Hundreds of women — and a few men — with one of the most aggressive forms of breast cancer lived longer after being treated with a combination of immunotherapy and chemotherapy, a finding that could change the standard of care, according to new research.
Doctors expect the standard to change from chemotherapy to the new combination treatment for a formidable percentage of patients with a type of breast cancer known as triple negative.
While the combination treatment is not a cure, it opens a new chapter for treating an advanced form of breast cancer known to stubbornly resist chemo. It’s now up to the U.S. Food and Drug Administration to decide whether the drug duo becomes the new standard of care.
For reasons not yet fully explained, triple-negative breast cancer occurs most frequently among young women, often under age 40, particularly those who are African-American or Hispanic. People with mutations in their BRCA 1 gene also are at elevated risk, as is a tiny fraction of men. The cancer's name means three markers are missing on tumor cells that are key targets of successful breast cancer therapy.
Although triple negative accounts for 10 percent to 20 percent of breast cancer cases in the United States, according to the National Breast Cancer Foundation, up to 40 percent of breast cancer deaths are attributed to the triple negative form of the disease.
“This study will be practice-changing,” said Dr. Sylvia Adams, a medical oncologist at NYU’s Perlmutter Cancer Center in Manhattan, the only site in New York to participate in the research project conducted at 246 medical centers worldwide. Results were reported in the New England Journal of Medicine and at an oncology meeting in Munich.
“The numbers are quite robust. There were 902 participants, and four of them were men,” said Adams, whose patients were from the metropolitan area, including Long Island.
Half of the patients in the study received combination therapy, an immunotherapy agent called Tecentriq and a chemotherapy drug called Abraxane. The other half received chemo alone. Combination therapy patients generally lived 21.3 months compared with 17.6 for those who received only chemo. The difference was statistically insignificant.
However, for patients who had a certain biomarker on their cancer cells, PD-L1 — which 41 percent of patients had in the trial — survival was 25 months. Adams said the finding was extraordinary for people with triple-negative breast cancer.
Advocates for patients are applauding the research.
“Triple-negative has been difficult to treat,” said Hillary Rutter, executive director of the Adelphi New York Statewide Breast Cancer Hotline and Support Program at Adelphi University in Garden City. “To find a new treatment for women with triple-negative breast cancer that might prolong their lives is a tremendous breakthrough. This is encouraging.”
The absence of markers on the surface of tumor cells has truncated survival for countless patients, Rutter said.
When present, these markers for estrogen, progesterone or the protein HER2 are targets for drugs. Medications such as tamoxifen, which targets the estrogen marker, or Herceptin, which zeroes in on HER2, have made certain forms of breast cancer not only treatable, but long ago helped boost survival rates, and for many, cured the disease.
Adams said the study helped prove that immunotherapy can be effectively used in the treatment of breast cancer. Immunotherapy had not proved effective in studies involving other forms of the disease.
Various types of immunotherapy have been prescribed as treatments for several forms of cancer in recent years. Former President Jimmy Carter was effectively treated with an immunotherapeutic agent for melanoma that had spread to his brain. Patients with lung, cervical and bladder cancers also have benefited from immunotherapy.
Some agents, like the one used in the study, help to unmask cancer cells that are hiding from the immune system. There have been mixed responses to immunotherapy among patients with other forms of cancer. However, immunotherapy has successfully treated cancers and prevented relapses in some patients who had advanced disease.