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Exciting New Advancements in Personalized Breast Cancer Treatment Are Improving Outcomes and Patients’ Lives
By Neelima Denduluri, M.D. | October, 2017
In my career as a medical oncology and breast cancer specialist, I have seen great advancements in the treatment of breast cancer with innovative new drugs and therapy. The outlook for breast cancer patients has never been better, as promising new developments are leading to more effective preventative strategies and late-stage treatments.
Over the last decade, we have seen dramatic advancements in treating many different forms of breast cancer, from early onset to late-stage diagnosis. Progress has been made with estrogen receptor breast cancer using aromatase inhibitors and tamoxifen, or fulvestrant, to regulate the estrogen signaling pathway. This anti-estrogen therapy is the cornerstone of treatment for about two-thirds of women with breast cancer, as their tumors over express estrogen or progesterone. While we have had great success with anti-estrogen treatment for estrogen receptor breast cancer, in some women cancer cells escape the signaling pathway and continue to grow.
CDK4/6 inhibitors are transforming late-stage treatment
Recently there have been some exciting developments in treating patients with an oral oncolytic called abemaciclib, a CDK inhibitor selective for CDK4/6. Rampant cell growth in many cancers is triggered by a loss of cell cycle regulation due to intensified signaling from CDK4/6. Abemaciclib obstructs the growth of cancer cells by specifically blocking cyclin-dependent kinases, CDK4/6.1 This induces cell cycle arrest, especially when combined with endocrine therapy.2 CDK4/6 inhibitors have revolutionized how we treat estrogen receptor positive stage 4 breast cancer, delaying the time to chemotherapy and increasing the amount of time patients can stay on anti-estrogen therapy when these drugs are added to the anti-estrogen regimen.
Since CDK4/6 inhibitors have been so effective in late-stage breast cancer, several clinical trials are now evaluating their use for patients with hormone positive, HER2– negative early breast cancer who are at high risk for reoccurrence. Two of the CDK4/6 trials are currently in progress across the US Oncology Network (The Network) for early stage patients; one investigating a drug called ribociclib and another studying abemaciclib. Both drugs were recently approved for late stage indications. I am hopeful that the benefits translate to high-risk early disease, giving patients a positive outlook early in their breast cancer journey. As a breast cancer specialist, I am very excited to offer these cutting-edge trials within The Network, giving patients convenient access to these novel therapies within their own community.
New options for HER2 positive cancer
Many promising trials are also occurring throughout The Network for early high-risk HER2 positive patients. Most women treated for HER2 positive disease do well with Herceptin along with chemotherapy. However, 10 to 15 percent of women still have a reoccurrence of the disease. We can now treat these women with a drug called pertuzumab. Some sites within The Network participated in an exciting clinical trial investigating the addition of pertuzumab to standard-of-care Herceptin in early, high-risk HER2 positive patients. The APHINITY Trial found that adding pertuzumab as a second HER2-targeted medicine modestly improved outcomes in node-positive women with HER2 disease.
Another drug, neratinib, has recently been approved for maintenance in women with HER2 disease who have been treated with Herceptin and chemotherapy, providing a new treatment option for patients who remain at significant risk after targeted therapy.
Progress for triple-negative patients
Triple negative disease remains an elusive form of breast cancer to treat in some women, as there is no known actionable target as in other breast cancers, but we’re beginning to see progress. Traditional therapy utilizes chemotherapy by itself, which can be very effective in many women. However, we are trying to improve on that approach by testing for genetic mutations. We know, for example, that a greater proportion of triple negative patients harbor germline mutations inherited from their parents, making it even more important for us as physicians to know the familial history of our patients.
To gain this insight, The Network has a comprehensive cancer risk assessment initiative — the Genetic Risk Evaluation and Testing program — that advances precision care by providing individualized genetic data that may lead to cancer prevention opportunities and better treatment options. For instance, if triple negative patients are BRCA1/2 positive, they may be eligible for a class of drugs called PARP inhibitors.
For women with triple negative breast cancer where traditional chemotherapy has failed, immunotherapy looks promising. There is also a new drug, IMMU-132, that is demonstrating positive results in early studies. We encourage eligible patients to participate in clinical trials, as they may experience significant benefits while also playing a pivotal role in advancing cancer care for tomorrow’s patients.
A bright future for many breast cancer patients through targeted care
This is a very exciting time in breast cancer care, as the depth of knowledge we have accumulated is providing a strong foundation for successful treatment. We know that incorporating a healthy lifestyle with traditional anti-estrogen therapy and chemotherapy is very important. In addition, we are perfecting the ability to match the right patients with the right drug(s) at the right time, delivering more personalized, targeted care. For patients with advanced disease, we have many molecularly targeted trials, providing promising new treatments that deliver on the hope of a better tomorrow for all breast cancer patients. I am proud of the work we are doing in The Network to advance cancer care for patients everywhere and look forward to continued progress in providing our patients with the best advanced treatment options available.