Good news for women with breast cancer: many do not need chemotherapy

    Abdulaziz Sobh

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    Many women with early-stage breast cancer who would receive chemotherapy by current standards do not really need it, according to a major international study that is expected to quickly change medical treatment. "We can prevent thousands and thousands of women from receiving toxic treatment that does not really benefit them," said Dr. Ingrid A. Mayer of Vanderbilt University Medical Center, author of the study. "This is very powerful, it really changes the standard of care."
    The study found that genetic testing on tumor samples could identify women who could safely skip chemotherapy and take only one drug that blocks the hormone estrogen or prevents the body from making it. The hormone-blocking drug tamoxifen and related medications, called endocrine therapy, have become an essential part of treatment for most women because they reduce the risks of recurrence, new breast tumors, and death from the disease.
    "I think this is a very significant breakthrough," said Dr. Larry Norton of the Memorial Sloan Kettering Cancer Center in New York. He is not a study author, but his hospital participated. "I can look people in the eye and say, 'We analyze your tumor, you have a really good prognosis and you do not really need chemotherapy.' It's a nice thing to be able to tell someone."
    The findings apply to approximately 60,000 women a year in the United States, according to Dr. Joseph A. Sparano of Montefiore Medical Center in New York, the study leader.
    "The results indicate that we can now save chemotherapy in approximately 70 percent of patients who would be possible candidates based on clinical characteristics," said Dr. Sparano.
    But Dr. Sparano and Dr. Mayer added a note of caution: the data indicated that some women 50 years old and younger could benefit from chemotherapy even if the results of genetic testing suggested otherwise. It is not clear why. But those women require a particularly careful consultation, they said. (Most cases of breast cancer occur in older women: the average age at diagnosis in the United States is 62).
    The study, called TAILORx, is being published by The New England Journal of Medicine and will be presented Sunday at a meeting of the American Society of Clinical Oncology in Chicago. The study began in 2006 and was paid by the governments of the United States and Canada and philanthropic groups. Genomic Health, the company that does the genetic testing, helped pay after 2016.
    This year, approximately 260,000 new cases of breast cancer are expected in women in the United States, and 41,000 deaths. Worldwide, the most recent figures are from 2012, when there were 1.7 million new cases and more than half a million deaths.
    Chemotherapy can save lives, but it has serious risks that make it important to avoid treatment if it is not necessary. In addition to the hair loss and nausea that patients fear, chemotherapy can cause damage to the heart and nerves, leaving patients vulnerable to infections and increasing the risk of leukemia later in life. TAILORx is part of a larger effort to refine treatments and avoid adverse side effects to patients whenever possible.
    Endocrine therapy also has side effects, which can include hot flushes and other symptoms of menopause, weight gain and joint and muscle pain. Tamoxifen may increase the risk of uterine cancer.
    Patients affected by the new findings include women who, like most in the study, have early-stage breast tumors measuring one to five centimeters that have not spread to the lymph nodes; they are sensitive to estrogen; negative test for a protein called HER2; and have a score of 11 to 25 in a widely used test that measures the activity of a group of genes involved in cancer recurrence.
    The genetic test, called Oncotype DX Breast Cancer Assay, is the focus of the study. There are other genetic tests, but this is the most used in the United States. It is done on tumor samples after surgery to help determine if chemotherapy might help. Usually, the test is done for the early stage disease, not for more advanced tumors that clearly need chemotherapy because they have spread to the lymph nodes or more. The test, available since 2004, scores from 0 to 100. It costs around $ 3,000, and the insurance usually covers it. Previous research has shown that scores of 10 and below do not require chemotherapy, and scores of more than 25 do.
    But most women who are eligible for the test have scores of 11 to 25, which are considered intermediate.
    "This has been one of the big unanswered questions in the treatment of breast cancer in recent times, what to do with patients with intermediate scores," said Dr. Norton. "What must be done is totally unknown." He added: "Many patients in that range receive chemotherapy."
    Dr. Sparano said that many patients have been receiving chemotherapy because in 2000 the National Cancer Institute recommended it for most women, even those whose disease had not spread to the lymph nodes, according to studies showing that it could prevent cancer reappears in other parts of the body. incurable.
    "Recurrences were being prevented and lives were prolonged," Dr. Sparano said. "But we were probably overrunning many of these women, for every 100 women we were dealing with, we probably avoided about four distant recurrences."
    Dr. Mayer said: "We could not find out who we really needed to deal with."
    The availability of genetic testing in 2004 helped researchers classify women at very high or very low risk.
    "But we really did not know what to do with the women in the middle," Dr. Mayer said. "Some seemed to benefit and others did not." We went back to zero, safe instead of sorry, giving chemotherapy to many who did not need it.
    Data began to appear suggesting that women in the middle did not receive help from chemotherapy, and many doctors began to recommend it less frequently. But a definitive study was needed, which is how TAILORx came about.
    The study began in 2006 and finally included 10,253 women between 18 and 75 years old. Of the 9,719 patients with complete follow-up information, 70 percent had scores of 11 to 25 on the genetic test. They underwent surgery and radiation and then were randomly assigned to receive either endocrine therapy alone or endocrine therapy plus chemotherapy. The median follow-up was more than seven years.
    Over time, the two groups did just as well. Chemo had no advantage. After nine years, 93.9 percent were still alive in the endocrine-only group, compared to 93.8 percent in those who also received chemotherapy. In the endocrine group, 83.3 percent were free of invasive disease, compared to 84.3 percent who received both treatments. There were no significant differences.
    But the researchers wrote that the benefit of chemotherapy varied with the combination of recurrence score and age, "with some benefit of chemotherapy found in women 50 and younger with a recurrence score of 16 to 25."
    Bari Brooks, 58, a patient of Dr. Mayer of White House, Tennessee, learned from a mammogram that she had breast cancer in 2009 when she was 49 years old. Dr. Mayer told her that she was a candidate for chemotherapy and also for the study, in which she might or might not receive chemotherapy.
    Could you handle the risk of missing a treatment that could save your life? Or the risk of side effects that could be unnecessary?
    "It was not even a decision I had to think about," said Ms. Brooks, who works in human relations for Vanderbilt University. "Yes, I want to do it." She added: "You realize how insignificant everything is." Money, no matter how much you have. Work, what projects do you have, it does not matter. What have I contributed to my life and what do I want to contribute? This was a situation in which I could also contribute. I felt honored and grateful to be part of that. "
    She decided that if they assigned her to chemotherapy, "I would go to her and tell her I was being cleaned instead of poisoned."She landed in the group that received chemotherapy and endocrine therapy. Did chemotherapy help? Maybe, maybe not. She does not regret it. And there is no evidence of cancer.
    Dr. Mayer said that Ms. Brooks's philosophical attitude was not unusual and that the women who signed up for the studies understood that they were taking a step of faith and that they might end up receiving the "wrong" or less desirable treatment.
    "They are grateful that they have helped improve knowledge for other women," said Dr. Mayer. "I never underestimate how nice and altruistic people can be, women take care of each other."

     

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