Chemotherapy: Why women with early breast cancer might not need it

Dayton Physicians NetworkBreast cancer affects one-in-eight women in the United States, and until recently, chemotherapy was used throughout most stages of treatment. While it destroys cancer cells by targeting rapidly dividing cells, chemo also affects similar normal cells in the same way.

Healthy cells that also divide rapidly are found in the blood, mouth, intestinal tract, nose, hair, and so on. Chemotherapy attacks those “good” cells, as well, which is what causes the most common side effects of hair loss, nausea, vomiting, and brittle nails. However, a recent study indicates that women with early stage breast cancer may fare as well without this treatment as those who do receive it.

According to a June 4 report by NBC News, researchers have determined that patients with smaller-sized tumors that had not spread to the lymph nodes did just as well without chemotherapy as those who got the treatment. In short, the study looked at the effectiveness of hormone therapy alone against hormone therapy plus chemotherapy for early stage breast cancer with an intermediate Oncotype DX risk score.

The results of the “TAILORx” trial, a federally funded phase III trial with approximately 10,000 women enrolled, were presented in a plenary session at the June 2018 ASCO conference. They found that most women with hormone receptor-positive, lymph node-negative early-stage breast cancer, with a mid-range score on the Oncotype DX test risk scoring system do not need chemotherapy after surgery.

It also noted that there was no improvement in disease-free survival when chemotherapy was added to hormone therapy in this group, which accounts for about two-thirds of women who participated in the trial. The findings have already impacted clinical practice, sparing thousands of women the difficult side effects of chemotherapy.

“Based on the research, 70% of our patients with stage one and two breast cancer will not need chemotherapy,” explained Nkeiru Okoye, MD, medical hematologist and oncologist with Dayton Physicians Network.

Older trials previously had identified the gene panel used to predict how the patient with early breast cancer will respond to treatment and how the cancer will behave when treated with chemotherapy. Hence, the test had been previously proven to be predictive and prognostic. However, the Oncotype DX® results are not reported in a binary, yay or nay, answer. Instead, it provides an indication of a patient’s risk level in a scale of low (<10), intermediate (11-25), or high (>26).

“Up until recently, in those patients with early stage breast cancer with an intermediate risk score, we really couldn’t say with full certainty who would or would not benefit from taking hormonal treatment alone, versus benefit from the addition of chemotherapy to hormone therapy,” Dr. Okoye continued.

This study demonstrated that the success and survival rate was about the same for both groups, with and without chemotherapy in stage one and two hormone-positive breast cancer.

Okoye noted one primary caveat to the results of the study, as well. For patients in the trial who were less than 50 years of age, with intermediate risk score (about two percent of the total study group), there was a small benefit to using chemotherapy. What this means is that there is not a one-size-fits-all solution, and each patient must be evaluated individually to devise the best possible treatment plan.

The research also indicated that women with a breast cancer recurrence score of 10 or less had very low recurrence rates with hormone therapy alone, regardless of age or other factors. Those with a score of 26 or above had a recurrence rate of only 13%, despite the addition of chemotherapy, indicating an ongoing need for more effective therapies for that risk group.

“What this means for DPN patients is a level of confidence that treatment programs are based on data that has been validated by cutting-edge research,” noted Dr. Okoye. “The patient can rest assured that they are receiving world-class care, and that the doctors will sit down and talk about the information that supports the treatment plan.”

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