisciplinary panel. Sometimes, at treatment delivery centers, these teams can extend to include a variety of healthcare professionals, such as assistant physicians, nurses, pharmacists, counselors, nutritionists, and even social workers. For patients who are senior citizens (aged 65 and above), a geriatric oncologist may also be involved.