While new, mainstream therapies (such as immunotherapies) are becoming more common in treating cancer, chemotherapy is still the ‘go-to’ for oncologists. As opposed to surgery or radiation therapy — which concentrates on the tumor and the area surrounding it — chemotherapy will not only kill tumor cells but can negatively effect the whole body.

A recent study revealed that individuals with breast cancer can have their tumors analyzed using a gene test called the Oncotype DX. This examines how active 21 specific genes are and provides a “recurrence score” of 0–100. A score nearer to 100 denotes a cancer that is most likely to recur and infiltrate other parts of the body.

The study showed that when scores are high, oncologists tended to use chemotherapy following surgery or radiation therapy to lower the risk of the cancer returning. For individuals with lower scores, the tumors were considered less dangerous, and chemotherapy could be deemed as ‘less essential’.

In the study, participants were randomly separated into two groups. Half of them received hormone therapy and chemotherapy, and the other half received hormone therapy alone. The researchers followed the women and assessed them for certain outcomes: being cancer-free, cancer recurrence locally or in another part of the body, and overall survival. When the study group was analyzed as a whole, there were no significant differences between the two groups.

In women under the age of 50, outcomes were similar when test scores were 15 or below. For younger women with scores of 16–25, chemotherapy slightly improved outcomes.

With [the] results of this groundbreaking study, we now can safely avoid chemotherapy in about 70 percent of patients who are diagnosed with the most common form of breast cancer.” – Study co-author Dr. Kathy Albain

“For countless women and their doctors,” she adds, “the days of uncertainty are over.” Indeed, the study will have positive implications for thousands of women across the U.S. and farther afield. As Dr. Albain goes on to conclude, “Its findings will greatly expand the number of patients who can forgo chemotherapy without compromising their outcomes. We are de-escalating toxic therapy.”