A triple negative breast cancer (TNBC) diagnosis is one of exclusion. 

At its core, the term triple negative refers to what these cancers lack: the hormone receptors and HER2 protein that play essential roles in breast cancer treatment.

“That doesn't actually say much about what the cancer is,” said Dr. Jenny Chang, breast medical oncologist at Houston Methodist and world-renowned researcher with a focus on triple-negative breast cancer. 

She continued: “Because there's not one cancer, it's at least five cancers.” 

Triple negative has been found to have six subtypes: basal-like 1 and 2, immunomodulatory, mesenchymal, mesenchymal stem-like, and luminal. But we don’t talk about these subtypes, Dr. Chang explained, because as of right now, the differences between them have little impact on the way the cancer is treated. 

She said that in the future, these subtypes will hopefully give us more insight into who can benefit from what treatment, moving closer to individualized care. But for now, we continue to classify TNBC by the characteristics it doesn’t have, even if those qualifiers can sometimes feel murky.

The American Society of Clinical Oncology (ASCO) and College of American Pathologist (CAP) use 1 percent as the cutoff for classifying hormone-receptive positive cancers, but a “10 percent cut-off is often used in clinical practice for therapeutic purposes.”

Kelsey was first clued into this when, days after her diagnosis, she learned that she didn’t qualify for an immunotherapy clinical trial. 

The institute running the trial found that her cancer expressed estrogen positivity higher than they would like for a TNBC study, somewhere close to that 10 percent cut-off. But that didn’t change her treatment plan or encourage her team to reconsider endocrine therapy. Kelsey was still triple negative for all intents and purposes. Except for that one. 

Dr. Eleonora Teplinsky, a board-certified medical oncologist specializing in breast and gynecologic cancers, explained that in cases like Kelsey’s, ER-low breast cancers are often treated like triple-negative, especially if they have a pathological complete response to chemotherapy. However, there may be some benefit for endocrine therapy, especially for patients who do not achieve a complete pathologic response, explained Dr. Teplinsky. 

Narratives About TNBC

TNBC is known as one of the most aggressive types of breast cancer. It is more common among younger populations and has higher incidence rates among African American people. Because of our lack of knowledge about its subtypes, it has fewer lines of defense should it spread outside of the breast and lymph nodes. 

These differences are not superficial either, having been found to lead to worse outcomes. A 2021 study published in JAMA Oncology found that Black patients were two times more likely to be diagnosed with TNBC than white patients and 28 percent more likely to die of the disease, due in part to often being diagnosed at later stages and lower odds of undergoing surgery or receiving chemotherapy. 

But these statistics can also be what makes a TNBC diagnosis feel all the more isolating. A quick Google search will pull up statements like: “tends to grow and spread faster, has fewer treatment options, and tends to have a worse prognosis.” 

This rhetoric doesn’t just exist in healthcare spaces and medical literature—it trickles down into the community.

That label, “triple-negative,” sticks to Allie, a nearly 8-year triple negative breast cancer survivor, like a second skin. Every time she tells her story, she finds herself emphasizing it. Almost like a reflex. A disclaimer. But why? To validate her experience? To remind others (and maybe even herself) that this diagnosis was scary—“more aggressive” and “more uncertain”? The TNBC label validates the challenges faced and the fears that survivorship brings.

Or maybe to show that a triple-negative diagnosis isn’t always as scary as it seems. The treatment options can be effective, even without targeted post-treatment therapies. Using the TNBC identifier helps share experiences that challenge this rhetoric and highlight diverse survivorship stories.  

Rewriting the TNBC Story 

The current understanding of TNBC is just the beginning, and rewriting the narrative starts with research that goes beyond generalizations and dives deep into the complexities of this subtype of breast cancer. 

“That's the part we're trying to figure out,” said Dr. Teplinsky. “There's a huge focus on research and figuring out why some people get a pathologic complete response and why some people do not. Can we identify biomarkers that predict response?”

“We hope that future research really starts to break out TNBC in terms of the subtypes,” she said, but we’re not quite there yet. 

Dr. Teplinsky pointed to the I-SPY 2 trial as one example of ongoing research that looks beyond hormone receptor and HER-2 status to classify breast cancers into multiple different subtypes to better identify who can benefit from which treatments.  While that trial does not exclusively look at triple negative breast cancers, it can provide hope that more individualized treatment options can become a reality with a deeper understanding of what makes each breast cancer unique. 

Research alone isn’t enough— survivors play a crucial role in this process. The current narrative about TNBC reflects some realities, but not all.  By sharing personal experiences, we can reshape the conversation and ensure TNBC is not solely defined by its limitations. Amplifying the diverse voices of TNBC Breasties can result in advancements in care, advocacy and awareness. So share your story, because your voice matters and has the power to create change!