Not your grandmother's breast cancer treatment

photo of a doctor showing patient the results of a test; doctor is holding papers in her hand, and there is a light box on the wall next to them showing a mammogram

Some things never change: a breast cancer diagnosis still evokes a storm of anxiety — just as it did decades ago — despite the fact that survival rates have soared. Indeed, while more than two million women worldwide receive a breast cancer diagnosis each year, the average risk of dying in the following five years has dropped from 14% to 5% since just the 1990s, according to a June 2023 study involving more than a half-million women.

"For many women, a breast cancer diagnosis is particularly unsettling because we often don't know why a patient developed it," says Dr. Harold Burstein, a medical oncologist at Harvard-affiliated Dana-Farber Cancer Institute. "But the good news is, outcomes are getting better and better."

There's good reason for this survival swing. While breast cancer was once believed to be a single disease requiring a single treatment approach, scientists can now categorize breast tumors by cell type, opening the door for treatment combinations tailored toward each. (See "Types of breast cancer.")

Nowadays, surgery is still de rigueur for most types of breast cancer. But once-mainstay chemotherapy may be used in smaller amounts or skipped entirely. Meanwhile, newer drugs have enabled doctors to personalize each woman's arsenal of options. These include immunotherapy — which harnesses the power of the immune system to kill cancer cells — and targeted therapies aimed at gene mutations or proteins active in cancer growth.

"As we recognize these important subsets of breast cancer, we're tailoring treatment to the individual and the special characteristics of each breast cancer," Dr. Burstein says. "There isn't an infinite number of treatments, but the toolbox keeps getting bigger."

Types of breast cancer

Breast cancer types are typically named for the kinds of hormone receptors present in tumor cells. Knowing the type enables doctors to choose the most appropriate treatments.

ER-positive. The cancer cells contain hormone receptors for estrogen.

HER2-positive. The cancer cells have high numbers of receptors for HER2, a protein that fuels cancer growth.

ER-negative, HER2-negative. Cancer cells don't contain receptors for estrogen or HER2, respectively.

Triple negative. Cells don't have receptors for estrogen, progesterone, or HER2.

Why treatments are improving

Even the past 10 years brought marked shifts in treatment approach, thanks to extensive research that clarifies how genes and cells behave in various cancer subtypes. This, in turn, fueled the development of groundbreaking tests. Some can identify women with BRCA gene mutations that drastically raise their risk of developing breast cancer, while other tests help predict the likelihood a tumor will grow or spread to better pinpoint treatment needs.

These efforts have revealed that some types of breast cancer may respond to less intensive chemotherapy, while one especially aggressive type needs more.

ER-positive, HER2-negative breast cancer, which accounts for up to three-quarters of all cases, has undergone a treatment overhaul, Dr. Burstein says. "By the year 2000, we were giving chemo to almost every woman with this type of cancer. We understood it was overkill, that most women received very little benefit, but we didn't have a robust tool to distinguish who did and didn't need chemo," he says. "Now we have powerful genomic tools that allow us to say a patient might not need chemo as part of her treatment plan."

Additionally, a class of medications called CDK4/6 inhibitors — which target proteins that can fuel growth of ER-positive breast cancers — is often added to a patient's blend of treatments if her cancer is considered at high risk for spread (metastasis).

HER2-positive breast cancer, a more aggressive subtype that constitutes about one in five cases, has become more curable thanks to targeted therapies that disrupt the HER2 proteins that fuel its growth. The monoclonal antibody trastuzumab (Herceptin) revolutionized treatment over the past two decades, making chemotherapy less necessary, though doctors may combine the two to maximize effectiveness.

In the wake of this development, a newer approach known as an antibody drug conjugate pairs chemotherapy with manufactured proteins to deliver potent results with fewer side effects. "It acts like a smart bomb, delivering chemo directly to tumor cells," Dr. Burstein says. "This has emerged as a very powerful tool for the treatment of metastatic breast cancer. Hopefully, we'll see this approach used soon in early-stage breast cancer because it looks more effective than any chemotherapy option."

Triple-negative breast cancer is a rapidly growing type that remains a holdout in attempts to reduce chemotherapy. "We're actually using more and more treatment because we've found more drugs that are effective," Dr. Burstein says. "We've amped up chemo, started adding immunotherapy, and have some specific therapies for women with hereditary breast cancers as well."

Reasons for optimism

In coming years, nascent technologies not yet in widespread use are likely to hit the mainstream, Dr. Burstein says. These include so-called liquid biopsies: blood tests that look for the presence or absence of DNA from tumor cells in the bloodstream. "The test results will help us decide who needs more or less treatment based on circulating cell tumor DNA," he says.

Many women with metastatic breast cancer, which isn't yet curable, now thrive for many years as a parade of new treatments extend their lives while bolstering energy levels and the ability to live more normally.

"Patients are living longer and doing better with metastatic breast cancer," Dr. Burstein says. "It's fair to say that most women will live for many years after that diagnosis, and many are likely to be treated with drugs that don't exist today because progress is happening so quickly."

Without a telltale lump, inflammatory breast cancer can be deceiving—and deadly

If your breast seems red or swollen, feels unusually warm, or the skin has thickened or dimpled, don't pass it off as a bug bite or heat rash. Even without a discernible lump, breast cancer could be the culprit.

A form of the disease called inflammatory breast cancer (IBC), which is responsible for just 1% to 5% of all cases of breast cancer, shows up very differently from most breast cancers. Because it's so rare and initial signs are easy to miss, many women aren't on the lookout for IBC — but they should be, says Dr. Filipa Lynce, director of the Inflammatory Breast Center at Harvard-affiliated Dana-Farber Cancer Institute.

IBC is especially dangerous because symptoms often develop rapidly, over a few weeks or months. By then, the disease is already at an advanced stage because cancer cells have grown into the skin.

"Someone wakes up and notices her breasts feel heavier. A couple of weeks later, she may notice redness," Dr. Lynce says. "Then the skin around her nipples looks like the skin of an orange. It's all relatively quick."

Many women with such symptoms are treated with antibiotics, since their symptoms can resemble a breast infection. A doctor may also attribute symptoms to an allergic reaction or other minor problem. "A diagnosis that's missed or delayed is one of the challenges associated with this disease," Dr. Lynce says.

Don't wait to see a doctor, especially if these signs don't quickly resolve. Diagnosing IBC involves breast imaging such as a mammogram, which is often followed by an ultrasound of the breast and nearby lymph nodes and/or a breast MRI. A biopsy is required to confirm the diagnosis.

"Any woman who develops inflammatory changes in the breast, even without a lump, should understand it can be cancer," she says. "If your symptoms don't resolve right away with a short course of antibiotics, don't sit on it. Further workup is needed."

Tips for better care

Women who've been diagnosed with breast cancer can help maximize treatment results with these strategies.

Seek a multidisciplinary care team. Blending clinicians in medical oncology, radiology, surgery, genetics, and other specialties, this care model promotes collaboration that can lead to better outcomes for women with early-stage breast cancer. Patient navigation and social work services can also be valuable parts of a multidisciplinary team. "Go to a center where everyone is familiar with each other," Dr. Burstein says. "Women with early-stage disease almost always need surgery, medications, and radiation, so it's important the team works together effectively."

Speak up. Don't take a passive role in your treatment. While your care team may possess great expertise, clinicians may not understand your personal priorities or concerns. "Make sure your questions are being answered by the team, so you understand where things are and where they're going," he says.