Metastatic breast cancer (also called advanced breast cancer) means the cancer has spread from the breast to other places in the body. It’s still considered breast cancer because the metastases have the same type of cancer cells.
Treatment options depend on the specific characteristics of the tumor, such as whether it’s hormone receptor-positive and whether it’s HER2-positive. Other factors include current health, any treatment you’ve previously received, and how long it took the cancer to recur.
Treatment also depends on how widespread the cancer is and whether you’ve gone through menopause. Here are some questions to ask your doctor about advanced breast cancer as it relates to menopause.
Hormonal therapy, or endocrine therapy, is usually the primary component of treatment for women with hormone receptor-positive metastatic breast cancer. It’s sometimes called anti-hormone treatment because it acts like the opposite of hormone replacement therapy (HRT).
The goal is to lower the levels of estrogen and progesterone in the body to block these hormones from getting to cancer cells and getting the estrogen they need to grow.
Hormonal therapy can be used to interrupt the influence of hormones on the cells’ growth and overall functioning. If the hormones are blocked or removed, the cancer cells are less likely to survive.
Hormonal therapy also stops healthy breast cells from receiving hormones that could stimulate cancerous cells to regrow within the breast or elsewhere.
Metastatic breast cancer treatment in premenopausal women with hormone receptor-positive cancers usually involves ovarian suppression. This procedure lowers hormone levels in the body to deprive the tumor of the estrogen it needs to grow.
Ovarian suppression can be achieved in one of two ways:
- Drugs can stop the ovaries from making estrogen, which induces menopause for a period of time.
- A surgical procedure called oophorectomy can remove the ovaries and stop estrogen production permanently.
An aromatase inhibitor may be prescribed in premenopausal women in conjunction with ovarian suppression. Aromatase inhibitors may include:
- anastrozole (Arimidex)
- exemestane (Aromasin)
- letrozole (Femara)
Tamoxifen, an antiestrogen, is also commonly used to treat metastatic breast cancer in premenopausal women. It can prevent the cancer from returning or spreading elsewhere.
Tamoxifen may not be an option if the cancer progressed during previous tamoxifen treatment. Combining ovarian suppression and tamoxifen has been found to improve survival compared to tamoxifen alone.
Ovarian suppression isn’t necessary for postmenopausal women. Their ovaries have already stopped making large amounts of estrogen. They only make a small amount in their fat tissue and adrenal glands.
Postmenopausal hormone therapy usually includes an aromatase inhibitor. These drugs reduce the amount of estrogen in the body by stopping tissues and organs besides the ovaries from making estrogen.
Common side effects of aromatase inhibitors include:
- hot flashes
- painful bones or joints
More serious side effects include thinning bones and an increase in cholesterol.
Postmenopausal women may be prescribed tamoxifen for a number of years, usually five or more. If the drug is used for less than five years, an aromatase inhibitor often may be given for the remaining years.
Other drugs that may be prescribed include CDK4/6 inhibitors or fulvestrant.
Chemotherapy is the main treatment option for triple-negative breast cancers (hormone receptor-negative and HER2-negative). Chemotherapy may also be used in conjunction with HER2-targeted therapies for HER2-positive breast cancers.
Chemotherapy may be used in more serious cases for hormone receptor-positive, HER2-negative cancers.
If the first chemotherapy drug, or combination of drugs, stops working and the cancer spreads, a second or third drug can be used.
Finding the right treatment may take some trial and error. What’s right for someone else won’t necessarily be right for you. Follow your treatment plan and communicate to your doctor. Let them know when something is or isn’t working.
You may have difficult days ahead, but it helps to be aware of all your treatment options.