How Advances in Genetics are Transforming Breast Cancer Care and The Patient Experience

For years, the popular understanding of breast cancer care has focused on three different approaches to treatment: chemotherapy, surgery, and radiation. And as far as preventive efforts went, self-checking and staying up to date on your mammogram were often your primary options.

But in recent years, the impact of the genetics revolution has started to change how breast cancer care is approached, leading to whole new ways of treating, testing, and preventing cancer. It’s changing the care system, and everyone from physicians to nurses to health systems to insurance providers are rushing to catch up. If you know how to navigate it, it can transform everything from your own cancer care to the preventive care of your family and generations to come—before breast cancer can even become a threat.

The Original Revolution

In some ways, the last few years have been an acceleration and culmination of a revolution that began in the 1970s. That’s when breast cancer treatment took its first big advance, with the development of one of the first tests that could identify the molecular behaviors of certain kinds of breast cancers. 

Cancers identified as estrogen-receptor positive became one of the first cancers where a test at the beginning of treatment would shape how the tumor is treated. These cancers shrink when exposed to a now-widely used drug called tamoxifen, which gained approval in part through clinical trials funded by ACS. This key innovation gave oncologists a way to combat cancer outside of the well-known routes of chemotherapy, radiation and surgery. 

“That might be considered the greatest breakthrough in cancer treatment during the first two thirds of the 20th century,” says Dr. Steven Sorscher, medical director at Biotheranostics. 

In the past few years, what was once a slow process that saw intermittent breakthroughs has become a flood of new ways to treat cancer. No longer is breast cancer treatment limited to a few types of molecular profiles. In 2003, the human genome project—a moonshot effort to develop an understanding of every gene that composes the human body—was completed, and since then, physicians have begun to use that information to transform treatment. 

BRCA And its Imitators

Being able to understand how cancer operates on a genetic level has led to several key innovations. For one, inherited genes increasingly function as what physicians call biomarkers—biological material associated only with a specific kind of cancer cell and nothing else—allowing physicians to create treatments that target their unique genetic signature. Previously, breast cancer had three main types of biomarkers, but genetics has opened up the potential for growth. 

“I think of BRCA and these cancers tied to genetics almost as a fourth bucket,” says Dr. Nadine Tung, medical director at Beth Israel Deacon Medical Center. “And even within that now, we’re starting to get very personalized, very targeted treatments that are specific for a particular patient and their cancer.” As Tung notes, that potential is already being realized. The BRCA gene was the first inherited gene to be linked directly to breast cancer, and a consistent treatment for BRCA-related cancers has been developed that can allow those afflicted with the cancer to bypass chemotherapy for successful treatment. Because of their genetic structure, BRCA cancers have limited ability to repair themselves. When you deprive them of a particular enzyme through medications (called PARP inhibitors), the cancer can die of its own accord. 

Even more exciting is the fact that BRCA-related cancers are not the only type of cancers that have this flaw. Tung herself is currently studying cancers linked to the gene PALB2, which have a similar function. The more genes that are shown to be associated with the behavior, the more treatments can be designed that target particular vulnerabilities in the cancer themselves, without having to resort to medicine that affects healthy cells. 

Refining the Classics

Understanding an individual’s genetic profile can even make traditional treatments safer, more effective and more efficient. Receiving an oncotype (a type of genetic) test, has become the standard approach to determining if a person will benefit from chemotherapy post treatment. 

And physicians are at work refining that concept to connect more treatment results with more genetic profiles. Sorscher’s work at Biotheranostics, for example, focuses on their genetics index test, which refines the original breast cancer breakthrough, tamoxifen. Prolonged use of tamoxifen can cause dangerous side effects and quality of life issues, but it also decreases the risk of cancer recurrence in many women. Biotheranostics’ genetics index test tells patients if the tamoxifen is likely to have much effect 10 years out, so they don’t have to stay on the medication long term. 

Preventing Cancer Altogether

The new revolution in genetics is important not just for improved cancer treatment, but preventing it altogether. One of the key factors in the importance of BRCA genes and other, new forms of genetics linked to breast cancers is that the gene is passed, of course, to the patient from their parents. This allows for something even more hopeful than personalized cancer treatment: preventive cancer treatment. 

Now, if a parent has a BRCA gene, you may receive a recommendation to get screened earlier and more regularly. You may qualify for more powerful, more advanced mammograms whose expense might otherwise be prohibitive. 

And in the clearest indicator of the sea change that has occurred in cancer care, you may even be enrolled in a clinical trial for a vaccine against breast cancer. The unique genetic signature of a BRCA-related cancer may allow physicians to train your own body’s immune system to battle your cancer, as it would an outside invader. 

That means in the future, in some cases, a family history of breast cancer need not instill dread, but rather serve as a call to get proactive.