New Study: Metastatic Breast Cancer and a Decade of Survivorship
Researchers were pleased to discover that some women with metastatic breast cancer were still alive 10 years after being treated with radiotherapy to the sites where their cancer had spread. The study results are being used to guide treatment decisions at UR Medicine’s Wilmot Cancer Institute.
“The prognosis for metastatic breast cancer is generally poor, so this is remarkable,” said corresponding author Michael Milano, M.D., Ph.D., a professor of Radiation Oncology at Wilmot. “Ideally, we will want to know what factors predict who will do better.”
Metastatic breast cancer (or stage 4 disease) means the cancer has spread beyond the original tumor to other parts of the body. Common sites of metastases include the bones, lungs, liver, and brain. For this study, Milano and colleagues investigated the long-term outcomes of 48 patients who had oligometastases, meaning that they only had a few spots of metastatic cancers as opposed to widespread disease.
The standard care for this stage of breast cancer is often hormonal therapy and/or chemotherapy or targeted medications, with radiation considered for symptom control. The use of radiation to prolong survival was not yet a standard option when the
Wilmot Cancer Institute opened the current study in 2001 — but investigators wondered if they could positively impact long-term survival in patients treated with metastasis-directed radiotherapy. No other researchers had followed breast cancer patients in this clinical category beyond five years of radiation treatment to the metastatic sites.
Milano’s study, published by the journal Radiotherapy and Oncology, showed the best results for women whose metastases was limited to the bones. In those cases, 75 percent of them were still alive at 10 years after receiving a precision treatment called hypofractionated stereotactic radiotherapy. Among the women whose cancer had spread to other sites, the 10-year survival rate was 17 percent. While this number is low, Milano said, it’s still impressive that some women with metastases to organs such as the liver and lungs survived for such a long time. With new drug development and the ability to treat tumors with more aggressive radiation doses than were used a decade ago, researchers expect that more women will survive longer in the future, he added.
The University of Rochester emerged as a leader in the early 2000s for stereotactic radiotherapy — which delivers a high dose of external beam radiation to a precise target inside the body. The UR Medical Center was one of the first facilities in the country to offer this treatment for cancer and began to study its impact.
The next step is to encourage women to consider entering a newer national clinical study to which Wilmot is enrolling patients; that study is investigating the optimal timing of radiotherapy treatment. “When patients are not eligible for the study,” Milano added, “we can still treat them with radiotherapy protocols stemming from what we’ve learned from research about safety and effectiveness.”
Study co-authors include Alan Katz, M.D., M.P.H., in the Department of Radiation Oncology at URMC, and Paul Okunieff, M.D., of the University of Florida and a former chair of URMC Radiation Oncology, who helped to develop the study and commission precision radiotherapy treatment at Wilmot.
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