For both DCIS and early-stage breast cancer, surgery is recommended to remove the tumor. Women with a very high risk of developing a new cancer in the other breast may consider a bilateral mastectomy. This includes women with BRCA1 or BRCA2 gene mutations and women with cancer in both breasts.

For larger cancers, or those with rapid growth, our oncologists at Onco Life Centre will recommend systemic treatment with chemotherapy or hormonal therapy for breast cancer before surgery (neo-adjuvant therapy), which could result in breast conserving surgery if the tumor shrinks appreciably before surgery. Treatment given after surgery is called adjuvant therapy. Adjuvant therapies may include radiation therapy, chemotherapy, targeted therapy, and/or hormonal therapy.

For recurrent and metastatic cancer, treatment options depend on how the cancer was first treated and tumor characteristics such as ER, PR, HER2, PDL1 and PIK3CA gene mutation

The most common type of radiation treatment for breast cancer is called external-beam radiation therapy. Most commonly, radiation therapy is given after a lumpectomy, and following adjuvant chemotherapy if recommended. This helps lower the risk of cancer recurrence in the breast. In fact, with modern surgery and radiation therapy, recurrence rates in breast cancer are now less than 5%.

Adjuvant radiation therapy may also be recommended for some women after a mastectomy, depending on the age of the patient, tumor size, the number of positive lymph nodes, ER, PR, and HER2 status.

There are three categories of systemic therapy used for breast cancer, namely, chemotherapy, hormonal therapy, and targeted therapy.

Chemotherapy can be used to treat Stage 1, Stage 2, Stage 3 and Stage 4 breast cancer. Chemotherapy destroys cancer cells by stopping the cancer cells’ ability to grow and divide. Chemotherapy may be given before surgery to shrink a large tumor (neo-adjuvant chemotherapy). It may also be given after surgery to reduce the risk of recurrence (adjuvant chemotherapy). Chemotherapy is also given for metastatic breast cancer. There are many different types of chemotherapy schedules. Research has shown that combinations of certain drugs are sometimes more effective than single drugs for adjuvant treatment. The number of chemotherapy cycles will depend on the chosen treatment protocol.

Hormonal therapy is an effective treatment for ER and PR expressing tumors in both early-stage and metastatic breast cancer. Blocking the hormones can help prevent a cancer recurrence and death from breast cancer when used for early-stage disease. Hormone therapy for breast cancer shrinks the cancer and improves cancer-related symptoms in metastatic breast cancer.

Options for adjuvant hormonal therapy for premenopausal women include five or more years of a certain class of selective estrogen receptor modulator (SERM) drug and switch to an AI after menopause begins. Ovarian suppression for 5 years along with SERM or an AI may be recommended in women who are diagnosed with breast cancer at a very young age or in women with a high risk of cancer recurrence.

Options for hormonal therapy used in metastatic breast cancer include SERM, ovarian suppression and AIs. A selective estrogen receptive degrader (SERD) drug may work better when combined with CDK4/6 inhibitor, an AI or PI3K inhibitor for PIK3CA gene mutated breast cancer.

Targeted therapy for breast cancer targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. Anti HER2 monoclonal antibody treatment is approved for both adjuvant therapy and advanced HER2-positive breast cancer. A combination of two different types of monoclonal antibody and chemotherapy improves the treatment effectiveness, and lengthen lives in the first-line setting. Additionally, there are other second-line approved anti HER2 options available for the treatment of metastatic breast cancer after failure of first-line treatment.

A new drug has been recently FDA approved for breast cancer patients with hormone receptor-positive, HER2-negative metastatic breast cancer that has a PIK3CA gene mutation. You may ask more about this new drug during consultation with our oncologists.

Drugs that target the CDK4/6 protein are approved for women with ER-positive, HER2-negative advanced or metastatic breast cancer and may be combined with AI.

PARP inhibitors, which destroy cancer cells by preventing them from fixing damage, may be used for patients with metastatic HER2-negative breast cancer and a BRCA1 or BRCA2 gene mutation.

Immunotherapy for breast cancer is designed to boost the body's natural defenses to fight the cancer. In 2019, the U.S. Food and Drug Administration (FDA) approved a combination of Immune checkpoint inhibitor and a plus-protein-bound chemotherapy drug for advanced PD-L1 expressing triple-negative breast cancer.

Immune checkpoint inhibitors are also approved by the FDA to treat metastatic breast cancer with a molecular alteration called microsatellite instability-high (MSI-H) or DNA mismatch repair deficiency (dMMR).

Bisphosphonates are drugs that block the cells that destroy bone, called osteoclasts. Bisphosphonates can be used for bone metastasis. Research suggests that it may reduce breast cancer recurrences, particularly in bone, when given in postmenopausal women.

There is another osteoclast-targeted therapy called a RANK ligand inhibitor, may be better than bisphosphonates at controlling the symptoms of bone metastases.