How to make sense of all the different types.
Every case of breast cancer is different, but what’s true across the board is medications can play a key role in beating it. And there are many different treatment options, depending on the type, stage, and whether or not it has spread. Doctors may also use these drugs alongside local treatments like surgery or radiation to reduce the chances of your cancer returning.
If you’ve found yourself in the unfortunate position of staring down a breast cancer diagnosis or are doing research for a friend or loved one, don’t get overwhelmed. Here’s a simplified overview of the different medications on the market for breast cancer so you have the knowledge you need to make informed decisions, whether it’s for you or someone else
Medications for early stages of breast cancer
In the beginning stages of breast cancer, doctors often turn to hormone therapies. The two most common ones are aromatase inhibitors and tamoxifen, both of which reduce the amount of estrogen in the body, according to Halle Moore, MD, director of Breast Medical Oncology in the Department of Hematology and Oncology at Cleveland Clinic Taussig Cancer Institute.
But if patients are hormone sensitive, she adds that treatment can include medications that shut down the ovaries altogether (you’ve probably heard of cancer treatment sending patients into early menopause, which we’ll get into). This might consist of newer forms of drugs, such as Kisqali.
For those getting their chemotherapy before surgery, patients might also be prescribed immunotherapy drugs, such as pembrolizumab, or more targeted drugs, like trastuzumab (Herceptin) or olaparib (Lynparza). That said, it also depends on the type of cancer you have — for instance, she adds that surgery and chemotherapy would be a “mainstay for patients with triple-negative breast cancer.”
Medications for late-stage breast cancer
Late-stage cancer, also known as metastatic or stage IV breast cancer, is when breast cancer cells have spread beyond the breast to other parts of the body, including the bones, lungs, or liver.
Dr. Moore tells us that “all of the treatments they use in early-stage breast cancer are also used in advanced-stage breast cancer.”
As in earlier stages, treatments can differ, depending on your specific type of breast cancer. For instance, for hormone receptor-positive breast cancer, your doctor might prescribe anything from targeted therapy drugs, such as everolimus (Afinitor), to tamoxifen and other aromatase inhibitors. On the other hand, if you have hormone receptor-negative cancer, a doctor may prescribe chemotherapy drugs like eribulin (Halaven), Ixabepilone (Ixempra), and vinorelbine (Navelbine).
Does your menopausal status matter?
Patients are treated differently based on whether or not they’ve gone through menopause. On average, most women in the U.S. experience this natural transition at around 51 years of age — that’s when their ovaries stop producing the two hormones that cause periods (estrogen and progesterone).
So if you’ve already gone through the change, you’re more likely to be prescribed aromatase inhibitors like Arimidex (anastrozole). Dr. Moore explains that they tend to be used in women over the age of 50 as opposed to premenopausal women because they’re no longer producing estrogen. “This treatment doesn’t target the ovarian estrogen production; it only targets that additional estrogen that you make after menopause,” she tells us.
On the other hand, some treatments might be less effective in women who’ve finished menopause. For instance, the Trial Assigning Individualized Options for Treatment (TAILORx) found that some postmenopausal women over the age of 50 with early-stage breast cancer may not see any significant benefit from adding chemotherapy to hormone therapy, while premenopausal women often do.
However, this trial applied only to women whose cancer didn’t reach the lymph nodes. Luckily, another study called RxPONDER answered a similar question in women with HR-positive, HER2-negative breast cancer that had spread to between one and three lymph nodes. As with TAILORx, a majority of postmenopausal women saw no added benefit with chemo. “Some of that may be due to hormonal effects since chemotherapy may result in premature ovarian insufficiency, which results in lower estrogen levels, which in turn can be beneficial in the treatment of hormone-driven cancers,” Dr. Moore says.
For premenopausal women under age 50, it was a different story. In fact, adding chemo made a significant difference: Five years after treatment, 94 percent of the premenopausal women who opted for chemotherapy plus hormone therapy did not have invasive cancer, compared to 89 percent of those who only had hormone therapy.
What are some of the side effects of breast cancer medications?
Side effects depend on your specific breast cancer treatment, and even then, they vary from patient to patient. If you’re undergoing chemotherapy, you could experience everything from hair loss and anemia (low red blood count cells) to nausea and vomiting. You should also keep in mind that if you’re premenopausal and in your early- to mid-40s, chemotherapy might permanently push you into early menopause.
As for hormone-based breast cancer treatments, Dr. Moore says you’ll likely experience symptoms that are traditionally associated with menopause, such as hot flashes, vaginal dryness, and joint stiffness.
Immunotherapy, on the other hand, can lead to an overactive immune system. This can lead to autoimmune conditions such as hypothyroidism or can sometimes affect the lungs or other organs if the body’s immune system attacks those other organs. “Each of these drugs has very different side effect profiles,” Dr. Moore points out.
Are there any new medications to treat breast cancer?
The good news is that breast cancer research is constantly evolving, and new remedies are often discovered. While not new, a medication called Kisqali was recently approved by the FDA for women with some forms of early breast cancer, in combination with hormone therapy. It was already approved for people with advanced breast cancer.
The drug — also referred to as ribociclib — is generally taken for three years following surgery to prevent the cancer from coming back. It comes in pill form, which is taken daily for 21 consecutive days, followed by a week of the treatment.
Dennis J. Slamon, MD, who led the research study that prompted the FDA’s approval, called the development “a pivotal moment” in offering treatment to a “significantly broader group of people.”
Dr. Moore explains: “Kisqali is a type of drug called a CDK four six inhibitor, which is a targeted treatment that works with hormonal-based treatments for breast cancer to help them work better and longer.”
More broadly speaking, Dr. Moore says that the fastest-growing class of medication is antibody-drug conjugates, which have proven especially effective at treating breast cancer.
“What these drugs do is they take an antibody that targets something more specific to cancer cells and attach a chemotherapy drug to the antibody,” Dr. Moore tells us. “And often we’ll use a chemotherapy drug that’s kind of too potent to give by itself, but by giving it attached to the antibody, it brings it preferentially to the cancer cells so that we can get good drug activity into the cancer cells without a severe effect on normal cells.”
Getting a breast cancer diagnosis is no doubt scary, but as you can see, you have options — and with new research, even more could be on the way.
