A few decades or even just a few years ago, chemotherapy as treatment for breast cancer was a foregone conclusion for patients with even a moderate chance of recurrence.
But the findings of a new trial released in June have challenged that assumption, allowing those with an intermediate risk of breast cancer recurrence to attack their cancerous cells with hormones — no chemotherapy required.
The results from the Trial Assigning Individualized Options for Treatment (Rx), or TAILORx trial, showed no benefit from chemotherapy for a whopping 70 percent of women with the most common type of breast cancer. The findings apply to cancers that are hormone receptor-positive, HER2-negative and axillary lymph node-negative.
“Why? Because depriving the breast cancer of the estrogen will stop the cancer in its tracks. We have tools to do that,” said Dr. Cory Donovan, a breast oncology surgeon at Legacy Salmon Creek Medical Center.
The comprehensive trial, which started in 2006, identified more than 10,000 women in the intermediate range of risk for cancer recurrence (on a 100-point risk scale, they rated between 11 and 25). The women who fell into this bracket were randomly assigned to undergo both chemotherapy and hormone therapy, or hormone therapy alone.
The women came from 1,182 sites across the United States, Australia, Canada, Ireland, New Zealand and Peru.
At both the five-year and nine-year mark, the difference between recurrence and survival rates from both groups was so miniscule as to be insignificant.
The study has the potential to be hugely impactful for cancer patients. Until now, oncologists knew that those in the low-risk range (0-10) could undergo hormone treatment only, and those in the high-risk range (26-100) needed both chemical and hormone therapy.
But for that middle group, patients now have the ability to forgo chemotherapy with no increased long-term risk.
“We didn’t really always know what to do with the moderate women anymore, and we guessed. Now we don’t have to guess. Now, we can tell them confidently,” Donovan said.
There are, of course, caveats. The results only change treatment options for hormone receptor (HR)-positive, HER2-negative, axillary lymph node-negative breast cancer. The study also found that younger breast cancer patients — younger than 50 — improved their long-term survival rates by undergoing both chemotherapy and hormone therapy, even if they fell within the moderate-risk group.
Hormone therapy, too, is not a walk in the park. Endocrine therapy drugs such as tamoxifen and aromatase inhibitors come with their own set of side effects such as mood swings, joint aches and hot flashes.
“Any time you’re messing with hormones, that kind of constellation of symptoms come into play,” Donovan said. “It’s also tough to do something for five years. I will not belittle the difficulty of taking a pill every day for five years … but if it can cut your risk of recurrence, your risk of distant recurrence, by 50 percent, that’s pretty hot.”
The findings from TAILORx also grants patients the peace of mind they need to prevent overtreatment, Donovan said. And for millions of women, the ability to forgo chemotherapy during cancer treatment helps preserve their quality of life, maintaining their well-being and sense of normalcy without increasing their chance of recurrence.
“I feel like women want to do everything. They want to know at the end of the day that they did all of the things they had to. It’s pretty reassuring for me to be able to tell them, ‘Taking this drug for five years, that is enough.’ “
