Drug Combo can fight a difficult form of breast cancer | Health
WEDNESDAY, Dec. 15, 2021 (HealthDay News) — An experimental drug, added to chemotherapy, could benefit women with an aggressive form of breast cancer, an early study suggests with much-needed good news.
The study looked at women with “triple-negative” breast cancer, which accounts for about 15-20% of breast cancers in American women. It is so called because cancers lack receptors for the hormones estrogen and progesterone, and for the protein HER-2.
This means that women with triple negative cancer cannot benefit from two key breast cancer treatments: hormone therapies and HER-2-targeting drugs.
Traditionally, surgery and chemotherapy have been the mainstays of treatment for triple negative breast cancer. Unfortunately, the disease often resists or becomes resistant to chemotherapy – and that was the case for the women in the new study.
So the researchers tried a new approach. They added an experimental agent, called L-NMMA, to docetaxel, a standard chemotherapy drug. Twenty-four patients received up to six three-week cycles of the combo.
At the end of treatment, 11 patients had responded, showing regression of their cancer. For two women, there were no more signs of breast cancer.
The study group included both women with metastatic cancer, meaning it had spread to distant sites in the body, and women with locally advanced cancer. These are advanced tumors that have not yet spread throughout the body.
Women with locally advanced cancer responded better to the experimental treatment combo: nine out of 11 had at least a partial response. This was true for two of the 13 women with metastatic cancer, according to the report.
The conclusions, reported on December 15 in Science Translational Medicinelay the groundwork for larger trials, the researchers said.
A next step is a larger study of women with advanced triple-negative cancer, said study author Dr. Jenny Chang, director of the Houston Methodist Cancer Center in Texas.
The researchers also want to test the approach against metaplastic breast cancera rare form of the disease that is often triple negative.
L-NMMA works by inhibiting so-called nitric oxide signaling. It refers to a group of enzymes in the body that are necessary for normal health. But in triple-negative breast cancer, increased nitric oxide signaling is linked to a poorer prognosis, Chang explained.
In laboratory research, his team discovered that L-NMMA can inhibit the growth and spread of tumors.
However, experts who reviewed the new study said much more research is needed to find out how L-NMMA might fit into the treatment of triple-negative breast cancer.
“I applaud the idea,” said Dr. Julie Gralow, chief medical officer of the American Society of Clinical Oncology. Essentially, she noted, the approach is to improve patients’ responses to chemotherapy.
Larger studies are needed to further test the efficacy and safety of the treatment, said Gralow, who was not involved in the research.
She also highlighted the recent advances that have been made against triple negative breast cancer. While chemotherapy was once the only option, several new treatments have been approved or are currently being studied.
Earlier this year, the U.S. Food and Drug Administration approved Keytruda (pembrolizumab) immunotherapy for women with early-stage triple-negative cancer, as well as some women whose cancer has spread. at other sites of the body. The drug releases a “brake” on the immune system, allowing it to find and attack cancer cells.
For women with early-stage triple-negative cancer, Keytruda is used with chemotherapy before surgery and then alone afterwards. And that, Gralow said, is now the standard of therapy.
Another drug, called sacituzumab (Trodelvy) also became available this year. It is an antibody that delivers chemo directly to cancer cells. The FDA has approved it for patients who have already received standard treatments for locally advanced or metastatic triple-negative breast cancer.
Meanwhile, Gralow said, research has shown that some triple-negative cancers have receptors for androgens (‘male’ hormones like testosterone). And studies are now testing anti-androgen drugs in these patients.
“We have traditionally defined triple negative disease by what it is not,” Gralow noted. “We are learning more about what he is.”
Dr. Charles Shapiro, a professor and oncologist at the Icahn School of Medicine at Mount Sinai, New York, made similar remarks.
He said treatment for women with advanced triple-negative cancer has gone from “dismal”, when chemo was the only weapon, to more encouraging, with the new options.
Blocking nitric oxide signaling in the disease is a “new therapeutic approach,” Shapiro said, and should be investigated further.
According to Chang, a question for the future is whether L-NMMA can also boost the response to immunotherapy.
The American Cancer Society has more on the treatment triple negative breast cancer.
SOURCES: Jenny C. Chang, MD, director, Houston Methodist Cancer Center, Houston; Julie Gralow, MD, chief medical officer, American Society for Clinical Oncology, Alexandria, Virginia; Charles Shapiro, MD, professor of medicine, hematology, and medical oncology, Icahn School of Medicine at Mount Sinai, New York City; Science Translational Medicine15 December 2021, online